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Cole HD, Vali A, Roque JA, Shi G, Talgatov A, Kaur G, Francés-Monerris A, Alberto ME, Cameron CG, McFarland SA. Ru(II) Oligothienyl Complexes with Fluorinated Ligands: Photophysical, Electrochemical, and Photobiological Properties. Inorg Chem 2024. [PMID: 38728376 DOI: 10.1021/acs.inorgchem.3c04382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2024]
Abstract
A series of Ru(II) complexes incorporating two 4,4'-bis(trifluoromethyl)-2,2'-bipyridine (4,4'-btfmb) coligands and thienyl-appended imidazo[4,5-f][1,10]phenanthroline (IP-nT) ligands was characterized and assessed for phototherapy effects toward cancer cells. The [Ru(4,4'-btfmb)2(IP-nT)]2+ scaffold has greater overall redox activity compared to Ru(II) polypyridyl complexes such as [Ru(bpy)3]2+. Ru-1T-Ru-4T have additional oxidations due to the nT group and additional reductions due to the 4,4'-btfmb ligands. Ru-2T-Ru-4T also exhibit nT-based reductions. Ru-4T exhibits two oxidations and eight reductions within the potential window of -3 to +1.5 V. The lowest-lying triplets (T1) for Ru-0T-2T are metal-to-ligand charge-transfer (3MLCT) excited states with lifetimes around 1 μs, whereas T1 for Ru-3T-4T is longer-lived (∼20-24 μs) and of significant intraligand charge-transfer (3ILCT) character. Phototoxicity toward melanoma cells (SK-MEL-28) increases with n, with Ru-4T having a visible EC50 value as low as 9 nM and PI as large as 12,000. Ru-3T and Ru-4T retain some of this activity in hypoxia, where Ru-4T has a visible EC50 as low as 35 nM and PI as high as 2900. Activity over six biological replicates is consistent and within an order of magnitude. These results demonstrate the importance of lowest-lying 3ILCT states for phototoxicity and maintaining activity in hypoxia.
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Affiliation(s)
- Houston D Cole
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019-0065, United States
| | - Abbas Vali
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019-0065, United States
| | - John A Roque
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019-0065, United States
| | - Ge Shi
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019-0065, United States
| | - Alisher Talgatov
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019-0065, United States
| | - Gurleen Kaur
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019-0065, United States
| | | | - Marta E Alberto
- Dipartimento di Chimica e Tecnologie Chimiche, Università della Calabria, Arcavacata di Rende 87036, Italy
| | - Colin G Cameron
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019-0065, United States
| | - Sherri A McFarland
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019-0065, United States
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Cole HD, Vali A, Roque JA, Shi G, Kaur G, Hodges RO, Francés-Monerris A, Alberto ME, Cameron CG, McFarland SA. Ru(II) Phenanthroline-Based Oligothienyl Complexes as Phototherapy Agents. Inorg Chem 2023; 62:21181-21200. [PMID: 38079387 PMCID: PMC10754219 DOI: 10.1021/acs.inorgchem.3c03216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2023]
Abstract
Ru(II) polypyridyl complexes have gained widespread attention as photosensitizers for photodynamic therapy (PDT). Herein, we systematically investigate a series of the type [Ru(phen)2(IP-nT)]2+, featuring 1,10-phenanthroline (phen) coligands and imidazo[4,5-f][1,10]phenanthroline ligands tethered to n = 0-4 thiophene rings (IP-nT). The complexes were characterized and investigated for their electrochemical, spectroscopic, and (photo)biological properties. The electrochemical oxidation of the nT unit shifted by -350 mV as n = 1 → 4 (+920 mV for Ru-1T, +570 mV for Ru-4T); nT reductions were observed in complexes Ru-3T (-2530 mV) and Ru-4T (-2300 mV). Singlet oxygen quantum yields ranged from 0.53 to 0.88, with Ru-3T and Ru-4T being equally efficient (∼0.88). Time-resolved absorption spectra of Ru-0T-1T were dominated by metal-to-ligand charge-transfer (3MLCT) states (τTA = 0.40-0.85 μs), but long-lived intraligand charge-transfer (3ILCT) states were observed in Ru-2T-4T (τTA = 25-148 μs). The 3ILCT energies of Ru-3T and Ru-4T were computed to be 1.6 and 1.4 eV, respectively. The phototherapeutic efficacy against melanoma cells (SK-MEL-28) under broad-band visible light (400-700 nm) increases as n = 0 → 4: Ru-0T was inactive up to 300 μM, Ru-1T-2T were moderately active (EC50 ∼ 600 nM, PI = 200), and Ru-3T (EC50 = 57 nM, PI > 1100) and Ru-4T (EC50 = 740 pM, PI = 114,000) were the most phototoxic. The activity diminishes with longer wavelengths of light and is completely suppressed for all complexes except Ru-3T and Ru-4T in hypoxia. Ru-4T is the more potent and robust PS in 1% O2 over seven biological replicates (avg EC50 = 1.3 μM, avg PI = 985). Ru-3T exhibited hypoxic activity in five of seven replicates, underscoring the need for biological replicates in compound evaluation. Singlet oxygen sensitization is likely responsible for phototoxic effects of the compounds in normoxia, but the presence of redox-active excited states may facilitate additional photoactive pathways for complexes with three or more thienyl groups. The 3ILCT state with its extended lifetime (30-40× longer than the 3MLCT state for Ru-3T and Ru-4T) implicates its predominant role in photocytotoxicity.
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Affiliation(s)
- Houston D. Cole
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas, 76019-0065 USA
| | - Abbas Vali
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas, 76019-0065 USA
| | - John A. Roque
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas, 76019-0065 USA
- Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, North Carolina 27402 USA
| | - Ge Shi
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas, 76019-0065 USA
| | - Gurleen Kaur
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas, 76019-0065 USA
| | - Rachel O. Hodges
- Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, North Carolina 27402 USA
| | | | - Marta E. Alberto
- Dipartimento di Chimica e Tecnologie Chimiche, Università della Calabria, Arcavacata di Rende, 87036 Italy
| | - Colin G. Cameron
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas, 76019-0065 USA
| | - Sherri A. McFarland
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas, 76019-0065 USA
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Azad AK, Lilge L, Usmani NH, Lewis JD, Cole HD, Cameron CG, McFarland SA, Dinakaran D, Moore RB. High quantum efficiency ruthenium coordination complex photosensitizer for improved radiation-activated Photodynamic Therapy. Front Oncol 2023; 13:1244709. [PMID: 37700826 PMCID: PMC10494715 DOI: 10.3389/fonc.2023.1244709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 08/08/2023] [Indexed: 09/14/2023] Open
Abstract
Traditional external light-based Photodynamic Therapy (PDT)'s application is limited to the surface and minimal thickness tumors because of the inefficiency of light in penetrating deep-seated tumors. To address this, the emerging field of radiation-activated PDT (radioPDT) uses X-rays to trigger photosensitizer-containing nanoparticles (NPs). A key consideration in radioPDT is the energy transfer efficiency from X-rays to the photosensitizer for ultimately generating the phototoxic reactive oxygen species (ROS). In this study, we developed a new variant of pegylated poly-lactic-co-glycolic (PEG-PLGA) encapsulated nanoscintillators (NSCs) along with a new, highly efficient ruthenium-based photosensitizer (Ru/radioPDT). Characterization of this NP via transmission electron microscopy, dynamic light scattering, UV-Vis spectroscopy, and inductively coupled plasma mass-spectroscopy showed an NP size of 120 nm, polydispersity index (PDI) of less than 0.25, high NSCs loading efficiency over 90% and in vitro accumulation within the cytosolic structure of endoplasmic reticulum and lysosome. The therapeutic efficacy of Ru/radioPDT was determined using PC3 cell viability and clonogenic assays. Ru/radioPDT exhibited minimal cell toxicity until activated by radiation to induce significant cancer cell kill over radiation alone. Compared to protoporphyrin IX-mediated radioPDT (PPIX/radioPDT), Ru/radioPDT showed higher capacity for singlet oxygen generation, maintaining a comparable cytotoxic effect on PC3 cells.
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Affiliation(s)
- Abul Kalam Azad
- Department of Oncology, University of Alberta, Edmonton, AB, Canada
| | - Lothar Lilge
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada
| | - Nawaid H. Usmani
- Department of Oncology, University of Alberta, Edmonton, AB, Canada
| | - John D. Lewis
- Department of Oncology, University of Alberta, Edmonton, AB, Canada
| | - Houston D. Cole
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, TX, United States
| | - Colin G. Cameron
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, TX, United States
| | - Sherri A. McFarland
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, TX, United States
| | - Deepak Dinakaran
- Department of Oncology, University of Alberta, Edmonton, AB, Canada
- Radiation Oncology Branch, National Cancer Institute, National Institute of Health, Bethesda, MD, United States
| | - Ronald B. Moore
- Department of Oncology, University of Alberta, Edmonton, AB, Canada
- Department of Surgery, University of Alberta, Edmonton, AB, Canada
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Chettri A, Yang T, Cole HD, Shi G, Cameron CG, McFarland SA, Dietzek-Ivanšić B. Using Biological Photophysics to Map the Excited-State Topology of Molecular Photosensitizers for Photodynamic Therapy. Angew Chem Int Ed Engl 2023; 62:e202301452. [PMID: 36827484 PMCID: PMC10079593 DOI: 10.1002/anie.202301452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 02/23/2023] [Accepted: 02/24/2023] [Indexed: 02/26/2023]
Abstract
This study employs TLD1433, a RuII -based photodynamic therapy (PDT) agent in human clinical trials, as a benchmark to establish protocols for studying the excited-state dynamics of photosensitizers (PSs) in cellulo, in the local environment provided by human cancer cells. Very little is known about the excited-state properties of any PS in live cells, and for TLD1433, it is terra incognita. This contribution targets a general problem in phototherapy, which is how to interrogate the light-triggered, function-determining processes of the PSs in the relevant biological environment, and establishes methodological advances to study the ultrafast photoinduced processes for TLD1433 when taken up by MCF7 cells. We generalize the methodological developments and results in terms of molecular physics by applying them to TLD1433's analogue TLD1633, making this study a benchmark to investigate the excited-state dynamics of phototoxic compounds in the complex biological environment.
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Affiliation(s)
- Avinash Chettri
- Department Functional Interfaces, Leibniz-Institute of Photonic Technology Jena, Albert-Einstein-Straße 9, 07745, Jena, Germany
- Institute of Physical Chemistry, Friedrich-Schiller University Jena, Helmholtzweg 4, 07743, Jena, Germany
| | - Tingxiang Yang
- Department Functional Interfaces, Leibniz-Institute of Photonic Technology Jena, Albert-Einstein-Straße 9, 07745, Jena, Germany
- Institute of Physical Chemistry, Friedrich-Schiller University Jena, Helmholtzweg 4, 07743, Jena, Germany
| | - Houston D Cole
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, TX-76019, USA
| | - Ge Shi
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, TX-76019, USA
| | - Colin G Cameron
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, TX-76019, USA
| | - Sherri A McFarland
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, TX-76019, USA
| | - Benjamin Dietzek-Ivanšić
- Department Functional Interfaces, Leibniz-Institute of Photonic Technology Jena, Albert-Einstein-Straße 9, 07745, Jena, Germany
- Institute of Physical Chemistry, Friedrich-Schiller University Jena, Helmholtzweg 4, 07743, Jena, Germany
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Oladipupo OE, Prescott MC, Blevins ER, Gray JL, Cameron CG, Qu F, Ward NA, Pierce AL, Collinson ER, Hall JF, Park S, Kim Y, McFarland SA, Fedin I, Papish ET. Ruthenium Complexes with Protic Ligands: Influence of the Position of OH Groups and π Expansion on Luminescence and Photocytotoxicity. Int J Mol Sci 2023; 24:ijms24065980. [PMID: 36983054 PMCID: PMC10053956 DOI: 10.3390/ijms24065980] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 03/10/2023] [Accepted: 03/14/2023] [Indexed: 03/30/2023] Open
Abstract
Protic ruthenium complexes using the dihydroxybipyridine (dhbp) ligand combined with a spectator ligand (N,N = bpy, phen, dop, Bphen) have been studied for their potential activity vs. cancer cells and their photophysical luminescent properties. These complexes vary in the extent of π expansion and the use of proximal (6,6'-dhbp) or distal (4,4'-dhbp) hydroxy groups. Eight complexes are studied herein as the acidic (OH bearing) form, [(N,N)2Ru(n,n'-dhbp)]Cl2, or as the doubly deprotonated (O- bearing) form. Thus, the presence of these two protonation states gives 16 complexes that have been isolated and studied. Complex 7A, [(dop)2Ru(4,4'-dhbp)]Cl2, has been recently synthesized and characterized spectroscopically and by X-ray crystallography. The deprotonated forms of three complexes are also reported herein for the first time. The other complexes studied have been synthesized previously. Three complexes are light-activated and exhibit photocytotoxicity. The log(Do/w) values of the complexes are used herein to correlate photocytotoxicity with improved cellular uptake. For Ru complexes 1-4 bearing the 6,6'-dhbp ligand, photoluminescence studies (all in deaerated acetonitrile) have revealed that steric strain leads to photodissociation which tends to reduce photoluminescent lifetimes and quantum yields in both protonation states. For Ru complexes 5-8 bearing the 4,4'-dhbp ligand, the deprotonated Ru complexes (5B-8B) have low photoluminescent lifetimes and quantum yields due to quenching that is proposed to involve the 3LLCT excited state and charge transfer from the [O2-bpy]2- ligand to the N,N spectator ligand. The protonated OH bearing 4,4'-dhbp Ru complexes (5A-8A) have long luminescence lifetimes which increase with increasing π expansion on the N,N spectator ligand. The Bphen complex, 8A, has the longest lifetime of the series at 3.45 μs and a photoluminescence quantum yield of 18.7%. This Ru complex also exhibits the best photocytotoxicity of the series. A long luminescence lifetime is correlated with greater singlet oxygen quantum yields because the triplet excited state is presumably long-lived enough to interact with 3O2 to yield 1O2.
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Affiliation(s)
- Olaitan E Oladipupo
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Meredith C Prescott
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Emily R Blevins
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Jessica L Gray
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Colin G Cameron
- Department of Chemistry and Biochemistry, The University of Texas Arlington, Arlington, TX 76019, USA
| | - Fengrui Qu
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Nicholas A Ward
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Abigail L Pierce
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Elizabeth R Collinson
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - James Fletcher Hall
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Seungjo Park
- Department of Chemical and Biological Engineering, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Yonghyun Kim
- Department of Chemical and Biological Engineering, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Sherri A McFarland
- Department of Chemistry and Biochemistry, The University of Texas Arlington, Arlington, TX 76019, USA
| | - Igor Fedin
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Elizabeth T Papish
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
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Cole HD, Eroy M, Roque JA, Shi G, Guirguis M, Fakhry J, Cameron CG, Obaid G, McFarland SA. Establishing a Robust and Reliable Response from a Potent Osmium-Based Photosensitizer Via Lipid Nanoformulation †. Photochem Photobiol 2023; 99:751-760. [PMID: 36481983 PMCID: PMC10315168 DOI: 10.1111/php.13756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 12/04/2022] [Indexed: 12/13/2022]
Abstract
Osmium (Os) based photosensitizers (PSs) are a unique class of nontetrapyrrolic metal-containing PSs that absorb red light. We recently reported a highly potent Os(II) PS, rac-[Os(phen)2 (IP-4T)](Cl)2 , referred to as ML18J03 herein, with light EC50 values as low as 20 pm. ML18J03 also exhibits low dark toxicity and submicromolar light EC50 values in hypoxia in some cell lines. However, owing to its longer oligothiophene chain, ML18J03 is not completely water soluble and forms 1-2 μm sized aggregates in PBS containing 1% DMSO. This aggregation causes variability in PDT efficacy between assays and thus unreliable and irreproducible reports of in vitro activity. To that end, we utilized PEG-modified DPPC liposomes (138 nm diameter) and DSPE-mPEG2000 micelles (10.2 nm diameter) as lipid nanoformulation vehicles to mitigate aggregation of ML18J03 and found that the spectroscopic properties important to biological activity were maintained or improved. Importantly, the lipid formulations decreased the interassay variance between the EC50 values by almost 20-fold, with respect to the unformulated ML18J03 when using broadband visible light excitation (P = 0.0276). Herein, lipid formulations are presented as reliable platforms for more accurate in vitro photocytotoxicity quantification for PSs prone to aggregation (such as ML18J03) and will be useful for assessing their in vivo PDT effects.
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Affiliation(s)
- Houston D. Cole
- Department of Chemistry and Biochemistry, University of Texas at Arlington, Arlington, Texas 76019, United States
| | - Menitte Eroy
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX 75080, United States
| | - John A. Roque
- Department of Chemistry and Biochemistry, University of Texas at Arlington, Arlington, Texas 76019, United States
| | - Ge Shi
- Department of Chemistry and Biochemistry, University of Texas at Arlington, Arlington, Texas 76019, United States
| | - Mina Guirguis
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX 75080, United States
| | - John Fakhry
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX 75080, United States
| | - Colin G. Cameron
- Department of Chemistry and Biochemistry, University of Texas at Arlington, Arlington, Texas 76019, United States
| | - Girgis Obaid
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX 75080, United States
| | - Sherri A. McFarland
- Department of Chemistry and Biochemistry, University of Texas at Arlington, Arlington, Texas 76019, United States
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Shah D, Eroy M, Fakhry J, Moffat A, Fritz K, Cole HD, Cameron CG, McFarland SA, Obaid G. Enabling In Vivo Optical Imaging of an Osmium Photosensitizer by Micellar Formulation. Pharmaceutics 2022; 14:2426. [PMID: 36365244 PMCID: PMC9693841 DOI: 10.3390/pharmaceutics14112426] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 11/03/2022] [Accepted: 11/07/2022] [Indexed: 07/30/2023] Open
Abstract
Osmium (Os)-based photosensitizers (PSs) exhibit unique broad, red-shifted absorption, favoring PDT activity at greater tissue depths. We recently reported on a potent Os(II) PS, rac-[Os(phen)2(IP-4T)](Cl)2 (ML18J03) with submicromolar hypoxia activity. ML18J03 exhibits a low luminescence quantum yield of 9.8 × 10-5 in PBS, which limits its capacity for in vivo luminescence imaging. We recently showed that formulating ML18J03 into 10.2 nm DSPE-mPEG2000 micelles (Mic-ML18J03) increases its luminescence quantum yield by two orders of magnitude. Here, we demonstrate that Mic-ML18J03 exhibits 47-fold improved accumulative luminescence signals in orthotopic AT-84 head and neck tumors. We show, for the first time, that micellar formulation provides up to 11.7-fold tumor selectivity for ML18J03. Furthermore, Mic-ML18J03 does not experience the concentration-dependent quenching observed with unformulated ML18J03 in PBS, and formulation reduces spectral shifting of the emission maxima during PDT (variance = 6.5 and 27.3, respectively). The Mic-ML18J03 formulation also increases the production of reactive molecular species 2-3-fold. These findings demonstrate that micellar formulation is a versatile and effective approach to enable in vivo luminescence imaging options for an otherwise quenched, yet promising, PS.
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Affiliation(s)
- Drashti Shah
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX 75080, USA
| | - Menitte Eroy
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX 75080, USA
| | - John Fakhry
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX 75080, USA
| | - Azophi Moffat
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX 75080, USA
| | - Kevin Fritz
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX 75080, USA
| | - Houston D. Cole
- Department of Chemistry and Biochemistry, University of Texas at Arlington, Arlington, TX 76019, USA
| | - Colin G. Cameron
- Department of Chemistry and Biochemistry, University of Texas at Arlington, Arlington, TX 76019, USA
| | - Sherri A. McFarland
- Department of Chemistry and Biochemistry, University of Texas at Arlington, Arlington, TX 76019, USA
| | - Girgis Obaid
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX 75080, USA
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Obaid G, Bano S, Thomsen H, Callaghan S, Shah N, Swain JWR, Jin W, Ding X, Cameron CG, McFarland SA, Wu J, Vangel M, Stoilova‐McPhie S, Zhao J, Mino‐Kenudson M, Lin C, Hasan T. Remediating Desmoplasia with EGFR-Targeted Photoactivable Multi-Inhibitor Liposomes Doubles Overall Survival in Pancreatic Cancer. Adv Sci (Weinh) 2022; 9:e2104594. [PMID: 35748165 PMCID: PMC9404396 DOI: 10.1002/advs.202104594] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 05/31/2022] [Indexed: 05/20/2023]
Abstract
Desmoplasia is characteristic of pancreatic ductal adenocarcinoma (PDAC), which exhibits 5-year survival rates of 3%. Desmoplasia presents physical and biochemical barriers that contribute to treatment resistance, yet depleting the stroma alone is unsuccessful and even detrimental to patient outcomes. This study is the first demonstration of targeted photoactivable multi-inhibitor liposomes (TPMILs) that induce both photodynamic and chemotherapeutic tumor insult, while simultaneously remediating desmoplasia in orthotopic PDAC. TPMILs targeted with cetuximab (anti-EGFR mAb) contain lipidated benzoporphyrin derivative (BPD-PC) photosensitizer and irinotecan. The desmoplastic tumors comprise human PDAC cells and patient-derived cancer-associated fibroblasts. Upon photoactivation, the TPMILs induce 90% tumor growth inhibition at only 8.1% of the patient equivalent dose of nanoliposomal irinotecan (nal-IRI). Without EGFR targeting, PMIL photoactivation is ineffective. TPMIL photoactivation is also sixfold more effective at inhibiting tumor growth than a cocktail of Visudyne-photodynamic therapy (PDT) and nal-IRI, and also doubles survival and extends progression-free survival by greater than fivefold. Second harmonic generation imaging reveals that TPMIL photoactivation reduces collagen density by >90% and increases collagen nonalignment by >103 -fold. Collagen nonalignment correlates with a reduction in tumor burden and survival. This single-construct phototoxic, chemotherapeutic, and desmoplasia-remediating regimen offers unprecedented opportunities to substantially extend survival in patients with otherwise dismal prognoses.
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Affiliation(s)
- Girgis Obaid
- Department of DermatologyMassachusetts General Hospital and Harvard Medical SchoolBostonMA02114USA
- Present address:
Department of BioengineeringUniversity of Texas at DallasRichardsonTX75080USA
| | - Shazia Bano
- Department of DermatologyMassachusetts General Hospital and Harvard Medical SchoolBostonMA02114USA
| | - Hanna Thomsen
- Department of DermatologyMassachusetts General Hospital and Harvard Medical SchoolBostonMA02114USA
| | - Susan Callaghan
- Department of DermatologyMassachusetts General Hospital and Harvard Medical SchoolBostonMA02114USA
| | - Nimit Shah
- Present address:
Department of BioengineeringUniversity of Texas at DallasRichardsonTX75080USA
| | - Joseph W. R. Swain
- Department of DermatologyMassachusetts General Hospital and Harvard Medical SchoolBostonMA02114USA
| | - Wendong Jin
- Department of DermatologyMassachusetts General Hospital and Harvard Medical SchoolBostonMA02114USA
| | - Xiadong Ding
- Department of DermatologyMassachusetts General Hospital and Harvard Medical SchoolBostonMA02114USA
| | | | | | - Juwell Wu
- Department of DermatologyMassachusetts General Hospital and Harvard Medical SchoolBostonMA02114USA
| | - Mark Vangel
- Department of DermatologyMassachusetts General Hospital and Harvard Medical SchoolBostonMA02114USA
| | | | - Jie Zhao
- Department of DermatologyMassachusetts General Hospital and Harvard Medical SchoolBostonMA02114USA
| | - Mari Mino‐Kenudson
- Department of DermatologyMassachusetts General Hospital and Harvard Medical SchoolBostonMA02114USA
| | - Charles Lin
- Department of DermatologyMassachusetts General Hospital and Harvard Medical SchoolBostonMA02114USA
| | - Tayyaba Hasan
- Department of DermatologyMassachusetts General Hospital and Harvard Medical SchoolBostonMA02114USA
- Division of Health Sciences and TechnologyHarvard University and Massachusetts Institute of TechnologyCambridgeMA02139USA
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Roque Iii JA, Cole HD, Barrett PC, Lifshits LM, Hodges RO, Kim S, Deep G, Francés-Monerris A, Alberto ME, Cameron CG, McFarland SA. Intraligand Excited States Turn a Ruthenium Oligothiophene Complex into a Light-Triggered Ubertoxin with Anticancer Effects in Extreme Hypoxia. J Am Chem Soc 2022; 144:8317-8336. [PMID: 35482975 PMCID: PMC9098688 DOI: 10.1021/jacs.2c02475] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Ru(II) complexes that undergo photosubstitution reactions from triplet metal-centered (3MC) excited states are of interest in photochemotherapy (PCT) due to their potential to produce cytotoxic effects in hypoxia. Dual-action systems that incorporate this stoichiometric mode to complement the oxygen-dependent photosensitization pathways that define photodynamic therapy (PDT) are poised to maintain antitumor activity regardless of the oxygenation status. Herein, we examine the way in which these two pathways influence photocytotoxicity in normoxia and in hypoxia using the [Ru(dmp)2(IP-nT)]2+ series (where dmp = 2,9-dimethyl-1,10-phenanthroline and IP-nT = imidazo[4,5-f][1,10]phenanthroline tethered to n = 0-4 thiophene rings) to switch the dominant excited state from the metal-based 3MC state in the case of Ru-phen-Ru-1T to the ligand-based 3ILCT state for Ru-3T and Ru-4T. Ru-phen-Ru-1T, having dominant 3MC states and the largest photosubstitution quantum yields, are inactive in both normoxia and hypoxia. Ru-3T and Ru-4T, with dominant 3IL/3ILCT states and long triplet lifetimes (τTA = 20-25 μs), have the poorest photosubstitution quantum yields, yet are extremely active. In the best instances, Ru-4T exhibit attomolar phototoxicity toward SKMEL28 cells in normoxia and picomolar in hypoxia, with phototherapeutic index values in normoxia of 105-1012 and 103-106 in hypoxia. While maximizing excited-state deactivation through photodissociative 3MC states did not result in bonafide dual-action PDT/PCT agents, the study has produced the most potent photosensitizer we know of to date. The extraordinary photosensitizing capacity of Ru-3T and Ru-4T may stem from a combination of very efficient 1O2 production and possibly complementary type I pathways via 3ILCT excited states.
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Affiliation(s)
- John A Roque Iii
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019-0065, United States.,Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, North Carolina 27402, United States
| | - Houston D Cole
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019-0065, United States
| | - Patrick C Barrett
- Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, North Carolina 27402, United States
| | - Liubov M Lifshits
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019-0065, United States
| | - Rachel O Hodges
- Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, North Carolina 27402, United States
| | - Susy Kim
- Department of Cancer Biology, Wake Forest School of Medicine, Winston Salem, North Carolina 27157, United States
| | - Gagan Deep
- Department of Cancer Biology, Wake Forest School of Medicine, Winston Salem, North Carolina 27157, United States
| | | | - Marta E Alberto
- Dipartimento di Chimica e Tecnologie Chimiche, Università della Calabria, Arcavacata di Rende 87036, Italy
| | - Colin G Cameron
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019-0065, United States
| | - Sherri A McFarland
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019-0065, United States
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10
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Chettri A, Cole HD, Roque JA, Schneider KRA, Yang T, Cameron CG, McFarland SA, Dietzek-Ivanšić B. Interaction with a Biomolecule Facilitates the Formation of the Function-Determining Long-Lived Triplet State in a Ruthenium Complex for Photodynamic Therapy. J Phys Chem A 2022; 126:1336-1344. [PMID: 35179905 PMCID: PMC8903189 DOI: 10.1021/acs.jpca.1c09968] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
TLD1433 is the first ruthenium (Ru)-based photodynamic therapy (PDT) agent to advance to clinical trials and is currently in a phase II study for treating nonmuscle bladder cancer with PDT. Herein, we present a photophysical study of TLD1433 and its derivative TLD1633 using complex, biologically relevant solvents to elucidate the excited-state properties that are key for biological activity. The complexes incorporate an imidazo [4,5-f][1,10]phenanthroline (IP) ligand appended to α-ter- or quaterthiophene, respectively, where TLD1433 = [Ru(4,4'-dmb)2(IP-3T)]Cl2 and TLD1633 = [Ru(4,4'-dmb)2(IP-4T)]Cl2 (4,4'-dmb = 4,4'-dimethyl-2,2'-bipyridine; 3T = α-terthiophene; 4T = α-quaterthiophene). Time-resolved transient absorption experiments demonstrate that the excited-state dynamics of the complexes change upon interaction with biological macromolecules (e.g., DNA). In this case, the accessibility of the lowest-energy triplet intraligand charge-transfer (3ILCT) state (T1) is increased at the expense of a higher-lying 3ILCT state. We attribute this behavior to the increased rigidity of the ligand framework upon binding to DNA, which prolongs the lifetime of the T1 state. This lowest-lying state is primarily responsible for O2 sensitization and hence photoinduced cytotoxicity. Therefore, to gain a realistic picture of the excited-state kinetics that underlie the photoinduced function of the complexes, it is necessary to interrogate their photophysical dynamics in the presence of biological targets once they are known.
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Affiliation(s)
- Avinash Chettri
- Leibniz Institute of Photonic Technology Jena, Department Functional Interfaces, Albert-Einstein-Straße 9, 07745 Jena, Germany,Friedrich Schiller University Jena, Institute of Physical Chemistry and Abbe Center of Photonics, Helmholtzweg 4, 07743 Jena, Germany
| | - Houston D. Cole
- The University of Texas at Arlington, Department of Chemistry and Biochemistry, Arlington, TX 76019, USA
| | - John A. Roque
- The University of Texas at Arlington, Department of Chemistry and Biochemistry, Arlington, TX 76019, USA,The University of North Carolina at Greensboro, Department of Chemistry and Biochemistry, Greensboro, NC 27402, USA
| | - Kilian R. A. Schneider
- Leibniz Institute of Photonic Technology Jena, Department Functional Interfaces, Albert-Einstein-Straße 9, 07745 Jena, Germany,Friedrich Schiller University Jena, Institute of Physical Chemistry and Abbe Center of Photonics, Helmholtzweg 4, 07743 Jena, Germany
| | - Tingxiang Yang
- Leibniz Institute of Photonic Technology Jena, Department Functional Interfaces, Albert-Einstein-Straße 9, 07745 Jena, Germany,Friedrich Schiller University Jena, Institute of Physical Chemistry and Abbe Center of Photonics, Helmholtzweg 4, 07743 Jena, Germany
| | - Colin G. Cameron
- The University of Texas at Arlington, Department of Chemistry and Biochemistry, Arlington, TX 76019, USA
| | - Sherri A. McFarland
- The University of Texas at Arlington, Department of Chemistry and Biochemistry, Arlington, TX 76019, USA
| | - Benjamin Dietzek-Ivanšić
- Leibniz Institute of Photonic Technology Jena, Department Functional Interfaces, Albert-Einstein-Straße 9, 07745 Jena, Germany,Friedrich Schiller University Jena, Institute of Physical Chemistry and Abbe Center of Photonics, Helmholtzweg 4, 07743 Jena, Germany
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11
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Konda P, Roque III JA, Lifshits LM, Alcos A, Azzam E, Shi G, Cameron CG, McFarland SA, Gujar S. Photodynamic therapy of melanoma with new, structurally similar, NIR-absorbing ruthenium (II) complexes promotes tumor growth control via distinct hallmarks of immunogenic cell death. Am J Cancer Res 2022; 12:210-228. [PMID: 35141014 PMCID: PMC8822289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 10/06/2021] [Indexed: 06/14/2023] Open
Abstract
Cancer therapies that generate T cell-based anti-cancer immune responses are critical for clinical success and are favored over traditional therapies. One way to elicit T cell immune responses and generate long-lasting anti-cancer immunity is through induction of immunogenic cell death (ICD), a form of regulated cell death that promotes antigenicity and adjuvanticity within dying cells. Therefore, research in the last decade has focused on developing cancer therapies which stimulate ICD. Herein, we report novel photodynamic therapy (PDT) compounds with immunomodulatory and ICD inducing properties. PDT is a clinically approved, minimally invasive anti-cancer treatment option and has been extensively investigated for its tumor-destroying properties, lower side effects, and immune activation capabilities. In this study, we explore two structurally related ruthenium compounds, ML19B01 and ML19B02, that can be activated with near infrared light to elicit superior cytotoxic properties. In addition to its direct cell killing abilities, we investigated the effect of our PSs on immunological pathways upon activation. PDT treatment with ML19B01 and ML19B02 induced differential expression of reactive oxygen species, proinflammatory response-mediating genes, and heat shock proteins. Dying melanoma cells induced by ML19B01-PDT and ML19B02-PDT contained ICD hallmarks such as calreticulin, ATP, and HMGB1, initiated activation of antigen presenting cells, and were efficiently phagocytosed by bone marrow-derived dendritic cells. Most importantly, despite the distinct profiles of ICD hallmark inducing capacities, vaccination with both PDT-induced dying cancer cells established anti-tumor immunity that protected mice against subsequent challenge with melanoma cells.
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Affiliation(s)
- Prathyusha Konda
- Department of Microbiology & Immunology, Dalhousie UniversityHalifax, Nova Scotia B3H 1X5, Canada
| | - John A Roque III
- Department of Chemistry and Biochemistry, The University of Texas at ArlingtonArlington, Texas 76019-0065, USA
- Department of Chemistry and Biochemistry, The University of North Carolina at GreensboroGreensboro, North Carolina 27402, USA
| | - Liubov M Lifshits
- Department of Chemistry and Biochemistry, The University of Texas at ArlingtonArlington, Texas 76019-0065, USA
| | - Angelita Alcos
- Department of Pathology, Dalhousie UniversityHalifax, Nova Scotia B3H 1X5, Canada
| | - Eissa Azzam
- Department of Microbiology & Immunology, Dalhousie UniversityHalifax, Nova Scotia B3H 1X5, Canada
| | - Ge Shi
- Department of Chemistry and Biochemistry, The University of Texas at ArlingtonArlington, Texas 76019-0065, USA
| | - Colin G Cameron
- Department of Chemistry and Biochemistry, The University of Texas at ArlingtonArlington, Texas 76019-0065, USA
| | - Sherri A McFarland
- Department of Chemistry and Biochemistry, The University of Texas at ArlingtonArlington, Texas 76019-0065, USA
| | - Shashi Gujar
- Department of Microbiology & Immunology, Dalhousie UniversityHalifax, Nova Scotia B3H 1X5, Canada
- Department of Pathology, Dalhousie UniversityHalifax, Nova Scotia B3H 1X5, Canada
- Department of Biology, Dalhousie UniversityHalifax, Nova Scotia B3H 1X5, Canada
- Beatrice Hunter Cancer Research InstituteHalifax, Nova Scotia B3H 1X5, Canada
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12
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Oladipupo O, Brown SR, Lamb RW, Gray JL, Cameron CG, DeRegnaucourt AR, Ward NA, Hall JF, Xu Y, Petersen CM, Qu F, Shrestha AB, Thompson MK, Bonizzoni M, Webster CE, McFarland SA, Kim Y, Papish ET. Light-responsive and Protic Ruthenium Compounds Bearing Bathophenanthroline and Dihydroxybipyridine Ligands Achieve Nanomolar Toxicity towards Breast Cancer Cells. Photochem Photobiol 2022; 98:102-116. [PMID: 34411308 PMCID: PMC8810589 DOI: 10.1111/php.13508] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 08/16/2021] [Indexed: 01/03/2023]
Abstract
We report new ruthenium complexes bearing the lipophilic bathophenanthroline (BPhen) ligand and dihydroxybipyridine (dhbp) ligands which differ in the placement of the OH groups ([(BPhen)2 Ru(n,n'-dhbp)]Cl2 with n = 6 and 4 in 1A and 2A , respectively). Full characterization data are reported for 1A and 2A and single crystal X-ray diffraction for 1A . Both 1A and 2A are diprotic acids. We have studied 1A , 1B , 2A , and 2B (B = deprotonated forms) by UV-vis spectroscopy and 1 photodissociates, but 2 is light stable. Luminescence studies reveal that the basic forms have lower energy 3 MLCT states relative to the acidic forms. Complexes 1A and 2A produce singlet oxygen with quantum yields of 0.05 and 0.68, respectively, in acetonitrile. Complexes 1 and 2 are both photocytotoxic toward breast cancer cells, with complex 2 showing EC50 light values as low as 0.50 μM with PI values as high as >200 vs. MCF7. Computational studies were used to predict the energies of the 3 MLCT and 3 MC states. An inaccessible 3 MC state for 2B suggests a rationale for why photodissociation does not occur with the 4,4'-dhbp ligand. Low dark toxicity combined with an accessible 3 MLCT state for 1 O2 generation explains the excellent photocytotoxicity of 2.
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Affiliation(s)
- Olaitan Oladipupo
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Spenser R. Brown
- Department of Chemical and Biological Engineering, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Robert W. Lamb
- Department of Chemistry, Mississippi State University, Mississippi State, MS 39762, USA.,Oak Ridge Institute for Science and Education, Oak Ridge, TN 37830, USA
| | - Jessica L. Gray
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Colin G. Cameron
- Department of Chemistry and Biochemistry, University of Texas Arlington, Arlington, TX 76019, USA
| | - Alexa R. DeRegnaucourt
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Nicholas A. Ward
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - James Fletcher Hall
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Yifei Xu
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Courtney M. Petersen
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Fengrui Qu
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Ambar B. Shrestha
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Matthew K. Thompson
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Marco Bonizzoni
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Charles Edwin Webster
- Department of Chemistry, Mississippi State University, Mississippi State, MS 39762, USA.,Corresponding Authors’: (Charles Edwin Webster), (Sherri A. McFarland), (Yonghyun Kim), (Elizabeth T. Papish)
| | - Sherri A. McFarland
- Department of Chemistry and Biochemistry, University of Texas Arlington, Arlington, TX 76019, USA.,Corresponding Authors’: (Charles Edwin Webster), (Sherri A. McFarland), (Yonghyun Kim), (Elizabeth T. Papish)
| | - Yonghyun Kim
- Department of Chemical and Biological Engineering, The University of Alabama, Tuscaloosa, AL 35487, USA.,Corresponding Authors’: (Charles Edwin Webster), (Sherri A. McFarland), (Yonghyun Kim), (Elizabeth T. Papish)
| | - Elizabeth T. Papish
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL 35487, USA.,Corresponding Authors’: (Charles Edwin Webster), (Sherri A. McFarland), (Yonghyun Kim), (Elizabeth T. Papish)
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13
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Cole HD, Roque JA, Lifshits LM, Hodges R, Barrett PC, Havrylyuk D, Heidary D, Ramasamy E, Cameron CG, Glazer EC, McFarland SA. Fine-Feature Modifications to Strained Ruthenium Complexes Radically Alter Their Hypoxic Anticancer Activity †. Photochem Photobiol 2022; 98:73-84. [PMID: 33559191 PMCID: PMC8349932 DOI: 10.1111/php.13395] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 02/03/2021] [Accepted: 02/04/2021] [Indexed: 01/03/2023]
Abstract
In an earlier study of π-expansive ruthenium complexes for photodynamic and photochemo-therapies, it was shown that a pair of structural isomers differing only in the connection point of a naphthalene residue exhibited vastly different biological activity. These isomers are further explored in this paper through the activity of their functionalized derivatives. In normoxia, the inactive 2-NIP isomer (5) can be made as photocytotoxic as the active 1-NIP isomer (1) by functionalizing with methyl or methoxy groups, while methoxy variants of the 1-NIP isomer became inactive. In all cases, the singlet oxygen sensitization quantum yield was below 1%. Hypoxic photocytotoxicity was attenuated, with only three of the series showing any activity, notwithstanding the photodissociative ligands. The results here are consistent with the earlier findings in that seemingly minor structural modifications on the non-strained ligand can dramatically modulate the normoxic and hypoxic activity of these strained compounds and that these changes appear to exert a greater influence on photocytotoxicity than singlet oxygen sensitization or rates of photosubstitution in cell-free conditions would suggest.
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Affiliation(s)
- Houston D. Cole
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas, 76019-0065 United States
| | - John A. Roque
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas, 76019-0065 United States,Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, North Carolina 27402, United States
| | - Liubov M. Lifshits
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas, 76019-0065 United States
| | - Rachel Hodges
- Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, North Carolina 27402, United States
| | - Patrick C. Barrett
- Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, North Carolina 27402, United States
| | - Dmytro Havrylyuk
- Department of Chemistry, University of Kentucky, Lexington, KY, 76019-0065 United States, 40506-0055
| | - David Heidary
- Department of Chemistry, University of Kentucky, Lexington, KY, 76019-0065 United States, 40506-0055
| | - Elamparuthi Ramasamy
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas, 76019-0065 United States
| | - Colin G. Cameron
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas, 76019-0065 United States,Corresponding authors: C.G.C <>; E.C.G. <>; S.A.M. <>
| | - Edith C. Glazer
- Department of Chemistry, University of Kentucky, Lexington, KY, 76019-0065 United States, 40506-0055,Corresponding authors: C.G.C <>; E.C.G. <>; S.A.M. <>
| | - Sherri A. McFarland
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas, 76019-0065 United States,Corresponding authors: C.G.C <>; E.C.G. <>; S.A.M. <>
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14
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Cole HD, Roque JA, Shi G, Lifshits LM, Ramasamy E, Barrett PC, Hodges RO, Cameron CG, McFarland SA. Anticancer Agent with Inexplicable Potency in Extreme Hypoxia: Characterizing a Light-Triggered Ruthenium Ubertoxin. J Am Chem Soc 2021; 144:9543-9547. [PMID: 34882381 DOI: 10.1021/jacs.1c09010] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Tumor hypoxia renders treatments ineffective that are directly (e.g., radiotherapy and photodynamic therapy) or indirectly (e.g., chemotherapy) dependent on tumor oxygenation. This study introduces a ruthenium compound as a light-responsive anticancer agent that is water-soluble, has minimal dark cytotoxicity, is active at concentrations as low as 170 pM in ∼18.5% O2 normoxia and near 10 nM in 1% O2 hypoxia, and exhibits phototherapeutic indices as large as >500,000 in normoxia and >5,800 in 1% O2 hypoxia using broadband visible and monochromatic blue light treatments. These are the largest values reported to date for any compound class. We highlight the response in four different cell lines to improve rigor and reproducibility in the identification of promising clinical candidates.
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Affiliation(s)
- Houston D Cole
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019-0065, United States
| | - John A Roque
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019-0065, United States.,Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, North Carolina 27402, United States
| | - Ge Shi
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019-0065, United States
| | - Liubov M Lifshits
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019-0065, United States
| | - Elamparuthi Ramasamy
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019-0065, United States
| | - Patrick C Barrett
- Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, North Carolina 27402, United States
| | - Rachel O Hodges
- Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, North Carolina 27402, United States
| | - Colin G Cameron
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019-0065, United States
| | - Sherri A McFarland
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019-0065, United States
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15
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Lifshits LM, III JAR, Ramasamy E, Thummel RP, Cameron CG, McFarland SA. Ruthenium Photosensitizers for NIR PDT Require Lowest-Lying Triplet Intraligand (3IL) Excited States. Journal of Photochemistry and Photobiology 2021; 8. [DOI: 10.1016/j.jpap.2021.100067] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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16
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Chettri A, Schneider KRA, Cole HD, Roque JA, Cameron CG, McFarland SA, Dietzek B. String-Attached Oligothiophene Substituents Determine the Fate of Excited States in Ruthenium Complexes for Photodynamic Therapy. J Phys Chem A 2021; 125:6985-6994. [PMID: 34370485 DOI: 10.1021/acs.jpca.1c04900] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We explore the photophysical properties of a family of Ru(II) complexes, Ru-ip-nT, designed as photosensitizers (PSs) for photodynamic therapy (PDT). The complexes incorporate a 1H-imidazo[4,5-f][1,10]-phenanthroline (ip) ligand appended to one or more thiophene rings. One of the complexes studied herein, Ru-ip-3T (known as TLD1433), is currently in phase II human clinical trials for treating bladder cancer by PDT. The potent photocytotoxicity of Ru-ip-3T is attributed to a long-lived intraligand charge-transfer triplet state. The accessibility of this state changes upon varying the length (n) of the oligothiophene substituent. In this paper, we highlight the impact of n on the ultrafast photoinduced dynamics in Ru-ip-nT, leading to the formation of the function-determining long-lived state. Femtosecond time-resolved transient absorption combined with resonance Raman data was used to map the excited-state relaxation processes from the Franck-Condon point of absorption to the formation of the lowest-energy triplet excited state, which is a triplet metal-to-ligand charge-transfer excited state for Ru-ip-0T-1T and an oligothienyl-localized triplet intraligand charge-transfer excited state for Ru-ip-2T-4T. We establish the structure-activity relationships with regard to changes in the excited-state dynamics as a function of thiophene chain length, which alters the photophysics of the complexes and presumably impacts the photocytotoxicity of these PSs.
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Affiliation(s)
- Avinash Chettri
- Department Functional Interfaces, Leibniz-Institute of Photonic Technology Jena, Albert-Einstein-Straße 9, 07745 Jena, Germany.,Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich-Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - Kilian R A Schneider
- Department Functional Interfaces, Leibniz-Institute of Photonic Technology Jena, Albert-Einstein-Straße 9, 07745 Jena, Germany.,Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich-Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - Houston D Cole
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019, United States
| | - John A Roque
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019, United States.,Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, North Carolina 27402, United States
| | - Colin G Cameron
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019, United States
| | - Sherri A McFarland
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019, United States
| | - Benjamin Dietzek
- Department Functional Interfaces, Leibniz-Institute of Photonic Technology Jena, Albert-Einstein-Straße 9, 07745 Jena, Germany.,Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich-Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
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17
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Chettri A, Roque JA, Schneider KRA, Cole HD, Cameron CG, McFarland SA, Dietzek B. It Takes Three to Tango - the length of the oligothiophene determines the nature of the long-lived excited state and the resulting photocytotoxicity of a Ru(II) photodrug. CHEMPHOTOCHEM 2021; 5:421-425. [PMID: 34337147 PMCID: PMC8323708 DOI: 10.1002/cptc.202000283] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Indexed: 02/06/2023]
Abstract
TLD1433 is the first Ru(II) complex to be tested as a photodynamic therapy agent in a clinical trial. In this contribution we study TLD1433 in the context of structurally-related Ru(II)-imidozo[4,5-f][1,10]phenanthroline (ip) complexes appended with thiophene rings to decipher the unique photophysical properties which are associated with increasing oligothiophene chain length. Substitution of the ip ligand with ter- or quaterthiophene changes the nature of the long-lived triplet state from metal-to-ligand charge-transfer to 3ππ* character. The addition of the third thiophene thus presents a critical juncture which not only determines the photophysics of the complex but most importantly its capacity for 1O2 generation and hence the potential of the complex to be used as a photocytotoxic agent. ENTRY FOR THE TABLE OF CONTENTS A low-lying triplet intraligand state (3IL) determines the properties of the long-lived excited states in a series of Ru(II) complexes. The 3IL state can be accessed by increasing the length of an oligothiophene chain. The 3IL state is extremely efficient at generating 1O2 and thus enhances the potency of the complexes as PDT agents.
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Affiliation(s)
- Avinash Chettri
- Department Functional Interfaces Department, Leibniz Institute of Photonic Technology Jena, Albert-Einstein-Straße 9, 07745 Jena, Germany
- Institute of Physical Chemistry, Friedrich-Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - John A. Roque
- Department of Chemistry and Biochemistry, The University of Texas Arlington, Arlington, TX 76019, USA
- Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, North Carolina 27402, USA
| | - Kilian R. A. Schneider
- Department Functional Interfaces Department, Leibniz Institute of Photonic Technology Jena, Albert-Einstein-Straße 9, 07745 Jena, Germany
- Institute of Physical Chemistry, Friedrich-Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - Houston D. Cole
- Department of Chemistry and Biochemistry, The University of Texas Arlington, Arlington, TX 76019, USA
| | - Colin G. Cameron
- Department of Chemistry and Biochemistry, The University of Texas Arlington, Arlington, TX 76019, USA
| | - Sherri A. McFarland
- Department of Chemistry and Biochemistry, The University of Texas Arlington, Arlington, TX 76019, USA
| | - Benjamin Dietzek
- Department Functional Interfaces Department, Leibniz Institute of Photonic Technology Jena, Albert-Einstein-Straße 9, 07745 Jena, Germany
- Institute of Physical Chemistry, Friedrich-Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany
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18
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Bataglioli JC, Gomes LMF, Maunoir C, Smith JR, Cole HD, McCain J, Sainuddin T, Cameron CG, McFarland SA, Storr T. Modification of amyloid-beta peptide aggregation via photoactivation of strained Ru(ii) polypyridyl complexes. Chem Sci 2021; 12:7510-7520. [PMID: 34163842 PMCID: PMC8171320 DOI: 10.1039/d1sc00004g] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2021] [Accepted: 04/19/2021] [Indexed: 01/01/2023] Open
Abstract
Alzheimer's disease (AD) is a chronic neurodegenerative disorder characterized by progressive and irreversible damage to the brain. One of the hallmarks of the disease is the presence of both soluble and insoluble aggregates of the amyloid beta (Aβ) peptide in the brain, and these aggregates are considered central to disease progression. Thus, the development of small molecules capable of modulating Aβ peptide aggregation may provide critical insight into the pathophysiology of AD. In this work we investigate how photoactivation of three distorted Ru(ii) polypyridyl complexes (Ru1-3) alters the aggregation profile of the Aβ peptide. Photoactivation of Ru1-3 results in the loss of a 6,6'-dimethyl-2,2'-bipyridyl (6,6'-dmb) ligand, affording cis-exchangeable coordination sites for binding to the Aβ peptide. Both Ru1 and Ru2 contain an extended planar imidazo[4,5-f][1,10]phenanthroline ligand, as compared to a 2,2'-bipyridine ligand for Ru3, and we show that the presence of the phenanthroline ligand promotes covalent binding to Aβ peptide His residues, and in addition, leads to a pronounced effect on peptide aggregation immediately after photoactivation. Interestingly, all three complexes resulted in a similar aggregate size distribution at 24 h, forming insoluble amorphous aggregates as compared to significant fibril formation for peptide alone. Photoactivation of Ru1-3 in the presence of pre-formed Aβ1-42 fibrils results in a change to amorphous aggregate morphology, with Ru1 and Ru2 forming large amorphous aggregates immediately after activation. Our results show that photoactivation of Ru1-3 in the presence of either monomeric or fibrillar Aβ1-42 results in the formation of large amorphous aggregates as a common endpoint, with Ru complexes incorporating the extended phenanthroline ligand accelerating this process and thereby limiting the formation of oligomeric species in the initial stages of the aggregation process that are reported to show considerable toxicity.
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Affiliation(s)
| | - Luiza M F Gomes
- Department of Chemistry, Simon Fraser University BC Canada V5A-1S6
| | - Camille Maunoir
- Department of Chemistry, Simon Fraser University BC Canada V5A-1S6
| | - Jason R Smith
- Department of Chemistry, Simon Fraser University BC Canada V5A-1S6
| | - Houston D Cole
- Department of Chemistry and Biochemistry, University of Texas Arlington Texas USA 76019
| | - Julia McCain
- Department of Chemistry, Acadia University Wolfville Nova Scotia Canada B4P 2R6
| | - Tariq Sainuddin
- Department of Chemistry, Acadia University Wolfville Nova Scotia Canada B4P 2R6
| | - Colin G Cameron
- Department of Chemistry and Biochemistry, University of Texas Arlington Texas USA 76019
| | - Sherri A McFarland
- Department of Chemistry and Biochemistry, University of Texas Arlington Texas USA 76019
| | - Tim Storr
- Department of Chemistry, Simon Fraser University BC Canada V5A-1S6
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19
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Qu F, Lamb RW, Cameron CG, Park S, Oladipupo O, Gray JL, Xu Y, Cole HD, Bonizzoni M, Kim Y, McFarland SA, Webster CE, Papish ET. Singlet Oxygen Formation vs Photodissociation for Light-Responsive Protic Ruthenium Anticancer Compounds: The Oxygenated Substituent Determines Which Pathway Dominates. Inorg Chem 2021; 60:2138-2148. [PMID: 33534562 DOI: 10.1021/acs.inorgchem.0c02027] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Ruthenium complexes bearing protic diimine ligands are cytotoxic to certain cancer cells upon irradiation with blue light. Previously reported complexes of the type [(N,N)2Ru(6,6'-dhbp)]Cl2 with 6,6'-dhbp = 6,6'-dihydroxybipyridine and N,N = 2,2'-bipyridine (bipy) (1A), 1,10-phenanthroline (phen) (2A), and 2,3-dihydro-[1,4]dioxino[2,3-f][1,10]phenanthroline (dop) (3A) show EC50 values as low as 4 μM (for 3A) vs breast cancer cells upon blue light irradiation ( Inorg. Chem. 2017, 56, 7519). Herein, subscript A denotes the acidic form of the complex bearing OH groups, and B denotes the basic form bearing O- groups. This photocytotoxicity was originally attributed to photodissociation, but recent results suggest that singlet oxygen formation is a more plausible cause of photocytotoxicity. In particular, bulky methoxy substituents enhance photodissociation but these complexes are nontoxic ( Dalton Trans 2018, 47, 15685). Cellular studies are presented herein that show the formation of reactive oxygen species (ROS) and apoptosis indicators upon treatment of cells with complex 3A and blue light. Singlet oxygen sensor green (SOSG) shows the formation of 1O2 in cell culture for cells treated with 3A and blue light. At physiological pH, complexes 1A-3A are deprotonated to form 1B-3B in situ. Quantum yields for 1O2 (ϕΔ) are 0.87 and 0.48 for 2B and 3B, respectively, and these are an order of magnitude higher than the quantum yields for 2A and 3A. The values for ϕΔ show an increase with 6,6'-dhbp derived substituents as follows: OMe < OH < O-. TD-DFT studies show that the presence of a low lying triplet metal-centered (3MC) state favors photodissociation and disfavors 1O2 formation for 2A and 3A (OH groups). However, upon deprotonation (O- groups), the 3MLCT state is accessible and can readily lead to 1O2 formation, but the dissociative 3MC state is energetically inaccessible. The changes to the energy of the 3MLCT state upon deprotonation have been confirmed by steady state luminescence experiments on 1A-3A and their basic analogs, 1B-3B. This energy landscape favors 1O2 formation for 2B and 3B and leads to enhanced toxicity for these complexes under physiological conditions. The ability to convert readily from OH to O- groups allowed us to investigate an electronic change that is not accompanied by steric changes in this fundamental study.
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Affiliation(s)
- Fengrui Qu
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Robert W Lamb
- Department of Chemistry, Mississippi State University, Mississippi State, Mississippi 39762, United States
| | - Colin G Cameron
- Department of Chemistry and Biochemistry, University of Texas Arlington, Arlington, Texas 76019, United States
| | - Seungjo Park
- Department of Chemical and Biological Engineering, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Olaitan Oladipupo
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Jessica L Gray
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Yifei Xu
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Houston D Cole
- Department of Chemistry and Biochemistry, University of Texas Arlington, Arlington, Texas 76019, United States
| | - Marco Bonizzoni
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Yonghyun Kim
- Department of Chemical and Biological Engineering, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Sherri A McFarland
- Department of Chemistry and Biochemistry, University of Texas Arlington, Arlington, Texas 76019, United States
| | - Charles Edwin Webster
- Department of Chemistry, Mississippi State University, Mississippi State, Mississippi 39762, United States
| | - Elizabeth T Papish
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, Alabama 35487, United States
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20
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Konda P, Lifshits LM, Roque JA, Cole HD, Cameron CG, McFarland SA, Gujar S. Discovery of immunogenic cell death-inducing ruthenium-based photosensitizers for anticancer photodynamic therapy. Oncoimmunology 2020; 10:1863626. [PMID: 33457082 PMCID: PMC7781847 DOI: 10.1080/2162402x.2020.1863626] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 12/08/2020] [Indexed: 11/17/2022] Open
Abstract
We report a new class of ruthenium (Ru)-based photosensitizers that induce potent cytotoxicity in melanoma cells following activation with NIR light. In addition to the direct cytotoxic effect, this Ru-based photodynamic therapy induces immunogenic cell death in melanoma cells that can be therapeutically exploited to establish protective antitumor immunity.
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Affiliation(s)
- Prathyusha Konda
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Canada
| | - Liubov M. Lifshits
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, TX, USA
| | - John A. Roque
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, TX, USA
- Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, NC, USA
| | - Houston D. Cole
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, TX, USA
| | - Colin G. Cameron
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, TX, USA
| | - Sherri A. McFarland
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, TX, USA
| | - Shashi Gujar
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Canada
- Department of Pathology, Dalhousie University, Halifax, Canada
- Department of Biology, Dalhousie University, Halifax, Canada
- Beatrice Hunter Cancer Research Institute, Dalhousie University, Halifax, Canada
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21
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Lifshits LM, Roque JA, Cole HD, Thummel RP, Cameron CG, McFarland SA. NIR-Absorbing Ru II Complexes Containing α-Oligothiophenes for Applications in Photodynamic Therapy. Chembiochem 2020; 21:3594-3607. [PMID: 32761725 PMCID: PMC7736147 DOI: 10.1002/cbic.202000419] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 08/03/2020] [Indexed: 12/12/2022]
Abstract
The design of near-infrared (NIR)-active photosensitizers (PSs) for light-based cancer treatments such as photodynamic therapy (PDT) has been a challenge. While several NIR-RuII scaffolds have been reported, this approach has not been proven in cells. This is the first report of NIR-RuII PSs that are phototoxic to cancer cells, including highly pigmented B16F10 melanoma cells. The PS family incorporated a bis(1,8-naphthyridine)-based ligand (tpbn), a bidentate thiophene-based ligand (nT; n=0-4), and a monodentate 4-picoline ligand (4-pic). All compounds absorbed light >800 nm with maxima near 730 nm. Transient absorption (TA) measurements indicated that n=4 thiophene rings (4T) positioned the PDT-active triplet intraligand charge transfer (3 ILCT) excited state in energetic proximity to the lowest-lying triplet metal-to-ligand charge transfer (3 MLCT). 4T had low-micromolar phototoxicity with PIvis and PI733nm values as large as 90 and 12, respectively. Spectroscopic studies suggested that the longer-lived (τTA =3-6 μs) 3 ILCT state was accessible from the 3 MLCT state, but energetically uphill in the overall photophysics. The study highlights that phototoxic effects can be achieved with NIR-absorbing RuII PSs as long as the reactive 3 ILCT states are energetically accessible from the low-energy 3 MLCT states. It also demonstrates that tissue-penetrating NIR light can be used to activate the PSs in highly pigmented cells where melanin attenuates shorter wavelengths of light.
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Affiliation(s)
- Liubov M. Lifshits
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas, 76019-0065 United States
| | - John A. Roque
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas, 76019-0065 United States
- Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, North Carolina 27402, USA
| | - Houston D. Cole
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas, 76019-0065 United States
| | - Randolph P. Thummel
- Department of Chemistry, University of Houston, 112 Fleming Building, Houston, Texas, 77204-5003, USA
| | - Colin G. Cameron
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas, 76019-0065 United States
| | - Sherri A. McFarland
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas, 76019-0065 United States
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22
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Schneider KRA, Chettri A, Cole HD, Reglinski K, Brückmann J, Roque JA, Stumper A, Nauroozi D, Schmid S, Lagerholm CB, Rau S, Bäuerle P, Eggeling C, Cameron CG, McFarland SA, Dietzek B. Intracellular Photophysics of an Osmium Complex bearing an Oligothiophene Extended Ligand. Chemistry 2020; 26:14844-14851. [PMID: 32761643 PMCID: PMC7704931 DOI: 10.1002/chem.202002667] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 07/26/2020] [Indexed: 12/27/2022]
Abstract
This contribution describes the excited-state properties of an Osmium-complex when taken up into human cells. The complex 1 [Os(bpy)2 (IP-4T)](PF6 )2 with bpy=2,2'-bipyridine and IP-4T=2-{5'-[3',4'-diethyl-(2,2'-bithien-5-yl)]-3,4-diethyl-2,2'-bithiophene}imidazo[4,5-f][1,10]phenanthroline) can be discussed as a candidate for photodynamic therapy in the biological red/NIR window. The complex is taken up by MCF7 cells and localizes rather homogeneously within in the cytoplasm. To detail the sub-ns photophysics of 1, comparative transient absorption measurements were carried out in different solvents to derive a model of the photoinduced processes. Key to rationalize the excited-state relaxation is a long-lived 3 ILCT state associated with the oligothiophene chain. This model was then tested with the complex internalized into MCF7 cells, since the intracellular environment has long been suspected to take big influence on the excited state properties. In our study of 1 in cells, we were able to show that, though the overall model remained the same, the excited-state dynamics are affected strongly by the intracellular environment. Our study represents the first in depth correlation towards ex-vivo and in vivo ultrafast spectroscopy for a possible photodrug.
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Affiliation(s)
- Kilian R. A. Schneider
- Department Functional Interfaces (K.R.A.S., A.C., B.D.)Department Biophysical Imaging (K.R., C.E.)Leibniz Institute of Photonic Technology (IPHT) e. V.Albert-Einstein-Straße 907745JenaGermany
- Institute of Physical Chemistry and Abbe Center of PhotonicsFriedrich-Schiller-University JenaHelmholtzweg 407743JenaGermany
| | - Avinash Chettri
- Department Functional Interfaces (K.R.A.S., A.C., B.D.)Department Biophysical Imaging (K.R., C.E.)Leibniz Institute of Photonic Technology (IPHT) e. V.Albert-Einstein-Straße 907745JenaGermany
- Institute of Physical Chemistry and Abbe Center of PhotonicsFriedrich-Schiller-University JenaHelmholtzweg 407743JenaGermany
| | - Houston D. Cole
- Department of Chemistry and BiochemistryThe University of Texas at ArlingtonArlingtonTX76019-0065USA
| | - Katharina Reglinski
- Department Functional Interfaces (K.R.A.S., A.C., B.D.)Department Biophysical Imaging (K.R., C.E.)Leibniz Institute of Photonic Technology (IPHT) e. V.Albert-Einstein-Straße 907745JenaGermany
- Institute of Applied Optic and BiophysicsFriedrich-Schiller University JenaMax-Wien-Platz 107743JenaGermany
- University Hospital JenaBachstraße 1807743JenaGermany
| | - Jannik Brückmann
- Institute of Inorganic Chemistry IUlm UniversityAlbert-Einstein-Allee 1189081UlmGermany
| | - John A. Roque
- Department of Chemistry and BiochemistryThe University of Texas at ArlingtonArlingtonTX76019-0065USA
- Department of Chemistry and BiochemistryThe University of North Carolina at GreensboroGreensboroNorth Carolina27402USA
| | - Anne Stumper
- Institute of Inorganic Chemistry IUlm UniversityAlbert-Einstein-Allee 1189081UlmGermany
| | - Djawed Nauroozi
- Institute of Inorganic Chemistry IUlm UniversityAlbert-Einstein-Allee 1189081UlmGermany
| | - Sylvia Schmid
- Institute of Organic Chemistry II and Advanced MaterialsUlm UniversityAlbert-Einstein-Allee 1189081UlmGermany
| | | | - Sven Rau
- Institute of Inorganic Chemistry IUlm UniversityAlbert-Einstein-Allee 1189081UlmGermany
| | - Peter Bäuerle
- Institute of Organic Chemistry II and Advanced MaterialsUlm UniversityAlbert-Einstein-Allee 1189081UlmGermany
| | - Christian Eggeling
- Department Functional Interfaces (K.R.A.S., A.C., B.D.)Department Biophysical Imaging (K.R., C.E.)Leibniz Institute of Photonic Technology (IPHT) e. V.Albert-Einstein-Straße 907745JenaGermany
- Institute of Applied Optic and BiophysicsFriedrich-Schiller University JenaMax-Wien-Platz 107743JenaGermany
- <MRC Human Immunology Unit & Wolfson Imaging Center OxfordHeadley WayOxfordOX3 9DSUK
| | - Colin G. Cameron
- Department of Chemistry and BiochemistryThe University of Texas at ArlingtonArlingtonTX76019-0065USA
| | - Sherri A. McFarland
- Department of Chemistry and BiochemistryThe University of Texas at ArlingtonArlingtonTX76019-0065USA
| | - Benjamin Dietzek
- Department Functional Interfaces (K.R.A.S., A.C., B.D.)Department Biophysical Imaging (K.R., C.E.)Leibniz Institute of Photonic Technology (IPHT) e. V.Albert-Einstein-Straße 907745JenaGermany
- Institute of Physical Chemistry and Abbe Center of PhotonicsFriedrich-Schiller-University JenaHelmholtzweg 407743JenaGermany
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23
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Roque JA, Barrett PC, Cole HD, Lifshits LM, Bradner E, Shi G, von Dohlen D, Kim S, Russo N, Deep G, Cameron CG, Alberto ME, McFarland SA. Os(II) Oligothienyl Complexes as a Hypoxia-Active Photosensitizer Class for Photodynamic Therapy. Inorg Chem 2020; 59:16341-16360. [PMID: 33126792 PMCID: PMC7669743 DOI: 10.1021/acs.inorgchem.0c02137] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Hypoxia presents a challenge to anticancer therapy, reducing the efficacy of many available treatments. Photodynamic therapy is particularly susceptible to hypoxia, given that its mechanism relies on oxygen. Herein, we introduce two new osmium-based polypyridyl photosensitizers that are active in hypoxia. The lead compounds emerged from a systematic study of two Os(II) polypyridyl families derived from 2,2'-bipyridine (bpy) or 4,4'-dimethyl-2,2'-bipyridine (dmb) as coligands combined with imidazo[4,5-f][1,10]phenanthroline ligands tethered to n = 0-4 thiophenes (IP-nT). The compounds were characterized and investigated for their spectroscopic and (photo)biological activities. The two hypoxia-active Os(II) photosensitizers had n = 4 thiophenes, with the bpy analogue 1-4T being the most potent. In normoxia, 1-4T had low nanomolar activity (half-maximal effective concentration (EC50) = 1-13 nM) with phototherapeutic indices (PI) ranging from 5500 to 55 000 with red and visible light, respectively. A sub-micromolar potency was maintained even in hypoxia (1% O2), with light EC50 and PI values of 732-812 nM and 68-76, respectively -currently among the largest PIs for hypoxic photoactivity. This high degree of activity coincided with a low-energy, long-lived (0.98-3.6 μs) mixed-character intraligand charge-transfer (3ILCT)/ligand-to-ligand charge-transfer (3LLCT) state only accessible in quaterthiophene complexes 1-4T and 2-4T. The coligand identity strongly influenced the photophysical and photobiological results in this study, whereby the bpy coligand led to longer lifetimes (3.6 μs) and more potent photo-cytotoxicity relative to those of dmb. The unactivated compounds were relatively nontoxic both in vitro and in vivo. The maximum tolerated dose for 1-4T and 2-4T in mice was greater than or equal to 200 mg kg-1, an excellent starting point for future in vivo validation.
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Affiliation(s)
- John A. Roque
- Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, North Carolina, 27402 USA
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas, 76019 USA
| | - Patrick C. Barrett
- Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, North Carolina, 27402 USA
| | - Houston D. Cole
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas, 76019 USA
| | - Liubov M. Lifshits
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas, 76019 USA
| | - Evan Bradner
- Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, North Carolina, 27402 USA
| | - Ge Shi
- Department of Pathology, Dalhousie University, Halifax, Nova Scotia B3H 1×5, Canada
| | - David von Dohlen
- Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, North Carolina, 27402 USA
| | - Susy Kim
- Department of Cancer Biology, Wake Forest School of Medicine, Winston Salem, NC, 27157 USA
| | - Nino Russo
- Dipartimento di Chimica e Tecnologie Chimiche, Università della Calabria, Arcavacata di Rende, 87036 Italy
| | - Gagan Deep
- Department of Cancer Biology, Wake Forest School of Medicine, Winston Salem, NC, 27157 USA
| | - Colin G. Cameron
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas, 76019 USA
| | - Marta E. Alberto
- Dipartimento di Chimica e Tecnologie Chimiche, Università della Calabria, Arcavacata di Rende, 87036 Italy
| | - Sherri A. McFarland
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas, 76019 USA
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Smithen DA, Monro S, Pinto M, Roque J, Diaz-Rodriguez RM, Yin H, Cameron CG, Thompson A, McFarland SA. Bis[pyrrolyl Ru(ii)] triads: a new class of photosensitizers for metal-organic photodynamic therapy. Chem Sci 2020; 11:12047-12069. [PMID: 33738086 PMCID: PMC7953431 DOI: 10.1039/d0sc04500d] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Accepted: 10/06/2020] [Indexed: 12/22/2022] Open
Abstract
A new family of ten dinuclear Ru(ii) complexes based on the bis[pyrrolyl Ru(ii)] triad scaffold, where two Ru(bpy)2 centers are separated by a variety of organic linkers, was prepared to evaluate the influence of the organic chromophore on the spectroscopic and in vitro photodynamic therapy (PDT) properties of the compounds. The bis[pyrrolyl Ru(ii)] triads absorbed strongly throughout the visible region, with several members having molar extinction coefficients (ε) ≥ 104 at 600-620 nm and longer. Phosphorescence quantum yields (Φ p) were generally less than 0.1% and in some cases undetectable. The singlet oxygen quantum yields (Φ Δ) ranged from 5% to 77% and generally correlated with their photocytotoxicities toward human leukemia (HL-60) cells regardless of the wavelength of light used. Dark cytotoxicities varied ten-fold, with EC50 values in the range of 10-100 μM and phototherapeutic indices (PIs) as large as 5400 and 260 with broadband visible (28 J cm-2, 7.8 mW cm-2) and 625 nm red (100 J cm-2, 42 mW cm-2) light, respectively. The bis[pyrrolyl Ru(ii)] triad with a pyrenyl linker (5h) was especially potent, with an EC50 value of 1 nM and PI > 27 000 with visible light and subnanomolar activity with 625 nm light (100 J cm-2, 28 mW cm-2). The lead compound 5h was also tested in a tumor spheroid assay using the HL60 cell line and exhibited greater photocytotoxicity in this more resistant model (EC50 = 60 nM and PI > 1200 with 625 nm light) despite a lower dark cytotoxicity. The in vitro PDT effects of 5h extended to bacteria, where submicromolar EC50 values and PIs >300 against S. mutans and S. aureus were obtained with visible light. This activity was attenuated with 625 nm red light, but PIs were still near 50. The ligand-localized 3ππ* state contributed by the pyrenyl linker of 5h likely plays a key role in its phototoxic effects toward cancer cells and bacteria.
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Affiliation(s)
- Deborah A Smithen
- Department of Chemistry , Dalhousie University , P. O. Box 15000 , Halifax , NS B3H 4R2 , Canada .
| | - Susan Monro
- Department of Chemistry , Acadia University , Wolfville , NS B4P 2R6 , Canada
| | - Mitch Pinto
- Department of Chemistry , Acadia University , Wolfville , NS B4P 2R6 , Canada
| | - John Roque
- Department of Chemistry and Biochemistry , The University of North Carolina at Greensboro , PO Box 26170 , Greensboro , NC 27402-6170 , USA.,Department of Chemistry and Biochemistry , The University of Texas at Arlington , 700 Planetarium Pl , Arlington , TX 76019-0065 , USA .
| | - Roberto M Diaz-Rodriguez
- Department of Chemistry , Dalhousie University , P. O. Box 15000 , Halifax , NS B3H 4R2 , Canada .
| | - Huimin Yin
- Department of Chemistry , Acadia University , Wolfville , NS B4P 2R6 , Canada
| | - Colin G Cameron
- Department of Chemistry and Biochemistry , The University of Texas at Arlington , 700 Planetarium Pl , Arlington , TX 76019-0065 , USA .
| | - Alison Thompson
- Department of Chemistry , Dalhousie University , P. O. Box 15000 , Halifax , NS B3H 4R2 , Canada .
| | - Sherri A McFarland
- Department of Chemistry and Biochemistry , The University of Texas at Arlington , 700 Planetarium Pl , Arlington , TX 76019-0065 , USA .
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25
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Roque JA, Barrett PC, Cole HD, Lifshits LM, Shi G, Monro S, von Dohlen D, Kim S, Russo N, Deep G, Cameron CG, Alberto ME, McFarland SA. Breaking the barrier: an osmium photosensitizer with unprecedented hypoxic phototoxicity for real world photodynamic therapy. Chem Sci 2020; 11:9784-9806. [PMID: 33738085 PMCID: PMC7953430 DOI: 10.1039/d0sc03008b] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 08/03/2020] [Indexed: 12/15/2022] Open
Abstract
Hypoxia presents a two-fold challenge in the treatment of cancer, as low oxygen conditions induce biological changes that make malignant tissues simultaneously more aggressive and less susceptible to standard chemotherapy. This paper reports the first metal-based photosensitizer that approaches the ideal properties for a phototherapy agent. The Os(phen)2-based scaffold was combined with a series of IP-nT ligands, where phen = 1,10-phenanthroline and IP-nT = imidazo[4,5-f][1,10]phenanthroline tethered to n = 0-4 thiophene rings. Os-4T (n = 4) emerged as the most promising complex in the series, with picomolar activity and a phototherapeutic index (PI) exceeding 106 in normoxia. The photosensitizer exhibited an unprecedented PI > 90 (EC50 = 0.651 μM) in hypoxia (1% O2) with visible and green light, and a PI > 70 with red light. Os-4T was also active with 733 nm near-infrared light (EC50 = 0.803 μM, PI = 77) under normoxia. Both computation and spectroscopic studies confirmed a switch in the nature of the lowest-lying triplet excited state from triplet metal-to-ligand charge transfer (3MLCT) to intraligand charge transfer (3ILCT) at n = 3, with a lower energy and longer lifetime for n = 4. All compounds in the series were relatively nontoxic in the dark but became increasingly phototoxic with additional thiophenes. These normoxic and hypoxic activities are the largest reported to date, demonstrating the utility of osmium for phototherapy applications. Moreover, Os-4T had a maximum tolerated dose (MTD) in mice that was >200 mg kg-1, which positions this photosensitizer as an excellent candidate for in vivo applications.
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Affiliation(s)
- John A Roque
- Department of Chemistry and Biochemistry , The University of North Carolina at Greensboro , Greensboro , North Carolina , 27402 USA
- Department of Chemistry and Biochemistry , The University of Texas at Arlington , Arlington , Texas , 76019 USA . ;
| | - Patrick C Barrett
- Department of Chemistry and Biochemistry , The University of North Carolina at Greensboro , Greensboro , North Carolina , 27402 USA
| | - Houston D Cole
- Department of Chemistry and Biochemistry , The University of Texas at Arlington , Arlington , Texas , 76019 USA . ;
| | - Liubov M Lifshits
- Department of Chemistry and Biochemistry , The University of Texas at Arlington , Arlington , Texas , 76019 USA . ;
| | - Ge Shi
- Department of Chemistry , Acadia University , Wolfville , Nova Scotia , B4P 2R6 Canada
| | - Susan Monro
- Department of Chemistry , Acadia University , Wolfville , Nova Scotia , B4P 2R6 Canada
| | - David von Dohlen
- Department of Chemistry and Biochemistry , The University of North Carolina at Greensboro , Greensboro , North Carolina , 27402 USA
| | - Susy Kim
- Department of Cancer Biology , Wake Forest School of Medicine , Winston Salem , NC , 27157, USA
| | - Nino Russo
- Dipartimento di Chimica e Tecnologie Chimiche , Università della Calabria , Arcavacata di Rende , 87036 Italy .
| | - Gagan Deep
- Department of Cancer Biology , Wake Forest School of Medicine , Winston Salem , NC , 27157, USA
| | - Colin G Cameron
- Department of Chemistry and Biochemistry , The University of North Carolina at Greensboro , Greensboro , North Carolina , 27402 USA
- Department of Chemistry and Biochemistry , The University of Texas at Arlington , Arlington , Texas , 76019 USA . ;
| | - Marta E Alberto
- Dipartimento di Chimica e Tecnologie Chimiche , Università della Calabria , Arcavacata di Rende , 87036 Italy .
| | - Sherri A McFarland
- Department of Chemistry and Biochemistry , The University of North Carolina at Greensboro , Greensboro , North Carolina , 27402 USA
- Department of Chemistry and Biochemistry , The University of Texas at Arlington , Arlington , Texas , 76019 USA . ;
- Department of Chemistry , Acadia University , Wolfville , Nova Scotia , B4P 2R6 Canada
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Lifshits LM, Roque Iii JA, Konda P, Monro S, Cole HD, von Dohlen D, Kim S, Deep G, Thummel RP, Cameron CG, Gujar S, McFarland SA. Near-infrared absorbing Ru(ii) complexes act as immunoprotective photodynamic therapy (PDT) agents against aggressive melanoma. Chem Sci 2020; 11:11740-11762. [PMID: 33976756 PMCID: PMC8108386 DOI: 10.1039/d0sc03875j] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 09/04/2020] [Indexed: 12/15/2022] Open
Abstract
Mounting evidence over the past 20 years suggests that photodynamic therapy (PDT), an anticancer modality known mostly as a local treatment, has the capacity to invoke a systemic antitumor immune response, leading to protection against tumor recurrence. For aggressive cancers such as melanoma, where chemotherapy and radiotherapy are ineffective, immunomodulating PDT as an adjuvant to surgery is of interest. Towards the development of specialized photosensitizers (PSs) for treating pigmented melanomas, nine new near-infrared (NIR) absorbing PSs based on a Ru(ii) tris-heteroleptic scaffold [Ru(NNN)(NN)(L)]Cln, were explored. Compounds 2, 6, and 9 exhibited high potency toward melanoma cells, with visible EC50 values as low as 0.292–0.602 μM and PIs as high as 156–360. Single-micromolar phototoxicity was obtained with NIR-light (733 nm) with PIs up to 71. The common feature of these lead NIR PSs was an accessible low-energy triplet intraligand (3IL) excited state for high singlet oxygen (1O2) quantum yields (69–93%), which was only possible when the photosensitizing 3IL states were lower in energy than the lowest triplet metal-to-ligand charge transfer (3MLCT) excited states that typically govern Ru(ii) polypyridyl photophysics. PDT treatment with 2 elicited a pro-inflammatory response alongside immunogenic cell death in mouse B16F10 melanoma cells and proved safe for in vivo administration (maximum tolerated dose = 50 mg kg−1). Female and male mice vaccinated with B16F10 cells that were PDT-treated with 2 and challenged with live B16F10 cells exhibited 80 and 55% protection from tumor growth, respectively, leading to significantly improved survival and excellent hazard ratios of ≤0.2. Ru(ii) photosensitizers (PSs) destroy aggressive melanoma cells, triggering an immune response that leads to protection against tumor challenge and mouse survival.![]()
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Affiliation(s)
- Liubov M Lifshits
- Department of Chemistry and Biochemistry, The University of Texas at Arlington Arlington Texas 76019-0065 USA
| | - John A Roque Iii
- Department of Chemistry and Biochemistry, The University of Texas at Arlington Arlington Texas 76019-0065 USA .,Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro Greensboro North Carolina 27402 USA
| | - Prathyusha Konda
- Department of Microbiology and Immunology, Dalhousie University Halifax Nova Scotia B3H 1X5 Canada
| | - Susan Monro
- Department of Chemistry, Acadia University Wolfville Nova Scotia B4P 2R6 Canada
| | - Houston D Cole
- Department of Chemistry and Biochemistry, The University of Texas at Arlington Arlington Texas 76019-0065 USA
| | - David von Dohlen
- Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro Greensboro North Carolina 27402 USA
| | - Susy Kim
- Department of Cancer Biology, Wake Forest School of Medicine Winston Salem NC 27157 USA
| | - Gagan Deep
- Department of Cancer Biology, Wake Forest School of Medicine Winston Salem NC 27157 USA
| | - Randolph P Thummel
- Department of Chemistry, University of Houston 112 Fleming Building Houston Texas 77204-5003 USA
| | - Colin G Cameron
- Department of Chemistry and Biochemistry, The University of Texas at Arlington Arlington Texas 76019-0065 USA
| | - Shashi Gujar
- Department of Microbiology and Immunology, Dalhousie University Halifax Nova Scotia B3H 1X5 Canada .,Department of Pathology, Dalhousie University Halifax Nova Scotia B3H 1X5 Canada.,Department of Biology, Dalhousie University Halifax Nova Scotia B3H 1X5 Canada.,Beatrice Hunter Cancer Research Institute Halifax Nova Scotia B3H 4R2 Canada
| | - Sherri A McFarland
- Department of Chemistry and Biochemistry, The University of Texas at Arlington Arlington Texas 76019-0065 USA
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Roque J, Havrylyuk D, Barrett PC, Sainuddin T, McCain J, Colón K, Sparks WT, Bradner E, Monro S, Heidary D, Cameron CG, Glazer EC, McFarland SA. Strained, Photoejecting Ru(II) Complexes that are Cytotoxic Under Hypoxic Conditions. Photochem Photobiol 2019; 96:327-339. [PMID: 31691282 DOI: 10.1111/php.13174] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 10/14/2019] [Indexed: 01/01/2023]
Abstract
A series of strained Ru(II) complexes were studied for potential anticancer activity in hypoxic tissues. The complexes were constructed with methylated ligands that were photolabile and an imidizo[4,5-f][1,10]phenanthroline ligand that contained an appended aromatic group to potentially allow for contributions of ligand-centered excited states. A systematic variation of the size and energy of the aromatic group was performed using systems containing 1-4 fused rings, and the photochemical and photobiological behaviors of all complexes were assessed. The structure and nature of the aromatic group had a subtle impact on photochemistry, altering environmental sensitivity, and had a significant impact on cellular cytotoxicity and photobiology. Up to 5-fold differences in cytotoxicity were observed in the absence of light activation; this rose to 50-fold differences upon exposure to 453 nm light. Most significantly, one complex retained activity under conditions with 1% O2 , which is used to induce hypoxic changes. This system exhibited a photocytotoxicity index (PI) of 15, which is in marked contrast to most other Ru(II) complexes, including those designed for O2 -independent mechanisms of action.
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Affiliation(s)
- John Roque
- Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, NC
| | | | - Patrick C Barrett
- Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, NC
| | - Tariq Sainuddin
- Department of Chemistry, Acadia University, Wolfville, Canada
| | - Julia McCain
- Department of Chemistry, Acadia University, Wolfville, Canada
| | - Katsuya Colón
- Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, NC
| | - William T Sparks
- Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, NC
| | - Evan Bradner
- Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, NC
| | - Susan Monro
- Department of Chemistry, Acadia University, Wolfville, Canada
| | - David Heidary
- Department of Chemistry, University of Kentucky, Lexington, KY
| | - Colin G Cameron
- Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, NC
| | - Edith C Glazer
- Department of Chemistry, University of Kentucky, Lexington, KY
| | - Sherri A McFarland
- Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, NC.,Department of Chemistry, Acadia University, Wolfville, Canada
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Liu B, Monro S, Jabed MA, Cameron CG, Colón KL, Xu W, Kilina S, McFarland SA, Sun W. Neutral iridium(iii) complexes bearing BODIPY-substituted N-heterocyclic carbene (NHC) ligands: synthesis, photophysics, in vitro theranostic photodynamic therapy, and antimicrobial activity. Photochem Photobiol Sci 2019; 18:2381-2396. [PMID: 31432864 PMCID: PMC6785369 DOI: 10.1039/c9pp00142e] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 08/08/2019] [Indexed: 12/29/2022]
Abstract
The synthesis, photophysics, and photobiological activities of a series of novel neutral heteroleptic cyclometalated iridium(iii) complexes incorporating boron dipyrromethene (BODIPY) substituted N-heterocyclic carbene (NHC) ligands (Ir1-Ir5) are reported. The effect of the substitution position of BODIPY on the NHC ligands, either on C4 of the phenyl ring (Ir1-Ir3) or C5 of the benzimidazole unit (Ir4 and Ir5), and its linker type (single or triple bond) on the photophysical properties was studied. Ir1-Ir5 exhibited BODIPY-localized intense 1IL (intraligand transition)/1MLCT (metal-to-ligand charge transfer) absorption at 530-543 nm and 1,3IL/1,3CT (charge transfer) emission at 582-610 nm. The nanosecond transient absorption results revealed that the lowest triplet excited states of these complexes were the BODIPY-localized 3π,π* states. Complexes Ir4 and Ir5 exhibited blue-shifted 1IL absorption and 1,3IL/1,3CT emission bands compared to the corresponding absorption and emission bands in complexes Ir1 and Ir3. However, replacing the methyl substituents on N3 of benzimidazole in complexes Ir1 and Ir4 with oligoether substituents in Ir3 and Ir5, respectively, did not impact the energies of the low-energy absorption and emission bands in the corresponding complexes. Water-soluble complexes Ir3 and Ir5 have been explored as photosensitizers for in vitro photodynamic therapy (PDT) effects toward human SKMEL28 melanoma cells. Ir3 showed no dark cytotoxicity (EC50 > 300 μM) but good photocytotoxic activity (9.66 ± 0.28 μM), whereas Ir5 exhibited a higher dark cytotoxicity (20.2 ± 1.26 μM) and excellent photocytotoxicity (0.15 ± 0.01 μM). The phototherapeutic indices with visible light (400-700 nm) activation were >31 for Ir3 and 135 for Ir5. Ir3 and Ir5 displayed 1O2 quantum yields of 38% and 22% in CH3CN, respectively, upon 450 nm excitation. Ir5 was more effective at generating reactive oxygen species (ROS) in vitro. Ir5 was also active against Staphylococcus aureus upon visible light activation, with a phototherapeutic index of >15 and EC50 value of 6.67 μM. These photobiological activities demonstrated that these neutral Ir(iii) complexes are promising in vitro PDT reagents, and substitution at C5 on the benzimidazole group of the NHC ligand was superior to C4 substitution on the phenyl ring.
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Affiliation(s)
- Bingqing Liu
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, ND 58108-6050, USA.
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McCain J, Colón KL, Barrett PC, Monro SMA, Sainuddin T, Roque Iii J, Pinto M, Yin H, Cameron CG, McFarland SA. Photophysical Properties and Photobiological Activities of Ruthenium(II) Complexes Bearing π-Expansive Cyclometalating Ligands with Thienyl Groups. Inorg Chem 2019; 58:10778-10790. [PMID: 31386351 DOI: 10.1021/acs.inorgchem.9b01044] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
A new family of cyclometalated ruthenium(II) complexes [Ru(N^N)2(C^N)]+ derived from the π-extended benzo[h]imidazo[4,5-f]quinolone ligand appended with thienyl groups (n = 1-4, compounds 1-4) was prepared and its members were characterized for their chemical, photophysical, and photobiological properties. The lipophilicities of 1-4, determined as octanol-water partition coefficients (log Po/w), were positive and increased with the number of thienyl units. The absorption and emission bands of the C^N compounds were red-shifted by up to 200 nm relative to the analogous Ru(II) diimine systems. All of the complexes exhibited dual emission with the intraligand fluorescence (1IL, C^N-based) shifting to lower energies with increasing n and the metal-to-ligand charge transfer phosphorescence (3MLCT, N^N-based) remaining unchanged. Compounds 1-3 exhibited excited state absorption (ESA) profiles consistent with lowest-lying 3MLCT states when probed by nanosecond transient absorption (TA) spectroscopy with 532 nm excitation and had contributions from 1IL(C^N) states with 355 nm excitation. These assignments were supported by the lifetimes observed (<10 ns for the 1IL states and around 20 ns for the 3MLCT states) as well as a noticeable ESA for 3 with 355 nm excitation that did not occur with 532 nm excitation. Compound 4 was the only member of the family with two 3MLCT emissive lifetimes (15, 110 ns), and the TA spectra collected with both 355 and 532 nm excitation was assigned to the 3IL state, which was corroborated by its 4-6 μs lifetime. The ESA for 4 had a rise time of approximately 10 ns and an initial decay of 110 ns, which suggests a possible 3MLCT-3IL excited state equilibrium that results in delayed emission from the 3MLCT state. Compound 4 was nontoxic toward human skin melanoma cells (SKMEL28) in the dark (EC50 = >300 μM); 1-3 were cytotoxic and yielded EC50 values between 1 and 20 μM. The photocytotoxicites with visible light ranged from 87 nM with a phototherapeutic index (PI) of 13 for 1 to approximately 1 μM (PI = >267) for 4. With red light, EC50 values varied from 270 nM (PI = 21) for 3 to 12 μM for 4 (PI = >25). The larger PIs for 4, especially with visible light, were attributed to the much lower dark cytotoxicity for this compound. Because the dark cytotoxicity contributes substantially to the observed photocytotoxicity for 1-3, it was not possible to assess whether the 3IL state of 4 led to a much more potent phototoxic mechanism in the absence of dark toxicity. There was no stark contrast in cellular uptake and accumulation by laser scanning confocal and differential interference contrast microscopy to explain the large differences in dark toxicities between 1-3 and 4. Nevertheless, the study highlights a new family of Ru(II) C^N complexes where π-conjugation beyond a certain point results in low dark cytotoxicity with high photocytotoxicity, opposing the notion that cyclometalated Ru(II) systems are too toxic to be phototherapeutic agents.
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Affiliation(s)
- Julia McCain
- Department of Chemistry , Acadia University , Wolfville , Nova Scotia B4P 2R6 , Canada
| | - Katsuya L Colón
- Department of Chemistry and Biochemistry , The University of North Carolina at Greensboro , Greensboro , North Carolina 27402 , United States
| | - Patrick C Barrett
- Department of Chemistry and Biochemistry , The University of North Carolina at Greensboro , Greensboro , North Carolina 27402 , United States
| | - Susan M A Monro
- Department of Chemistry , Acadia University , Wolfville , Nova Scotia B4P 2R6 , Canada
| | - Tariq Sainuddin
- Department of Chemistry , Acadia University , Wolfville , Nova Scotia B4P 2R6 , Canada
| | - John Roque Iii
- Department of Chemistry and Biochemistry , The University of North Carolina at Greensboro , Greensboro , North Carolina 27402 , United States
| | - Mitch Pinto
- Department of Chemistry , Acadia University , Wolfville , Nova Scotia B4P 2R6 , Canada
| | - Huimin Yin
- Department of Chemistry , Acadia University , Wolfville , Nova Scotia B4P 2R6 , Canada
| | - Colin G Cameron
- Department of Chemistry and Biochemistry , The University of North Carolina at Greensboro , Greensboro , North Carolina 27402 , United States
| | - Sherri A McFarland
- Department of Chemistry , Acadia University , Wolfville , Nova Scotia B4P 2R6 , Canada.,Department of Chemistry and Biochemistry , The University of North Carolina at Greensboro , Greensboro , North Carolina 27402 , United States
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Liu B, Monro S, Li Z, Jabed MA, Ramirez D, Cameron CG, Colón K, Roque J, Kilina S, Tian J, McFarland SA, Sun W. A New Class of Homoleptic and Heteroleptic Bis(terpyridine) Iridium(III) Complexes with Strong Photodynamic Therapy Effects. ACS Appl Bio Mater 2019; 2:2964-2977. [PMID: 31844844 PMCID: PMC6913535 DOI: 10.1021/acsabm.9b00312] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Six homo- or heteroleptic tricationic Ir(R1-tpy)(R2-tpy)3+ complexes (Ir1-Ir6, R1/R2 = Ph, 4'-N(CH3)2Ph, pyren-1-yl, or 4'-{2-[2-(2-methoxyethoxy)ethoxy]ethoxy}Ph, tpy = 2,2';6',2"-terpyridine) were synthesized and tested for photodynamic therapy (PDT) effects. The ground- and excited-state characteristics of these complexes were studied systematically via spectroscopic methods and quantum chemistry calculations. All complexes possessed intraligand charge transfer (1ILCT) / metal-to-ligand charge transfer (1MLCT) dominated transition(s) in their low-energy absorption bands, which red-shifted with the increased electron-releasing strength of the R1/R2 substituent. Five of the complexes exhibited ligand-centered 3 π,π*/3ILCT/3MLCT emission. With a stronger electron-releasing R1/R2 substituent, the degree of charge transfer contribution increased, leading to a decrease of the emission quantum yield. When the 4'-N(CH3)2Ph substituent was introduced on both tpy ligands, the emission of Ir3 was completely quenched. Our study on the transient absorption of these complexes demonstrated that they all possessed broadband triplet excited-state absorption in the 400-800 nm region. Pyrenyl substitution of one or more tpy ligands, as in Ir4 and Ir5, increased the lifetimes of the lowest triplet excited state and the singlet oxygen (1O2) production efficiencies. Ir1-Ir5 were nontoxic toward SK-MEL-28 cells, with photocytotoxicities that varied from 0.18 to 153 µM. Among them, Ir4 had the highest 1O2 quantum yield (0.81) in cell-free conditions, showing the largest photocytotoxicity against SK-MEL-28 cells for Ir(III) PSs to date, and was the most efficient generator of reactive oxygen species (ROS) in vitro. Ir4 possessed a very large phototherapeutic index (PI = dark EC50 / light EC50) of >1657, the largest reported for an Ir(III) complex photosensitizer upon broadband visible light (400-700 nm) activation. Ir4 also exhibited a very strong PDT effect toward MCF-7 breast cancer cells and its xenograft tumor model. Upon 450-nm light activation, Ir4 dramatically inhibited the xenograft tumor growth and exhibited negligible side effects upon PDT treatment.
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Affiliation(s)
- Bingqing Liu
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, ND 58108–6050, USA
| | - Susan Monro
- Department of Chemistry, Acadia University, 6 University Avenue, Wolfville, NS B4P 2R6, Canada
| | - Zhike Li
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery (MOE), Hubei Province Engineering and Technology Research Center for Fluorinated Pharmaceuticals, School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071, P. R. China
| | - Mohammed A. Jabed
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, ND 58108–6050, USA
| | - Daniel Ramirez
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, ND 58108–6050, USA
| | - Colin G. Cameron
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC 27402–6170, USA
| | - Katsuya Colón
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC 27402–6170, USA
| | - John Roque
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC 27402–6170, USA
| | - Svetlana Kilina
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, ND 58108–6050, USA
| | - Jian Tian
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery (MOE), Hubei Province Engineering and Technology Research Center for Fluorinated Pharmaceuticals, School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071, P. R. China
| | - Sherri A. McFarland
- Department of Chemistry, Acadia University, 6 University Avenue, Wolfville, NS B4P 2R6, Canada
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC 27402–6170, USA
| | - Wenfang Sun
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, ND 58108–6050, USA
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Liu B, Lystrom L, Cameron CG, Kilina S, McFarland SA, Sun W. Monocationic Iridium(III) Complexes with Far‐Red Charge‐Transfer Absorption and Near‐IR Emission: Synthesis, Photophysics, and Reverse Saturable Absorption. Eur J Inorg Chem 2019. [DOI: 10.1002/ejic.201900156] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Bingqing Liu
- Department of Chemistry and Biochemistry North Dakota State University Fargo North Dakota 58108‐6050 USA
| | - Levi Lystrom
- Department of Chemistry and Biochemistry North Dakota State University Fargo North Dakota 58108‐6050 USA
| | - Colin G. Cameron
- Department of Chemistry and Biochemistry University of North Carolina at Greensboro Greensboro North Carolina 27402‐6170 USA
| | - Svetlana Kilina
- Department of Chemistry and Biochemistry North Dakota State University Fargo North Dakota 58108‐6050 USA
| | - Sherri A. McFarland
- Department of Chemistry and Biochemistry University of North Carolina at Greensboro Greensboro North Carolina 27402‐6170 USA
| | - Wenfang Sun
- Department of Chemistry and Biochemistry North Dakota State University Fargo North Dakota 58108‐6050 USA
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Reichardt C, Monro S, Sobotta FH, Colón KL, Sainuddin T, Stephenson M, Sampson E, Roque J, Yin H, Brendel JC, Cameron CG, McFarland S, Dietzek B. Predictive Strength of Photophysical Measurements for in Vitro Photobiological Activity in a Series of Ru(II) Polypyridyl Complexes Derived from π-Extended Ligands. Inorg Chem 2019; 58:3156-3166. [PMID: 30763081 PMCID: PMC6500734 DOI: 10.1021/acs.inorgchem.8b03223] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This study investigates the correlation between photocytotoxicity and the prolonged excited-state lifetimes exhibited by certain Ru(II) polypyridyl photosensitizers comprised of π-expansive ligands. The eight metal complexes selected for this study differ markedly in their triplet state configurations and lifetimes. Human melanoma SKMEL28 and human leukemia HL60 cells were used as in vitro models to test photocytotoxicity induced by the compounds when activated by either broadband visible or monochromatic red light. The photocytotoxicities of the metal complexes investigated varied over 2 orders of magnitude and were positively correlated with their excited-state lifetimes. The complexes with the longest excited-state lifetimes, contributed by low-lying 3IL states, were the most phototoxic toward cancer cells under all conditions.
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Affiliation(s)
- Christian Reichardt
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Helmholtzweg 4, 07743, Jena, Germany
- Leibniz Institute of Photonic Technology (IPHT) Jena, Department Functional Interfaces, Albert-Einstein-Straße 9, 07745, Jena, Germany
| | - Susan Monro
- Department of Chemistry, Acadia University, Wolfville, NS B4P 2R6, Canada
| | - Fabian H. Sobotta
- Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstrasse 10, 07743 Jena, Germany
- Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, Philosophenweg 7, 07743 Jena, Germany
| | - Katsuya L. Colón
- Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, NC 27402, USA
| | - Tariq Sainuddin
- Department of Chemistry, Acadia University, Wolfville, NS B4P 2R6, Canada
| | - Mat Stephenson
- Department of Chemistry, Acadia University, Wolfville, NS B4P 2R6, Canada
| | - Eric Sampson
- Department of Chemistry, Acadia University, Wolfville, NS B4P 2R6, Canada
| | - John Roque
- Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, NC 27402, USA
| | - Huimin Yin
- Department of Chemistry, Acadia University, Wolfville, NS B4P 2R6, Canada
| | - Johannes C. Brendel
- Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstrasse 10, 07743 Jena, Germany
- Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, Philosophenweg 7, 07743 Jena, Germany
| | - Colin G. Cameron
- Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, NC 27402, USA
| | - Sherri McFarland
- Department of Chemistry, Acadia University, Wolfville, NS B4P 2R6, Canada
- Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, Greensboro, NC 27402, USA
| | - Benjamin Dietzek
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Helmholtzweg 4, 07743, Jena, Germany
- Leibniz Institute of Photonic Technology (IPHT) Jena, Department Functional Interfaces, Albert-Einstein-Straße 9, 07745, Jena, Germany
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Wang L, Monro S, Cui P, Yin H, Liu B, Cameron CG, Xu W, Hetu M, Fuller A, Kilina S, McFarland SA, Sun W. Heteroleptic Ir(III)N 6 Complexes with Long-Lived Triplet Excited States and in Vitro Photobiological Activities. ACS Appl Mater Interfaces 2019; 11:3629-3644. [PMID: 30608121 PMCID: PMC6355354 DOI: 10.1021/acsami.8b14744] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
A series of cationic heteroleptic iridium(III) complexes bearing tris-diimine ligands [Ir(phen)2(R-phen)]3+ (R-phen = phenanthroline (1), 3,8-diphenylphenanthroline (2), 3,8-dipyrenylphenanthroline (3), 3-phenylphenanthroline (4), 3-pyrenylphenanthroline (5), and 3,8-diphenylethynylphenanthroline (6)) were synthesized and characterized. These complexes possessed phen ligand-localized 1π,π* transitions below 300 nm, and charge transfer (1CT) and/or 1π,π* transitions between 300 and 520 nm. In 1, 2, 4, and 6, the low-energy bands were mixed 1CT/1π,π*. However, the increased π-donating ability of the pyrenyl substituent(s) in 3 and 5 split the low-energy bands into a pyrene-based 1π,π* transition at 300-380 nm and an intraligand charge transfer (1ILCT) transition at 380-520 nm. All complexes were emissive at room temperature in CH3CN, but the parentage of the emitting state varied depending on the R substituent(s). Complex 1 exhibited predominantly phen ligand-localized 3π,π* emission mixed with metal-to-ligand charge transfer (3MLCT) character, whereas the emission of 2, 4, and 6 was predominantly from the excited-state with 3π,π*/3ILCT/3MLCT character. The emission from 3 and 5 was dominated by pyrene-based 3π,π* states mixed with 3ILCT character. The different natures of the lowest triplet excited states were also reflected by the different spectral features and lifetimes of the triplet transient absorption of these complexes. Complexes 3 and 5 had singlet oxygen quantum yields as high as 81 and 72%, respectively. Both gave submicromolar phototoxicities toward cancer cells (SK-MEL-28 human melanoma) and bacteria ( S. aureus and S. mutans) with visible-light activation (and marginal to no photobiological activity with red light). Their visible-light phototherapeutic indices (PIs) toward SK-MEL-28 cells were 248 for 3 and >435 for 5; PIs were lower in bacteria (≤62) because of their inherent antimicrobial activities. Both complexes were shown to produce substantial amounts of intracellular reactive oxygen species (ROS), which may account for their photobiological activities.
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Affiliation(s)
- Li Wang
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108-6050, United States
| | - Susan Monro
- Department of Chemistry, Acadia University, 6 University Avenue, Wolfville, NS B4P 2R6, Canada
| | - Peng Cui
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108-6050, United States
- Materials and Nanotechnology Program, North Dakota State University, Fargo, North Dakota 58108-6050, United States
| | - Huimin Yin
- Department of Chemistry, Acadia University, 6 University Avenue, Wolfville, NS B4P 2R6, Canada
| | - Bingqing Liu
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108-6050, United States
| | - Colin G. Cameron
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, North Carolina 27402-6170, United States
| | - Wei Xu
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108-6050, United States
| | - Marc Hetu
- Department of Chemistry, Acadia University, 6 University Avenue, Wolfville, NS B4P 2R6, Canada
| | - Anderson Fuller
- Department of Chemistry, Acadia University, 6 University Avenue, Wolfville, NS B4P 2R6, Canada
| | - Svetlana Kilina
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108-6050, United States
| | - Sherri A. McFarland
- Department of Chemistry, Acadia University, 6 University Avenue, Wolfville, NS B4P 2R6, Canada
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, North Carolina 27402-6170, United States
| | - Wenfang Sun
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108-6050, United States
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Monro S, Colón KL, Yin H, Roque J, Konda P, Gujar S, Thummel RP, Lilge L, Cameron CG, McFarland SA. Transition Metal Complexes and Photodynamic Therapy from a Tumor-Centered Approach: Challenges, Opportunities, and Highlights from the Development of TLD1433. Chem Rev 2019; 119:797-828. [PMID: 30295467 PMCID: PMC6453754 DOI: 10.1021/acs.chemrev.8b00211] [Citation(s) in RCA: 744] [Impact Index Per Article: 148.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Transition metal complexes are of increasing interest as photosensitizers in photodynamic therapy (PDT) and, more recently, for photochemotherapy (PCT). In recent years, Ru(II) polypyridyl complexes have emerged as promising systems for both PDT and PCT. Their rich photochemical and photophysical properties derive from a variety of excited-state electronic configurations accessible with visible and near-infrared light, and these properties can be exploited for both energy- and electron-transfer processes that can yield highly potent oxygen-dependent and/or oxygen-independent photobiological activity. Selected examples highlight the use of rational design in coordination chemistry to control the lowest-energy triplet excited-state configurations for eliciting a particular type of photoreactivity for PDT and/or PCT effects. These principles are also discussed in the context of the development of TLD1433, the first Ru(II)-based photosensitizer for PDT to enter a human clinical trial. The design of TLD1433 arose from a tumor-centered approach, as part of a complete PDT package that includes the light component and the protocol for treating non-muscle invasive bladder cancer. Briefly, this review summarizes the challenges to bringing PDT into mainstream cancer therapy. It considers the chemical and photophysical solutions that transition metal complexes offer, and it puts into context the multidisciplinary effort needed to bring a new drug to clinical trial.
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Affiliation(s)
- Susan Monro
- Department of Chemistry, Acadia University, Wolfville, Nova
Scotia B4P 2R6, Canada
| | - Katsuya L. Colón
- Department of Chemistry and Biochemistry, The University of
North Carolina at Greensboro, Greensboro, North Carolina 27402, United States
| | - Huimin Yin
- Department of Chemistry, Acadia University, Wolfville, Nova
Scotia B4P 2R6, Canada
| | - John Roque
- Department of Chemistry and Biochemistry, The University of
North Carolina at Greensboro, Greensboro, North Carolina 27402, United States
| | - Prathyusha Konda
- Department of Microbiology and Immunology, Dalhousie
University Halifax, Nova Scotia, Canada B3H 1X5
| | - Shashi Gujar
- Department of Microbiology and Immunology, Dalhousie
University Halifax, Nova Scotia, Canada B3H 1X5
- Department of Pathology, Dalhousie University, Halifax,
Nova Scotia, Canada B3H 1X5
- Department of Biology, Dalhousie University, Halifax, Nova
Scotia, Canada B3H 1X5
- Centre for Innovative and Collaborative Health Services
Research, IWK Health Centre, Halifax, Nova Scotia, Canada B3K 6R8
| | - Randolph P. Thummel
- Department of Chemistry, University of Houston, Houston,
Texas 77204-5003, United States
| | - Lothar Lilge
- Princess Margaret Cancer Centre, University Health Network,
101 College Street, Toronto, Ontario, Canada M6R1Z7
| | - Colin G. Cameron
- Department of Chemistry and Biochemistry, The University of
North Carolina at Greensboro, Greensboro, North Carolina 27402, United States
| | - Sherri A. McFarland
- Department of Chemistry, Acadia University, Wolfville, Nova
Scotia B4P 2R6, Canada
- Department of Chemistry and Biochemistry, The University of
North Carolina at Greensboro, Greensboro, North Carolina 27402, United States
- Department of Pathology, Dalhousie University, Halifax,
Nova Scotia, Canada B3H 1X5
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Monro S, Cameron CG, Zhu X, Colón KL, Yin H, Sainuddin T, Hetu M, Pinto M, Fuller A, Bennett L, Roque J, Sun W, McFarland SA. Synthesis, Characterization and Photobiological Studies of Ru(II) Dyads Derived from α-Oligothiophene Derivatives of 1,10-Phenanthroline. Photochem Photobiol 2018; 95:267-279. [PMID: 30193398 DOI: 10.1111/php.13012] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 08/26/2018] [Indexed: 12/24/2022]
Abstract
Three new bis(2,2'-bipyridine)-heteroleptic Ru(II) dyads incorporating thienyl groups (n = 1-3, compounds 1, 2 and 3, respectively) appended to 1,10-phenanthroline were synthesized and characterized to investigate the impact of n on the photophysical and photobiological properties within the series. All three complexes showed unstructured emission near 618 nm from a triplet metal-to-ligand charge transfer (3 MLCT) state with a lifetime (τem ) of approximately 1 μs. Transient absorption measurements revealed an additional excited state that was nonemissive and long-lived (τTA = 43 μs for 2 and 27 μs for 3), assigned as a triplet intraligand (3 IL) state that was accessible only in 2 and 3. All three complexes were strong singlet oxygen (1 O2 ) sensitizers, with quantum yields (Φ∆ ) for 2 and 3 being the largest (74-78%), and all three were photocytotoxic to cancer cells with visible light activation in the order: 3 > 2 > 1. Cell-free DNA photodamage followed the same trend, where potency increased with decreasing 3 IL energy. Compounds 2 and 3 also showed in vitro photobiological effects with red light (625 nm), where their molar absorptivities were <100 m-1 cm-1 . These findings highlight that Ru(II) dyads derived from α-oligothiophenes directly appended to 1,10-phenanthroline-namely 2 and 3-possess low-lying 3 IL states that are highly photosensitizing, and they may therefore be of interest for photobiological applications such as photodynamic therapy (PDT).
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Affiliation(s)
- Susan Monro
- Department of Chemistry, Acadia University, Wolfville, NS, Canada
| | - Colin G Cameron
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC
| | - Xiaolin Zhu
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, ND
| | - Katsuya L Colón
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC
| | - Huimin Yin
- Department of Chemistry, Acadia University, Wolfville, NS, Canada
| | - Tariq Sainuddin
- Department of Chemistry, Acadia University, Wolfville, NS, Canada
| | - Marc Hetu
- Department of Chemistry, Acadia University, Wolfville, NS, Canada
| | - Mitch Pinto
- Department of Chemistry, Acadia University, Wolfville, NS, Canada
| | - Anderson Fuller
- Department of Chemistry, Acadia University, Wolfville, NS, Canada
| | - Leah Bennett
- Department of Chemistry, Acadia University, Wolfville, NS, Canada
| | - John Roque
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC
| | - Wenfang Sun
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, ND
| | - Sherri A McFarland
- Department of Chemistry, Acadia University, Wolfville, NS, Canada.,Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC
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Monjo ALA, Pringle ES, Thornbury M, Duguay BA, Monro SMA, Hetu M, Knight D, Cameron CG, McFarland SA, McCormick C. Photodynamic Inactivation of Herpes Simplex Viruses. Viruses 2018; 10:v10100532. [PMID: 30274257 PMCID: PMC6213367 DOI: 10.3390/v10100532] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 09/27/2018] [Accepted: 09/28/2018] [Indexed: 02/04/2023] Open
Abstract
Herpes simplex virus (HSV) infections can be treated with direct acting antivirals like acyclovir and foscarnet, but long-term use can lead to drug resistance, which motivates research into broadly-acting antivirals that can provide a greater genetic barrier to resistance. Photodynamic inactivation (PDI) employs a photosensitizer, light, and oxygen to create a local burst of reactive oxygen species that inactivate microorganisms. The botanical plant extract OrthoquinTM is a powerful photosensitizer with antimicrobial properties. Here we report that Orthoquin also has antiviral properties. Photoactivated Orthoquin inhibited herpes simplex virus type 1 (HSV-1) and herpes simplex virus type 2 (HSV-2) infection of target cells in a dose-dependent manner across a broad range of sub-cytotoxic concentrations. HSV inactivation required direct contact between Orthoquin and the inoculum, whereas pre-treatment of target cells had no effect. Orthoquin did not cause appreciable damage to viral capsids or premature release of viral genomes, as measured by qPCR for the HSV-1 genome. By contrast, immunoblotting for HSV-1 antigens in purified virion preparations suggested that higher doses of Orthoquin had a physical impact on certain HSV-1 proteins that altered protein mobility or antigen detection. Orthoquin PDI also inhibited the non-enveloped adenovirus (AdV) in a dose-dependent manner, whereas Orthoquin-mediated inhibition of the enveloped vesicular stomatitis virus (VSV) was light-independent. Together, these findings suggest that the broad antiviral effects of Orthoquin-mediated PDI may stem from damage to viral attachment proteins.
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Affiliation(s)
- Andrea L-A Monjo
- Department of Microbiology and Immunology, Dalhousie University, 5850 College Street, Halifax, NS B3H 4R2, Canada.
| | - Eric S Pringle
- Department of Microbiology and Immunology, Dalhousie University, 5850 College Street, Halifax, NS B3H 4R2, Canada.
| | - Mackenzie Thornbury
- Department of Microbiology and Immunology, Dalhousie University, 5850 College Street, Halifax, NS B3H 4R2, Canada.
- Department of Pathology and Cell Biology, University of Montreal, V-541 Pavillon Roger Gaudry, 2900 Boulevard Édouard-Montpetit, Montreal, QC H3C 3J7, Canada.
| | - Brett A Duguay
- Department of Microbiology and Immunology, Dalhousie University, 5850 College Street, Halifax, NS B3H 4R2, Canada.
| | - Susan M A Monro
- Department of Chemistry, Acadia University, 6 University Avenue, Wolfville, NS B4P 2R6, Canada.
- Photodynamic, Inc., 1344 Summer Street, Halifax, NS B3H 0A8, Canada.
| | - Marc Hetu
- Department of Chemistry, Acadia University, 6 University Avenue, Wolfville, NS B4P 2R6, Canada.
- Photodynamic, Inc., 1344 Summer Street, Halifax, NS B3H 0A8, Canada.
| | - Danika Knight
- Department of Microbiology and Immunology, Dalhousie University, 5850 College Street, Halifax, NS B3H 4R2, Canada.
| | - Colin G Cameron
- Photodynamic, Inc., 1344 Summer Street, Halifax, NS B3H 0A8, Canada.
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, 301 McIver Street, Greensboro, NC 27402, USA.
| | - Sherri A McFarland
- Photodynamic, Inc., 1344 Summer Street, Halifax, NS B3H 0A8, Canada.
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, 301 McIver Street, Greensboro, NC 27402, USA.
| | - Craig McCormick
- Department of Microbiology and Immunology, Dalhousie University, 5850 College Street, Halifax, NS B3H 4R2, Canada.
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Liu B, Monro S, Lystrom L, Cameron CG, Colon K, Yin H, Kilina S, McFarland SA, Sun W. Photophysical and Photobiological Properties of Dinuclear Iridium(III) Bis-tridentate Complexes. Inorg Chem 2018; 57:9859-9872. [PMID: 30091916 PMCID: PMC6337720 DOI: 10.1021/acs.inorgchem.8b00789] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A series of cationic dinuclear iridium(III) complexes (Ir1-Ir5) bearing terpyridine-capped fluorenyl bridging ligands and different polypyridyl or cyclometalating terminal tridentate ligands were synthesized, characterized, and evaluated for their photophysical and photobiological activities. The influence of the bridging and terminal ligands on the photophysical properties of the complexes was investigated by UV-vis absorption, emission, and transient absorption spectroscopy and simulated by TDDFT calculations. All of the complexes displayed strong bridging-ligand localized visible 1π,π* absorption and red- or near-infrared phosphorescence as well as broad triplet excited-state absorption across both visible and NIR wavelengths. These triplet states were assigned as predominantly 3π,π* for Ir1 (τ = 3.1 μs) and Ir4 (τ = 48 μs) and 3CT (charge transfer) for Ir2, Ir3, and Ir5 (τ = 1.7-2.7 μs). Complexes Ir1-Ir5 acted as in vitro photodynamic therapy (PDT) agents toward human SK-MEL-28 melanoma cells when activated with visible light, with submicromolar photocytotoxicity and phototherapeutic indices ranging from 20 to almost 300. The in vitro PDT effects with visible light did not correlate with singlet oxygen (1O2) quantum yields or DNA photocleaving capacity probed under cell-free conditions. All of the Ir(III) complexes phosphoresced brightly when associated with compromised cells (with or without light treatment) and exhibited photoactivated cellular uptake, highlighting the theranostic potential of this new class of Ir(III) complex photosensitizers.
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Affiliation(s)
- Bingqing Liu
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, ND 58108-6050, USA
| | - Susan Monro
- Department of Chemistry, Acadia University, 6 University Avenue, Wolfville, NS B4P 2R6, Canada
| | - Levi Lystrom
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, ND 58108-6050, USA
| | - Colin G. Cameron
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC 27402-6170, USA
| | - Katsuya Colon
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC 27402-6170, USA
| | - Huimin Yin
- Department of Chemistry, Acadia University, 6 University Avenue, Wolfville, NS B4P 2R6, Canada
| | - Svetlana Kilina
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, ND 58108-6050, USA
| | - Sherri A. McFarland
- Department of Chemistry, Acadia University, 6 University Avenue, Wolfville, NS B4P 2R6, Canada
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC 27402-6170, USA
| | - Wenfang Sun
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, ND 58108-6050, USA
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Ghosh G, Colón KL, Fuller A, Sainuddin T, Bradner E, McCain J, Monro SMA, Yin H, Hetu MW, Cameron CG, McFarland SA. Cyclometalated Ruthenium(II) Complexes Derived from α-Oligothiophenes as Highly Selective Cytotoxic or Photocytotoxic Agents. Inorg Chem 2018; 57:7694-7712. [PMID: 29927243 DOI: 10.1021/acs.inorgchem.8b00689] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The photophysical and photobiological properties of a new class of cyclometalated ruthenium(II) compounds incorporating π-extended benzo[ h]imidazo[4,5- f]quinoline (IBQ) cyclometalating ligands (C^N) bearing thienyl rings ( n = 1-4, compounds 1-4) were investigated. Their octanol-water partition coefficients (log Po/w) were positive and increased with n. Their absorption and emission energies were red-shifted substantially compared to the analogous Ru(II) diimine (N^N) complexes. They displayed C^N-based intraligand (IL) fluorescence and triplet excited-state absorption that shifted to longer wavelengths with increasing n and N^N-based metal-to-ligand charge transfer (MLCT) phosphorescence that was independent of n. Their photoluminescence lifetimes (τem) ranged from 4-10 ns for 1IL states and 12-18 ns for 3MLCT states. Transient absorption lifetimes (τTA) were 5-8 μs with 355 nm excitation, ascribed to 3IL states that became inaccessible for 1-3 with 532 nm excitation (1-3, τTA = 16-17 ns); the 3IL of 4 only was accessible by lower energy excitation, τTA = 3.8 μs. Complex 4 was nontoxic (EC50 > 300 μM) to SK-MEL-28 melanoma cells and CCD1064-Sk normal skin fibroblasts in the dark, while 3 was selectively cytotoxic to melanoma (EC50= 5.1 μM) only. Compounds 1 and 2 were selective for melanoma cells in the dark, with submicromolar potencies (EC50 = 350-500 nM) and selectivity factors (SFs) around 50. The photocytotoxicities of compounds 1-4 toward melanoma cells were similar, but only compounds 3 and 4 displayed significant phototherapeutic indices (PIs; 3, 43; 4, >1100). The larger cytotoxicities for compounds 1 and 2 were attributed to increased cellular uptake and nuclear accumulation, and possibly related to the DNA-aggregating properties of all four compounds as demonstrated by cell-free gel mobility-shift assays. Together, these results demonstrate a new class of thiophene-containing Ru(II) cyclometalated compounds that contain both highly selective chemotherapeutic agents and extremely potent photocytotoxic agents.
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Affiliation(s)
- Goutam Ghosh
- Department of Chemistry , Acadia University , Wolfville , Nova Scotia B4P 2R6 , Canada
| | - Katsuya L Colón
- Department of Chemistry and Biochemistry , The University of North Carolina at Greensboro , Greensboro , North Carolina 27402 , United States
| | - Anderson Fuller
- Department of Chemistry , Acadia University , Wolfville , Nova Scotia B4P 2R6 , Canada
| | - Tariq Sainuddin
- Department of Chemistry , Acadia University , Wolfville , Nova Scotia B4P 2R6 , Canada
| | - Evan Bradner
- Department of Chemistry and Biochemistry , The University of North Carolina at Greensboro , Greensboro , North Carolina 27402 , United States
| | - Julia McCain
- Department of Chemistry , Acadia University , Wolfville , Nova Scotia B4P 2R6 , Canada
| | - Susan M A Monro
- Department of Chemistry , Acadia University , Wolfville , Nova Scotia B4P 2R6 , Canada
| | - Huimin Yin
- Department of Chemistry , Acadia University , Wolfville , Nova Scotia B4P 2R6 , Canada
| | - Marc W Hetu
- Department of Chemistry , Acadia University , Wolfville , Nova Scotia B4P 2R6 , Canada
| | - Colin G Cameron
- Department of Chemistry and Biochemistry , The University of North Carolina at Greensboro , Greensboro , North Carolina 27402 , United States
| | - Sherri A McFarland
- Department of Chemistry , Acadia University , Wolfville , Nova Scotia B4P 2R6 , Canada.,Department of Chemistry and Biochemistry , The University of North Carolina at Greensboro , Greensboro , North Carolina 27402 , United States
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Wang L, Yin H, Cui P, Hetu M, Wang C, Monro S, Schaller RD, Cameron CG, Liu B, Kilina S, McFarland SA, Sun W. Near-infrared-emitting heteroleptic cationic iridium complexes derived from 2,3-diphenylbenzo[g]quinoxaline as in vitro theranostic photodynamic therapy agents. Dalton Trans 2017; 46:8091-8103. [DOI: 10.1039/c7dt00913e] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Cationic iridium complexes are promising near-infrared-emittingin vitrotheranostic photodynamic therapy agents.
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Affiliation(s)
- Li Wang
- Department of Chemistry and Biochemistry
- North Dakota State University
- Fargo
- USA
| | - Huimin Yin
- Department of Chemistry
- Acadia University
- 6 University Avenue
- Wolfville
- Canada
| | - Peng Cui
- Department of Chemistry and Biochemistry
- North Dakota State University
- Fargo
- USA
- Materials and Nanotechnology Program
| | - Marc Hetu
- Department of Chemistry
- Acadia University
- 6 University Avenue
- Wolfville
- Canada
| | - Chengzhe Wang
- Department of Chemistry and Biochemistry
- North Dakota State University
- Fargo
- USA
| | - Susan Monro
- Department of Chemistry
- Acadia University
- 6 University Avenue
- Wolfville
- Canada
| | | | - Colin G. Cameron
- Department of Chemistry and Biochemistry
- University of North Carolina at Greensboro
- Greensboro
- USA
| | - Bingqing Liu
- Department of Chemistry and Biochemistry
- North Dakota State University
- Fargo
- USA
| | - Svetlana Kilina
- Department of Chemistry and Biochemistry
- North Dakota State University
- Fargo
- USA
| | | | - Wenfang Sun
- Department of Chemistry and Biochemistry
- North Dakota State University
- Fargo
- USA
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Bravo-Grimaldo E, Hachey S, Cameron CG, Freund MS. Metastable Reaction Mixtures for the in Situ Polymerization of Conducting Polymers. Macromolecules 2007. [DOI: 10.1021/ma070463q] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Elda Bravo-Grimaldo
- Defence R&D Canada, CFB Halifax Bldg D-20, PO Box 99000 Stn Forces, Halifax NS B3K 5X5, Canada, and Department of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
| | - Sarah Hachey
- Defence R&D Canada, CFB Halifax Bldg D-20, PO Box 99000 Stn Forces, Halifax NS B3K 5X5, Canada, and Department of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
| | - Colin G. Cameron
- Defence R&D Canada, CFB Halifax Bldg D-20, PO Box 99000 Stn Forces, Halifax NS B3K 5X5, Canada, and Department of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
| | - Michael S. Freund
- Defence R&D Canada, CFB Halifax Bldg D-20, PO Box 99000 Stn Forces, Halifax NS B3K 5X5, Canada, and Department of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
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Abstract
The emerging field of materials-based actuation continues to be the focus of considerable research because of its inherent scalability and its promise to drive micromechanical devices that cannot be realized with conventional mechanical actuator strategies. The electrolytic phase transformation actuator offers a new broad-spectrum solution to the problem of direct conversion of electrical to mechanical energy. Strains of 136,000% and unoptimized work cycle efficiencies near 50% are demonstrated in a prototype device. Conceivably capable of generating stress beyond 200 MPa, this new approach promises performance orders of magnitude beyond other novel actuation strategies.
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Affiliation(s)
- Colin G Cameron
- Molecular Materials Research Center, Beckman Institute M/C 139-74, California Institute of Technology, Pasadena, CA 91125, USA
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Abstract
The aim of this study was to evaluate the short-term and long-term treatment effects of rapid maxillary expansion in 2 groups of subjects treated with the Haas appliance. Treatment outcomes were evaluated before and after the peak in skeletal maturation, as assessed by the cervical vertebral maturation (CVM) method, in a sample of 42 patients compared to a control sample of 20 subjects. Posteroanterior cephalograms were analyzed for the treated subjects at T1 (pretreatment), T2 (immediate post-expansion) and T3 (long-term observation), and were available at T1 and at T3 for the controls. The mean age (years: months) at T1 was 11:10 for both the treated and the control groups. The mean ages at T3 also were comparable (20:6 for the treated group and 17:8 for the controls). Following expansion and retention (2 months on average), fixed standard edgewise appliances were placed. The study included transverse measurements on dentoalveolar structures, maxillary and mandibular bases and other craniofacial regions (nasal, zygomatic, orbital, and cranial). Treated and control samples were divided into 2 groups according to individual skeletal maturation. The early-treated and early-control groups had not reached the pubertal peak in skeletal growth velocity at T1 (CVM 1 to 3), whereas the late-treated and late-control groups were during or slightly after the peak at T1 (CVM 4 to 6). The group treated before the pubertal peak showed significantly greater short-term increases in the width of the nasal cavities. In the long-term, maxillary skeletal width, maxillary intermolar width, lateronasal width, and lateroorbitale width were significantly greater in the early-treated group. The late-treated group exhibited significant increases in lateronasal width and in maxillary and mandibular intermolar widths. Rapid Maxillary Expansion treatment before the peak in skeletal growth velocity is able to induce more pronounced transverse craniofacial changes at the skeletal level.
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Affiliation(s)
- T Baccetti
- Department of Orthodontics, The University of Florence, Italy.
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Affiliation(s)
- Colin G. Cameron
- Department of Chemistry, Memorial University of Newfoundland, St. John's, Newfoundland, Canada A1B 3X7
| | - Timothy J. Pittman
- Department of Chemistry, Memorial University of Newfoundland, St. John's, Newfoundland, Canada A1B 3X7
| | - Peter G. Pickup
- Department of Chemistry, Memorial University of Newfoundland, St. John's, Newfoundland, Canada A1B 3X7
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Affiliation(s)
- Colin G. Cameron
- Contribution from the Department of Chemistry, Memorial University of Newfoundland, St. John's, Newfoundland, Canada A1B 3X7
| | - Peter G. Pickup
- Contribution from the Department of Chemistry, Memorial University of Newfoundland, St. John's, Newfoundland, Canada A1B 3X7
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Cameron CG, Pickup PG. Electron Transport in a Conjugated Metallopolymer Containing Binuclear Osmium Centers with Strong Electronic Communication. J Am Chem Soc 1999. [DOI: 10.1021/ja9915246] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Colin G. Cameron
- Department of Chemistry Memorial University of Newfoundland St. John's, Newfoundland, Canada A1B 3X7
| | - Peter G. Pickup
- Department of Chemistry Memorial University of Newfoundland St. John's, Newfoundland, Canada A1B 3X7
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Cameron CG, Pickup PG. A conjugated polymer/redox polymer hybrid with electronic communication between metal centres. Chem Commun (Camb) 1997. [DOI: 10.1039/a607671h] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Cameron CG. Quality assurance through government regulation. A provider association viewpoint. J Am Health Care Assoc 1985; 11:24-5. [PMID: 10272407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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