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Wang L, Liu Q, Buchwald A, Wackenhut F, Brecht M, Gierschner J, Meixner AJ. Deuterium Isotope Effect in Single Molecule Photophysics and Photochemistry of Hypericin. Chemphyschem 2024:e202400374. [PMID: 38837881 DOI: 10.1002/cphc.202400374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Revised: 05/20/2024] [Accepted: 06/05/2024] [Indexed: 06/07/2024]
Abstract
The peripherical protons of the dye molecule hypericin can undergo structural interconversion (tautomerization) between different isomers separated by a low energy barrier with rates that depends sensitively on the interaction with local chemical environment defined by the nature of host material. We investigate the deuterium (D) isotope effect of hypericin tautomerism at the single-molecule level to avoid ensemble averaging in different polymer matrices by a combined spectroscopic and computational approach. In the 'innocent' PMMA matrix only intramolecular isotope effects on the internal conversion channel and tautomerization are observed; while PVA specifically interacts with the probe via H- and D-bonding. This establishes a single molecular picture on intra- and intermolecular nano-environment effects to control chromophore photophysics and -chemistry.
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Affiliation(s)
- Liangxuan Wang
- Institute of Physical and Theoretical Chemistry, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 18, Tübingen, 72076, Germany
- Madrid Institute for Advanced Studies, IMDEA Nanoscience, Ciudad Universitaria de Cantoblanco, C/Faraday 9, Madrid, 28049, Spain
| | - Quan Liu
- Institute of Physical and Theoretical Chemistry, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 18, Tübingen, 72076, Germany
| | - Andrea Buchwald
- Institute of Physical and Theoretical Chemistry, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 18, Tübingen, 72076, Germany
| | - Frank Wackenhut
- Institute of Physical and Theoretical Chemistry, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 18, Tübingen, 72076, Germany
- Center for Process Analysis and Technology (PA&T), School of Life Sciences
- Reutlingen Research Institute (RRI), Reutlingen University, Alteburgstraße 150, Reutlingen, 72762, Germany
| | - Marc Brecht
- Institute of Physical and Theoretical Chemistry, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 18, Tübingen, 72076, Germany
- Center for Process Analysis and Technology (PA&T), School of Life Sciences
- Reutlingen Research Institute (RRI), Reutlingen University, Alteburgstraße 150, Reutlingen, 72762, Germany
| | - Johannes Gierschner
- Institute of Physical and Theoretical Chemistry, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 18, Tübingen, 72076, Germany
- Madrid Institute for Advanced Studies, IMDEA Nanoscience, Ciudad Universitaria de Cantoblanco, C/Faraday 9, Madrid, 28049, Spain
| | - Alfred J Meixner
- Institute of Physical and Theoretical Chemistry, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 18, Tübingen, 72076, Germany
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Woźniak M, Nowak-Perlak M. Hypericin-Based Photodynamic Therapy Displays Higher Selectivity and Phototoxicity towards Melanoma and Squamous Cell Cancer Compared to Normal Keratinocytes In Vitro. Int J Mol Sci 2023; 24:16897. [PMID: 38069219 PMCID: PMC10707231 DOI: 10.3390/ijms242316897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 11/24/2023] [Accepted: 11/27/2023] [Indexed: 12/18/2023] Open
Abstract
The aim of this study was to explore the potential of hypericin, a naturally occurring photosensi-tizer, for photodynamic therapy (PDT) in skin cancer, investigating its phototoxic effects and mechanisms of action in cancer cells compared to normal skin keratinocytes, squamous cell cancer (SCC-25) cells and melanoma (MUG-Mel2) cells. Hypericin was applied at concentrations ranging from 0.1-40 μM to HaCaT, SCC-25, and MUG-Mel2 cells. After 24 h of incubation, the cells were exposed to orange light at 3.6 J/cm2 or 7.2 J/cm2. Phototoxicity was assessed using MTT and SRB tests. Cellular uptake was measured by flow cytometry. Apoptosis-positive cells were estimated through TUNEL for apoptotic bodies' visualization. Hypericin exhibited a higher phototoxic reaction in cancer cells compared to normal keratinocytes after irradiation. Cancer cells demonstrated increased and selective uptake of hypericin. Apoptosis was observed in SCC-25 and MUG-Mel2 cells following PDT. Our findings suggest that hypericin-based PDT is a promising and less invasive approach for treating skin cancer. The higher phototoxic reaction, selective uptake by cancer cells, and observed proapoptotic properties support the promising role of hypericin-based PDT in skin cancer treatment.
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Affiliation(s)
- Marta Woźniak
- Department of Clinical and Experimental Pathology, Division of General and Experimental Pathology, Wroclaw Medical University, 50-368 Wroclaw, Poland;
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Qiu C, Zhang JZ, Wu B, Xu CC, Pang HH, Tu QC, Lu YQ, Guo QY, Xia F, Wang JG. Advanced application of nanotechnology in active constituents of Traditional Chinese Medicines. J Nanobiotechnology 2023; 21:456. [PMID: 38017573 PMCID: PMC10685519 DOI: 10.1186/s12951-023-02165-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 10/16/2023] [Indexed: 11/30/2023] Open
Abstract
Traditional Chinese Medicines (TCMs) have been used for centuries for the treatment and management of various diseases. However, their effective delivery to targeted sites may be a major challenge due to their poor water solubility, low bioavailability, and potential toxicity. Nanocarriers, such as liposomes, polymeric nanoparticles, inorganic nanoparticles and organic/inorganic nanohybrids based on active constituents from TCMs have been extensively studied as a promising strategy to improve the delivery of active constituents from TCMs to achieve a higher therapeutic effect with fewer side effects compared to conventional formulations. This review summarizes the recent advances in nanocarrier-based delivery systems for various types of active constituents of TCMs, including terpenoids, polyphenols, alkaloids, flavonoids, and quinones, from different natural sources. This review covers the design and preparation of nanocarriers, their characterization, and in vitro/vivo evaluations. Additionally, this review highlights the challenges and opportunities in the field and suggests future directions for research. Nanocarrier-based delivery systems have shown great potential in improving the therapeutic efficacy of TCMs, and this review may serve as a comprehensive resource to researchers in this field.
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Affiliation(s)
- Chong Qiu
- State Key Laboratory for Quality Ensurance and Sustainable Use of Dao-Di Herbs, Artemisinin Research Center, and Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Jun Zhe Zhang
- State Key Laboratory for Quality Ensurance and Sustainable Use of Dao-Di Herbs, Artemisinin Research Center, and Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Bo Wu
- Department of Traditional Chinese Medical Science, Sixth Medical Center of the Chinese PLA General Hospital, Beijing, 100037, China
| | - Cheng Chao Xu
- State Key Laboratory for Quality Ensurance and Sustainable Use of Dao-Di Herbs, Artemisinin Research Center, and Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Huan Huan Pang
- State Key Laboratory for Quality Ensurance and Sustainable Use of Dao-Di Herbs, Artemisinin Research Center, and Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Qing Chao Tu
- State Key Laboratory for Quality Ensurance and Sustainable Use of Dao-Di Herbs, Artemisinin Research Center, and Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Yu Qian Lu
- State Key Laboratory for Quality Ensurance and Sustainable Use of Dao-Di Herbs, Artemisinin Research Center, and Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Qiu Yan Guo
- State Key Laboratory for Quality Ensurance and Sustainable Use of Dao-Di Herbs, Artemisinin Research Center, and Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China.
| | - Fei Xia
- State Key Laboratory for Quality Ensurance and Sustainable Use of Dao-Di Herbs, Artemisinin Research Center, and Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China.
| | - Ji Gang Wang
- State Key Laboratory for Quality Ensurance and Sustainable Use of Dao-Di Herbs, Artemisinin Research Center, and Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China.
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117600, Singapore.
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Pevná V, Zauška Ľ, Benziane A, Vámosi G, Girman V, Miklóšová M, Zeleňák V, Huntošová V, Almáši M. Effective transport of aggregated hypericin encapsulated in SBA-15 nanoporous silica particles for photodynamic therapy of cancer cells. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2023; 247:112785. [PMID: 37714000 DOI: 10.1016/j.jphotobiol.2023.112785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 08/25/2023] [Accepted: 09/08/2023] [Indexed: 09/17/2023]
Abstract
Photodynamic therapy (PDT) represents an interesting modality for the elimination of damaged biomaterials and cells. This treatment takes advantage of the photosensitizing properties of molecules that are active only when irradiated with light. In the present work, a dual property of hypericin, a hydrophobic molecule with high performance in photodiagnostics and photodynamic therapy, was exploited. The non-fluorescent and photodynamically inactive form of hypericin aggregates was loaded into the nanopores of SBA-15 silica particles. The synthesized particles were characterized by infrared spectroscopy, thermogravimetry, differential thermal analysis, small-angle X-ray scattering and transmission electron microscopy. Hypericin aggregates were confirmed by absorption spectra typical of aggregated hypericin and by its short fluorescence lifetime. Release of hypericin from the particles was observed toward serum proteins, mimicking physiological conditions. Temperature- and time-dependent uptake of hypericin by cancer cells showed gradual release of hypericin from the particles and active cellular transport by endocytosis. A closer examination of SBA-15-hypericin uptake by fluorescence lifetime imaging showed that aggregated hypericin molecules, characterized by a short fluorescence lifetime (∼4 ns), were still present in the SBA-15 particles upon uptake by cells. However, monomerization of hypericin in cancer cells was observed by extending the hypericin fluorescence lifetime by ∼8 ns, preferentially in lipid compartments and the plasma membrane. This suggests a promising prognosis for delayed biological activity of the entire cargo, which was confirmed by effective PDT in vitro. In summary, this work presents an approach for safe, inactive delivery of hypericin that is activated at the target site in cells and tissues.
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Affiliation(s)
- Viktória Pevná
- Department of Biophysics, Institute of Physics, Faculty of Science, P.J. Šafárik University in Košice, Jesenná 5, SK-041 54 Košice, Slovakia
| | - Ľuboš Zauška
- Department of Inorganic Chemistry, Faculty of Science, P. J. Šafárik University in Košice, Moyzesova 11, SK-041 54, Košice, Slovakia
| | - Anass Benziane
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary
| | - György Vámosi
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary
| | - Vladimír Girman
- Department of Solid State Physics, Faculty of Science, P.J. Šafárik University in Košice, Park Angelinum, SK-041 54, Košice, Slovakia
| | - Monika Miklóšová
- 2(nd) Department of Surgery, Faculty of Medicine, P.J. Šafárik University in Košice, Rastislavova 43, SK-040 01 Košice, Slovakia
| | - Vladimír Zeleňák
- Department of Inorganic Chemistry, Faculty of Science, P. J. Šafárik University in Košice, Moyzesova 11, SK-041 54, Košice, Slovakia
| | - Veronika Huntošová
- Center for Interdisciplinary Biosciences, Technology and Innovation Park, P.J. Šafárik University in Košice, Jesenná 5, SK-041 54 Košice, Slovakia.
| | - Miroslav Almáši
- Department of Inorganic Chemistry, Faculty of Science, P. J. Šafárik University in Košice, Moyzesova 11, SK-041 54, Košice, Slovakia
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Da A, Wu-Lu M, Dragelj J, Mroginski MA, Ebrahimi KH. Multi-structural molecular docking (MOD) combined with molecular dynamics reveal the structural requirements of designing broad-spectrum inhibitors of SARS-CoV-2 entry to host cells. Sci Rep 2023; 13:16387. [PMID: 37773489 PMCID: PMC10541870 DOI: 10.1038/s41598-023-42015-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 09/04/2023] [Indexed: 10/01/2023] Open
Abstract
New variants of SARS-CoV-2 that can escape immune response continue to emerge. Consequently, there is an urgent demand to design small molecule therapeutics inhibiting viral entry to host cells to reduce infectivity rate. Despite numerous in silico and in situ studies, the structural requirement of designing viral-entry inhibitors effective against multiple variants of SARS-CoV-2 has yet to be described. Here we systematically screened the binding of various natural products (NPs) to six different SARS-CoV-2 receptor-binding domain (RBD) structures. We demonstrate that Multi-structural Molecular Docking (MOD) combined with molecular dynamics calculations allowed us to predict a vulnerable site of RBD and the structural requirement of ligands binding to this vulnerable site. We expect that our findings lay the foundation for in silico screening and identification of lead molecules to guide drug discovery into designing new broad-spectrum lead molecules to counter the threat of future variants of SARS-CoV-2.
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Affiliation(s)
- Anqi Da
- Institute of Pharmaceutical Science, King's College London, London, UK
| | - Meritxell Wu-Lu
- Institute of Chemistry, Technische Universität Berlin, Berlin, Germany
| | - Jovan Dragelj
- Institute of Chemistry, Technische Universität Berlin, Berlin, Germany
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Wu JJ, Zhang J, Xia CY, Ding K, Li XX, Pan XG, Xu JK, He J, Zhang WK. Hypericin: A natural anthraquinone as promising therapeutic agent. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2023; 111:154654. [PMID: 36689857 DOI: 10.1016/j.phymed.2023.154654] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 12/31/2022] [Accepted: 01/06/2023] [Indexed: 06/17/2023]
Abstract
BACKGROUND Hypericin is a prominent secondary metabolite mainly existing in genus Hypericum. It has become a research focus for a quiet long time owing to its extensively pharmacological activities especially the anti-cancer, anti-bacterial, anti-viral and neuroprotective effects. This review concentrated on summarizing and analyzing the existing studies of hypericin in a comprehensive perspective. METHODS The literature with desired information about hypericin published after 2010 was gained from electronic databases including PubMed, SciFinder, Science Direct, Web of Science, China National Knowledge Infrastructure databases and Wan Fang DATA. RESULTS According to extensive preclinical and clinical studies conducted on the hypericin, an organized and comprehensive summary of the natural and artificial sources, strategies for improving the bioactivities, pharmacological activities, drug combination of hypericin was presented to explore the future therapeutic potential of this active compound. CONCLUSIONS Overall, this review offered a theoretical guidance for the follow-up research of hypericin. However, the pharmacological mechanisms, pharmacokinetics and structure activity relationship of hypericin should be further studied in future research.
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Affiliation(s)
- Jing-Jing Wu
- China-Japan Friendship Hospital (Institute of Clinical Medical Sciences), Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100029, China; Institute of Clinical Medical Sciences & Department of Pharmacy, China-Japan Friendship Hospital, Beijing, 100029, China
| | - Jia Zhang
- School of Life Sciences & School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, 100029, China
| | - Cong-Yuan Xia
- Institute of Clinical Medical Sciences & Department of Pharmacy, China-Japan Friendship Hospital, Beijing, 100029, China
| | - Kang Ding
- School of Life Sciences & School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, 100029, China
| | - Xin-Xin Li
- School of Life Sciences & School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, 100029, China
| | - Xue-Ge Pan
- School of Life Sciences & School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, 100029, China
| | - Jie-Kun Xu
- School of Life Sciences & School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, 100029, China.
| | - Jun He
- Institute of Clinical Medical Sciences & Department of Pharmacy, China-Japan Friendship Hospital, Beijing, 100029, China.
| | - Wei-Ku Zhang
- China-Japan Friendship Hospital (Institute of Clinical Medical Sciences), Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100029, China; Institute of Clinical Medical Sciences & Department of Pharmacy, China-Japan Friendship Hospital, Beijing, 100029, China.
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Galinari CB, Biachi TDP, Gonçalves RS, Cesar GB, Bergmann EV, Malacarne LC, Kioshima Cotica ÉS, Bonfim-Mendonça PDS, Svidzinski TIE. Photoactivity of hypericin: from natural product to antifungal application. Crit Rev Microbiol 2023; 49:38-56. [PMID: 35171731 DOI: 10.1080/1040841x.2022.2036100] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Considering the multifaceted and increasing application of photodynamic therapy (PDT), in recent years the antimicrobial employment of this therapy has been highlighted, because of the antiviral, antibacterial, antiparasitic, and antifungal activities that have already been demonstrated. In this context, research focussed on antimycological action, especially for treatment of superficial infections, presents promising growth due to the characteristics of these infections that facilitate PDT application as new therapeutic options are needed in the field of medical mycology. Among the more than one hundred classes of photosensitizers the antifungal action of hypericin (Hyp) stands out due to its ability to permeate the lipid membrane and accumulate in different cytoplasmic organelles of eukaryotic cells. In this review, we aim to provide a complete overview of the origin, physicochemical characteristics, and optimal alternative drug deliveries that promote the photodynamic action of Hyp (Hyp-PDT) against fungi. Furthermore, considering the lack of a methodological consensus, we intend to compile the best strategies to guide researchers in the antifungal application of Hyp-PDT. Overall, this review provides a future perspective of new studies and clinical possibilities for the advances of such a technique in the treatment of mycoses in humans.
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Affiliation(s)
- Camila Barros Galinari
- Department of Analysis Clinics & Biomedicine, State University of Maringá, Paraná, Brazil
| | - Tiago de Paula Biachi
- Department of Analysis Clinics & Biomedicine, State University of Maringá, Paraná, Brazil
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Choudhary N, Collignon TE, Tewari D, Bishayee A. Hypericin and its anticancer effects: From mechanism of action to potential therapeutic application. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2022; 105:154356. [PMID: 35985181 DOI: 10.1016/j.phymed.2022.154356] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 07/05/2022] [Accepted: 07/23/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND Emerging studies indicate that hypericin has diverse pharmacological actions and exhibits potential for treatment of various types of cancer. PURPOSE The current review evaluates the pharmacological activity, associated molecular mechanism, and therapeutic application of hypericin as an anticancer agent according to the most recent state of knowledge with special emphasis on clinical trials and safety profile. METHOD This review follows The Preferred Reporting Items for Systematic Reviews criteria. Various databases, including PubMed, Scopus and Science Direct, were used to search and collect relevant literature. The major keywords used included the following: cancer, distribution, property, signaling pathway, pharmacological effect, treatment, prevention, in vitro and in vivo studies, toxicity, bioavailability, and clinical trials. RESULTS One hundred three articles met the established inclusion and exclusion criteria. Hypericin has shown anticancer activity against the expansion of several cell types including breast cancer, cervical cancer, colorectal cancer, colon cancer, hepatocellular carcinoma, stomach carcinoma, leukemia, lung cancer, melanoma, and glioblastoma cancer. Hypericin exerts its anticancer activity by inhibiting pro-inflammatory mediators, endothelial growth factor, fibroblast growth factor, cell adhesion, angiogenesis, and mitochondrial thioredoxin. It has also been shown to cause an increase in the levels of caspase-3 and caspase-4, arrest the cell cycle at metaphase leading to cancer cell apoptosis, and affect various protein and gene expression patterns. CONCLUSION Hypericin exhibits significant inhibitory activity against various types of in vitro and in vivo cancer models. However, well-designed, high quality, large-scale and multi-center randomized clinical studies are required to establish the safety and clinical utility of hypericin in cancer patients.
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Affiliation(s)
- Neeraj Choudhary
- Department of Pharmacognosy, Adesh Institute of Pharmacy and Biomedical Sciences, Adesh University, Bathinda, Punjab 151101, India
| | - Taylor E Collignon
- College of Osteopathic Medicine, Lake Erie College of Osteopathic Medicine, 5000 Lakewood Ranch Boulevard, Bradenton, FL 34211, USA
| | - Devesh Tewari
- Department of Pharmacognosy and Phytochemistry, School of Pharmaceutical Sciences, Delhi Pharmaceutical Sciences and Research University, New Delhi 110017, India.
| | - Anupam Bishayee
- College of Osteopathic Medicine, Lake Erie College of Osteopathic Medicine, 5000 Lakewood Ranch Boulevard, Bradenton, FL 34211, USA.
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Gradient SERS Substrates with Multiple Resonances for Analyte Screening: Fabrication and SERS Applications. Molecules 2022; 27:molecules27165097. [PMID: 36014328 PMCID: PMC9414786 DOI: 10.3390/molecules27165097] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 08/05/2022] [Accepted: 08/08/2022] [Indexed: 11/16/2022] Open
Abstract
Surface-enhanced Raman spectroscopy (SERS) provides a strong enhancement to an inherently weak Raman signal, which strongly depends on the material, design, and fabrication of the substrate. Here, we present a facile method of fabricating a non-uniform SERS substrate based on an annealed thin gold (Au) film that offers multiple resonances and gap sizes within the same sample. It is not only chemically stable, but also shows reproducible trends in terms of geometry and plasmonic response. Scanning electron microscopy (SEM) reveals particle-like and island-like morphology with different gap sizes at different lateral positions of the substrate. Extinction spectra show that the plasmonic resonance of the nanoparticles/metal islands can be continuously tuned across the substrate. We observed that for the analytes 1,2-bis(4-pyridyl) ethylene (BPE) and methylene blue (MB), the maximum SERS enhancement is achieved at different lateral positions, and the shape of the extinction spectra allows for the correlation of SERS enhancement with surface morphology. Such non-uniform SERS substrates with multiple nanoparticle sizes, shapes, and interparticle distances can be used for fast screening of analytes due to the lateral variation of the resonances within the same sample.
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Conformational heterogeneity of molecules physisorbed on a gold surface at room temperature. Nat Commun 2022; 13:4133. [PMID: 35840568 PMCID: PMC9287342 DOI: 10.1038/s41467-022-31576-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 06/22/2022] [Indexed: 11/16/2022] Open
Abstract
A quantitative single-molecule tip-enhanced Raman spectroscopy (TERS) study at room temperature remained a challenge due to the rapid structural dynamics of molecules exposed to air. Here, we demonstrate the hyperspectral TERS imaging of single or a few brilliant cresyl blue (BCB) molecules at room temperature, along with quantitative spectral analyses. Robust chemical imaging is enabled by the freeze-frame approach using a thin Al2O3 capping layer, which suppresses spectral diffusions and inhibits chemical reactions and contamination in air. For the molecules resolved spatially in the TERS image, a clear Raman peak variation up to 7.5 cm−1 is observed, which cannot be found in molecular ensembles. From density functional theory-based quantitative analyses of the varied TERS peaks, we reveal the conformational heterogeneity at the single-molecule level. This work provides a facile way to investigate the single-molecule properties in interacting media, expanding the scope of single-molecule vibrational spectroscopy studies. Tip-enhanced vibrational spectroscopy at room temperature is complicated by molecular conformational dynamics, photobleaching, contaminations, and chemical reactions in air. This study demonstrates that a sub-nm protective layer of Al2O3 provides robust conditions for probing single-molecule conformations.
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Bassler MC, Rammler T, Wackenhut F, Zur Oven-Krockhaus S, Secic I, Ritz R, Meixner AJ, Brecht M. Accumulation and penetration behavior of hypericin in glioma tumor spheroids studied by fluorescence microscopy and confocal fluorescence lifetime imaging microscopy. Anal Bioanal Chem 2022; 414:4849-4860. [PMID: 35538227 PMCID: PMC9234035 DOI: 10.1007/s00216-022-04107-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 04/14/2022] [Accepted: 04/28/2022] [Indexed: 12/17/2022]
Abstract
Glioblastoma WHO IV belongs to a group of brain tumors that are still incurable. A promising treatment approach applies photodynamic therapy (PDT) with hypericin as a photosensitizer. To generate a comprehensive understanding of the photosensitizer-tumor interactions, the first part of our study is focused on investigating the distribution and penetration behavior of hypericin in glioma cell spheroids by fluorescence microscopy. In the second part, fluorescence lifetime imaging microscopy (FLIM) was used to correlate fluorescence lifetime (FLT) changes of hypericin to environmental effects inside the spheroids. In this context, 3D tumor spheroids are an excellent model system since they consider 3D cell-cell interactions and the extracellular matrix is similar to tumors in vivo. Our analytical approach considers hypericin as probe molecule for FLIM and as photosensitizer for PDT at the same time, making it possible to directly draw conclusions of the state and location of the drug in a biological system. The knowledge of both state and location of hypericin makes a fundamental understanding of the impact of hypericin PDT in brain tumors possible. Following different incubation conditions, the hypericin distribution in peripheral and central cryosections of the spheroids were analyzed. Both fluorescence microscopy and FLIM revealed a hypericin gradient towards the spheroid core for short incubation periods or small concentrations. On the other hand, a homogeneous hypericin distribution is observed for long incubation times and high concentrations. Especially, the observed FLT change is crucial for the PDT efficiency, since the triplet yield, and hence the O2 activation, is directly proportional to the FLT. Based on the FLT increase inside spheroids, an incubation time > 30 min is required to achieve most suitable conditions for an effective PDT.
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Affiliation(s)
- Miriam C Bassler
- Process Analysis and Technology (PA&T), Reutlingen University, Alteburgstr. 150, 72762, Reutlingen, Germany.,Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 18, 72076, Tübingen, Germany
| | - Tim Rammler
- Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 18, 72076, Tübingen, Germany
| | - Frank Wackenhut
- Process Analysis and Technology (PA&T), Reutlingen University, Alteburgstr. 150, 72762, Reutlingen, Germany.
| | - Sven Zur Oven-Krockhaus
- Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 18, 72076, Tübingen, Germany
| | - Ivona Secic
- Process Analysis and Technology (PA&T), Reutlingen University, Alteburgstr. 150, 72762, Reutlingen, Germany
| | - Rainer Ritz
- Department of Neurosurgery, Schwarzwald-Baar Clinic, Klinikstr. 11, 78052, Villingen-Schwenningen, Germany
| | - Alfred J Meixner
- Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 18, 72076, Tübingen, Germany
| | - Marc Brecht
- Process Analysis and Technology (PA&T), Reutlingen University, Alteburgstr. 150, 72762, Reutlingen, Germany. .,Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 18, 72076, Tübingen, Germany.
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Wang L, Liu Q, Wackenhut F, Brecht M, Adam PM, Gierschner J, Meixner AJ. Monitoring tautomerization of single hypericin molecules in a tunable optical λ/2 microcavity. J Chem Phys 2022; 156:014203. [PMID: 34998354 DOI: 10.1063/5.0078117] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Hypericin tautomerization that involves the migration of the labile protons is believed to be the primary photophysical process relevant to its light-activated antiviral activity. Despite the difficulty in isolating individual tautomers, it can be directly observed in single-molecule experiments. We show that the tautomerization of single hypericin molecules in free space is observed as an abrupt flipping of the image pattern accompanied with fluorescence intensity fluctuations, which are not correlated with lifetime changes. Moreover, the study can be extended to a λ/2 Fabry-Pérot microcavity. The modification of the local photonic environment by a microcavity is well simulated with a theoretical model that shows good agreement with the experimental data. Inside a microcavity, the excited state lifetime and fluorescence intensity of single hypericin molecules are correlated, and a distinct jump of the lifetime and fluorescence intensity reveals the temporal behavior of the tautomerization with high sensitivity and high temporal resolution. The observed changes are also consistent with time-dependent density functional theory calculations. Our approach paves the way to monitor and even control reactions for a wider range of molecules at the single molecule level.
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Affiliation(s)
- Liangxuan Wang
- Institute of Physical and Theoretical Chemistry, Eberhard Karls University Tübingen, 72076 Tübingen, Germany
| | - Quan Liu
- Institute of Physical and Theoretical Chemistry, Eberhard Karls University Tübingen, 72076 Tübingen, Germany
| | - Frank Wackenhut
- Institute of Physical and Theoretical Chemistry, Eberhard Karls University Tübingen, 72076 Tübingen, Germany
| | - Marc Brecht
- Institute of Physical and Theoretical Chemistry, Eberhard Karls University Tübingen, 72076 Tübingen, Germany
| | - Pierre-Michel Adam
- Laboratoire Lumiére, Nanomatériaux et Nanotechnologies (L2n), CNRS ERL 7004, Université de Technologie de Troyes, 10004 Troyes, France
| | - Johannes Gierschner
- Madrid Institute for Advanced Studies, IMDEA in Nanoscience, C/ Faraday 9, Ciudad Universitaria Cantoblanco, 28049 Madrid, Spain
| | - Alfred J Meixner
- Institute of Physical and Theoretical Chemistry, Eberhard Karls University Tübingen, 72076 Tübingen, Germany
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Lian S, Gao X, Song C, Li H, Lin J. Chemical Enhancement Effect of Icotinib-Au Complex Studied by Combined Density Functional Theory and Surface-Enhanced Raman Scattering. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:12907-12918. [PMID: 34705473 DOI: 10.1021/acs.langmuir.1c01957] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Icotinib is an epidermal growth factor receptor tyrosine kinase inhibitor used in the treatment of non-small cell lung cancer. The charge transfer effect between gold nanoparticles (AuNPs) and icotinib molecules can be used as a model to study the adsorption mechanism between molecules and metal. The adsorption of icotinib on the AuNP surface was confirmed by UV-vis and transmission electron microscopy (TEM) experiments. To explain the nature of chemisorption between icotinib and AuNPs from a theoretical perspective, the molecular correlation properties of the complex model of icotinib-Au6 were studied by the density functional theory method. By studying the molecular electrostatic potential of an icotinib molecule, four potential binding sites of the icotinib molecule were predicted. The calculation results of binding energy showed that the complex formed by chemisorption of icotinib through acetylene group and Au6 was the most stable one. The molecular frontier orbitals of icotinib and icotinib-Au6 confirmed that the charge transfer effect occurred on the acetylene group, benzene ring, and quinazoline ring of the icotinib molecule. The Herzberg-Teller surface selection rule was used to explain selective enhancement in the theoretically calculated Raman spectra. By comparing the spectra of theory and experiment, the cause of spectral peak shift and broadening that appeared in the surface-enhanced Raman scattering spectrum compared with the normal Raman spectrum was explained as well. This work would contribute to the development and application of the icotinib-Au drug carrier system.
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Affiliation(s)
- Shuai Lian
- School of Science, Changchun University of Science and Technology, Changchun, Jilin 130022, China
| | - Xun Gao
- School of Science, Changchun University of Science and Technology, Changchun, Jilin 130022, China
| | - Chao Song
- School of Chemistry and Environmental Engineering, Changchun University of Science and Technology, Changchun, Jilin 130022, China
| | - Hui Li
- School of Science, Changchun University of Science and Technology, Changchun, Jilin 130022, China
| | - Jingquan Lin
- School of Science, Changchun University of Science and Technology, Changchun, Jilin 130022, China
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Liu Q, Wackenhut F, Wang L, Hauler O, Roldao JC, Adam PM, Brecht M, Gierschner J, Meixner AJ. Direct Observation of Structural Heterogeneity and Tautomerization of Single Hypericin Molecules. J Phys Chem Lett 2021; 12:1025-1031. [PMID: 33470816 DOI: 10.1021/acs.jpclett.0c03459] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Tautomerization is a fundamental chemical reaction which involves the relocation of a proton in the reactants. Studying the optical properties of tautomeric species is challenging because of ensemble averaging. Many molecules, such as porphines, porphycenes, or phenanthroperylene quinones, exhibit a reorientation of the transition dipole moment (TDM) during tautomerization, which can be directly observed in single-molecule experiments. Here, we study single hypericin molecules, which is a prominent phenanthroperylene quinone showing antiviral, antidepressive, and photodynamical properties. Observing abrupt flipping of the image pattern combined with time-dependent density functional theory calculations allows drawing conclusions about the coexistence of four tautomers and their conversion path. This approach allows the unambiguous assignment of a TDM orientation to a specific tautomer and enables the determination of the chemical structure in situ. Our approach can be applied to other molecules showing TDM reorientation during tautomerization, helping to gain a deeper understanding of this important process.
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Affiliation(s)
- Quan Liu
- Institute of Physical and Theoretical Chemistry, Eberhard Karls University Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
- Laboratoire Lumière, Nanomatériaux & Nanotechnologies - L2n and CNRS ERL 7004, Universitéde Technologie de Troyes, 10000 Troyes, France
| | - Frank Wackenhut
- Institute of Physical and Theoretical Chemistry, Eberhard Karls University Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
| | - Liangxuan Wang
- Institute of Physical and Theoretical Chemistry, Eberhard Karls University Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
- Madrid Institute for Advanced Studies, IMDEA Nanoscience, Ciudad Universitaria de Cantoblanco, C/Faraday 9, 28049 Madrid, Spain
| | - Otto Hauler
- Institute of Physical and Theoretical Chemistry, Eberhard Karls University Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
- Reutlingen Research Institute, Process Analysis and Technology (PA&T), Reutlingen University, Alteburgstraße 150, 72762 Reutlingen, Germany
| | - Juan Carlos Roldao
- Madrid Institute for Advanced Studies, IMDEA Nanoscience, Ciudad Universitaria de Cantoblanco, C/Faraday 9, 28049 Madrid, Spain
| | - Pierre-Michel Adam
- Laboratoire Lumière, Nanomatériaux & Nanotechnologies - L2n and CNRS ERL 7004, Universitéde Technologie de Troyes, 10000 Troyes, France
| | - Marc Brecht
- Institute of Physical and Theoretical Chemistry, Eberhard Karls University Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
- Reutlingen Research Institute, Process Analysis and Technology (PA&T), Reutlingen University, Alteburgstraße 150, 72762 Reutlingen, Germany
| | - Johannes Gierschner
- Institute of Physical and Theoretical Chemistry, Eberhard Karls University Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
- Madrid Institute for Advanced Studies, IMDEA Nanoscience, Ciudad Universitaria de Cantoblanco, C/Faraday 9, 28049 Madrid, Spain
| | - Alfred J Meixner
- Institute of Physical and Theoretical Chemistry, Eberhard Karls University Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
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