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Bi X, Watts DB, Dorman I, Kirk CM, Thomas M, Singleton I, Malcom C, Barnes T, Carter C, Liang A. Polyamidoamine dendrimer-mediated hydrogel for solubility enhancement and anti-cancer drug delivery. J Biomater Appl 2024; 38:733-742. [PMID: 37933579 DOI: 10.1177/08853282231213712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2023]
Abstract
The application of hydrogels for anti-cancer drug delivery has garnered considerable interest in the medical field. Current cancer treatment approaches, such as chemotherapy and radiation therapy, often induce severe side effects, causing significant distress and substantial health complications to patients. Hydrogels present an appealing solution as they can be precisely injected into specific sites within the body, facilitating the sustainable release of encapsulated drugs. This localized treatment approach holds great potential for reducing toxicity levels and improving drug delivery efficacy. In this study we developed a hydrogel delivery system containing polyamidoamine (PAMAM) dendrimer and polyethylene glycol (PEG) for solubility enhancement and sustained delivery of hydrophobic anti-cancer drugs. The three selected model drugs, e.g. silibinin, camptothecin, and methotrexate, possess limited aqueous solubility and thus face restricted application. In the presence of vinyl sulfone functionalized PAMAM dendrimer at 45 mg/mL concentration, drug solubility is increased by 37-fold, 4-fold, and 10-fold for silibinin, camptothecin, and methotrexate, respectively. By further crosslinking of the functionalized PAMAM dendrimer and thiolated PEG, we successfully developed a fast-crosslinking hydrogel capable of encapsulating a significant payload of solubilized cancer drugs for sustained release. In water, the drug encapsulated hydrogels release 30%-80% of their loads in 1-4 days. MTT assays of J82 and MCF7 cells with various doses of drug encapsulated hydrogels reveal that cytotoxicity is observed for all three drugs on both J82 and MCF7 cell lines after 48 h. Notably, camptothecin exhibits higher cytotoxicity to both cell lines than silibinin and methotrexate, achieving up to 95% cell death at experimental conditions, despite its lower solubility. Our experiments provide evidence that the PAMAM dendrimer-mediated hydrogel system significantly improves the solubility of hydrophobic drugs and facilitates their sustained release. These findings position the system as a promising platform for controlled delivery of hydrophobic drugs for intratumoral cancer treatment.
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Affiliation(s)
- Xiangdong Bi
- Department of Chemistry, Charleston Southern University, Charleston, SC, USA
| | - Darra B Watts
- Department of Chemistry, Charleston Southern University, Charleston, SC, USA
| | - Ian Dorman
- Department of Chemistry, Charleston Southern University, Charleston, SC, USA
| | - Casianna M Kirk
- Department of Chemistry, Charleston Southern University, Charleston, SC, USA
| | - Marisa Thomas
- Department of Chemistry, Charleston Southern University, Charleston, SC, USA
| | - Isaiah Singleton
- Department of Chemistry, Charleston Southern University, Charleston, SC, USA
| | - Colleen Malcom
- Department of Chemistry, Charleston Southern University, Charleston, SC, USA
| | - Taylor Barnes
- Department of Chemistry, Charleston Southern University, Charleston, SC, USA
| | - Colby Carter
- Department of Chemistry, Charleston Southern University, Charleston, SC, USA
| | - Aiye Liang
- Department of Chemistry, Charleston Southern University, Charleston, SC, USA
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2
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Tu CK, Mou W, Shen ZL. Computer simulation of the structural properties of fatty-acid modified PAMAM dendrimers at pH 5 and 7. J Mol Graph Model 2023; 124:108570. [PMID: 37487373 DOI: 10.1016/j.jmgm.2023.108570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 07/19/2023] [Accepted: 07/19/2023] [Indexed: 07/26/2023]
Abstract
In this work, we performed coarse-grained molecular dynamics (CGMD) simulations of G3, G4, and G5 polyamidoamine (PAMAM) dendrimers grafting with fatty acid (FTA) chains. The FTA chains of varying length and grafting densities (50% and 100% of surface terminals) correspond to pH 7 and 5, respectively. Our findings suggested that the structural properties of dendrimers were determined by dendrimer generation, polymerization degrees, and pH. With one exception, the size of the FTA grafting dendrimer shrank after fatty acid attachment. Because of the protonation of the dendrimer's interior amines at low pH, the FTA chains are distributed at the dendrimer's surface group. At pH 7, the FTA chains that have aggregated in the interior of the dendrimer cause chain crowding. Our research provided references on drug encapsulation and the lower toxicity of these hydrophobically modified nanoparticles.
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Affiliation(s)
- Chen-Kun Tu
- Kangda College, Nanjing Medical University, Lianyungang, China.
| | - Wei Mou
- Kangda College, Nanjing Medical University, Lianyungang, China
| | - Zhuang-Lin Shen
- Shenzhen Key Laboratory of Environmental Chemistry and Ecological Remediation, College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, China.
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3
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Johnston BM, Grodzinsky AJ, Hammond PT. Charge shielding effects of PEG bound to NH 2-terminated PAMAM dendrimers - an experimental approach. SOFT MATTER 2023; 19:3033-3046. [PMID: 37038739 PMCID: PMC10131161 DOI: 10.1039/d2sm01698b] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Cationic poly(amido amine) (PAMAM) dendrimers exhibit great potential for use in drug delivery, but their high charge density leads to an inherent cytotoxicity. To increase biocompatibility, many studies have attached poly(ethylene glycol) (PEG) chains to the dendrimer surface. It is unclear how these tethered PEG chains influence the physicochemical properties of the dendrimer. Here, we develop a fluorescence-based assay utilizing anionic biological tissue to quantify the electrostatic binding affinity of a library of PEG-PAMAM conjugates with various PEG chain lengths and grafting densities. We find that covalently bound PEG chains reduce the electrostatic binding affinity more significantly than what can be achieved through covalent bonds only. Contrary to previous thought, this reduction is not explained by the steric hindrance effects of PEG chains, suggesting that other, non-covalent interactions between PEG and PAMAM are present. Using acetylated PAMAM conjugates, we convert electrostatic binding affinity to the number of charged amines accessible to the physiological environment. These data, coupled with 1H-NMR, allows us to study more closely the non-covalent interactions between PEG and PAMAM. We find that increasing PEG chain length increases the number of non-covalent interactions. Additionally, at low grafting densities, increasing the number of PEG chains on the PAMAM surface also increases the non-covalent interactions. At higher grafting densities, however, PEG chains sterically repel one another, forcing chains to elongate away from the surface and reducing the number of interactions between PAMAM and individual PEG chains. The data presented here provides a framework for a more precise mechanistic understanding of how the length and density of tethered PEG chains on PAMAM dendrimers influence drug delivery properties.
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Affiliation(s)
- Brandon M Johnston
- Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA, 02139, USA.
- Koch Institute for Integrative Cancer Research, 500 Main St, Cambridge, MA, 02139, USA
| | - Alan J Grodzinsky
- Department of Biological Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA, 02139, USA
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA, 02139, USA
- Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA, 02139, USA
| | - Paula T Hammond
- Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA, 02139, USA.
- Koch Institute for Integrative Cancer Research, 500 Main St, Cambridge, MA, 02139, USA
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4
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Badalkhani-Khamseh F, Ebrahim-Habibi A, Hadipour NL, Behmanesh M. PEGylated PAMAM Dendrimers as Eptifibatide Nanocarriers: An Atomistic View from Molecular Dynamics Simulations. Chem Eng Sci 2022. [DOI: 10.1016/j.ces.2022.118283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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5
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Fatemi SM, Fatemi SJ, Abbasi Z. PAMAM dendrimer-based macromolecules and their potential applications: recent advances in theoretical studies. Polym Bull (Berl) 2020. [DOI: 10.1007/s00289-019-03076-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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6
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Wang B, Sun Y, Davis TP, Ke PC, Wu Y, Ding F. Understanding Effects of PAMAM Dendrimer Size and Surface Chemistry on Serum Protein Binding with Discrete Molecular Dynamics Simulations. ACS SUSTAINABLE CHEMISTRY & ENGINEERING 2018; 6:11704-11715. [PMID: 30881771 PMCID: PMC6413314 DOI: 10.1021/acssuschemeng.8b01959] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Polyamidoamine (PAMAM) dendrimers, a class of polymeric nanoparticles (NPs) with highly-controllable sizes and surface chemistry, are promising candidates for many biomedical applications, including drug and gene delivery, imaging, and inhibition of amyloid aggregation. In circulation, binding of serum proteins with dendritic NPs renders the formation of protein corona and alters the biological identity of the NP core, which may subsequently elicit immunoresponse and cytotoxicity. Understanding the effects of PAMAM size and surface chemistry on serum protein binding is, therefore, crucial to enable their broad biomedical applications. Here, by applying atomistic discrete molecular dynamics (DMD) simulations, we first uncovered the binding of PAMAM with HSA and Ig and detailed the dependences of such binding on PAMAM size and surface modification. Compared to either anionic or cationic surfaces, modifications with neutral phosphorylcholine (PC), polyethylene glycol (PEG), and hydroxyls (OH) significantly reduced binding with proteins. The relatively strong binding between proteins and PAMAM dendrimers with charged surface groups was mainly driven by electrostatic interactions as well as hydrophobic interactions. Using steered DMD (SDMD) simulations, we conducted a force-pulling experiment in silico estimating the critical forces separating PAMAM-protein complexes and deriving the corresponding free energy barriers for dissociation. The SDMD-derived HSA-binding affinities were consistent with existing experimental measurements. Our results highlighted the association dynamics of protein-dendrimer interactions and binding affinities, whose implications range from fundamental nanobio interfacial phenomena to the development of "stealth NPs".
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Affiliation(s)
- Bo Wang
- department of Physics and Astronomy, Clemson University,
Clemson, SC 29634, USA
- Department of Systems and Computational Biology, Albert
Einstein College of Medicine, Bronx, NY 10461, USA
| | - Yunxiang Sun
- department of Physics and Astronomy, Clemson University,
Clemson, SC 29634, USA
| | - Thomas P. Davis
- ARC Centre of Excellence in Convergent Bio-Nano Science and
Technology, Monash Institute of Pharmaceutical Sciences, Monash University, 381
Royal Parade, Parkville, VIC 3052, Australia
| | - Pu Chun Ke
- ARC Centre of Excellence in Convergent Bio-Nano Science and
Technology, Monash Institute of Pharmaceutical Sciences, Monash University, 381
Royal Parade, Parkville, VIC 3052, Australia
| | - Yinghao Wu
- Department of Systems and Computational Biology, Albert
Einstein College of Medicine, Bronx, NY 10461, USA
| | - Feng Ding
- department of Physics and Astronomy, Clemson University,
Clemson, SC 29634, USA
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7
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Badalkhani-Khamseh F, Ebrahim-Habibi A, Hadipour NL. Atomistic computer simulations on multi-loaded PAMAM dendrimers: a comparison of amine- and hydroxyl-terminated dendrimers. J Comput Aided Mol Des 2017; 31:1097-1111. [DOI: 10.1007/s10822-017-0091-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 12/05/2017] [Indexed: 12/14/2022]
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8
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Ganda IS, Zhong Q, Hali M, Albuquerque RLC, Padilha FF, da Rocha SRP, Whittum-Hudson JA. Dendrimer-conjugated peptide vaccine enhances clearance of Chlamydia trachomatis genital infection. Int J Pharm 2017; 527:79-91. [PMID: 28546072 PMCID: PMC5522616 DOI: 10.1016/j.ijpharm.2017.05.045] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 05/07/2017] [Accepted: 05/21/2017] [Indexed: 12/12/2022]
Abstract
Peptide-based vaccines have emerged in recent years as promising candidates in the prevention of infectious diseases. However, there are many challenges to maintaining in vivo peptide stability and enhancement of peptide immunogenicity to generate protective immunity which enhances clearance of infections. Here, a dendrimer-based carrier system is proposed for peptide-based vaccine delivery, and shows its anti-microbial feasibility in a mouse model of Chlamydia trachomatis. Chlamydiae are the most prevalent sexually transmitted bacteria worldwide, and also the causal agent of trachoma, the leading cause of preventable infectious blindness. In spite of the prevalence of this infectious agent and the many previous vaccine-related studies, there is no vaccine commercially available. The carrier system proposed consists of generation 4, hydroxyl-terminated, polyamidoamine (PAMAM) dendrimers (G4OH), to which a peptide mimic of a chlamydial glycolipid antigen-Peptide 4 (Pep4, AFPQFRSATLLL) was conjugated through an ester bond. The ester bond between G4OH and Pep4 is expected to break down mainly in the intracellular environment for antigen presentation. Pep4 conjugated to dendrimer induced Chlamydia-specific serum antibodies after subcutaneous immunizations. Further, this new vaccine formulation significantly protected immunized animals from vaginal challenge with infectious Chlamydia trachomatis, and it reduced infectious loads and tissue (genital tract) damage. Pep4 conjugated to G4OH or only mixed with peptide provided enhanced protection compared to Pep4 and adjuvant (i.e. alum), suggesting a potential adjuvant effect of the PAMAM dendrimer. Combined, these results demonstrate that hydroxyl-terminated PAMAM dendrimer is a promising polymeric nanocarrier platform for the delivery of peptide vaccines and this approach has potential to be expanded to other infectious intracellular bacteria and viruses of public health significance.
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Affiliation(s)
- Ingrid S Ganda
- Biomaterials Laboratory, Technology and Research Institute, Tiradentes University, Aracaju, SE, 49032-490, Brazil; Department of Chemical Engineering and Materials Science, Wayne State University, Detroit, MI 48202, USA; Departments of Immunology and Microbiology, Internal Medicine (Rheumatology), and Ophthalmology, School of Medicine, Wayne State University, Detroit, MI 48201, USA.
| | - Qian Zhong
- Department of Chemical Engineering and Materials Science, Wayne State University, Detroit, MI 48202, USA.
| | - Mirabela Hali
- Departments of Immunology and Microbiology, Internal Medicine (Rheumatology), and Ophthalmology, School of Medicine, Wayne State University, Detroit, MI 48201, USA.
| | - Ricardo L C Albuquerque
- Laboratory of Morphology and Structural Biology, Technology and Research Institute, Tiradentes University, Aracaju, SE, 49032-490, Brazil.
| | - Francine F Padilha
- Biomaterials Laboratory, Technology and Research Institute, Tiradentes University, Aracaju, SE, 49032-490, Brazil.
| | - Sandro R P da Rocha
- Biomaterials Laboratory, Technology and Research Institute, Tiradentes University, Aracaju, SE, 49032-490, Brazil; Department of Chemical Engineering and Materials Science, Wayne State University, Detroit, MI 48202, USA.
| | - Judith A Whittum-Hudson
- Departments of Immunology and Microbiology, Internal Medicine (Rheumatology), and Ophthalmology, School of Medicine, Wayne State University, Detroit, MI 48201, USA.
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9
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Diaz C, Guzmán J, Jiménez VA, Alderete JB. Partially PEGylated PAMAM dendrimers as solubility enhancers of Silybin. Pharm Dev Technol 2017; 23:689-696. [DOI: 10.1080/10837450.2017.1315134] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Carola Diaz
- Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad de Concepción, Concepción, Chile
| | - José Guzmán
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Verónica A. Jiménez
- Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andrés Bello, Sede Concepción, Talcahuano, Chile
| | - Joel B. Alderete
- Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad de Concepción, Concepción, Chile
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10
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Heyder RS, Zhong Q, Bazito RC, da Rocha SRP. Cellular internalization and transport of biodegradable polyester dendrimers on a model of the pulmonary epithelium and their formulation in pressurized metered-dose inhalers. Int J Pharm 2017; 520:181-194. [PMID: 28161666 DOI: 10.1016/j.ijpharm.2017.01.057] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 12/23/2016] [Accepted: 01/28/2017] [Indexed: 02/08/2023]
Abstract
The purpose of this study was to evaluate the effect of generation and surface PEGylation of degradable polyester-based dendrimers nanocarriers on their interactions with an in vitro model of the pulmonary epithelium as well as to assess the ability to formulate such carriers in propellant-based, portable oral-inhalation devices to determine their potential for local and systemic delivery of drugs to and through the lungs. Hydroxyl (-OH) terminated polyester dendrimers of generation 3 and 4 (G3, and G4) were synthesized using a divergent approach. G4 was surface-modified with PEG (1,000Da). All dendrimers and their building blocks were determined to be highly compatible with the model pulmonary epithelium, with toxicity profiles much more favorable than non-degradable polyamidoamine dendrimers (PAMAM). The transport of the species from the apical to basolateral side across polarized Calu-3 monolayers showed to be generation and surface-chemistry (PEGylation) dependent. The extent of the transport is modulated by their interaction with the polarized epithelium and their transient opening of the tight junctions. G3 was the one most efficiently internalized by the epithelium, and had a small impact on the integrity of the monolayer. On the other hand, the PEGylated G4 was the one least internalized by the polarized epithelium, and at the same time had a more pronounced transient impact on the cellular junctions, resulting in more efficient transport across the cell monolayer. PEGylation of the dendrimer surface played other roles as well. PEGylation modulated the degradation profile of the dendrimer, slowing the process in a step-wise fashion - first the PEG layer is shed and then the dendrimer starts degrading. PEGylation also helped increase the solvation of the nanocarriers by the hydrofluoroalkane propellant used in pressurized metered-dose inhalers, resulting in formulations with excellent dispersibility and aerosol quality (deep lung deposition of 88.5%), despite their very small geometric diameter. The combined in vitro and formulation performance results shown here demonstrated that degradable, modified polyester dendrimers may serve as a valuable platform that can be tailored to target the lung tissue for treating local diseases, or the circulation, using the lungs as pathway to the bloodstream.
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Affiliation(s)
- Rodrigo S Heyder
- Department of Chemical Engineering and Materials Science, Wayne State University, 48202, Detroit, MI, USA; Institute of Chemistry, Department of Fundamental Chemistry, University of São Paulo, São Paulo, SP, 05508-000, Brazil
| | - Qian Zhong
- Department of Chemical Engineering and Materials Science, Wayne State University, 48202, Detroit, MI, USA
| | - Reinaldo C Bazito
- Institute of Chemistry, Department of Fundamental Chemistry, University of São Paulo, São Paulo, SP, 05508-000, Brazil
| | - Sandro R P da Rocha
- Department of Chemical Engineering and Materials Science, Wayne State University, 48202, Detroit, MI, USA.
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11
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Barraza LF, Jiménez VA, Alderete JB. Association of Methotrexate with Native and PEGylated PAMAM-G4 Dendrimers: Effect of the PEGylation Degree on the Drug-Loading Capacity and Preferential Binding Sites. J Phys Chem B 2016; 121:4-12. [DOI: 10.1021/acs.jpcb.6b08882] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Luis F. Barraza
- Departamento de
Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andres Bello, Sede Concepción, Talcahuano, 4260000, Chile
| | - Verónica A. Jiménez
- Departamento de
Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andres Bello, Sede Concepción, Talcahuano, 4260000, Chile
| | - Joel B. Alderete
- Departamento de Química Orgánica, Facultad de Ciencias
Químicas, Universidad de Concepción, Casilla 160-C, Concepción, 4070371, Chile
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12
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Zhong Q, Merkel OM, Reineke JJ, da Rocha SRP. Effect of the Route of Administration and PEGylation of Poly(amidoamine) Dendrimers on Their Systemic and Lung Cellular Biodistribution. Mol Pharm 2016; 13:1866-78. [PMID: 27148629 DOI: 10.1021/acs.molpharmaceut.6b00036] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
There are many opportunities in the development of oral inhalation (oi) formulations for the delivery of small molecule therapeutics and biologics to and through the lungs. Nanocarriers have the potential to play a key role in advancing oi technologies and pushing the boundary of the pulmonary delivery market. In this work we investigate the effect of the route of administration and PEGylation on the systemic and lung cellular biodistribution of generation 3, amino-terminated poly(amidoamine) (PAMAM) dendrimers (G3NH2). Pharmacokinetic profiles show that the dendrimers reach their peak concentration in systemic circulation within a few hours after pulmonary delivery, independent of their chemistry (PEGylated or not), charge (+24 mV for G3NH2 vs -3.7 mV for G3NH2-24PEG1000), or size (5.1 nm for G3NH2 and 9.9 nm for G3NH2-24PEG1000). However, high density of surface modification with PEG enhances pulmonary absorption and the peak plasma concentration upon pulmonary delivery. The route of administration and PEGylation also significantly impact the whole body and local (lung cellular) distribution of the dendrimers. While ca. 83% of G3NH2 is found in the lungs upon pulmonary delivery at 6.5 h post administration, only 2% reached the lungs upon intravenous (iv) delivery. Moreover, no measurable concentration of either G3NH2 or G3NH2-24PEG1000 is found in the lymph nodes upon iv administration, while these are the tissues with the second highest mass distribution of dendrimers post pulmonary delivery. Dendrimer chemistry also significantly impacts the (cellular) distribution of the nanocarriers in the lung tissue. Upon pulmonary delivery, approximately 20% of the lung endothelial cells are seen to internalize G3NH2-24PEG1000, compared to only 6% for G3NH2. Conversely, G3NH2 is more readily taken up by lung epithelial cells (35%) when compared to its PEGylated counterpart (24%). The results shown here suggest that both the pulmonary route of administration and dendrimer chemistry combined can be used to passively target tissues and cell populations of great interest, and can thus be used as guiding principles in the development of dendrimer-based drug delivery strategies in the treatment of medically relevant diseases including lung ailments as well as systemic disorders.
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Affiliation(s)
- Qian Zhong
- Department of Chemical Engineering and Materials Science, College of Engineering, Wayne State University , Detroit, Michigan 48202, United States
| | - Olivia M Merkel
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy & Health Sciences, Wayne State University , Detroit, Michigan 48201, United States.,Department of Pharmacy, Pharmaceutical Technology and Biopharmaceutics, Ludwig-Maximilians-Universität München , 81377 München, Germany
| | - Joshua J Reineke
- Department of Pharmaceutical Sciences, College of Pharmacy, South Dakota State University , Brookings, South Dakota 57007, United States
| | - Sandro R P da Rocha
- Department of Chemical Engineering and Materials Science, College of Engineering, Wayne State University , Detroit, Michigan 48202, United States
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13
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Ramezanpour M, Leung SSW, Delgado-Magnero KH, Bashe BYM, Thewalt J, Tieleman DP. Computational and experimental approaches for investigating nanoparticle-based drug delivery systems. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:1688-709. [PMID: 26930298 DOI: 10.1016/j.bbamem.2016.02.028] [Citation(s) in RCA: 105] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2016] [Revised: 02/20/2016] [Accepted: 02/23/2016] [Indexed: 12/21/2022]
Abstract
Most therapeutic agents suffer from poor solubility, rapid clearance from the blood stream, a lack of targeting, and often poor translocation ability across cell membranes. Drug/gene delivery systems (DDSs) are capable of overcoming some of these barriers to enhance delivery of drugs to their right place of action, e.g. inside cancer cells. In this review, we focus on nanoparticles as DDSs. Complementary experimental and computational studies have enhanced our understanding of the mechanism of action of nanocarriers and their underlying interactions with drugs, biomembranes and other biological molecules. We review key biophysical aspects of DDSs and discuss how computer modeling can assist in rational design of DDSs with improved and optimized properties. We summarize commonly used experimental techniques for the study of DDSs. Then we review computational studies for several major categories of nanocarriers, including dendrimers and dendrons, polymer-, peptide-, nucleic acid-, lipid-, and carbon-based DDSs, and gold nanoparticles. This article is part of a Special Issue entitled: Membrane Proteins edited by J.C. Gumbart and Sergei Noskov.
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Affiliation(s)
- M Ramezanpour
- Centre for Molecular Simulation, Department of Biological Sciences, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - S S W Leung
- Department of Physics, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
| | - K H Delgado-Magnero
- Centre for Molecular Simulation, Department of Biological Sciences, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - B Y M Bashe
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
| | - J Thewalt
- Department of Physics, Simon Fraser University, Burnaby, BC V5A 1S6, Canada; Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
| | - D P Tieleman
- Centre for Molecular Simulation, Department of Biological Sciences, University of Calgary, Calgary, AB T2N 1N4, Canada
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14
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Zhong Q, da Rocha SRP. Poly(amidoamine) Dendrimer-Doxorubicin Conjugates: In Vitro Characteristics and Pseudosolution Formulation in Pressurized Metered-Dose Inhalers. Mol Pharm 2016; 13:1058-72. [PMID: 26832992 DOI: 10.1021/acs.molpharmaceut.5b00876] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Lung cancers are the leading cause of cancer death for both men and women. A series of PEGylated poly(amidoamine) dendrimer-based doxorubicin (DOX) nanocarriers (G3NH2-mPEG-nDOX) were synthesized and their chemistry tailored for the development of novel pseudosolution formulations in propellant-based metered-dose inhalers (pMDIs) with enhanced aerosol characteristics. A pH-labile bond was used to conjugate DOX to dendrimer for controlled intracellular release. We employed a two-step PEGylation strategy to cover a range of DOX loading and PEGylation density. We investigated the impact of pH, PEGylation density, and DOX payload on the release of DOX from the conjugate. We also determined the cellular internalization of the conjugate, the intracellular release kinetics of DOX from the conjugate, and their ability to kill human alveolar carcinoma cells (A549). The acid-labile conjugates sustained the release of DOX in acidic medium, and also intracellularly, as determined by nuclear colocalization studies with confocal microscopy. Meanwhile, DOX was retained in the conjugate at extracellular physiological conditions, indicating their potential to achieve spatial and temporal controlled release profiles. We also observed that the kinetics of cellular entry of the conjugates with DOX increased significantly compared to free DOX. Due to controlled release, the G3NH2-mPEG-nDOX conjugates showed time-dependent cell kill, but their cell kill ability was comparable to free DOX, which suggests their potential in vivo as compared to free DOX. The conjugates were formulated in pMDIs as pseudosolution formulations, with the help of a minimum amount of cosolvent (ethanol; <0.4%; v/v). The physical stability and aerosol characteristics of the conjugates were controlled by the PEGylation density of the carriers: the higher the PEG density, the better the dispersibility and the better the deep lung deposition of the conjugates (fine particle fraction up to ca. 80%).
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Affiliation(s)
- Qian Zhong
- Department of Chemical Engineering and Materials Science, College of Engineering, Wayne State University , 5050 Anthony Wayne Drive, Detroit, Michigan 48202, United States
| | - Sandro R P da Rocha
- Department of Chemical Engineering and Materials Science, College of Engineering, Wayne State University , 5050 Anthony Wayne Drive, Detroit, Michigan 48202, United States.,Pharmaceutics and Chemical and Life Science Engineering, Virginia Commonwealth University , 410 N 12th Street, Richmond, Virginia 23298-0533, United States
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15
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Kanchi S, Suresh G, Priyakumar UD, Ayappa KG, Maiti PK. Molecular Dynamics Study of the Structure, Flexibility, and Hydrophilicity of PETIM Dendrimers: A Comparison with PAMAM Dendrimers. J Phys Chem B 2015; 119:12990-3001. [DOI: 10.1021/acs.jpcb.5b07124] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Subbarao Kanchi
- Center
for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bangalore, 560012, India
- Department
of Chemical Engineering, Center for Biosystems Science and Engineering, Indian Institute of Science, Bangalore, 560012, India
| | - Gorle Suresh
- Center
for Computational Natural Sciences and Bioinformatics, International Institute of Information Technology, Hyderabad, 500032, India
| | - U. Deva Priyakumar
- Center
for Computational Natural Sciences and Bioinformatics, International Institute of Information Technology, Hyderabad, 500032, India
| | - K. G. Ayappa
- Department
of Chemical Engineering, Center for Biosystems Science and Engineering, Indian Institute of Science, Bangalore, 560012, India
| | - Prabal K Maiti
- Center
for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bangalore, 560012, India
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16
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Bielski ER, Zhong Q, Brown M, da Rocha SRP. Effect of the Conjugation Density of Triphenylphosphonium Cation on the Mitochondrial Targeting of Poly(amidoamine) Dendrimers. Mol Pharm 2015; 12:3043-53. [PMID: 26158804 DOI: 10.1021/acs.molpharmaceut.5b00320] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Many clinically relevant diseases with known poor therapeutic outcomes, including cancer and neurodegenerative disorders, have been directly linked to mitochondrial dysfunction. The ability to efficiently target therapeutics to intracellular organelles such as mitochondria may represent new opportunities for the effective treatment of such ailments. The present study reports the synthesis, cellular uptake, cytotoxicity, and mitochondrial colocalization of conjugates of triphenylphosphonium cation (TPP) to amine-terminated, generation 4, poly(amidoamine) (PAMAM) dendrimer (G4NH2) nanocarriers. The mitochondrial-targeting moiety TPP was either directly conjugated to G4NH2 (G4NH2-TPP) or to the dendrimer through a flexible polyethylene glycol (PEG) linker (G4NH2-PEGTPP). Conjugation was done at various TPP densities to assess their biological activity and potential for mitochondrial-targeted drug delivery. Tests in an in vitro model of the human alveolar carcinoma (A549 cells) showed that even at a low TPP density (∼5 TPP) both the cellular internalization and mitochondrial targeting increase significantly, as determined by fluorescence activated cell sorting (FACS) and confocal microscopy (CM), respectively. At a density of ∼10 TPP per G4NH2, further increase in cellular internalization and mitochondrial targeting was achieved. However, at this higher density, the nanocarriers also showed pronounced cytotoxicity. It was observed that the toxicity of the conjugates is decreased upon the addition of a PEG linker between the dendrimer and TPP (G4NH2-PEGTPP), while the mitochondrial targeting ability of the nanocarriers is not affected as the PEG density increases. The proposed strategies indicate that TPP-conjugated G4NH2 dendrimers represent a potentially viable strategy for the targeting of therapeutic molecules to mitochondria, which may help improve therapeutic outcomes of diseases related to mitochondrial dysfunction.
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Affiliation(s)
- Elizabeth R Bielski
- Department of Chemical Engineering and Materials Science, Wayne State University, Detroit, Michigan 48202, United States
| | - Qian Zhong
- Department of Chemical Engineering and Materials Science, Wayne State University, Detroit, Michigan 48202, United States
| | - Matthew Brown
- Department of Chemical Engineering and Materials Science, Wayne State University, Detroit, Michigan 48202, United States
| | - Sandro R P da Rocha
- Department of Chemical Engineering and Materials Science, Wayne State University, Detroit, Michigan 48202, United States
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17
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Barraza LF, Jiménez VA, Alderete JB. Effect of PEGylation on the Structure and Drug Loading Capacity of PAMAM-G4 Dendrimers: A Molecular Modeling Approach on the Complexation of 5-Fluorouracil with Native and PEGylated PAMAM-G4. MACROMOL CHEM PHYS 2015. [DOI: 10.1002/macp.201500179] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Luis F. Barraza
- Departamento de Química Orgánica; Facultad de Ciencias Químicas; Universidad de Concepción; Casilla 160-C Concepción 4070371 Chile
| | - Verónica A. Jiménez
- Departamento de Ciencias Químicas; Facultad de Ciencias Exactas; Universidad Andres Bello; Sede Concepción; Talcahuano 4260000 Chile
| | - Joel B. Alderete
- Departamento de Química Orgánica; Facultad de Ciencias Químicas; Universidad de Concepción; Casilla 160-C Concepción 4070371 Chile
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18
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High-Resolution Imaging of Polyethylene Glycol Coated Dendrimers via Combined Atomic Force and Scanning Tunneling Microscopy. JOURNAL OF DRUG DELIVERY 2015; 2015:535683. [PMID: 25685559 PMCID: PMC4313004 DOI: 10.1155/2015/535683] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Accepted: 12/11/2014] [Indexed: 12/18/2022]
Abstract
Dendrimers have shown great promise as drug delivery vehicles in recent years because they can be synthesized with designed size and functionalities for optimal transportation, targeting, and biocompatibility. One of the most well-known termini used for biocompatibility is polyethylene glycol (PEG), whose performance is affected by its actual conformation. However, the conformation of individual PEG bound to soft materials such as dendrimers has not been directly observed. Using atomic force microscopy (AFM) and scanning tunneling microscopy (STM), this work characterizes the structure adopted by PEGylated dendrimers with the highest resolution reported to date. AFM imaging enables visualization of the individual dendrimers, as well as the differentiation and characterization of the dendrimer core and PEG shell. STM provides direct imaging of the PEG extensions with high-resolution. Collectively, this investigation provides important insight into the structure of coated dendrimers, which is crucial for the design and development of better drug delivery vehicles.
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19
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DeFever RS, Sarupria S. Association of small aromatic molecules with PAMAM dendrimers. Phys Chem Chem Phys 2015; 17:29548-57. [DOI: 10.1039/c5cp03717d] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Dendrimer pockets enable association by reducing naphthalene hydration even near the dendrimer periphery.
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Affiliation(s)
- Ryan S. DeFever
- Department of Chemical & Biomolecular Engineering
- Clemson University
- Clemson
- USA
| | - Sapna Sarupria
- Department of Chemical & Biomolecular Engineering
- Clemson University
- Clemson
- USA
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20
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Geitner NK, Wang B, Andorfer RE, Ladner DA, Ke PC, Ding F. Structure-function relationship of PAMAM dendrimers as robust oil dispersants. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:12868-12875. [PMID: 25279688 DOI: 10.1021/es5038194] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
PAMAM dendrimers have recently been investigated as efficient and biocompatible oil dispersants utilizing their encapsulation capacity; however, their high cationic charge density has been shown to be cytotoxic. It is therefore imperative to mitigate cationic charge-induced toxicity and understand the effects of such changes. Presented here is a synergistic experimental and computational approach to examine the effects of varying terminal surface charge on the capacity of dendrimers to disperse model liner, polycyclic aromatic, and hybrid hydrocarbons. Uncharged dendrimers collapse by forming intramolecular hydrogen bonds, which reduce the hosting capability. On the other hand, changing the surface charges from positive to negative greatly shifts the pKa of tertiary amines of the PAMAM dendrimer interior. As a result, the negatively charged dendrimers have a significant percentage of tertiary amines protonated, ∼30%. This unexpected change in the interior protonation state causes electrostatic interactions with the anionic terminal groups, leading to contraction and a marked decrease in hydrocarbon hosting capacity. The present work highlights the robust nature of dendrimer oil dispersion and also illuminates potentially unintended or unanticipated effects of varying dendrimer surface chemistry on their encapsulation or hosting efficacy, which is important for their environmental, industrial, and biomedical applications.
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Affiliation(s)
- Nicholas K Geitner
- Department of Physics and Astronomy and ‡Department of Environmental Engineering and Earth Sciences, Clemson University , Clemson, South Carolina 29634, United States
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21
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Kim Y, Kwak Y, Chang R. Free Energy of PAMAM Dendrimer Adsorption onto Model Biological Membranes. J Phys Chem B 2014; 118:6792-802. [DOI: 10.1021/jp501755k] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Yongbin Kim
- Department of Chemistry, Kwangwoon University, Seoul 139-701, Republic of Korea
| | - Yongkyu Kwak
- Department of Chemistry, Kwangwoon University, Seoul 139-701, Republic of Korea
| | - Rakwoo Chang
- Department of Chemistry, Kwangwoon University, Seoul 139-701, Republic of Korea
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