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Patel S, McNelles SA, Adronov A, Duhamel J. Intramacromolecular Conformational Changes in Low Generation PAMAM Dendrimers Probed by Pyrene Excimer Formation. J Phys Chem B 2023; 127:8040-8048. [PMID: 37673692 DOI: 10.1021/acs.jpcb.3c04053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/08/2023]
Abstract
Pyrene excimer formation (PEF) was used to probe the intramacromolecular conformational change experienced by low generation pyrene-labeled PAMAM dendrimers referred to as PyCX-PAMAM-GY, where X (=4, 8, or 12) and Y (=0, 1, or 2) represent the number of atoms in the pyrenyl linker and the dendrimer generation, respectively. Each sample was studied in N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) with and without 5 mM HCl. Global analysis of the monomer and excimer time-resolved fluorescence decays using the model free analysis (MFA) yielded the average rate constant of excimer formation, ⟨k⟩, which was compared with the local pyrene concentration ([Py]loc) of the PyCX-PAMAM-GY samples calculated by assuming that the oligomeric segments constituting the dendrimer's interior obeyed Gaussian statistics. A notable decrease in ⟨k⟩ was observed upon the addition of 5 mM HCl to the PyCX-PAMAM-GY solutions and was attributed to swelling of the dendrimers resulting from the protonation of the internal tertiary amines. The reversibility of this conformational change could also be monitored via PEF. Solvent differences between DMF and DMSO were accounted for by dividing ⟨k⟩ by kdiff, the bimolecular rate constant for diffusive PEF of a n-hexyl-1-pyrenebutyramide model compound, to yield the ⟨k⟩/kdiff ratio. Comparison between the ⟨k⟩/kdiff ratios obtained for all the PyCX-PAMAM-GY samples with and without 5 mM HCl revealed a 13% increase in the radius of the PAMAM-GY dendrimers upon protonation of their internal tertiary amines in agreement with earlier reports. These experiments illustrate that PEF represents a powerful experimental means to quantitatively probe the intramacromolecular conformational changes of complex macromolecules in solution, in a manner that complements scattering techniques.
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Affiliation(s)
- Sanjay Patel
- Institute for Polymer Research, Waterloo Institute for Nanotechnology, Department of Chemistry, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada
| | - Stuart A McNelles
- Department of Chemistry and Chemical Biology, Brockhouse Institute for Materials Research, McMaster University, 1280 Main Street W., Hamilton, ON L8S 4M1, Canada
| | - Alex Adronov
- Department of Chemistry and Chemical Biology, Brockhouse Institute for Materials Research, McMaster University, 1280 Main Street W., Hamilton, ON L8S 4M1, Canada
| | - Jean Duhamel
- Institute for Polymer Research, Waterloo Institute for Nanotechnology, Department of Chemistry, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada
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2
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Poly(amidoamine) Dendrimer/Camptothecin Complex: From Synthesis to In Vitro Cancer Cell Line Studies. Molecules 2023; 28:molecules28062696. [PMID: 36985668 PMCID: PMC10052527 DOI: 10.3390/molecules28062696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 03/10/2023] [Accepted: 03/12/2023] [Indexed: 03/19/2023] Open
Abstract
Camptothecin (CPT), an alkaloid with potent anticancer activity, is still not used in clinical practice due to its high hydrophobicity, toxicity, and poor active-form stability. To address these shortcomings, our research focuses on the encapsulation of this drug in the poly(amidoamine) (PAMAM) dendrimer macromolecule. The PAMAM dendrimer/CPT complex was synthesized and thoroughly characterized. The in vitro drug release study revealed that the drug was released in a slow and controlled manner in acidic and physiological conditions and that more than 80% of the drug was released after 168 h of incubation. Furthermore, it was demonstrated that CPT was released with first-order kinetics and non-Fickian transport. The studies on the hemolytic activity of the synthesized complex indicated that it is hemocompatible for potential intravenous administration at a concentration ≤ 5 µg/mL. Additionally, the developed product was shown to reduce the viability of non-small-cell lung cancer cells (A549) in a concentration- and time-dependent manner, and cancer cells were more susceptible to the complex than normal fibroblasts. Lastly, molecular modeling studies revealed that the lactone or carboxylic forms of CPT had a significant impact on the shape and stability of the complex and that its formation with the lactone form of CPT was more energetically favorable for each subsequent molecule than the carboxylic form. The report represents a systematic and structured approach to develop a PAMAM dendrimer/CPT complex that can be used as an effective drug delivery system (DDS) for the potential treatment of non-small-cell lung cancer.
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3
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Synthesis, dynamics and applications (cytotoxicity and biocompatibility) of dendrimers: a mini-review. Eur Polym J 2022. [DOI: 10.1016/j.eurpolymj.2022.111708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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4
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Evans CW, Ho D, Marlow JB, King JJ, Hee C, Wong LN, Atkin R, Smith NM, Warr GG, Norret M, Iyer KS. Intracellular Communication between Synthetic Macromolecules. J Am Chem Soc 2022; 144:14112-14120. [PMID: 35901278 DOI: 10.1021/jacs.2c02793] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Non-viral delivery is an important strategy for selective and efficient gene therapy, immunization, and RNA interference, which overcomes problems of genotoxicity and inherent immunogenicity associated with viral vectors. Liposomes and polymers are compelling candidates as carriers for intracellular, non-viral delivery, but maximal efficiencies of around 1% have been reported for the most advanced non-viral carriers. Here, we develop a library of dendronized bottlebrush polymers with controlled defects, displaying a level of precision surpassed only by biological molecules like DNA, RNA, and proteins. We test concurrent and competitive delivery of DNA and show for the first time that, while intracellular communication is thought to be an exclusively biomolecular phenomenon, such communication between synthetic macromolecular complexes can also take place. Our findings challenge the assumption that delivery agents behave as bystanders that enable transfection by passive intracellular release of genetic cargo and improve upon coarse strategies in intracellular carrier design lacking control over polymer sequence, architecture, and composition, leading to a hit-or-miss outcome. Understanding the communication that takes place between macromolecules will help improve the design of non-viral delivery agents and facilitate translation of genome engineering, vaccines, and nucleic acid-based therapies.
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Affiliation(s)
- Cameron W Evans
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Diwei Ho
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Joshua B Marlow
- School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
| | - Jessica J King
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Charmaine Hee
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Lucas N Wong
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Rob Atkin
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Nicole M Smith
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Gregory G Warr
- School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
| | - Marck Norret
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - K Swaminathan Iyer
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
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5
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Sztandera K, Gorzkiewicz M, Dias Martins AS, Pallante L, Zizzi EA, Miceli M, Ba̧tal M, Reis CP, Deriu MA, Klajnert-Maculewicz B. Noncovalent Interactions with PAMAM and PPI Dendrimers Promote the Cellular Uptake and Photodynamic Activity of Rose Bengal: The Role of the Dendrimer Structure. J Med Chem 2021; 64:15758-15771. [PMID: 34546755 PMCID: PMC8591609 DOI: 10.1021/acs.jmedchem.1c01080] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Indexed: 12/26/2022]
Abstract
Rose bengal is an anionic dye considered as a potential photosensitizer for anticancer photodynamic therapy. The clinical utility of rose bengal is hampered by its short half-life, limited transmembrane transport, aggregation, and self-quenching; consequently, efficient drug carriers that overcome these obstacles are urgently required. In this study, we performed multilevel in vitro and in silico characterization of interactions between rose bengal and cationic poly(amidoamine) (PAMAM) and poly(propyleneimine) (PPI) dendrimers of the third and fourth generation and assessed the ability of the resultant complexes to modulate the photosensitizing properties of the drug. We focused on explaining the molecular basis of this phenomenon and proved that the generation- and structure-dependent binding of the dye by the dendrimers increases the cellular uptake and production of singlet oxygen and intracellular reactive oxygen species, leading to an increase in phototoxicity. We conclude that the application of dendrimer carriers could enable the design of efficient photodynamic therapies based on rose bengal.
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Affiliation(s)
- Krzysztof Sztandera
- Department
of General Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, 141/143 Pomorska St., 90-236 Lodz, Poland
| | - Michał Gorzkiewicz
- Department
of General Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, 141/143 Pomorska St., 90-236 Lodz, Poland
| | - Ana Sofia Dias Martins
- iMed.ULisboa−Research
Institute for Medicines, Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal
| | - Lorenzo Pallante
- PolitoMedLab, Department of Mechanical and Aerospace
Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Turin, Italy
| | - Eric Adriano Zizzi
- PolitoMedLab, Department of Mechanical and Aerospace
Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Turin, Italy
| | - Marcello Miceli
- PolitoMedLab, Department of Mechanical and Aerospace
Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Turin, Italy
| | - Mateusz Ba̧tal
- Department
of General Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, 141/143 Pomorska St., 90-236 Lodz, Poland
| | - Catarina Pinto Reis
- iMed.ULisboa−Research
Institute for Medicines, Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal
- Instituto
de Biofísica e Engenharia Biomédica, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal
| | - Marco A. Deriu
- PolitoMedLab, Department of Mechanical and Aerospace
Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Turin, Italy
| | - Barbara Klajnert-Maculewicz
- Department
of General Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, 141/143 Pomorska St., 90-236 Lodz, Poland
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Study on the mechanism of PAMAM(DETA as the core) against silica scale. J Mol Model 2021; 27:304. [PMID: 34586514 DOI: 10.1007/s00894-021-04932-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 09/21/2021] [Indexed: 10/20/2022]
Abstract
Molecular simulation was performed to study the interaction between PAMAM(DETA as the core) with different generations and silicic acid molecules, and discussed the inhibition effect mechanism against silica scale through gyration radius and radial distribution function et al. The results showed that adsorption interactions between silicic acid molecules and the PAMAM with -NH2 terminated groups molecule (G1.0 and G2.0) were stronger than those and the PAMAM with -COOH terminated groups molecule (G0.5 and G1.5). The adsorption interactions were primarily divided into electrostatic interactions, vdW interactions as well as H-bond interactions, where electrostatic interaction was dominant. Molecular simulation results were consistent with our experimental results.
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7
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Ramos MC, Horta VAC, Horta BAC. Molecular Dynamics Simulations of PAMAM and PPI Dendrimers Using the GROMOS-Compatible 2016H66 Force Field. J Chem Inf Model 2019; 59:1444-1457. [DOI: 10.1021/acs.jcim.8b00911] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Mayk C. Ramos
- Instituto de Química, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-909, Brazil
| | - Vitor A. C. Horta
- Departamento de Ciência da Computação, Universidade Federal de Juiz de Fora, Juiz de Fora, 36036-900, Brazil
| | - Bruno A. C. Horta
- Instituto de Química, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-909, Brazil
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8
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Abstract
Using fully atomistic molecular dynamics simulation that are several hundred nanoseconds long, we demonstrate the pH-controlled sponge action of PAMAM dendrimer. We show how at varying pH levels, the PAMAM dendrimer acts as a wet sponge; at neutral or low pH levels, the dendrimer expands noticeably and the interior of the dendrimer opens up to host several hundreds to thousands of water molecules depending on the generation number. Increasing the pH (i.e., going from low pH to high pH) leads to the collapse of the dendrimer size, thereby expelling the inner water, which mimics the ‘sponge’ action. As the dendrimer size swells up at a neutral pH or low pH due to the electrostatic repulsion between the primary and tertiary amines that are protonated at this pH, there is dramatic increase in the available solvent accessible surface area (SASA), as well as solvent accessible volume (SAV).
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Affiliation(s)
- Prabal K. Maiti
- Center for Condensed Matter Theory, Department of Physics, Bangalore, India, 560012
- Center for Condensed Matter Theory, Department of Physics, Bangalore, India, 560012
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9
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Asandei A, Ciuca A, Apetrei A, Schiopu I, Mereuta L, Seo CH, Park Y, Luchian T. Nanoscale Investigation of Generation 1 PAMAM Dendrimers Interaction with a Protein Nanopore. Sci Rep 2017; 7:6167. [PMID: 28733599 PMCID: PMC5522495 DOI: 10.1038/s41598-017-06435-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 06/13/2017] [Indexed: 12/20/2022] Open
Abstract
Herein, we describe at uni-molecular level the interactions between poly(amidoamine) (PAMAM) dendrimers of generation 1 and the α-hemolysin protein nanopore, at acidic and neutral pH, and ionic strengths of 0.5 M and 1 M KCl, via single-molecule electrical recordings. The results indicate that kinetics of dendrimer-α-hemolysin reversible interactions is faster at neutral as compared to acidic pH, and we propose as a putative explanation the fine interplay among conformational and rigidity changes on the dendrimer structure, and the ionization state of the dendrimer and the α-hemolysin. From the analysis of the dendrimer's residence time inside the nanopore, we posit that the pH- and salt-dependent, long-range electrostatic interactions experienced by the dendrimer inside the ion-selective α-hemolysin, induce a non-Stokesian diffusive behavior of the analyte inside the nanopore. We also show that the ability of dendrimer molecules to adapt their structure to nanoscopic spaces, and control the flow of matter through the α-hemolysin nanopore, depends non-trivially on the pH- and salt-induced conformational changes of the dendrimer.
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Affiliation(s)
- Alina Asandei
- Interdisciplinary Research Department, Alexandru I. Cuza University, Iasi, Romania
| | - Andrei Ciuca
- Department of Physics, Alexandru I. Cuza University, Iasi, Romania
| | - Aurelia Apetrei
- Department of Physics, Alexandru I. Cuza University, Iasi, Romania
| | - Irina Schiopu
- Interdisciplinary Research Department, Alexandru I. Cuza University, Iasi, Romania
| | - Loredana Mereuta
- Department of Physics, Alexandru I. Cuza University, Iasi, Romania
| | - Chang Ho Seo
- Department of Bioinformatics, Kongju National University, Kongju, South Korea
| | - Yoonkyung Park
- Department of Department of Biomedical Science and Research Center for Proteinaceous Materials (RCPM), Chosun University, Gwangju, Korea.
| | - Tudor Luchian
- Department of Physics, Alexandru I. Cuza University, Iasi, Romania.
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10
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Rai GJ, Biswas P. Topology driven structural transition of dendrimers with a dimensional cross-over. POLYMER 2017. [DOI: 10.1016/j.polymer.2017.03.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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11
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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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12
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Kłos JS, Sommer JU. Coarse grained simulations of neutral and charged dendrimers. POLYMER SCIENCE SERIES C 2013. [DOI: 10.1134/s1811238213070023] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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13
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van Dongen MA, Desai A, Orr BG, Baker JR, Holl MMB. Quantitative analysis of generation and branch defects in G5 poly(amidoamine) dendrimer. POLYMER 2013; 54:4126-4133. [PMID: 24058210 DOI: 10.1016/j.polymer.2013.05.062] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Although methods have been developed to synthesize and isolate generation 5 (G5) PAMAM dendrimers containing precise numbers of ligands per polymer particle, the presence of skeletal and generational defects in this material can substantially hamper the process. Here we provide a quantitative analysis of G5 PAMAM dendrimer defects via high performance liquid chromatography, potentiometric titration, mass spectrometry, size exclusion chromatography, and nuclear magnetic resonance. We identified, isolated, and characterized the major structural defects of G5 dendrimer, trailing generations, and dimer, trimer, and tetramer species. We determine that the G5 material present in the as-received mixture contains 93 arms on average. We have developed two model systems capable of generating the experimentally observed mass range and polydispersity at defect rates of 8-15%.
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Affiliation(s)
- Mallory A van Dongen
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA ; Michigan Nanotechnology Institute for Medicine and Biological Sciences, University of Michigan, Ann Arbor, MI 48109, USA
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14
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Tian WD, Ma YQ. Theoretical and computational studies of dendrimers as delivery vectors. Chem Soc Rev 2013; 42:705-27. [PMID: 23114420 DOI: 10.1039/c2cs35306g] [Citation(s) in RCA: 179] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
It is a great challenge for nanomedicine to develop novel dendrimers with maximum therapeutic potential and minimum side-effects for drug and gene delivery. As delivery vectors, dendrimers must overcome lots of barriers before delivering the bio-agents to the target in the cell. Extensive experimental investigations have been carried out to elucidate the physical and chemical properties of dendrimers and explore their behaviors when interacting with biomolecules, such as gene materials, proteins, and lipid membranes. As a supplement of the experimental techniques, it has been proved that computer simulations could facilitate the progress in understanding the delivery process of bioactive molecules. The structures of dendrimers in dilute solutions have been intensively investigated by monomer-resolved simulations, coarse-grained simulations, and atom-resolved simulations. Atomistic simulations have manifested that the hydrophobic interactions, hydrogen-bond interactions, and electrostatic attraction play critical roles in the formation of dendrimer-drug complexes. Multiscale simulations and statistical field theories have uncovered some physical mechanisms involved in the dendrimer-based gene delivery systems. This review will focus on the current status and perspective of theoretical and computational contributions in this field in recent years. (275 references).
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Affiliation(s)
- Wen-de Tian
- Center for Soft Condensed Matter Physics and Interdisciplinary Research, Soochow University, Suzhou 215006, China
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15
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Freeman EC, Weiland LM, Meng WS. Modeling the proton sponge hypothesis: examining proton sponge effectiveness for enhancing intracellular gene delivery through multiscale modeling. JOURNAL OF BIOMATERIALS SCIENCE. POLYMER EDITION 2012; 24:398-416. [PMID: 23565683 PMCID: PMC3623018 DOI: 10.1080/09205063.2012.690282] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Dendrimers have been proposed as therapeutic gene delivery platforms. Their superior transfection efficiency is attributed to their ability to buffer the acidification of the endosome and attach to the nucleic acids. For effective transfection, the strategy is to synthesize novel dendrimers that optimize both of these traits, but the prediction of the buffering behavior in the endosome remains elusive. It is suggested that buffering dendrimers induce an osmotic pressure sufficient to rupture the endosome and release nucleic acids, which forms to sequestrate most internalized exogenous materials. Presented here are the results of a computational study modeling osmotically driven endosome burst or the 'proton sponge effect.' The approach builds on previous cellular simulation efforts by linking the previous model with a sponge protonation model, then observing the impact on endosomal swelling and acidification. Calibrated and validated using reported experimental data, the simulations offer insights into defining the properties of suitable dendrimers for enhancing gene delivery as a function of polymer structure.
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Affiliation(s)
- Eric C Freeman
- Department of Mechanical Engineering and Material Science, University of Pittsburgh, Pittsburgh, PA, USA.
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16
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Maingi V, Jain V, Bharatam PV, Maiti PK. Dendrimer building toolkit: Model building and characterization of various dendrimer architectures. J Comput Chem 2012; 33:1997-2011. [DOI: 10.1002/jcc.23031] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2012] [Accepted: 05/07/2012] [Indexed: 11/08/2022]
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17
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Wu B, Kerkeni B, Egami T, Do C, Liu Y, Wang Y, Porcar L, Hong K, Smith SC, Liu EL, Smith GS, Chen WR. Structured water in polyelectrolyte dendrimers: Understanding small angle neutron scattering results through atomistic simulation. J Chem Phys 2012; 136:144901. [DOI: 10.1063/1.3697479] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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18
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Wu B, Li X, Do C, Kim TH, Shew CY, Liu Y, Yang J, Hong K, Porcar L, Chen CY, Liu EL, Smith GS, Herwig KW, Chen WR. Spatial distribution of intra-molecular water and polymeric components in polyelectrolyte dendrimers revealed by small angle scattering investigations. J Chem Phys 2011; 135:144903. [DOI: 10.1063/1.3651364] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
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19
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Sebby KB, Walter ED, Usselman RJ, Cloninger MJ, Singel DJ. End-group distributions of multiple generations of spin-labeled PAMAM dendrimers. J Phys Chem B 2011; 115:4613-20. [PMID: 21469686 PMCID: PMC3424105 DOI: 10.1021/jp112390d] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Dendrimers are attractive templates to display functional molecular components. Since the behavior of dendrimer systems can depend greatly on the accessibility of these molecular components to the external environment, and on the spatial arrangement of functional groups attached to the dendrimer terminal branches (end-groups), techniques to determine the locations of end-groups are highly desirable. In this report, we describe a method to analyze the EPR spectra of multiple generations of poly(amidoamine) (PAMAM) dendrimers which have spin-labels attached to end-groups in variable percentages of the total number of available sites. The spectra are treated as a convolution of a narrow spin-label spectrum and a variable line broadening function. Trends in the parameters that describe the best-fit line broadening function with spin-label loading reveal the spatial arrangements and homogeneity of spin environments of the labels. We observe a shift in the end-group distribution from generation 3 (G(3)) to G(4) dendrimers that indicates a change in morphology from an open, extended structure to a more dense, compact arrangement.
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Affiliation(s)
- Karl B Sebby
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717, United States.
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20
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Ke PC, Lamm MH. A biophysical perspective of understanding nanoparticles at large. Phys Chem Chem Phys 2011; 13:7273-83. [PMID: 21394374 DOI: 10.1039/c0cp02891f] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
In this article we present a biophysical perspective that describes the fate of nanoparticles in both the aqueous phase and in living systems. Specifically, we show the correlations between the physicochemistry of fullerenes and their uptake, translocation, transformation, transport, and biodistribution in mammalian and plant systems, at the molecular, cellular, and whole organism level. In addition to fullerenes and their structural derivatives, we describe the biological and environmental implications and applications of the condensed matter of carbon nanotubes and quantum dots, and the soft condensed matter of plastic and dendrimers. The main purpose of this article is to demonstrate the vast opportunities and unique advantages of applying experimental and simulation biophysics to the nascent research field of understanding nanoparticles at large.
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Affiliation(s)
- Pu Chun Ke
- Department of Physics and Astronomy, COMSET, Clemson University, Clemson, SC 29634, USA.
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21
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Roncaglia DI, Carballido-Landeira J, Muñuzuri AP. Pattern formation in the Belousov–Zhabotinsky-PAMAM dendrimer system. Phys Chem Chem Phys 2011; 13:7426-32. [DOI: 10.1039/c0cp02656e] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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22
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Pijnenburg NJM, Lutz M, Siegler MA, Spek A, van Koten G, Gebbink RJMK. The role of the dendritic support in the catalytic performance of peripheral pincer Pd-complexes. NEW J CHEM 2011. [DOI: 10.1039/c1nj20366e] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Wu C. pH response of conformation of poly(propylene imine) dendrimer in water: a molecular simulation study. MOLECULAR SIMULATION 2010. [DOI: 10.1080/08927022.2010.509860] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Kłos JS, Sommer JU. Simulations of Dendrimers with Flexible Spacer Chains and Explicit Counterions under Low and Neutral pH Conditions. Macromolecules 2010. [DOI: 10.1021/ma102055w] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- J. S. Kłos
- Leibniz Institute of Polymer Research Dresden e. V., 01069 Dresden, Germany
- Faculty of Physics, A. Mickiewicz University, Umultowska 85, 61-614 Poznań, Poland
| | - J.-U. Sommer
- Leibniz Institute of Polymer Research Dresden e. V., 01069 Dresden, Germany
- Institute for Theoretical Physics, Technische Universität Dresden, 01069 Dresden, Germany
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Liu Y, Porcar L, Hong K, Shew CY, Li X, Liu E, Butler PD, Herwig KW, Smith GS, Chen WR. Effect of counterion valence on the pH responsiveness of polyamidoamine dendrimer structure. J Chem Phys 2010; 132:124901. [PMID: 20370144 DOI: 10.1063/1.3358349] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
An accurate determination of the structure characteristics of protonated generation 5 polyamidoamine dendrimers in aqueous solution has been conducted by analyzing the small angle neutron scattering databased on a statistical mechanics model. In our investigation, the primary focus is to elucidate the effect of counterion valence on the counterion association and its impact on the intramolecular density profile within a dendrimer. In the range of our study for molecular protonation, a strong dependence of the structural properties of charged dendrimers on counterion valence is revealed. Our findings indicate that the association of a large amount of divalent counterions significantly reduces the effective charge of a dendrimer molecule. Surprisingly, no discernible transition of the density distribution profile is observed for the dendrimer charged by D(2)SO(4), as opposed to our previous observation of a pronounced transition in intramolecular density profile for the dendrimer charged by DCl. These findings may be understood from the thermodynamic processes of counterions.
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Affiliation(s)
- Yun Liu
- The NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6100, USA
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Liu Y, Bryantsev VS, Diallo MS, Goddard WA. PAMAM dendrimers undergo pH responsive conformational changes without swelling. J Am Chem Soc 2010; 131:2798-9. [PMID: 19199433 DOI: 10.1021/ja8100227] [Citation(s) in RCA: 203] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Atomistic molecular dynamics (MD) simulations of a G4-NH(2) PAMAM dendrimer were carried out in aqueous solution using explicit water molecules and counterions (with the Dreiding III force field optimized using quantum mechanics). Our simulations predict that the radius of gyration (R(g)) of the dendrimer changes little with pH from 21.1 A at pH approximately 10 (uncharged PAMAM) to 22.1 A at pH approximately 5 (charged with 126 protons), which agrees quantitatively with recent small angle neutron scattering (SANS) experiments (from 21.4 A at pH 10 to 21.5 A at pH 5). Even so we predict a dramatic change in the conformation. The ion pairing in the low pH form leads to a locally compact dense shell with an internal surface area only 37% of the high pH form with a dense core. This transformation from "dense core" at high pH to "dense shell" at low pH could facilitate the encapsulation and release of guest molecules (e.g., drugs) using pH as the trigger, making dendrimers a unique drug delivery vehicle.
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Affiliation(s)
- Yi Liu
- Materials and Process Simulation Center (M/C 139-74), California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125, USA
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Pavan GM, Albertazzi L, Danani A. Ability to adapt: different generations of PAMAM dendrimers show different behaviors in binding siRNA. J Phys Chem B 2010; 114:2667-75. [PMID: 20146540 DOI: 10.1021/jp100271w] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
This paper reports a molecular dynamic study to explore the diverse behavior of different generations of poly(amidoamine) (PAMAM) dendrimers in binding siRNA. Our models show good accordance with experimental measurements. Simulations demonstrate that the molecular flexibility of PAMAMs plays a crucial role in the binding event, which is controlled by the modulation between enthalpy and entropy of binding. Importantly, the ability of dendrimers to adapt to siRNA is strongly dependent on the generation and on the pH due to backfolding. While G4 demonstrates good adaptability to siRNA, G6 behaves like a rigid sphere with a consistent loss in the binding affinity. G5 shows a hybrid behavior, maintaining rigid and flexible aspects, with a strong dependence of its properties on the pH. To define the "best binder", the mere energetic definition of binding affinity appears to be no longer effective and a novel concept of "efficiency" should be considered, being the balance between enthalpy and entropy of binding indivisible from the structural flexibility. With this aim, we propose an original criterion to define and rank the ability of these molecules to adapt their structure to bind a charged target.
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Affiliation(s)
- Giovanni M Pavan
- University for Applied Sciences of Southern Switzerland (SUPSI)-Institute of Computer Integrated Manufacturing for Sustainable Innovation, Centro Galleria 2, Manno, CH-6928, Switzerland.
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Pavan GM, Kostiainen MA, Danani A. Computational Approach for Understanding the Interactions of UV-Degradable Dendrons with DNA and siRNA. J Phys Chem B 2010; 114:5686-93. [DOI: 10.1021/jp911439q] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Giovanni M. Pavan
- Mathematical and Physical Sciences Research Unit (SMF), University for Applied Sciences of Southern Switzerland (SUPSI), Centro Galleria 2, Manno, CH-6928, Switzerland, and Institute for Molecules and Materials, Radboud University Nijmegen, Toernooiveld 1, 6525 ED Nijmegen, The Netherlands
| | - Mauri A. Kostiainen
- Mathematical and Physical Sciences Research Unit (SMF), University for Applied Sciences of Southern Switzerland (SUPSI), Centro Galleria 2, Manno, CH-6928, Switzerland, and Institute for Molecules and Materials, Radboud University Nijmegen, Toernooiveld 1, 6525 ED Nijmegen, The Netherlands
| | - Andrea Danani
- Mathematical and Physical Sciences Research Unit (SMF), University for Applied Sciences of Southern Switzerland (SUPSI), Centro Galleria 2, Manno, CH-6928, Switzerland, and Institute for Molecules and Materials, Radboud University Nijmegen, Toernooiveld 1, 6525 ED Nijmegen, The Netherlands
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Lard M, Kim SH, Lin S, Bhattacharya P, Ke PC, Lamm MH. Fluorescence resonance energy transfer between phenanthrene and PAMAM dendrimers. Phys Chem Chem Phys 2010; 12:9285-91. [DOI: 10.1039/b924522g] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Maiti PK, Bagchi B. Diffusion of flexible, charged, nanoscopic molecules in solution: Size and pH dependence for PAMAM dendrimer. J Chem Phys 2009; 131:214901. [DOI: 10.1063/1.3266512] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Maiti PK, Li Y, Cagin T, Goddard WA. Structure of polyamidoamide dendrimers up to limiting generations: a mesoscale description. J Chem Phys 2009; 130:144902. [PMID: 19368466 DOI: 10.1063/1.3105338] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The polyamidoamide (PAMAM) class of dendrimers was one of the first dendrimers synthesized by Tomalia and co-workers at Dow. Since its discovery the PAMAMs have stimulated many discussions on the structure and dynamics of such hyperbranched polymers. Many questions remain open because the huge conformation disorder combined with very similar local symmetries have made it difficult to characterize experimentally at the atomistic level the structure and dynamics of PAMAM dendrimers. The higher generation dendrimers have also been difficult to characterize computationally because of the large size (294,852 atoms for generation 11) and the huge number of conformations. To help provide a practical means of atomistic computational studies, we have developed an atomistically informed coarse-grained description for the PAMAM dendrimer. We find that a two-bead per monomer representation retains the accuracy of atomistic simulations for predicting size and conformational complexity, while reducing the degrees of freedom by tenfold. This mesoscale description has allowed us to study the structural properties of PAMAM dendrimer up to generation 11 for time scale of up to several nanoseconds. The gross properties such as the radius of gyration compare very well with those from full atomistic simulation and with available small angle x-ray experiment and small angle neutron scattering data. The radial monomer density shows very similar behavior with those obtained from the fully atomistic simulation. Our approach to deriving the coarse-grain model is general and straightforward to apply to other classes of dendrimers.
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Affiliation(s)
- Prabal K Maiti
- Center for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bangalore 560012, India.
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Amirkhanov NV, Dimitrov I, Opitz AW, Zhang K, Lackey JP, Cardi CA, Lai S, Wagner NJ, Thakur ML, Wickstrom E. Design of (Gd-DO3A)n-polydiamidopropanoyl-peptide nucleic acid-D(Cys-Ser-Lys-Cys) magnetic resonance contrast agents. Biopolymers 2008; 89:1061-76. [PMID: 18680101 DOI: 10.1002/bip.21059] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
We hypothesized that chelating Gd(III) to 1,4,7-tris(carboxymethylaza)cyclododecane-10-azaacetylamide (DO3A) on peptide nucleic acid (PNA) hybridization probes would provide a magnetic resonance genetic imaging agent capable of hybridization to a specific mRNA. Because of the low sensitivity of Gd(III) as an magnetic resonance imaging (MRI) contrast agent, a single Gd-DO3A complex per PNA hybridization agent could not provide enough contrast for detection of cancer gene mRNAs, even at thousands of mRNA copies per cell. To increase the Gd(III) shift intensity of MRI genetic imaging agents, we extended a novel DO3An-polydiamidopropanoyl (PDAPm) dendrimer, up to n = 16, from the N-terminus of KRAS PNA hybridization agents by solid phase synthesis. A C-terminal D(Cys-Ser-Lys-Cys) cyclized peptide analog of insulin-like growth factor 1 (IGF1) was included to enable receptor-mediated cellular uptake. Molecular dynamic simulation of the (Gd-DO3A-AEEA)16-PDAP4-AEEA2-KRAS PNA-AEEA-D(Cys-Ser-Lys-Cys) genetic imaging nanoparticles in explicit water yielded a pair correlation function similar to that of PAMAM dendrimers, and a predicted structure in which the PDAP dendron did not sequester the PNA. Thermal melting measurements indicated that the size of the PDAP dendron included in the (DO3A-AEEA)n-PDAPm-AEEA2-KRAS PNA-AEEA-D(Cys-Ser-Lys-Cys) probes (up to 16 Gd(III) cations per PNA) did not depress the melting temperatures (Tm) of the complementary PNA/RNA hybrid duplexes. The Gd(III) dendrimer PNA genetic imaging agents in phantom solutions displayed significantly greater T1 relaxivity per probe (r1 = 30.64 +/- 2.68 mM(-1) s(-1) for n = 2, r1 = 153.84 +/- 11.28 mM(-1) s(-1) for n = 8) than Gd-DTPA (r1 = 10.35 +/- 0.37 mM(-1) s(-1)), but less than that of (Gd-DO3A)32-PAMAM dendrimer (r1 = 771.84 +/- 20.48 mM(-1) s(-1)) (P < 0.05). Higher generations of PDAP dendrimers with 32 or more Gd-DO3A residues attached to PNA-D(Cys-Ser-Lys-Cys) genetic imaging agents might provide greater contrast for more sensitive detection.
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Affiliation(s)
- Nariman V Amirkhanov
- Laboratory of Nucleic Acids Chemistry, Institute of Chemical Biology and Fundamental Medicine, Philadelphia, PA 19107, USA
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Gomez MV, Guerra J, Velders AH, Crooks RM. NMR Characterization of Fourth-Generation PAMAM Dendrimers in the Presence and Absence of Palladium Dendrimer-Encapsulated Nanoparticles. J Am Chem Soc 2008; 131:341-50. [DOI: 10.1021/ja807488d] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- M. Victoria Gomez
- NMR & MS Department, SupraMolecular Chemistry and Technology, MESA+ Institute for Nanotechnology, Faculty of Science and Technology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands, and the Department of Chemistry and Biochemistry, Center for Nano and Molecular Science and Technology, and the Texas Materials Institute, The University of Texas at Austin, 1 University Station, A5300, Austin, Texas 78712-0165
| | - Javier Guerra
- NMR & MS Department, SupraMolecular Chemistry and Technology, MESA+ Institute for Nanotechnology, Faculty of Science and Technology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands, and the Department of Chemistry and Biochemistry, Center for Nano and Molecular Science and Technology, and the Texas Materials Institute, The University of Texas at Austin, 1 University Station, A5300, Austin, Texas 78712-0165
| | - Aldrik H. Velders
- NMR & MS Department, SupraMolecular Chemistry and Technology, MESA+ Institute for Nanotechnology, Faculty of Science and Technology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands, and the Department of Chemistry and Biochemistry, Center for Nano and Molecular Science and Technology, and the Texas Materials Institute, The University of Texas at Austin, 1 University Station, A5300, Austin, Texas 78712-0165
| | - Richard M. Crooks
- NMR & MS Department, SupraMolecular Chemistry and Technology, MESA+ Institute for Nanotechnology, Faculty of Science and Technology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands, and the Department of Chemistry and Biochemistry, Center for Nano and Molecular Science and Technology, and the Texas Materials Institute, The University of Texas at Austin, 1 University Station, A5300, Austin, Texas 78712-0165
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Li T, Hong K, Porcar L, Verduzco R, Butler PD, Smith GS, Liu Y, Chen WR. Assess the Intramolecular Cavity of a PAMAM Dendrimer in Aqueous Solution by Small-Angle Neutron Scattering. Macromolecules 2008. [DOI: 10.1021/ma801555j] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Tianfu Li
- The NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8562; China Institute of Atomic Energy, P.O. Box 275-30, 102413, P. R. China; The Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831; Institut Laue-Langevin, B.P. 156, F-38042 Grenoble Cedex 9, France; Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742-2115; and Neutron Scattering Science
| | - Kunlun Hong
- The NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8562; China Institute of Atomic Energy, P.O. Box 275-30, 102413, P. R. China; The Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831; Institut Laue-Langevin, B.P. 156, F-38042 Grenoble Cedex 9, France; Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742-2115; and Neutron Scattering Science
| | - Lionel Porcar
- The NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8562; China Institute of Atomic Energy, P.O. Box 275-30, 102413, P. R. China; The Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831; Institut Laue-Langevin, B.P. 156, F-38042 Grenoble Cedex 9, France; Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742-2115; and Neutron Scattering Science
| | - Rafael Verduzco
- The NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8562; China Institute of Atomic Energy, P.O. Box 275-30, 102413, P. R. China; The Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831; Institut Laue-Langevin, B.P. 156, F-38042 Grenoble Cedex 9, France; Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742-2115; and Neutron Scattering Science
| | - Paul D. Butler
- The NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8562; China Institute of Atomic Energy, P.O. Box 275-30, 102413, P. R. China; The Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831; Institut Laue-Langevin, B.P. 156, F-38042 Grenoble Cedex 9, France; Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742-2115; and Neutron Scattering Science
| | - Gregory S. Smith
- The NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8562; China Institute of Atomic Energy, P.O. Box 275-30, 102413, P. R. China; The Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831; Institut Laue-Langevin, B.P. 156, F-38042 Grenoble Cedex 9, France; Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742-2115; and Neutron Scattering Science
| | - Yun Liu
- The NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8562; China Institute of Atomic Energy, P.O. Box 275-30, 102413, P. R. China; The Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831; Institut Laue-Langevin, B.P. 156, F-38042 Grenoble Cedex 9, France; Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742-2115; and Neutron Scattering Science
| | - Wei-Ren Chen
- The NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8562; China Institute of Atomic Energy, P.O. Box 275-30, 102413, P. R. China; The Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831; Institut Laue-Langevin, B.P. 156, F-38042 Grenoble Cedex 9, France; Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742-2115; and Neutron Scattering Science
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Porcar L, Liu Y, Verduzco R, Hong K, Butler PD, Magid LJ, Smith GS, Chen WR. Structural Investigation of PAMAM Dendrimers in Aqueous Solutions Using Small-Angle Neutron Scattering: Effect of Generation. J Phys Chem B 2008; 112:14772-8. [DOI: 10.1021/jp805297a] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Lionel Porcar
- Institut Laue-Langevin, B.P. 156, F-38042 Grenoble Cedex 9, France; The NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6100; Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742; The Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831; Department of Chemistry, the University of Tennessee, Knoxville, Tennessee 37996-1600; and Neutron Scattering
| | - Yun Liu
- Institut Laue-Langevin, B.P. 156, F-38042 Grenoble Cedex 9, France; The NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6100; Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742; The Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831; Department of Chemistry, the University of Tennessee, Knoxville, Tennessee 37996-1600; and Neutron Scattering
| | - Rafael Verduzco
- Institut Laue-Langevin, B.P. 156, F-38042 Grenoble Cedex 9, France; The NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6100; Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742; The Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831; Department of Chemistry, the University of Tennessee, Knoxville, Tennessee 37996-1600; and Neutron Scattering
| | - Kunlun Hong
- Institut Laue-Langevin, B.P. 156, F-38042 Grenoble Cedex 9, France; The NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6100; Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742; The Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831; Department of Chemistry, the University of Tennessee, Knoxville, Tennessee 37996-1600; and Neutron Scattering
| | - Paul D. Butler
- Institut Laue-Langevin, B.P. 156, F-38042 Grenoble Cedex 9, France; The NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6100; Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742; The Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831; Department of Chemistry, the University of Tennessee, Knoxville, Tennessee 37996-1600; and Neutron Scattering
| | - Linda J. Magid
- Institut Laue-Langevin, B.P. 156, F-38042 Grenoble Cedex 9, France; The NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6100; Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742; The Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831; Department of Chemistry, the University of Tennessee, Knoxville, Tennessee 37996-1600; and Neutron Scattering
| | - Gregory S. Smith
- Institut Laue-Langevin, B.P. 156, F-38042 Grenoble Cedex 9, France; The NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6100; Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742; The Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831; Department of Chemistry, the University of Tennessee, Knoxville, Tennessee 37996-1600; and Neutron Scattering
| | - Wei-Ren Chen
- Institut Laue-Langevin, B.P. 156, F-38042 Grenoble Cedex 9, France; The NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6100; Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742; The Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831; Department of Chemistry, the University of Tennessee, Knoxville, Tennessee 37996-1600; and Neutron Scattering
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Affiliation(s)
- Prabal K. Maiti
- Center for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bangalore, India, 560012; Institut für Theoretische Physik II, Heinrich-Heine-Universität Düsseldorf, Universitätsstrasse 1, D-40225 Düsseldorf, Germany
| | - René Messina
- Center for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bangalore, India, 560012; Institut für Theoretische Physik II, Heinrich-Heine-Universität Düsseldorf, Universitätsstrasse 1, D-40225 Düsseldorf, Germany
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