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Li Z, Cai B, Yang W, Chen CL. Hierarchical Nanomaterials Assembled from Peptoids and Other Sequence-Defined Synthetic Polymers. Chem Rev 2021; 121:14031-14087. [PMID: 34342989 DOI: 10.1021/acs.chemrev.1c00024] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In nature, the self-assembly of sequence-specific biopolymers into hierarchical structures plays an essential role in the construction of functional biomaterials. To develop synthetic materials that can mimic and surpass the function of these natural counterparts, various sequence-defined bio- and biomimetic polymers have been developed and exploited as building blocks for hierarchical self-assembly. This review summarizes the recent advances in the molecular self-assembly of hierarchical nanomaterials based on peptoids (or poly-N-substituted glycines) and other sequence-defined synthetic polymers. Modern techniques to monitor the assembly mechanisms and characterize the physicochemical properties of these self-assembly systems are highlighted. In addition, discussions about their potential applications in biomedical sciences and renewable energy are also included. This review aims to highlight essential features of sequence-defined synthetic polymers (e.g., high stability and protein-like high-information content) and how these unique features enable the construction of robust biomimetic functional materials with high programmability and predictability, with an emphasis on peptoids and their self-assembled nanomaterials.
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Affiliation(s)
- Zhiliang Li
- Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99354, United States.,Institute of Molecular Science and Engineering, Institute of Frontier and Interdisciplinary Science, Shandong University, Qingdao, Shandong 266237, China
| | - Bin Cai
- Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99354, United States.,School of Chemistry and Chemical Engineering, Shandong University, Shandong 250100, China
| | - Wenchao Yang
- Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99354, United States.,School of Chemical Engineering and Technology, State Key Laboratory of Chemical Engineering, Tianjin University, Tianjin 300072, China
| | - Chun-Long Chen
- Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99354, United States.,Department of Chemical Engineering, University of Washington, Seattle, Washington 98195, United States
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Yang C, Wu KB, Deng Y, Yuan J, Niu J. Geared Toward Applications: A Perspective on Functional Sequence-Controlled Polymers. ACS Macro Lett 2021; 10:243-257. [PMID: 34336395 PMCID: PMC8320758 DOI: 10.1021/acsmacrolett.0c00855] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Sequence-controlled polymers are an emerging class of synthetic polymers with a regulated sequence of monomers. In the past decade, tremendous progress has been made in the synthesis of polymers with the sophisticated sequence control approaching the level manifested in biopolymers. In contrast, the exploration of novel functions that can be achieved by controlling synthetic polymer sequences represents an emerging focus in polymer science. This Viewpoint will survey recent advances in the functional applications of sequence-controlled polymers and provide a perspective on the challenges and outlook for pursuing future applications of this fascinating class of macromolecules.
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Affiliation(s)
- Cangjie Yang
- Department of Chemistry, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Kevin B. Wu
- Department of Chemistry, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Yu Deng
- Department of Chemistry, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Jingsong Yuan
- Department of Chemistry, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Jia Niu
- Department of Chemistry, Boston College, Chestnut Hill, Massachusetts 02467, United States
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3
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Altering the edge chemistry of bicelles with peptoids. Chem Phys Lipids 2018; 217:43-50. [PMID: 30391486 DOI: 10.1016/j.chemphyslip.2018.10.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 09/10/2018] [Accepted: 10/23/2018] [Indexed: 01/23/2023]
Abstract
Cell function is tied to the interactions that occur within and across the cell membrane. Therefore, understanding membrane-affiliated interactions is important to many biomedical applications. Advancing the body of knowledge about these interactions will lead to discoveries in biomarker detection and therapeutic targets for disease detection and treatment. Model membrane systems are an effective way to study membrane proteins for such discoveries, allowing for stable protein structure and maintaining native activity. Bicelles, disc-shaped lipid bilayers created by combining long- and short-chain phospholipids, are the model membrane system of focus in this study. Bicelles are accessible from both sides and have a wide size range, which makes them attractive for studying membrane interactions without affecting function. In this work, bicelles were functionalized with peptoids to alter the edge chemistry. Peptoids are suitable for this application because of the large diversity of available side chain chemistries that can be easily incorporated in a sequence-specific manner. The peptoid sequence consists of three functional regions to promote insertion into the edge of bicelles. The insertion sequence at the C-terminus contains two alkyl chains and two hydrophobic, chiral aromatic groups that anchor into the bicelle edge. The facially amphipathic helix contains chiral aromatic groups on one side that interact with the lipid tails and positively charged groups on the other side, which interact with the lipid head groups. Thiol groups are included at the N-terminus to allow for visualization of peptoid location in the bicelle. Bicelle morphology and size were assessed by transmission electron microscopy (TEM) and dynamic light scattering (DLS). Peptoid location in the bicelle was determined by attachment of gold nanoparticles, which confirmed preferential incorporation of the peptoid into the bicelle edge with 82% specificity. Additionally, the peptoid-functionalized bicelles are of similar size and morphology to non-functionalized bicelles. Results from this study show that peptoid-functionalized bicelles are a promising model membrane system with potential applications in biosensors or bioseparations.
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Zhu L, Simpson JM, Xu X, He H, Zhang D, Yin L. Cationic Polypeptoids with Optimized Molecular Characteristics toward Efficient Nonviral Gene Delivery. ACS APPLIED MATERIALS & INTERFACES 2017; 9:23476-23486. [PMID: 28653538 DOI: 10.1021/acsami.7b06031] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The rational design of gene vectors relies on the understanding of their structure-property relationship. Polypeptoids, which are structural isomers of natural polypeptides, hold great potential as gene delivery vectors due to their facile preparation, structural tunability, and most importantly, their desirable proteolytic stability. We herein designed a library of polypeptoids with different cationic side-chain terminal groups, degree of polymerizations (DPs), side-chain lengths, and incorporated aliphatic side chains, to unravel the structure-property relationships so that gene delivery efficiency can be maximized and cytotoxicity can be minimized. In HeLa cells, a polypeptoid bearing a primary amine side-chain terminal group exhibited remarkably higher transfection efficiency than that of its analogues containing secondary, tertiary, or quaternary amine groups. Elongation of the polypeptoid backbone length (from 28 to 251 mer) led to enhanced DNA condensation as well as cellular uptake levels, however it also caused higher cytotoxicity. Upon a proper balance between DNA uptake and cytotoxicity, the polypeptoid with a DP of 46 afforded the highest transfection efficiency. Elongating the aliphatic spacer between the backbone and side amine groups enhanced the hydrophobicity of the side chains, which resulted in notably increased membrane activities and transfection efficiency. Further incorporation of hydrophobic decyl side chains led to an improvement in transfection efficiency of ∼6 fold. The top-performing material identified, P11, mediated successful gene transfection under serum-containing conditions, outperforming the commercial transfection reagent poly(ethylenimine) by nearly 4 orders of magnitude. Reflecting its excellent serum-resistant properties, P11 further enabled effective transfection in vivo following intratumoral injection to melanoma-bearing mice. This study will help the rational design of polypeptoid-based gene delivery materials, and the best-performing material identified may provide a potential supplement to existing gene vectors.
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Affiliation(s)
- Lipeng Zhu
- Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Institute of Functional Nano and Soft Materials (FUNSOM), Soochow University , Suzhou 215123, P. R. China
| | - Jessica M Simpson
- Department of Chemistry and Macromolecular Studies Group, Louisiana State University , Baton Rouge, Louisiana 70803, United States
| | - Xin Xu
- Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Institute of Functional Nano and Soft Materials (FUNSOM), Soochow University , Suzhou 215123, P. R. China
| | - Hua He
- Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Institute of Functional Nano and Soft Materials (FUNSOM), Soochow University , Suzhou 215123, P. R. China
| | - Donghui Zhang
- Department of Chemistry and Macromolecular Studies Group, Louisiana State University , Baton Rouge, Louisiana 70803, United States
| | - Lichen Yin
- Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Institute of Functional Nano and Soft Materials (FUNSOM), Soochow University , Suzhou 215123, P. R. China
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Ma J, Xuan S, Guerin AC, Yu T, Zhang D, Kuroda DG. Unusual molecular mechanism behind the thermal response of polypeptoids in aqueous solutions. Phys Chem Chem Phys 2017; 19:10878-10888. [DOI: 10.1039/c6cp08536a] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The molecular mechanism behind the thermal response of the aqueous solutions of two identical polypeptoids with different architecture was studied. It was found the thermal response is initiated by a conformational change of the polymer backbone irrespective of the architecture.
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Affiliation(s)
- Jianbo Ma
- Department of Chemistry
- Louisiana State University
- Baton Rouge
- USA
| | - Sunting Xuan
- Department of Chemistry
- Louisiana State University
- Baton Rouge
- USA
| | - Abby C. Guerin
- Department of Chemistry
- Louisiana State University
- Baton Rouge
- USA
| | - Tianyi Yu
- Department of Chemistry
- Louisiana State University
- Baton Rouge
- USA
| | - Donghui Zhang
- Department of Chemistry
- Louisiana State University
- Baton Rouge
- USA
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Gangloff N, Ulbricht J, Lorson T, Schlaad H, Luxenhofer R. Peptoids and Polypeptoids at the Frontier of Supra- and Macromolecular Engineering. Chem Rev 2015; 116:1753-802. [DOI: 10.1021/acs.chemrev.5b00201] [Citation(s) in RCA: 190] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Niklas Gangloff
- Functional Polymer
Materials, Chair for Chemical Technology of Materials Synthesis, University of Würzburg, Röntgenring 11, 97070 Würzburg, Germany
| | - Juliane Ulbricht
- Functional Polymer
Materials, Chair for Chemical Technology of Materials Synthesis, University of Würzburg, Röntgenring 11, 97070 Würzburg, Germany
| | - Thomas Lorson
- Functional Polymer
Materials, Chair for Chemical Technology of Materials Synthesis, University of Würzburg, Röntgenring 11, 97070 Würzburg, Germany
| | - Helmut Schlaad
- Institute of Chemistry, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany
| | - Robert Luxenhofer
- Functional Polymer
Materials, Chair for Chemical Technology of Materials Synthesis, University of Würzburg, Röntgenring 11, 97070 Würzburg, Germany
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Knight AS, Zhou EY, Francis MB, Zuckermann RN. Sequence Programmable Peptoid Polymers for Diverse Materials Applications. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2015; 27:5665-5691. [PMID: 25855478 DOI: 10.1002/adma.201500275] [Citation(s) in RCA: 169] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2015] [Revised: 02/13/2015] [Indexed: 06/04/2023]
Abstract
Polymer sequence programmability is required for the diverse structures and complex properties that are achieved by native biological polymers, but efforts towards controlling the sequence of synthetic polymers are, by comparison, still in their infancy. Traditional polymers provide robust and chemically diverse materials, but synthetic control over their monomer sequences is limited. The modular and step-wise synthesis of peptoid polymers, on the other hand, allows for precise control over the monomer sequences, affording opportunities for these chains to fold into well-defined nanostructures. Hundreds of different side chains have been incorporated into peptoid polymers using efficient reaction chemistry, allowing for a seemingly infinite variety of possible synthetically accessible polymer sequences. Combinatorial discovery techniques have allowed the identification of functional polymers within large libraries of peptoids, and newly developed theoretical modeling tools specifically adapted for peptoids enable the future design of polymers with desired functions. Work towards controlling the three-dimensional structure of peptoids, from the conformation of the amide bond to the formation of protein-like tertiary structure, has and will continue to enable the construction of tunable and innovative nanomaterials that bridge the gap between natural and synthetic polymers.
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Affiliation(s)
- Abigail S Knight
- UC Berkeley Chemistry Department, Latimer Hall, Berkeley, CA, 94720, USA
| | - Effie Y Zhou
- UC Berkeley Chemistry Department, Latimer Hall, Berkeley, CA, 94720, USA
| | - Matthew B Francis
- UC Berkeley Chemistry Department, Latimer Hall, Berkeley, CA, 94720, USA
- The Molecular Foundry Lawrence Berkeley National Lab, 1 Cyclotron Road, Berkeley, CA, 94720, USA
| | - Ronald N Zuckermann
- The Molecular Foundry Lawrence Berkeley National Lab, 1 Cyclotron Road, Berkeley, CA, 94720, USA
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Mándity IM, Fülöp F. An overview of peptide and peptoid foldamers in medicinal chemistry. Expert Opin Drug Discov 2015; 10:1163-77. [PMID: 26289578 DOI: 10.1517/17460441.2015.1076790] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
INTRODUCTION Foldamers are artificial self-organizing systems with various critical properties: i) a stable and designable secondary structure; ii) a larger molecular surface as compared with ordinary organic drug molecules; iii) appropriate control of the orientation of the side-chain functional groups; iv) resistance against proteolytic degradation, which leads to potentially increased oral bioavailability and a longer serum half-life relative to ordinary α-peptides; and v) the lower conformational freedom may result in increased receptor binding in comparison with the natural analogs. AREAS COVERED This article covers the general properties and types of foldamers. This includes highlighted examples of medicinal chemical applications, including antibacterial and cargo molecules, anti-Alzheimer compounds and protein-protein interaction modifiers. EXPERT OPINION Various new foldamers have been created with a range of structures and biological applications. Membrane-acting antibacterial foldamers have been introduced. A general property of these structures is their amphiphilic nature. The amphiphilicity can be stationary or induced by the membrane binding. Cell-penetrating foldamers have been described which serve as cargo molecules, and foldamers have been used as autophagy inducers. Anti-Alzheimer compounds too have been created and the greatest breakthrough was attained via the modification of protein-protein interactions. This can serve as the chemical and pharmaceutical basis for the relevance of foldamers in the future.
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Affiliation(s)
| | - Ferenc Fülöp
- a University of Szeged Institute of Pharmaceutical Chemistry , H-6720 Szeged, Eötvös u. 6, Hungary +36 62 545 768 ; +36 62 545 564 ; +36 62 545 705 ; ;
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Haxton TK, Mannige RV, Zuckermann RN, Whitelam S. Modeling Sequence-Specific Polymers Using Anisotropic Coarse-Grained Sites Allows Quantitative Comparison with Experiment. J Chem Theory Comput 2014; 11:303-15. [DOI: 10.1021/ct5010559] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Thomas K. Haxton
- Molecular
Foundry, Lawrence Berkeley
National Laboratory, Berkeley, California 94720, United States
| | - Ranjan V. Mannige
- Molecular
Foundry, Lawrence Berkeley
National Laboratory, Berkeley, California 94720, United States
| | - Ronald N. Zuckermann
- Molecular
Foundry, Lawrence Berkeley
National Laboratory, Berkeley, California 94720, United States
| | - Stephen Whitelam
- Molecular
Foundry, Lawrence Berkeley
National Laboratory, Berkeley, California 94720, United States
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Konca YU, Kirshenbaum K, Zuckermann RN. Nanometer-scale siRNA carriers incorporating peptidomimetic oligomers: physical characterization and biological activity. Int J Nanomedicine 2014; 9:2271-85. [PMID: 24872690 PMCID: PMC4026564 DOI: 10.2147/ijn.s57449] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Synthetic short interfering RNA (siRNA) oligonucleotides can trigger the RNA interference pathway and lead to selective gene silencing. Despite considerable enthusiasm and investment, formidable challenges remain that may deter translating this breakthrough discovery into clinical applications. In particular, the development of efficient, nontoxic, nonimmunogenic methods for delivering siRNA in vivo has proven to be exceptionally challenging. Thorough analysis of the relationship between the structure and function of siRNA carrier systems, both in isolation and in complex with RNA, will facilitate the design of efficient nonviral siRNA delivery vehicles. In this study, we explore the relationship between the physicochemical characteristics and the biological activity of “lipitoid” compounds as potent siRNA delivery vehicles. Lipitoids are cationic peptidomimetic oligomers incorporating a peptoid and a phospholipid moiety. Lipitoids can associate with siRNA oligonucleotides and self-assemble into spherical lipitoid-based nanoparticles (LNPs), with dimensions that are dependent upon the medium and the stoichiometric ratio between the cationic monomers of the lipitoid and anionic siRNA oligonucleotides. The morphology, gene silencing efficiency, and cytotoxicity of the siRNA-loaded LNPs are similarly sensitive to the stoichiometry of the complexes. The medium in which the LNPs are formed affects the assembled cargo particles’ characteristics such as particle size, transfection efficiency, and stability. Formation of the LNPs in the biological, serum-free medium OptiMEM resulted in LNPs an order of magnitude larger than LNPs formed in water, and were twice as efficient in siRNA transfection compared to LNPs formed in water. Inhibitor studies were conducted to elucidate the efficiency of lysosomal escape and the uptake mechanism of the siRNA-loaded LNPs. Our results suggest that these lipitoid-based, siRNA-loaded spherical LNPs are internalized through a lipid raft-dependent and dynamin-mediated pathway, circumventing endosomal and lysosomal encapsulation. The lipitoid-siRNA nanospheres proved to be suitable platforms for investigating the critical parameters determining the efficiency of transfection agents, revealing the necessity for conducting characterization studies in biological media. The investigation of the LNP internalization pathway points to an alternative uptake route that bypasses the lysosome, explaining the surprisingly high efficiency of LNPs and suggesting that the uptake mechanism should be probed rather than assumed for the next generation of rationally designed transfection agents.
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11
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Baoum AA, Middaugh CR, Berkland C. DNA complexed with TAT peptide and condensed using calcium possesses unique structural features compared to PEI polyplexes. Int J Pharm 2014; 465:11-7. [DOI: 10.1016/j.ijpharm.2014.01.040] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2013] [Revised: 12/17/2013] [Accepted: 01/29/2014] [Indexed: 11/29/2022]
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Sun J, Zuckermann RN. Peptoid polymers: a highly designable bioinspired material. ACS NANO 2013; 7:4715-32. [PMID: 23721608 DOI: 10.1021/nn4015714] [Citation(s) in RCA: 307] [Impact Index Per Article: 27.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Bioinspired polymeric materials are attracting increasing attention due to significant advantages over their natural counterparts: the ability to precisely tune their structures over a broad range of chemical and physical properties, increased stability, and improved processability. Polypeptoids, a promising class of bioinspired polymer based on a N-substituted glycine backbone, have a number of unique properties that bridge the material gap between proteins and bulk polymers. Peptoids combine the sequence specificity of biopolymers with the simpler intra/intermolecular interactions and robustness of traditional synthetic polymers. They are highly designable because hundreds of chemically diverse side chains can be introduced from simple building blocks. Peptoid polymers can be prepared by two distinct synthetic techniques offering access to two material subclasses: (1) automated solid-phase synthesis which enables precision sequence control and near absolute monodispersity up to chain lengths of ~50 monomers, and (2) a classical polymerization approach which allows access to higher molecular weights and larger-scale yields, but with less control over length and sequence. This combination of facile synthetic approaches makes polypeptoids a highly tunable, rapid polymer prototyping platform to investigate new materials that are intermediate between proteins and bulk polymers, in both their structure and their properties. In this paper, we review the methods to synthesize peptoid polymers and their applications in biomedicine and nanoscience, as both sequence-specific materials and as bulk polymers.
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Affiliation(s)
- Jing Sun
- Molecular Foundry, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA
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13
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Bertin A. Polyelectrolyte Complexes of DNA and Polycations as Gene Delivery Vectors. ADVANCES IN POLYMER SCIENCE 2013. [DOI: 10.1007/12_2013_218] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Jorge P, Lourenço A, Pereira MO. New trends in peptide-based anti-biofilm strategies: a review of recent achievements and bioinformatic approaches. BIOFOULING 2012; 28:1033-1061. [PMID: 23016989 DOI: 10.1080/08927014.2012.728210] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Antimicrobial peptides (AMPs) have a broad spectrum of activity and unspecific mechanisms of action. Therefore, they are seen as valid alternatives to overcome clinically relevant biofilms and reduce the chance of acquired resistance. This paper reviews AMPs and anti-biofilm AMP-based strategies and discusses ongoing and future work. Recent studies report successful AMP-based prophylactic and therapeutic strategies, several databases catalogue AMP information and analysis tools, and novel bioinformatics tools are supporting AMP discovery and design. However, most AMP studies are performed with planktonic cultures, and most studies on sessile cells test AMPs on growing rather than mature biofilms. Promising preliminary synergistic studies have to be consubstantiated and the study of functionalized coatings with AMPs must be further explored. Standardized operating protocols, to enforce the repeatability and reproducibility of AMP anti-biofilm tests, and automated means of screening and processing the ever-expanding literature are still missing.
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Affiliation(s)
- Paula Jorge
- IBB - Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
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Antimicrobial peptoids are effective against Pseudomonas aeruginosa biofilms. Antimicrob Agents Chemother 2011; 55:3054-7. [PMID: 21422218 DOI: 10.1128/aac.01516-10] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The resistance of biofilms to conventional antibiotics complicates the treatment of chronic cystic fibrosis (CF). We investigated the effects of peptoids, peptides, and conventional antibiotics on the biomass and cell viability within Pseudomonas aeruginosa biofilms. At their MICs, peptoids 1 and 1-C13(4mer) caused maximum reductions in biomass and cell viability, respectively. These results suggest that peptoids of this class could be worth exploring for the treatment of pulmonary infections occurring in CF patients.
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Culf AS, Ouellette RJ. Solid-phase synthesis of N-substituted glycine oligomers (alpha-peptoids) and derivatives. Molecules 2010; 15:5282-335. [PMID: 20714299 PMCID: PMC6257730 DOI: 10.3390/molecules15085282] [Citation(s) in RCA: 139] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2010] [Revised: 07/14/2010] [Accepted: 08/02/2010] [Indexed: 12/02/2022] Open
Abstract
Peptoids (N-substituted polyglycines and extended peptoids with variant backbone amino-acid monomer units) are oligomeric synthetic polymers that are becoming a valuable molecular tool in the biosciences. Of particular interest are their applications to the exploration of peptoid secondary structures and drug design. Major advantages of peptoids as research and pharmaceutical tools include the ease and economy of synthesis, highly variable backbone and side-chain chemistry possibilities. At the same time, peptoids have been demonstrated as highly active in biological systems while resistant to proteolytic decay. This review with 227 references considers the solid-phase synthetic aspects of peptoid preparation and utilization up to 2010 from the instigation, by R. N. Zuckermann et al., of peptoid chemistry in 1992.
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Affiliation(s)
- Adrian S Culf
- Atlantic Cancer Research Institute, Moncton, NB, Canada.
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Abstract
Efficient delivery of genetic material to cells is needed for tasks of utmost importance in the laboratory and clinic, such as gene transfection and gene silencing. Synthetic cationic lipids can be used as delivery vehicles for nucleic acids and are now considered the most promising nonviral gene carriers. They form complexes (lipoplexes) with the polyanionic nucleic acids. A critical obstacle for clinical application of the lipid-mediated DNA delivery (lipofection) is its unsatisfactory efficiency for many cell types. Understanding the mechanism of lipid-mediated DNA delivery is essential for their successful application, as well as for a rational design and synthesis of novel cationic lipoid compounds for enhanced gene delivery. A viewpoint now emerging is that the critical factor in lipid-mediated transfection is the structural evolution of lipoplexes within the cell, upon interacting and mixing with cellular lipids. In particular, recent studies showed that the phase evolution of lipoplex lipids upon interaction and mixing with membrane lipids appears to be decisive for transfection success: specifically, lamellar lipoplex formulations, which were readily susceptible to undergoing lamellar-nonlamellar phase transition upon mixing with cellular lipids and were found rather consistently associated with superior transfection potency, presumably as a result of facilitated DNA release. Thus, understanding the lipoplex structure and the phase changes upon interacting with membrane lipids is important for the successful application of the cationic lipids as gene carriers.
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18
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Cationic lipids: molecular structure/ transfection activity relationships and interactions with biomembranes. Top Curr Chem (Cham) 2010; 296:51-93. [PMID: 21504100 DOI: 10.1007/128_2010_67] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Abstract Synthetic cationic lipids, which form complexes (lipoplexes) with polyanionic DNA, are presently the most widely used constituents of nonviral gene carriers. A large number of cationic amphiphiles have been synthesized and tested in transfection studies. However, due to the complexity of the transfection pathway, no general schemes have emerged for correlating the cationic lipid chemistry with their transfection efficacy and the approaches for optimizing their molecular structures are still largely empirical. Here we summarize data on the relationships between transfection activity and cationic lipid molecular structure and demonstrate that the transfection activity depends in a systematic way on the lipid hydrocarbon chain structure. A number of examples, including a large series of cationic phosphatidylcholine derivatives, show that optimum transfection is displayed by lipids with chain length of approximately 14 carbon atoms and that the transfection efficiency strongly increases with increase of chain unsaturation, specifically upon replacement of saturated with monounsaturated chains.
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Baoum A, Xie SX, Fakhari A, Berkland C. "Soft" calcium crosslinks enable highly efficient gene transfection using TAT peptide. Pharm Res 2009; 26:2619-29. [PMID: 19789962 PMCID: PMC4127430 DOI: 10.1007/s11095-009-9976-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2009] [Accepted: 09/14/2009] [Indexed: 02/02/2023]
Abstract
PURPOSE Typically, low molecular weight cationic peptides or polymers exhibit poor transfection efficiency due to an inability to condense plasmid DNA into small nanoparticles. Here, efficient gene delivery was attained using TAT/pDNA complexes containing calcium crosslinks. METHODS Electrostatic complexes of pDNA with TAT or PEI were studied with increasing calcium concentration. Gel electrophoresis was used to determine DNA condensation. The morphology of the complexes was probed by transmission electron microscopy. Transfection efficiency was assessed using a luciferase reporter plasmid. The accessibility of phosphate and amine groups within complexes was evaluated to determine the effect of calcium on structure. RESULTS TAT/pDNA complexes were condensed into small, 50-100 nm particles by optimizing the concentration of calcium. Complexes optimized for small size also exhibited higher transfection efficiency than PEI polyplexes in A549 cells. TAT and TAT complexes displayed negligible cytotoxicity up to 5 mg/mL, while PEI exhibited high cytotoxicity, as expected. Probing the TAT-Ca/pDNA structure suggested that calcium interacted with both phosphate and amine groups to compact the complexes; however, these "soft" crosslinks could be competitively disrupted to facilitate DNA release. CONCLUSION Small and stable TAT-Ca/pDNA complexes were obtained via "soft" calcium crosslinks leading to sustained gene expression levels higher than observed for control PEI gene vectors. TAT-Ca/pDNA complexes were stable, maintaining particle size and transfection efficiency even in the presence of 10% of FBS. TAT-Ca complexes offer an effective vehicle offering potential for translatable gene delivery.
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Affiliation(s)
- Abdulgader Baoum
- Department of Pharmaceutical Chemistry, The University of Kansas, 2030 Becker Drive, Lawrence, Kansas 66047, USA
| | - Sheng-Xue Xie
- Department of Pharmaceutical Chemistry, The University of Kansas, 2030 Becker Drive, Lawrence, Kansas 66047, USA
| | - Amir Fakhari
- Department of Bioengineering, The University of Kansas, 2030 Becker Drive, Lawrence, Kansas 66047, USA
| | - Cory Berkland
- Department of Pharmaceutical Chemistry, The University of Kansas, 2030 Becker Drive, Lawrence, Kansas 66047, USA
- Department of Chemical and Petroleum Engineering, The University of Kansas, 2030 Becker Drive, Lawrence, Kansas 66047, USA
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Lee H, Mijović J. Bio-nano complexes: DNA/surfactant/single-walled carbon nanotube interactions in electric field. POLYMER 2009. [DOI: 10.1016/j.polymer.2008.12.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Spectroscopic methods for the physical characterization and formulation of nonviral gene delivery systems. METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2008; 434:55-80. [PMID: 18470639 DOI: 10.1007/978-1-60327-248-3_5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2023]
Abstract
Currently, with the exception of naked DNA formulations, most pharmaceutical preparations of plasmid DNA employ some type of polycationic delivery vector such as synthetic cationic polymers and lipids to enhance delivery. A number of biophysical techniques are readily available for the structural characterization of plasmid DNA within synthetic gene delivery complexes. Here we present applications of ultraviolet (UV) absorption, circular dichroism (CD), infrared (IR), and fluorescence spectroscopies as well as dynamic light scattering to the structural analysis of the oligonucleotide component of nonviral gene delivery vectors. We also illustrate this approach for the investigation of the formulation of lipoplex and polyplex-based gene delivery systems. To summarize such data, we show how the macromolecular complexes can be represented as vectors in a highly dimensional space in which the components of the vector consist of normalized values of experimental parameters measured as a function of different solution conditions such as pH and ionic strength.
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Koynova R. Lipid Phases Eye View to Lipofection. Cationic Phosphatidylcholine Derivatives as Efficient DNA Carriers for Gene Delivery. Lipid Insights 2008. [DOI: 10.4137/lpi.s864] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Efficient delivery of genetic material to cells is needed for tasks of utmost importance in laboratory and clinic, such as gene transfection and gene silencing. Synthetic cationic lipids can be used as delivery vehicles for nucleic acids and are now considered the most promising non-viral gene carriers. They form complexes (lipoplexes) with the polyanionic nucleic acids. A critical obstacle for clinical application of the lipid-mediated DNA delivery (lipofection) is its unsatisfactory efficiency for many cell types. Understanding the mechanism of lipid-mediated DNA delivery is essential for their successful application, as well as for rational design and synthesis of novel cationic lipoid compounds for enhanced gene delivery. According to the current understanding, the critical factor in lipid-mediated transfection is the structural evolution of lipoplexes within the cell, upon interacting and mixing with cellular lipids. In particular, recent studies with cationic phosphatidylcholine derivatives showed that the phase evolution of lipoplex lipids upon interaction and mixing with membrane lipids appears to be decisive for transfection success: specifically, lamellar lipoplex formulations, which were readily susceptible to undergoing lamellar-nonlamellar (precisely lamellar-cubic) phase transition upon mixing with cellular lipids, were found rather consistently associated with superior transfection potency, presumably as a result of facilitated DNA release subsequent to lipoplex fusion with the cellular membranes. Further, hydrophobic moiety of the cationic phospholipids was found able to strongly modulate liposomal gene delivery into primary human umbilical artery endothelial cells; superior activity was found for cationic phosphatidylcholine derivatives with two 14-carbon atom monounsaturated hydrocarbon chains, able to induce formation of cubic phase in membranes. Thus, understanding the lipoplex structure and the phase changes upon interacting with membrane lipids is important for the rational design and successful application of cationic lipids as superior nucleotide delivery agents.
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Koynova R, Wang L, MacDonald RC. Cationic Phospholipids Forming Cubic Phases: Lipoplex Structure and Transfection Efficiency. Mol Pharm 2008; 5:739-44. [DOI: 10.1021/mp800011e] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Rumiana Koynova
- Department of Biochemistry, Molecular Biology and Cell Biology, Northwestern University, Evanston, Illinois 60208
| | - Li Wang
- Department of Biochemistry, Molecular Biology and Cell Biology, Northwestern University, Evanston, Illinois 60208
| | - Robert C. MacDonald
- Department of Biochemistry, Molecular Biology and Cell Biology, Northwestern University, Evanston, Illinois 60208
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Wang L, Koynova R, Parikh H, MacDonald RC. Transfection activity of binary mixtures of cationic o-substituted phosphatidylcholine derivatives: the hydrophobic core strongly modulates physical properties and DNA delivery efficacy. Biophys J 2006; 91:3692-706. [PMID: 16935955 PMCID: PMC1630455 DOI: 10.1529/biophysj.106.092700] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A combination of two cationic lipid derivatives having the same headgroup but tails of different chain lengths has been shown to have considerably different transfection activity than do the separate molecules. Such findings point to the importance of investigating the hydrophobic portions of cationic amphiphiles. Hence, we have synthesized a variety of cationic phosphatidylcholines with unusual hydrophobic moieties and have evaluated their transfection activity and that of their mixtures with the original molecule of this class, dioleoyl-O-ethylphosphatidylcholine (EDOPC). Four distinct relationships between transfection activity and composition of the mixture (plotted as percent of the new compound added to EDOPC) were found, namely: with a maximum or minimum; with a proportional change; or with essentially no change. Relevant physical properties of the lipoplexes were also examined; specifically, membrane fusion (by fluorescence resonance energy transfer between cationic and anionic lipids) and DNA unbinding (measured as accessibility of DNA to ethidium bromide by electrophoresis and by fluorescence resonance energy transfer between DNA and cationic lipid), both after the addition of negatively charged membrane lipids. Fusibility increased with increasing content of second cationic lipid, regardless of the transfection pattern. However, the extent of DNA unbinding after addition of negatively charged membrane lipids did correlate with extent of transfection. The phase behavior of cationic lipids per se as well as that of their mixtures with membrane lipids revealed structural differences that may account for and support the hypothesis that a membrane lipid-triggered, lamellar-->nonlamellar phase transition that facilitates DNA release is critical to efficient transfection by cationic lipids.
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Affiliation(s)
- Li Wang
- Department of Biochemistry, Molecular Biology and Cell Biology, Northwestern University, Evanston, Illinois, USA
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Tumanova I, Boyer J, Ausar SF, Burzynski J, Rosencrance D, White J, Scheidel J, Parkinson R, Maguire H, Middaugh CR, Weiner D, Green AP. Analytical and biological characterization of supercoiled plasmids purified by various chromatographic techniques. DNA Cell Biol 2006; 24:819-31. [PMID: 16332179 DOI: 10.1089/dna.2005.24.819] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Supercoiled plasmids are an important component of gene-based delivery vehicles. A number of production methods for clinical applications have been developed, each resulting in very high-quality product with low levels of residual contaminants. There is, however, no consensus on the optimal methods to characterize plasmid quality, and further, to determine if these methods are predictive of either product stability or biological activity. We have produced two plasmids using four production purification methodologies based on PolyFlo and hydrophobic interaction chromatography (HIC), either alone or in tandem processes. In each case, the product was analyzed using standard molecular biological methods. We also performed a number of biophysical analyses such as dynamic light scattering (DLS), circular dichroism (CD), Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC). Minimal differences were detected among the preparations based on the more standard molecular biological methods. Some small differences were detected, however, using biophysical techniques, particularly FTIR and DSC, which may reflect small variations in plasmid tertiary structure and thermal stability. Stability after heat exposure at 60 degrees C, exposure to fetal bovine serum and long-term storage at 4 degrees C varied between plasmids. One plasmid showed no difference in stability depending on the production process, but the other showed significant differences. Evaluation in vivo in models for gene immunization and gene therapy showed significant differences in the response depending on the method of purification. Preparations using a tandem process of PolyFlo used in two separation modes provided higher biological activity compared to a tandem HIC/PolyFlo process or either resin used alone in a single column process. These data indicate that the process by which supercoiled plasmids are made can influence plasmid stability and biological activity and emphasize the need for more rigorous methods to evaluate supercoiled plasmids as gene-delivery vehicles.
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Utku Y, Dehan E, Ouerfelli O, Piano F, Zuckermann RN, Pagano M, Kirshenbaum K. A peptidomimetic siRNA transfection reagent for highly effective gene silencing. MOLECULAR BIOSYSTEMS 2006; 2:312-7. [PMID: 16880950 DOI: 10.1039/b603229j] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
RNA interference (RNAi) techniques hold forth great promise for therapeutic silencing of deleterious genes. However, clinical applications of RNAi require the development of safe and efficient methods for intracellular delivery of small interfering RNA (siRNA) oligonucleotides specific to targeted genes. We describe the use of a lipitoid, a cationic oligopeptoid-phospholipid conjugate, for non-viral transfection of synthetic siRNA oligos in cell culture. This peptidomimetic delivery vehicle allows for efficient siRNA transfection in a variety of human cell lines with negligible toxicity and promotes extensive downregulation of the targeted genes at both the protein and the mRNA level. We compare the lipitoid reagent to a standard commercial transfection reagent. The lipitoid is highly efficient even in primary IMR-90 human lung fibroblasts in which other commercial reagents are typically ineffective.
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Affiliation(s)
- Yeliz Utku
- Department of Chemistry, New York University, New York, NY 10003, USA
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Braun CS, Vetro JA, Tomalia DA, Koe GS, Koe JG, Middaugh CR. Structure/Function Relationships of Polyamidoamine/DNA Dendrimers as Gene Delivery Vehicles. J Pharm Sci 2005; 94:423-36. [PMID: 15614818 DOI: 10.1002/jps.20251] [Citation(s) in RCA: 185] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
PAMAM dendrimers are members of a class of polyamine polymers that demonstrate significant gene delivery ability. In this study, a selection of PAMAM dendrimers, spanning a range of sizes (generations 2, 4, 7, and 9) and transfection efficiencies, are characterized by various biophysical methods to search for structural properties that correlate with transfection. Measurements of colloidal properties (size and zeta potential) as a function of charge ratio reveal that highly transfecting dendrimer/DNA complexes have size/zeta potential values between 4 and 8. Circular dichroism (CD) and FTIR spectroscopy of complexes confirm the DNA component remains in B form when associated with all dendrimer generations up to a 5:1 charge ratio (+/-). Isothermal titration calorimetry and differential scanning calorimetry detect changes that are related to polymer structure and charge ratio but do not directly correlate with transfection efficiency. Despite DNA structural and stability changes detected by CD, FTIR, DSC, and ITC that are similar to those seen with other cationic delivery vehicles [e.g., cationic lipids, peptoids/lipitoids, peptides, polyethyleneimines (PEIs), etc.], clear correlations with transfection activity are not readily apparent. This may be due, at least in part, to the heterogeneity of the complexes.
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Affiliation(s)
- Chad S Braun
- Department of Pharmaceutical Chemistry, University of Kansas, 2095 Constant Ave., Lawrence, Kansas 66047, USA
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Roth CM, Sundaram S. Engineering synthetic vectors for improved DNA delivery: insights from intracellular pathways. Annu Rev Biomed Eng 2004; 6:397-426. [PMID: 15255775 DOI: 10.1146/annurev.bioeng.6.040803.140203] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Significant progress has been made in the area of nonviral gene delivery to date. Yet, synthetic vectors remain less efficient by orders of magnitude than their viral counterparts. Research continues toward unraveling and overcoming various barriers to the efficient delivery of DNA, whether in plasmid form encoding a gene or as an oligonucleotide for the selective inhibition of target gene expression. Novel components for overcoming these hurdles are continually being incorporated into the design of synthetic vectors, leading to increasingly more virus-like particles. Despite these advances, general principles defining the design of synthetic vectors are yet to be developed fully. A more quantitative analysis of the cellular uptake and intracellular processing of these vectors is required for the rational manipulation of vector design. Mathematical frameworks with a more conceptual basis will help obtain an integrated perspective on these complex systems. In this review, we critically examine the progress made toward the improved design of synthetic vectors by the strategic exploitation of intracellular mechanisms and explore newer possibilities to overcome obstacles in the practical realization of this field.
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Affiliation(s)
- Charles M Roth
- Department of Chemical and Biochemical Engineering, Rutgers University, Piscataway, New Jersey 08854, USA.
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