101
|
Thomas M, Lu JJ, Ge Q, Zhang C, Chen J, Klibanov AM. Full deacylation of polyethylenimine dramatically boosts its gene delivery efficiency and specificity to mouse lung. Proc Natl Acad Sci U S A 2005; 102:5679-84. [PMID: 15824322 PMCID: PMC556302 DOI: 10.1073/pnas.0502067102] [Citation(s) in RCA: 303] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
High-molecular-mass polyethylenimines (PEIs) are widely used vectors for nucleic acid delivery. We found that removal of the residual N-acyl moieties from commercial linear 25-kDa PEI enhanced its plasmid DNA delivery efficiency 21 times in vitro, as well as 10,000 times in mice with a concomitant 1,500-fold enhancement in lung specificity. Several additional linear PEIs were synthesized by acid-catalyzed hydrolysis of poly(2-ethyl-2-oxazoline), yielding the pure polycations. PEI87 and PEI217 exhibited the highest efficiency in vitro: 115-fold and 6-fold above those of the commercial and deacylated PEI25s, respectively; moreover, PEI87 delivered DNA to mouse lung as efficiently as the pure PEI25 but at a lower concentration and with a 200-fold lung specificity. These improvements stem from an increase in the number of protonatable nitrogens, which presumably results in a tighter condensation of plasmid DNA and a better endosomal escape of the PEI/DNA complexes. As a validation of the potential of such linear, fully deacylated PEIs in gene therapy for lung diseases, systemic delivery in mice of the complexes of a short interfering RNA (siRNA) against a model gene, firefly luciferase, and PEI25 or PEI87 afforded a 77% and 93% suppression of the gene expression in the lungs, respectively. Furthermore, a polyplex of a siRNA against the influenza viral nucleocapsid protein gene and PEI87 resulted in a 94% drop of virus titers in the lungs of influenza-infected animals.
Collapse
Affiliation(s)
- Mini Thomas
- Department of Chemistry and Division of Biological Engineering, Center for Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | | | | | | | | | | |
Collapse
|
102
|
Chen DJ, Majors BS, Zelikin A, Putnam D. Structure–function relationships of gene delivery vectors in a limited polycation library. J Control Release 2005; 103:273-83. [PMID: 15710517 DOI: 10.1016/j.jconrel.2004.11.028] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2004] [Revised: 11/23/2004] [Accepted: 11/24/2004] [Indexed: 11/30/2022]
Abstract
A library of 13 polylysine-graft-imidazoleacetic acid conjugates was synthesized to examine the collective effects of polymer molecular weight, side chain substitution, and DNA:polymer ratio on cytotoxicity, transfection efficiency, and polycation-DNA interaction. In general, the relationships between the physicochemical characteristics and the gene transfer capabilities of these polycations appear nonlinear. The in vitro cytotoxicity of these polymers decreased, while total protein expression increased, with decreasing molecular weight and increasing imidazole content. Flow cytometry experiments indicated, however, that an increase in marker gene expression does not always correlate with the total number of cells transfected, even when similar polymer structures are used for transfection. The maximum level of luciferase gene expression was mediated by transfection with a low molecular weight, high imidazole content (9400 Mw, 95 mol% imidazole) polymer. The extent of DNA condensation, as determined by ethidium bromide fluorescence quenching, also decreased with decreasing polymer molecular weight and increasing imidazole content. Relative binding affinity between DNA and the polycations, measured via competitive binding in the presence of a synthetic polyanion, decreased with decreasing polymer molecular weight; however, the relative affinity also appeared to increase with increasing imidazole, suggesting that electrostatic contributions are not solely responsible for DNA-polycation binding interactions. This limited library and corresponding structure/function analysis forms the foundation upon which larger, more comprehensive polycationic libraries can be designed and evaluated to further understand how polycation transfection reagents function.
Collapse
Affiliation(s)
- David J Chen
- School of Chemical and Biomolecular Engineering, Cornell University, 120 Olin Hall, Ithaca, NY 14853, USA
| | | | | | | |
Collapse
|
103
|
Funhoff AM, van Nostrum CF, Lok MC, Kruijtzer JAW, Crommelin DJA, Hennink WE. Cationic polymethacrylates with covalently linked membrane destabilizing peptides as gene delivery vectors. J Control Release 2005; 101:233-46. [PMID: 15588908 DOI: 10.1016/j.jconrel.2004.06.023] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2004] [Accepted: 06/01/2004] [Indexed: 10/26/2022]
Abstract
A membrane-disrupting peptide derived from the influenza virus was covalently linked to different polymethacrylates (pDMAEMA, pDAMA and the degradable pHPMA-DMAE, monomers depicted in Fig. 1) using N-succinimidyl 3-(2-pyridyldithio)propionate (SPDP) as coupling agent to increase the transfection efficiency of polyplexes based on these polymers. It was shown by circular dichroism (CD) measurements that the polymer-conjugated peptide was, as the free peptide, able to undergo a conformational change of a random coil to an alpha helix upon lowering the pH to 5.0. This indicates that the property of the peptide to destabilize the endosomal membrane was preserved after its conjugation to the cationic polymers. In line herewith, a liposome leakage assay revealed that the polymer-bound peptide has comparable activity as the free peptide. The DNA condensing properties of the synthesized polymer-peptide conjugates were studied with dynamic light scattering and zeta-potential measurements, and it was shown that small (100 to 250 nm), positively charged (+15 to +20 mV) particles were formed. In vitro transfection and toxicity was tested in COS-7 cells, and these experiments showed that the polyplexes with grafted peptide had a substantially higher transfection activity than the control polyplexes, while the toxicity remained unchanged. Cellular uptake of the polyplexes was visualized with confocal laser scanning microscopy, and no differences in cellular uptake could be determined between the peptide containing systems and the control formulation. This shows that the increased transfection activity is indeed due to a better endosomal escape of the peptide grafted polyplexes. This study demonstrates that it is possible to covalently conjugate an endosome disruptive peptide to cationic gene delivery polymers with preservation of its membrane destabilization activity, making these conjugates suitable for in vivo DNA delivery.
Collapse
Affiliation(s)
- Arjen M Funhoff
- Department of Pharmaceutics, Utrecht Institute for Pharmaceutical Sciences (UIPS), Utrecht University, P.O. Box 80082, 3508 TB Utrecht, The Netherlands
| | | | | | | | | | | |
Collapse
|
104
|
Mao HQ, Leong KW. Design of Polyphosphoester‐DNA Nanoparticles for Non‐Viral Gene Delivery. NON-VIRAL VECTORS FOR GENE THERAPY, SECOND EDITION: PART 1 2005; 53PA:275-306. [PMID: 16243068 DOI: 10.1016/s0065-2660(05)53011-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
Development of safe and effective non-viral gene carriers is still critical to the ultimate success of gene therapy. This review highlights our attempt to design the gene carriers in a systematic manner. We have synthesized a series of polymers with a phosphoester backbone containing different charge groups in the sidechain connected to the backbone through a phosphate (PO) or a phosphoramide (PN) bond. These gene carriers have different charge groups, sidechain lengths, and branching structures, but they are structurally related to allow a systematic investigation of the structure-property relationship, including DNA binding capacity, cytotoxicity, DNA protection, biodegradability, DNA release kinetics, and transfection efficiency.
Collapse
Affiliation(s)
- Hai-Quan Mao
- Department of Materials Science and Engineering The Johns Hopkins University, Baltimore, Maryland 21205
| | | |
Collapse
|
105
|
Son S, Chae SY, Choi C, Kim MY, Ngugen VG, Jang MK, Nah JW, Kweon JK. Preparation of a hydrophobized chitosan oligosaccharide for application as an efficient gene carrier. Macromol Res 2004. [DOI: 10.1007/bf03218446] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
106
|
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.
Collapse
Affiliation(s)
- Charles M Roth
- Department of Chemical and Biochemical Engineering, Rutgers University, Piscataway, New Jersey 08854, USA.
| | | |
Collapse
|
107
|
Kim EM, Jeong HJ, Heo YJ, Moon HB, Bom HS, Kim CG. Intratumoral injection of 188Re labeled cationic polyethylenimine conjugates: a preliminary report. J Korean Med Sci 2004; 19:647-51. [PMID: 15483337 PMCID: PMC2816324 DOI: 10.3346/jkms.2004.19.5.647] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
188Re (Rhenium) is easily obtained from an in-house 188W/188Re generator that is similar to the current 99Mo/99mTc generator, making it very convenient for clinical use. This characteristic makes this radionuclide a promising candidate as a therapeutic agent. Polyethylenimine (PEI) is a cationic polymer and has been used as a gene delivery vector. Positively charged materials interact with cellular blood components, vascular endothelium, and plasma proteins. In this study, the authors investigated whether intratumoral injection of 188Re labeled transferrin (Tf)-PEI conjugates exert the effect of radionuclide therapy against the tumor cells. When the diameters of the Ramos lymphoma (human Burkitt's lymphoma) xenografted tumors reached approximately 1 cm, 3 kinds of 188Re bound compounds (HYNIC-PEI-Tf, HYNIC-PEI, 188Re perrhenate) were injected directly into the tumors. There were increases in the retention of 188Re inside the tumor when PEI was incorporated with 188Re compared to the use of free 188Re. The 188Re HYNIC-Tf-PEI showed the most retention inside the tumor (retention rate=approximately 97%). H&E stain of isolated tumor tissues showed that 188Re labeled HYNIC-PEI-Tf caused extensive tumor necrosis. These results support 188Re HYNIC-PEI-Tf as being a useful radiopharmaceutical agent to treat tumors when delivered by intratumoral injection.
Collapse
Affiliation(s)
- Eun-Mi Kim
- Department of Nuclear Medicine, Wonkwang University School of Medicine, Iksan, Korea
| | - Hwan-Jeong Jeong
- Department of Nuclear Medicine, Wonkwang University School of Medicine, Iksan, Korea
- Wonkwang University Institute of Medical Science, Wonkwang University School of Medicine, Iksan, Korea
| | - Young-Jun Heo
- Department of Nuclear Medicine, Chonnam National University School of Medicine, Gwangju, Korea
| | - Hyung-Bae Moon
- Wonkwang University Institute of Medical Science, Wonkwang University School of Medicine, Iksan, Korea
- Department of Pathology, Wonkwang University School of Medicine, Iksan, Korea
| | - Hee-Seung Bom
- Department of Nuclear Medicine, Chonnam National University School of Medicine, Gwangju, Korea
| | - Chang-Guhn Kim
- Department of Nuclear Medicine, Wonkwang University School of Medicine, Iksan, Korea
| |
Collapse
|
108
|
Kim EM, Jeong HJ, Park IK, Cho CS, Bom HS, Kim CG. Monitoring the effect of PEGylation on polyethylenimine in vivo using nuclear imaging technique. Nucl Med Biol 2004; 31:781-4. [PMID: 15246369 DOI: 10.1016/j.nucmedbio.2004.03.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2003] [Revised: 03/11/2004] [Accepted: 03/16/2004] [Indexed: 11/18/2022]
Abstract
Polyethyleneimine (PEI) has been extensively investigated for use as a nonviral gene delivery vector due to its "proton sponge" mechanism. This work monitored the effect of PEGylation in vivo using nuclear imaging technique. We synthesized galactosylated PEI-PEG with different levels of PEG substitution ranging from 4.1 to 13.3 mol% of PEI amino groups. Validation of the differences of the in vivo distribution in the varying degrees of PEG substitution was performed using nuclear imaging with a gamma camera. PEGylated PEIs could easily label with reduced 99mTc because of their interaction with PEI amino groups. After systemic administration of 99mTc PEGylated Gal-PEIs, rapid accumulation in the liver, spleen, and lung was observed. However, with increasing amounts of PEG, the lung uptake was markedly reduced. These results demonstrate that nuclear imaging technique may be used as a basic screening tool for determining the optimized system of PEGylated Gal-PEIs. Once optimized, this system could be used as a hepatocyte targeted non-viral gene delivery vector which minimizes unspecific interactions with cellular blood components such as vessel endothelia and plasma proteins.
Collapse
Affiliation(s)
- Eun-Mi Kim
- Department of Nuclear Medicine, Wonkwang University School of Medicine, Iksan, South Korea
| | | | | | | | | | | |
Collapse
|
109
|
Frisch B, Carrière M, Largeau C, Mathey F, Masson C, Schuber F, Scherman D, Escriou V. A New Triantennary Galactose-Targeted PEGylated Gene Carrier, Characterization of Its Complex with DNA, and Transfection of Hepatoma Cells. Bioconjug Chem 2004; 15:754-64. [PMID: 15264862 DOI: 10.1021/bc049971k] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Nonviral gene vectors remain inefficient in vivo largely because of their rapid clearance from the circulation and also their nonspecific association with the extracellular matrix. To overcome such drawbacks, cationic lipoplexes are now frequently coated with hydrophilic polymers such as PEGs to reduce nonspecific interactions, and ligands are also linked to their surface to obtain cell-specific gene transfer. In view of the development of vectors for systemic gene delivery, we have designed and studied lipoplexes that carry a triantennary galactosyl ligand attached to the distal end of a (PEG)45-conjugated lipid. We incorporated this targeted PEGylated lipid into lipoplexes using two strategies of formulation, i.e., using either preformed micelles or liposomes. We demonstrated that the incorporation of PEG chains stabilized lipoplexes and masked, but only partially, the positive charges exposed on the surface of the particles. We have also shown that incorporation into lipoplexes of a lipidated PEG chain, bearing a ligand at its distal end, yielded particles that exhibited an accessible ligand throughout the whole range of cationic lipid to DNA ratios. We obtained a targeted transfection in HepG2 cells with one of the formulations. Our results strengthen the validity of using a ligand carried by a long PEG spacer arm for targeted gene transfer.
Collapse
Affiliation(s)
- Benoît Frisch
- Unité de Pharmacologie Chimique et Génétique, CNRS FRE2463, INSERM U640, Faculté des Sciences Pharmaceutiques et Biologiques de Paris, 4 av de l'Observatoire, 75270 Paris Cedex 06, France
| | | | | | | | | | | | | | | |
Collapse
|
110
|
Goh SL, Murthy N, Xu M, Fréchet JMJ. Cross-Linked Microparticles as Carriers for the Delivery of Plasmid DNA for Vaccine Development. Bioconjug Chem 2004; 15:467-74. [PMID: 15149173 DOI: 10.1021/bc034159n] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Plasmid DNA was directly encapsulated into biocompatible polymer microparticles via radical polymerization in an inverse emulsion system. Acrylamide-based microspheres 0.2-1 microm in diameter were prepared using an acid-cleavable difunctional monomer. Retention of the DNA payload at physiological pH with complete release under acidic conditions at lysosomal pH was demonstrated. By trapping the plasmid DNA within the cross-linked microparticle, enzymatic degradation was prevented when exposed to serum nucleases. For vaccine development, these delivery vehicles were also investigated for their ability to generate immune responses when delivered to phagocytic cells of the immune system. Encapsulated plasmid DNA demonstrated immunostimulatory activity in macrophages, leading to cytokine secretion of IL-6 with a response approximately 40-fold higher than that achieved with DNA alone.
Collapse
Affiliation(s)
- Sarah L Goh
- Center for New Directions in Organic Synthesis, Department of Chemistry, University of California-Berkeley, Berkeley, CA 94720-1460, USA
| | | | | | | |
Collapse
|
111
|
Wen SY, Wang XH, Lin L, Guan W, Wang SQ. Preparation and property analysis of a hepatocyte targeting pH-sensitive liposome. World J Gastroenterol 2004; 10:244-9. [PMID: 14716832 PMCID: PMC4717013 DOI: 10.3748/wjg.v10.i2.244] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
AIM: To develop a hepatocyte targeting pH-sensitive liposome for drug delivery based on active targeting technology mediated by asialoglycoprotein receptors.
METHODS: Four types of targeting molecules with galactose residue were synthesized and mixed with pH-sensitive lipids DC-chol/DOPE to prepare liposome with integrated property of hepatocyte specificity and pH sensitivity. Liposome 18-gal was selected with the best transfection activity through cellular uptake experiment. Property analysis was made through experiments of competitive inhibition of receptors, red blood cell hemolysis, in vitro cytotoxicity test by MTS assay and mediation of inhibitory effects of antisense phosphorothioate ODN on gene expression, etc.
RESULTS: Liposome 18-gal had the desired properties of hepatocyte specificity, pH sensitivity, low cytotoxicity, and high transfection efficiency.
CONCLUSION: Liposome 18-gal can be further developed as a potential hepatocyte- targeting delivery system.
Collapse
Affiliation(s)
- Si-Yuan Wen
- Beijing Institute of Radiation Medicine, Beijing 100850, China
| | | | | | | | | |
Collapse
|