Covalent conjugation of polyethyleneimine on biodegradable microparticles for delivery of plasmid DNA vaccines.
ABSTRACT Microparticle-based delivery of nucleic acids has gained particular attention in recent years in view of improving the potency of DNA vaccination. Such improvement has been reported by encapsulation of pDNA within biodegradable microparticles or through surface adsorption on cationic microparticles. However, the intrinsic intracellular barriers for gene delivery to antigen presenting cells (APCs) have not been adequately addressed in the rational design of delivery systems for DNA vaccines. Here we report synthesis and characterization of biodegradable microparticles that (a) can passively target phagocytic APCs, (b) have intrinsic buffering ability that might allow for enhanced phagosomal escape, (c) are not cytotoxic and (d) have improved APC transfection efficiency. Branched polyethyleneimine (b-PEI) was covalently conjugated using carbodiimide chemistry to the surface of poly(lactide-coglycolide) (PLGA) microparticles to create cationic microparticles capable of simultaneously delivering both DNA vaccines as well as other immunomodulatory agents (cytokines or nucleic acids) within a single injectable delivery vehicle. Our results indicate that covalent conjugation of b-PEI allows efficient surface loading of nucleic acids, introduces intrinsic buffering properties to PLGA particles and enhances transfection of phagocytic cells without affecting the cytocompatibility of PLGA carriers.
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ABSTRACT: The goal of this study was to enhance gene delivery and tumor cell transfection in vivo by using a combination of ultrasonication with complex nanoparticles consisting of two types of nanoparticles: PEI/DNA beta-gal plasmid with highly positive zeta-potential and air-filled poly (lactic-co-glycolic acid) (PLGA) particles (with negative zeta-potential) manufactured in our laboratory. The PLGA/PEI/DNA nanoparticles were a colloid with positive zeta-potential and injected i.v. in nude mice with DU145 human prostate tumors. We found that the combination of PLGA/PEI/DNA nanoparticles with ultrasonication substantially enhanced tumor cell transfection in vivo. The overexpression of beta-gal gene was evaluated histochemically and by Western blot analysis. At least an 8-fold increase of the cell transfection efficacy was obtained in irradiated tumors compared to non-irradiated controls, while little to no cell death was produced by ultrasonication.Cancer Letters 04/2008; 261(2):215-25. DOI:10.1016/j.canlet.2007.11.023 · 5.02 Impact Factor
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ABSTRACT: Porcine reproductive and respiratory syndrome (PRRS) is an economically devastating viral disease of pigs. Safer and more effective vaccines are urgently needed. In this study, a synthetic ORF5 gene of porcine reproductive and respiratory syndrome virus (PRRSV) was adsorbed onto poly(D, L-lactide-co-glycolide)/polyethylenimine (PLGA/PEI) nanoparticles. We prepared a PLGA-nanoparticle-adsorbed PRRSV DNA vaccine and a PEI-DNA complex. The results showed that these model vaccines could significantly enhance humoral and cellular immune responses when compared with the responses induced by pcDNA3.1-SynORF5, a plasmid construct for expression of PRRSV ORF5. PLGA-branched PEI nanoparticles induced the most efficient immune response. The delivery system and adjuvant provide new models for the development of vaccines against PRRSV.Archives of Virology 04/2015; 160(6). DOI:10.1007/s00705-015-2396-0 · 2.28 Impact Factor
Dataset: 5 2012