Synthesis and properties of Polycaprolactone‐graft‐poly(2‐(dimethylamino)ethyl methacrylate‐co‐methoxy polyethylene glycol monomethacrylate) as non‐viral gene vector
ABSTRACT Polycaprolactone-graft-Poly(2-(dimethylamino)ethyl methacrylate-co-methoxy polyethylene glycol monomethacrylate) (PCL-graft-P(DMAEMA-co-mPEGMMA)) was synthesized by combination of ring-opening polymerization (ROP) and atom transfer radical polymerization (ATRP). PCL-graft-P(DMAEMA-co-mPEGMMA) was characterized by FTIR, 1H NMR, and GPC. PCL-graft-P(DMAEMA-co-mPEGMMA) with expected composition and structure was achieved. pH- and thermo-sensitive properties of the PCL-graft-P(DMAEMA-co-mPEGMMA) nanoparticles prepared by the nanoprecipitation method were investigated by TEM and DLS. With increase in the temperature, the size of PCL-graft-P(DMAEMA-co-mPEGMMA) nanoparticles is decreased under base environment. Furthermore, in vitro transfection and toxicity assays were tested in 293T cells. The results indicate that PCL-graft-P(DMAEMA-co-PEGMMA) has lower cytotoxicity at N/P ratios less than 10 with transfection efficiency concomitantly reducing at N/P ratios less than 20 compared to PCL-graft-PDMAEMA as the control. However, PCL-graft-P(DMAEMA-co-PEGMMA) presents higher transfection efficiency at N/P ratios more than 20 compared to PCL-graft-PDMAEMA. Copyright © 2010 John Wiley & Sons, Ltd.
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ABSTRACT: Nanoparticles (NPs) assembled from amphiphilic polycations has been certificated as potential carriers for gene delivery. Structural modification on polycation moieties may be an efficient route to further enhance gene delivery efficiency. In this study, two electroneutral monomers with different hydrophobicity, 2-hydroxyethyl methacrylate (HEMA) and 2-hydroxyethyl acrylate (HEA), are respectively incorporated into the cationic PDMAEMA side chains of amphiphilic poly(ε-caprolactone)-graft-poly(dimethylamino ethylmethacrylate) (PCD) by random copolymerization, to obtain poly(ε-caprolactone)-graft-poly(dimethylamino ethyl methacrylate-co-2-hydroxyethyl methacrylate) (PCD-HEMA) and poly(ε-caprolactone)-graft-poly(dimethylamino ethyl methacrylate-co-2-hydroxyethyl acrylate) (PCD-HEA). Minimal HEA or HEMA moieties in PDMAEMA do not lead to statistically significant changes in particle size, zeta potential, DNA condensation properties and buffering capacity of the naked NPs. But the incorporation of HEMA and HEA respectively leads to reduction and increase in the surface hydrophilicity of the naked NPs and NPs/DNA complexes which is confirmed by water contact angles assay. These simple modifications on PDMAEMA by HEA and HEMA moieties significantly affect the gene transfection efficiency on HeLa cells in vitro: PCD-HEMA NPs/DNA complexes show much higher transfection efficiency than PCD NPs/DNA complexes, while PCD-HEA NPs/DNA complexes show lower transfection efficiency than PCD NPs/DNA complexes. Fluorescence activated cell sorter and confocal laser scanning microscope results indicate that the incorporation of hydrophobic HEMA moieties facilitates the enhancement in both cellular uptake and endosomal/lysosomal escape, leading to the higher transfection efficiency. Moreover, the process of endosomal/lysosomal escape is confirmed in our research that the PCD and its derivatives do not just rely on the proton sponge mechanism, but the membranous damage owing to polycation chains, especially the hydrophobic modified ones. Hence, it is proved that hydrophobic modification of cationic side chains is a crucial route to improve gene transfection mediated by polycation NPs.Acta biomaterialia 10/2013; · 5.68 Impact Factor
- Journal of The American College of Cardiology - J AMER COLL CARDIOL. 01/2011; 57(14).
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ABSTRACT: Coating the polycation/DNA binary complexes with PEGylated polyanions can improve long-circulation and biocompatibility in vivo. However, it has been certificated PEG dilemma can reduces gene transfection efficiency because of inhibition in cellular uptake and endosomal escape. Herein, two PEGylated anionic polymers, PEGylated hyaluronic acid (HgP) and PEGylated polyglutamic acid (PGgP) were synthesized to coat the binary complexes of core-shell cationic polycaprolactone-graft-poly (N, N-dimethylaminoethyl methacrylate) nanoparticles/DNA (NP-D). The effects of polyanion structure were evaluated in terms of particle size, zeta potential, cytotoxicity, cellular uptake and transfect efficiency in vitro and in vivo. In vitro study illustrated that HgP coated complexes showed better efficiencies in both cell uptake and transfection than PGgP coated complexes. The coating of HgP on NP-D improved the biocompatibility without reduction in cell uptake and transfection efficacy, and resulted in higher accumulation and gene expression in tumor after IV injection. The success of HgP coating in overcoming PEG dilemma is attributed to the hyaluronic acid (HA)-receptor-mediated endocytosis and outer shell-detachment through the hyaluronidases catalyzed degradation of HA. These results demonstrated that HgP was a promising anionic polymer for coating the polycation/DNA complexes and ternary complexes (HgP coated NP-D) hold promising potential for cancer therapy.Biomaterials 05/2013; · 8.31 Impact Factor