Mixed micelles obtained by co-assembling comb-like and grafting copolymers as gene carriers for efficient gene delivery and expression in endothelial cells

Gene delivery can enhance the endothelialization of biomaterial surfaces. However, the lack of efficient target function is still the major concern that hinders the clinical application of gene therapy. With the aim to develop a specific targeting gene carrier for endothelial cells (ECs), the Cys-Arg-Glu-Asp-Val-Trp (CREDVW) peptide was linked to the comb-like copolymer of poly(lactide-co-3(S)-methyl-morpholine2,5- dione)-poly(poly(ethylene glycol) monomethacrylate) (PLMD-PPEGMA) to form the CREDVW modified copolymer PLMD-PPEGMA-CREDVW, which could enhance the special recognition of ECs. Mixed micelles were then prepared by co-assembling this comb-like copolymer and the amphiphilic grafting copolymer poly(lactide-co-3(S)-methyl-morpholine-2,5-dione)-g-polyethylenimine (PLMD-g-PEI). These mixed micelles with the CREDVW-functional peptide exhibited good pEGFP-ZNF580 (pDNA) binding ability and could condense it into complexes with proper size and positive zeta potential. The MTT results demonstrated the low cytotoxicity of the CREDVW-modified mixed micelle/pDNA complexes. The internalization efficiency of the CREDVW-modified complexes with targeting function was about two times higher than the dysfunctional CREVDW-modified complexes. Besides, the transfection efficiency of these complexes was more pronounced, compared to the control group, PEI(10 kDa)/pDNA, as detected by means of in vitro transfection studies. Western blot analysis demonstrated relatively high protein levels in the transfected cells by CREDVW-modified mixed micelle/pDNA complexes, up to 75%, in comparison to the control group (26%). In addition, the cell migration ability was significantly improved as demonstrated by the wound healing assay. These results indicated that the mixed micelles could act as an active targeting gene carrier, having both tunable gene transfection efficiency and low cytotoxicity, which are beneficial for the endothelialization of biomaterial surface.