title: The copolymer of Poly(2-dimethylaminoethyl methacrylate) and methacrylated chondroitin sulfate with low cytotoxicity for gene delivery.
abstract: Poly(2-dimethylaminoethyl methacrylate) (PDMAEMA) is one of the most potent synthetic nonviral gene-delivery vectors because of its high transfection efficiency. However, the cytotoxicity of PDMAEMA is a major concern for its clinical applications. An anionic crosslinker is synthesized based on a natural polysaccharide, chondroitin sulfate (CS), by introducing methacrylate groups (CSMA). By systematically adjusting the substitution degree of methacrylation on CS and the weight percent of CSMA and PDMAEMA, sol-type copolymers are obtained as a gene-delivery vector. The combination of CS and PDMAEMA is expected not only to reduce the cytotoxicity of PDMAEMA, but also to facilitate better transfection efficiency than PDMAEMA because of the recognition of CS by CD44 receptors on cell surfaces. Two CSMA-modified PDMAEMA copolymers with different CSMA constituents are selected and their polyplexes prepared with plasmid DNA. The cytotoxicity and gene transfection efficiency of the polyplexes are tested and compared with those of PDMAEMA/pDNA. The copolymers of CSMA and PDMAEMA show significantly improved cell viability as compared with PDMAEMA. Their formed polyplexes with pDNA also show lower cytotoxicity than does PDMAEMA/pDNA. The transfection efficiency remarkably increases as the CSMA-modified PDMAEMA/pDNA polyplex is prepared at a weight ratio of 2.4. The internalization mechanism of CSMA-modified PDMAEMA/pDNA in HEK 293T cells is mainly based on caveolae-mediated endocytosis. However, both caveolae-mediated and CD44-mediated endocytosis mechanisms are involved in U87 cells.
authors.affiliation: Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
authors.forename: Yu-Lun
authors.initials: YL
authors.lastname: Lo
authors.forename: Yao-Sheng
authors.initials: YS
authors.lastname: Wang
authors.forename: Li-Fang
authors.initials: LF
authors.lastname: Wang
mesh_terms: D016923:Cell Death / Q000187:drug effects; D002809:Chondroitin Sulfates / Q000138:chemical synthesis / Q000737:chemistry / Q000633:toxicity*; D004247:DNA / Q000378:metabolism; D004705:Endocytosis / Q000187:drug effects; D005434:Flow Cytometry; D016650:Fluorescein-5-isothiocyanate / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D018014:Gene Transfer Techniques; D057809:HEK293 Cells; D006801:Humans; D057446:Hydrodynamics; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D009682:Magnetic Resonance Spectroscopy; D008689:Methacrylates / Q000138:chemical synthesis / Q000737:chemistry / Q000633:toxicity*; D018613:Microscopy, Confocal; D046529:Microscopy, Electron, Transmission; D008970:Molecular Weight; D009757:Nylons; D010957:Plasmids / Q000378:metabolism; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry / Q000633:toxicity*; D017550:Spectroscopy, Fourier Transform Infrared; D055672:Static Electricity; D014162:Transfection
chemical_list: D008689:Methacrylates; D009757:Nylons; D011108:Polymers; C407037:poly(2-(dimethylamino)ethyl methacrylate); D002809:Chondroitin Sulfates; D004247:DNA; D016650:Fluorescein-5-isothiocyanate
keywords: chondroitin sulfate; nonviral vectors; poly(2-dimethylaminoethyl methacrylate); polyplexes; transfection