Onishi Yasuhiko, Eshita Yuki, Murashita Aya, Mizuno Masaaki, Yoshida Jun
School of Engineering, Nippon Bunri University, Oita, Japan.
Nanomedicine. 2007 Sep;3(3):184-91. doi: 10.1016/j.nano.2007.07.002.
A stable and soapless latex of diethylaminoethyl-dextran-methyl methacrylate (DEAE-dextran-MMA) graft copolymer (DDMC) has been developed for nonviral gene delivery vectors that are possible to autoclave. DDMC relatively easily formed a polyion complex between DNA and DDMC by the hydrophobic force of graft poly(MMA) depending on its large positive entropy change (DeltaS). DDMC has been confirmed as having a high protection facility for DNase by DNase degradation test.Transfection activity was determined using the beta-galactosidase assay, and a higher value of 16 times or more was confirmed for the DDMC samples in comparison with one of the starting DEAE-dextran hydrochloride samples. The resulting DDMC, having an amphiphilic domain so as to form a polymer micelle, should become a stable latex with a hydrophilic-hydrophobic microseparated domain. The complex of DDMC and plasmid DNA may be formed on the spherical structure of the amphiphilic microseparated domain of DDMC and have a good affinity to the cell membrane. The infrared absorption spectrum shift to a high-energy direction at around 3450 cm(-1), because of the complexes between DNA and DDMC, may cause the formation of more compact structures, not only by a coulomb force between the phosphoric acid of DNA and the DEAE group of DEAE-dextran copolymer but also by a force from the multi-intermolecule hydrogen bond in the backbone polymer DEAE-dextran and a hydrophobic force from the graft poly(MMA) in DDMC. It is thus concluded that DNA condensation may possibly have a high transfection efficiency via DDMC. The high efficiency of this graft copolymer, which is sterilized by an autoclave, may thus make it a valuable tool for safe gene delivery.
已开发出一种稳定且无皂的二乙氨基乙基-葡聚糖-甲基丙烯酸甲酯（DEAE-葡聚糖-MMA）接枝共聚物（DDMC）乳胶，用于可高压灭菌的非病毒基因递送载体。DDMC相对容易通过接枝聚（MMA）的疏水力在DNA和DDMC之间形成聚离子复合物，这取决于其较大的正熵变（ΔS）。通过DNase降解试验已证实DDMC对DNase具有高度保护作用。使用β-半乳糖苷酶测定法测定转染活性，与起始盐酸DEAE-葡聚糖样品之一相比，DDMC样品的转染活性值更高，证实为高16倍或更多。所得的具有两亲性结构域以形成聚合物胶束的DDMC应成为具有亲水-疏水微分离结构域的稳定乳胶。DDMC与质粒DNA的复合物可能在DDMC两亲性微分离结构域的球形结构上形成，并与细胞膜具有良好的亲和力。由于DNA和DDMC之间的复合物，红外吸收光谱在3450 cm(-1)左右向高能方向移动，这不仅可能通过DNA的磷酸与DEAE-葡聚糖共聚物的DEAE基团之间的库仑力，还可能通过主链聚合物DEAE-葡聚糖中的多分子氢键力以及DDMC中接枝聚（MMA）的疏水力，导致形成更紧密的结构。因此可以得出结论，通过DDMC进行DNA缩合可能具有较高的转染效率。这种可通过高压灭菌的接枝共聚物的高效率可能使其成为安全基因递送的有价值工具。
