Katayose S, Kataoka K
Department of Materials Science and Technology, University of Tokyo, Chiba, Japan.
J Pharm Sci. 1998 Feb;87(2):160-3. doi: 10.1021/js970304s.
Supramolecular associates of DNA with Poly(ethylene glycol)-poly(L-lysine) block copolymers (PEG-PLL) were prepared in aqueous milieu, and the water solubility under charge-neutralized (stoichiometric) conditions was maintained. Associates thus prepared achieved remarkable resistance against nuclease attack, probably due to the formation of PEG palisade surrounding the ion-complexed core of the DNA with the PLL segment of the block copolymer. Further, to estimate the stability of the associate, the rate of interexchange reaction of DNA in the associate with poly(vinyl sulfonate) was evaluated from a method using a metachromasy of toluidine blue dye. Of interest, the nuclease resistance of DNA in PEG-PLL/DNA associate had an inverse correlation with the rate of interexchange reaction and, thus, progressively increased with an increase in the molecular weight of PLL segment in the block copolymer, indicating the substantial importance of block copolymer design for DNA stabilization.
在水介质中制备了DNA与聚（乙二醇）-聚（L-赖氨酸）嵌段共聚物（PEG-PLL）的超分子缔合物，并在电荷中和（化学计量）条件下保持了其水溶性。由此制备的缔合物对核酸酶攻击具有显著抗性，这可能是由于嵌段共聚物的PLL链段围绕与离子复合的DNA核心形成了PEG栅栏。此外，为了评估缔合物的稳定性，通过使用甲苯胺蓝染料的变色法评估了缔合物中DNA与聚（乙烯磺酸盐）的交换反应速率。有趣的是，PEG-PLL/DNA缔合物中DNA的核酸酶抗性与交换反应速率呈负相关，因此随着嵌段共聚物中PLL链段分子量的增加而逐渐增加，这表明嵌段共聚物设计对DNA稳定化具有至关重要的意义。
