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目的:针对ED治疗方法的不足,设计和制备新型高效的高分子/基因复合药物控释体系,探讨pH、温度双敏感水凝胶体系在ED基因治疗中的可行性。方法:对聚赖氨酸/小干扰RNA(PLL/siRNA)基因复合物进行Zeta电位表征,制备最佳的siRNA基因纳米颗粒;以聚乙二醇-聚丙二醇-聚乙二醇嵌段共聚物(PEO-PPOPEO)为交联单元,通过化学改性在其两端引入苯甲醛基团,使其与壳聚糖反应形成苯甲酰亚胺键,从而制备pH、温度双敏感可注射基因药物控释体系,并对不同温度下控释体系的释放情况进行检测。结果:当PLL∶siRNA质量比为20∶1时,复合物的Zeta电势达到最大正值(+23.5 mV),siRNA被PLL最大程度的包裹;将环境pH由酸性(5.5)调至中性(7.4),壳聚糖和交联剂发生Schiff反应而交联,形成水凝胶;体系内包覆的siRNA在37℃时保持低释放,升高温度至60℃后释放量大幅增加,至1 000 min时,60℃条件下的累计释放量为(122.5±5.3)μg,而37℃下仅为(23.8±6.0)μg(P<0.05)。结论:成功制备高分子/基因复合药物控释体系,在保证基因药物高靶向性的同时,提高了基因载体的稳定性和容量,并实现siRNA的温控释放,将有望成为ED基因药物治疗中的新材料,为简捷方便的按需给药提供新手段。
OBJECTIVE: To design and prepare a novel and efficient polymer / gene drug-controlled drug delivery system for the treatment of ED deficiencies. To investigate the feasibility of pH sensitive dual temperature sensitive hydrogel system in ED gene therapy. Methods: The poly (lysine / small interfering RNA) (PLL / siRNA) gene complexes were characterized by Zeta potential to prepare the best siRNA gene nanoparticles. Polyethylene glycol - polypropylene glycol - polyethylene glycol block copolymer (PEO-PPOPEO) as a cross-linking unit, a benzaldehyde group is introduced into the both ends of the PEO-PPOPEO through chemical modification to react with the chitosan to form a benzimidazole bond, thereby preparing a pH- and temperature-sensitive injectable gene drug Controlled release system, and the release of controlled release system at different temperatures were detected. Results: When the molar ratio of PLL: siRNA was 20:1, the Zeta potential of the complex reached the maximum positive value (+23.5 mV) and the siRNA was maximally encapsulated by PLL. The pH of the environment was adjusted from acidic (5.5) to neutral 7.4), chitosan and cross-linking agent Schiff reaction and cross-linked to form a hydrogel; system siRNA coated at 37 ℃ to maintain a low release, increased the temperature to 60 ℃ after the release of a substantial increase to 1 The cumulative release at 60 ℃ was (122.5 ± 5.3) μg at 000 min and only (23.8 ± 6.0) μg at 37 ℃ (P <0.05). Conclusion: The successful preparation of polymer / gene combination drug controlled release system, in ensuring the high-targeted gene drug at the same time, improve the stability and capacity of the gene vector, and to achieve the controlled release of siRNA, will be expected to become ED gene therapy In the new material, as simple and convenient on-demand delivery of new tools.