治疗勃起功能障碍的高分子/基因复合药物控释体系建立与性能研究

Synthesis and experimental study of a novel polymer/gene compound drug controlled release system for the treatment of erectile dysfunction

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 overcome the deficiency in the current therapies for erectile dysfunction （ ED）, we designed and syn- thesized a novel high-efficiency polymer / gene compound drug controlled release system and discussed the feasibility of pH and temper- ature dually sensitive injectable hydrogel in ED gene therapy. Methods： We synthesized optimal siRNA gene nanoparticles by char-acterizing the zeta potential of polylysine （PLL）/siRNA gene compounds, and established a pH and temperature dually sensitive inject- able gene compound drug controlled release system via Schiffg reaction between glycol chitosan （GC） and benzaldehyde capped OHC- PEO-PPO-PEO-CHO. Then we demonstrated the sustained release of the system at different temperatures. Results ： When the mass ratio of PLL to siRNA was 20： 1, the zeta potential of the PLL/siRNA gene compound reached the peak （ ＋ 23.5 mV） and the siRNA was encapsulated by PLL in the maximal degree. GC and OHC-PEO-PPO-PEO-CHO was crosslinked via benzoic-imine reaction when environmental pH was changed from 5.5 to 7.4. The reslease of the siRNA encapsulated in this system kept at a low rate at 37 ℃, sig- nificantly enhanced with the increase of the temperature to 60 ℃, rising to （ 122.5 ±5.3）μg at 1 000 minutes as compared with （ 23.8 ± 6.0 ） μg at 37 ℃ （ P 〈 0.05 ）. Conclusion ： The polymer / gene compound drug controlled release system was successfully synthesized, which improved the stability and capacity of gene carriers and achieved siRNA release at different temperatures, promising to be a new approach to the gene therapy of ED. Natl J Androl, 2013, 19 （9） ： 771 - 775