可注射CS/PLLA-SA复合水凝胶的制备及载药性能

Preparation and the drug loading properties of injectable CS/PLLA-SA complex hydrogel

摘要:

摘要：采用先核后臂法以及丁二酸酐(SA)羧基化修饰合成了末端为羧基的四臂星型聚乳酸（PLLA-SA），将其加入丙酮中得到PLLA-SA纳米分散液。壳聚糖（CS）与分散液通过静电作用自组装形成可注射CS/PLLA-SA复合水凝胶，并采用Zeta电位及激光粒度仪、FTIR和SEM等对PLLA-SA、分散液及水凝胶的组成、结构和性能进行表征与测定。PLLA-SA的最大Zeta电位值为-21.89 mV，分散液的平均粒径约为200 nm。在温度为15 ℃，PLLA-SA质量浓度为5 g/L，布洛芬（IBU）与PLLA-SA质量比为1:2，650 r/min搅拌1 h，550 r/min搅拌5 h的条件下，制备出载IBU的PLLA-SA分散液。将分散液与质量浓度为10 g/L的壳聚糖盐酸盐（CS-HCl）按体积比为7:3混合，快速自组装形成载药CS/PLLA-SA复合水凝胶，包封率和载药量分别达到85.34%和28.46%。体外药物释放结果表明，可注射载药水凝胶对IBU具有明显的缓释作用，30 h内药物的累积释放率可达到95.81%。

Abstract:

Abstract: The star-shaped PLLA-SA copolymers with terminal carboxyl groups was synthesized successfully by the "core-first" method, and was dispersed into acetone to obtain PLLA-SA nano-dispersion. Then chitosan (CS) and dispersion were self-assembled via electrostatic action to form injectable CS/PLLA-SA complex hydrogel. The composition, structure and properties of PLLA-SA, PLLA-SA nano-dispersion and CS/PLLA-SA hydrogel were characterized by laser particle size and zeta potential analyzer, FTIR and SEM. The maximum zeta potential value of PLLA-SA was -21.89 mV. The average particle size of the PLLA-SA nano-dispersion was about 200 nm. Ibuprofen(IBU)-PLLA-SA nano-dispersion was prepared at PLLA-SA mass concentration of 5 g/L, the mass ratio between IBU and PLLA-SA of 1:2, stirring speed of 650 r/min for 1 h, then of 550 r/min for 5 h, and temperature of 15 ℃. When IBU-PLLA-SA nano-dispersion was mixed with 10 g/L chitosan hydrochloride (7 : 3 volume ratio), the hydrogel was reversible self-assembly formed，and the loading efficiency and loading content of the hydrogel can reach 85.38% and 28.46%, respectively. The in vitro study of drug release indicated that the injectable CS/PLLA-SA complex hydrogel exhibited a significant sustained-release capability for IBU, and the cumulative release rate of IBU could reach 95.81% within 30 h.