取一定体积的FK506胶束溶液分别加入到1 mL超纯水或壳聚糖凝胶溶液中，置于透析袋（MWCO=3500）中，再放入到20 mL超纯水（37 ℃）中，最后置于摇床（37 ℃）中进行体外释放，每隔24 h取一次样，并更换全部释放液，连续释放9 d。每个实验组平行三组。本实验利用FITC-BSA作为模型药物代替CNTF，评估壳聚糖基温敏型水凝胶对蛋白药物的缓释效果。将原浓度为5 mg/mL的FITC-BSA用PBS稀释成一系列浓度的FITC-BSA标准液。测定不同倍数下溶液的荧光强度（激发493 nm，发射550 nm），制作标准曲线。制备1%壳聚糖温敏凝胶10 mL （含5 mg FITC-BSA）。取3 mL置于15 mL玻璃瓶中，于37 ℃水浴中加热成胶。待成胶以后，缓缓加入3 mL PBS作为释放液，置于水浴锅中进行体外释放。每天取1次，连续取点9 d，每次取出1 mL(先将释放液混匀再取)，测定荧光强度，根据标准曲线计算出释放液中药物浓度，绘制体外释放曲线。

A certain volume of FK506 micelle solution was added to 1 mL of ultra-pure water or chitosan gel solution, placed in a dialysis bag (MWCO=3500), then placed in 20 mL of ultra-pure water (37 ℃), and finally placed in a shaking table (37 ℃) for in vitro release. Samples were taken every 24 h and all the released solution was replaced.Continuous release for 9 days.Each experimental group had three parallel groups.In this study, FITC-BSA was used as a model drug instead of CNTF to evaluate the sustained release effect of chitosan-based temperature-sensitive hydrogel on protein drugs.The original concentration of 5 mg/mL FITC-BSA was diluted with PBS into a series of concentrations of FITC-BSA standard solution.Fluorescence intensity (493 nm excitation, 550 nm emission) of the solution at different multiples was measured, and standard curves were made.Preparation of 1% chitosan temperature-sensitive gel 10 mL (containing 5 mg FITC-BSA).After the gel was formed, 3 mL PBS was slowly added as the release liquid and placed in a water bath for in vitro release.1 mL was taken out each time (the release solution was mixed before taking), the fluorescence intensity was measured, the drug concentration in the release solution was calculated according to the standard curve, and the in vitro release curve was plotted.