壳聚糖微花对原花青素的负载表征及缓释性能

采用离子交联法制备壳聚糖微花（chitosan microflowers，CSMF），通过扫描电镜、傅里叶变换红外光谱（Fourier transform infrared spectroscopy，FTIR）、X射线光电子能谱（X-ray photoelectron spectroscopy，XPS）等对CSMF表征，并以原花青素（procyanidins，PC）作为模型药物，考察不同条件下对PC的负载效果，分析负载后原花青素载药微花（PC-CSMF）的体外缓释和抗氧化性能。结果表明，CSMF的形貌是三维多层的微花结构，其直径为1.5 μm左右，层与层之间存在间隙；FTIR表明PC-CSMF在1 448 cm－1产生新的吸收峰，XPS显示PC-CSMF表面碳氧比例有所提高，两者协同证明了PC被成功负载；XRD和热重分析发现PC-CSMF的结晶性和热稳定性没有显著改变；单因素试验结果表明在27 ℃和PC质量浓度为10 mg/mL时，CSMF对PC负载量达到最大为352.88 mg/g；体外缓释和抗氧化性实验证明了PC-CSMF具有缓释作用且负载后的PC生物活性得到提升。

Characterization and Sustained Release Properties of Chitosan Microflowers Loaded with Procyanidins

In this study, chitosan microflowers (CSMF) were prepared by an ionic cross-linking method and were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS). The loading capacity of CSMF for procyanidins (PC) as a model drug under different conditions was investigated, and the in vitro sustained release and antioxidant properties of procyanidins-loaded microflowers (PC-CSMF) were analyzed. The results showed that the morphology of CSMF was a three-dimensional multi-layer micro-flower structure with a diameter of approximately 1.5 μm, and there was a gap between layers. The FTIR spectrum of PC-CSMF showed an absorption peak at 1 448 cm-1, and XPS showed that the ratio of carbon to oxygen on the surface of PC-CSMF increased, which proved that PC was successfully loaded onto CSMF. The results of X-ray diffraction (XRD) and thermogravimetric analysis (TG) demonstrated that the crystallinity and thermal stability of PC-CSMF did not change significantly. The results of single factor experiments showed that the maximum PC load of CSMF of 352.88 mg/g was obtained at room temperature (27 ℃) and a PC concentration of 10 mg/mL. PC-CSMF had sustained release properties and antioxidant activity in vitro.