为了提高活性物质的生物利用度，该研究以三聚磷酸钠（TPP）或六偏磷酸钠（SHMP）为交联剂，制备具有不同微观结构的壳聚糖基水凝胶，探讨其控释性能，并通过红外光谱、X-射线衍射和热重分析对水凝胶结构进行分析。热重分析结果表明，壳聚糖上的氨基与交联剂磷酸基团之间通过氢键进行交联，提高了壳聚糖水凝胶的热稳定性。同时，与TPP相比，SHMP为壳聚糖链段与阴离子基团间的结合提供更多静电作用位点，使得SHMP交联壳聚糖水凝胶在1530 cm-1附近表现出强的特征峰。此外，TPP交联水凝胶的溶胀性能优于SHMP交联水凝胶，但在体外模拟消化实验中，由于胃肠道的生理环境以及交联壳聚糖水凝胶的微观结构随pH的改变，SHMP交联水凝胶的活性蛋白累积释放率（30.47%~50.27%之间）小于TPP交联水凝胶（59.90%~76.57%之间）。通过控制交联过程中壳聚糖与交联剂的质量比，可改变交联壳聚糖水凝胶分子结构，调控壳聚糖分子链段的溶解/溶胀行为，从而影响水凝胶的控释性能。该研究结果可为壳聚糖载体材料的选用、缓释及改善活性蛋白类功能因子的生物利用情况提供一定的参考。

To delivery bioactive compound with good bioavailability, crosslinked chitosan (CS) hydrogel with different microstructure and its controlled-releasing property were investigated. These hydrogel particles were crosslinked by tripolyphosphate (TPP) or sodium hexametaphosphate (SHMP) and analyzed by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and thermal gravimetric analysis (TGA). SHMP-crosslinked CS hydrogels showeda stronger peak near 1530 cm-1, which presented the interaction between CS and anionic crosslinkers and related to more binding sites of the crosslinker. From the result of TGA, after crosslinking, the thermal stability of this hydrogel was increased by phosphate group of crosslinker enhancing the intramolecular hydrogen bond force among CS molecules. Moreover, the swelling behavior and controlled-releasing property of these materials were also tested. TPP-crosslinked CS hydrogel had better swelling capacity than SHMP-crosslinked one, but the in vitro releasing study revealed that the total cumulative release percentage of bovinsersum albumin from SHMP-crosslinked CS hydrogel particle (30.47~50.27%) was lower than those by TPP (59.90~76.57%) because of the reduction of crosslinking strength in acidic environment and compact network structure formed later. With the changes of crosslink processing, the molecular structure of crosslinked chitosan hydrogel was varied, which influnced itsswelling ability and controlled-releasing property. The results of this study can provide some reference for the selection of chitosan carrier materials, sustained release and improving the bioavailability of active protein functional factors.

国家自然科学基金资助项目（31601422）；广州市科技计划项目珠江新星专题（201806010184）；华南农业大学2020年度省级立项大学生创新创业训练项目（S202010564063）