制备CS-Ca2+-SAL中空凝胶球及其对碳纳米的缓释行为

Preparation of hollow Gel spheres by CS-Ca2+-SAL and its release behaviors for carbon nanodots

摘要:

将海藻酸钠溶液(SAL)滴入壳聚糖-钙(CS-Ca2+)分散溶液中，海藻酸钠与壳聚糖分子链之间发生物理交联的同时，也与钙离子进行同步交联，可一步制备毫米级壳聚糖-钙-海藻酸钠(CS-Ca2+-SAL) 水凝胶球。通过调控原料用量比例、滴加速度和方式，成功制备内部中空，球壁均匀，表面致密的凝胶球。以荧光性碳纳米点为标记物，考察凝胶球的溶胀性能和缓释性能。结果表明，凝胶球在中性水溶液中12h溶胀率可达26.09%，并能保持完整球形结构。溶胀性能受到pH的影响显著，处于pH=1.2的溶液体系中溶胀率最小，处于pH =6.8溶液环境中溶胀率最大。荧光凝胶球在pH=7.1的Tris-HCl缓冲液中的释放率实验结果表明，对碳纳米的释放模型最符合Hixon-crowell溶蚀方程，说明凝胶球的缓释机制以溶蚀为主，扩散为辅。

Abstract:

In this paper, natural polysaccharides sodium alginate (SAL) and chitosan (CS) are used as basic raw materials, and CaCl2 is used as a cross-linking agent. The sodium alginate solution is dropped into the chitosan-calcium dispersion solution. While physical crosslinking occurs between the sodium alginate and the chitosan molecular chain, it is also simultaneously crosslinked with calcium ions, the millimeter-grade chitosan-calcium-sodium alginate (CS-Ca2+-SAL) hydrogel with a sphere plastic form was prepared by one-step method. The hollow Gel spheres with smooth surface, uniform shape and shell were successfully prepared by adjusting the amount of raw materials, the speed of the centrifuge, the diameter of the needle and the crosslinking method. Using fluorescent carbon nanodots as label, the swelling properties and slow-release properties of Gel spheres were investigated. The results show that the swelling performance of the hydrogel spheres is significantly affected by pH. The swelling rate is the smallest when the solution is at pH = 1.2, and the swelling rate is the largest when it is at pH = 6.8. The experimental results of release rate of fluorescent carbon nanodots in pH=7.1 Tris-HCl buffer solution indicate that the release mechanism is fitted to Hixcon-Crowell models and it conclude that the Gel sphere has the dissolution sustained release process, accompany with diffusion of nano-drugs.