Lanzhou University Second Hospital, Lanzhou 730030, China.
J Biomed Mater Res B Appl Biomater. 2011 Apr;97(1):175-83. doi: 10.1002/jbm.b.31801. Epub 2011 Feb 2.
A chitosan(CS)-tripolyphosphate (TPP) hydrogel bead was prepared by the ionic gelation method for the controlled delivery of glipizide. The structure and surface morphology of the beads were characterized by FT-IR and SEM, separately. Factors influencing the swelling behavior of the hydrogel beads were also investigated, such as CS concentration (X(1)), TPP concentration (X(2)), the weight ratio of drug to polymer (X(3)), crosslinking time (X(4)), and the volume ratio of CS to TPP (X(5)). In addition, the swelling property and the delivery behavior of the hydrogel bead was studied as well. With decreasing of pH value, the swelling ratio of the bead was increasing. The swelling ratio of hydrogel bead at pH 1.5 was relatively high, while this value was low at pH 6.8. The amount of glipizide released from the hydrogel bead at pH 1.5 was about 90%, while this value approached 36% at pH 6.8. The results clearly suggested that the CS-TPP hydrogel beads were used as a pH-sensitive controlled release system for the delivery of glipizide.
采用离子凝胶法制备了壳聚糖（CS）-三聚磷酸钠（TPP）水凝胶珠，用于控制格列吡嗪的释放。分别通过傅里叶变换红外光谱（FT-IR）和扫描电子显微镜（SEM）对珠的结构和表面形态进行了表征。还研究了影响水凝胶珠溶胀行为的因素，如 CS 浓度（X(1)）、TPP 浓度（X(2)）、药物与聚合物的重量比（X(3)）、交联时间（X(4)）和 CS 与 TPP 的体积比（X(5)）。此外，还研究了水凝胶珠的溶胀性能和释放行为。随着 pH 值的降低，珠的溶胀比增加。在 pH 值为 1.5 时，水凝胶珠的溶胀比相对较高，而在 pH 值为 6.8 时，该值较低。在 pH 值为 1.5 时，从水凝胶珠中释放的格列吡嗪的量约为 90%，而在 pH 值为 6.8 时，该值接近 36%。结果清楚地表明，CS-TPP 水凝胶珠可用作 pH 敏感的控释系统，用于递送格列吡嗪。
