Onishi H, Machida Y
Department of Clinical Pharmacy, Hoshi University, Tokyo, Japan.
Biomaterials. 1999 Jan;20(2):175-82. doi: 10.1016/s0142-9612(98)00159-8.
Randomly 50% deacetylated chitin, called Chi, was examined on the biodegradability, body distribution and urinary excretion after the intraperitoneal (ip) administration to mice. These characteristics were investigated using fluorescein isothiocyanate (FITC)-labeled Chi (FTC-Chi). The in vitro biodegradability was investigated by incubation with lysozyme and murine plasma and urine. The degradation of Chi or FTC-Chi was accelerated by lysozyme, plasma and urine. The molecular weight was checked by gel-chromatography. The degradation product showed a fairly small molecular weight and contained no FTC-Chi of a large one. The body distribution and urinary excretion of FTC-Chi were investigated at 1, 14 and 24 h after the ip injection to mice. FTC-Chi moved fast to the kidney and urine, and was scarcely distributed to the liver, spleen, abdominal dropsy and plasma. Most of FTC-Chi was excreted into urine after 14 h, and the molecular weight of the excreted FTC-Chi was as small as that of the product obtained by the long in vitro incubation. Therefore, Chi is considered to be highly biodegradable and easily excreted in urine, and further it is suggested to have no problem on accumulation in the body; however, at the same time, Chi is found not to operate as a polymer support showing long retention in the body.
对50%随机脱乙酰化的几丁质（称为Chi）进行了研究，观察其经腹腔注射给小鼠后在生物降解性、体内分布及尿排泄方面的情况。使用异硫氰酸荧光素（FITC）标记的Chi（FTC-Chi）来研究这些特性。通过与溶菌酶、小鼠血浆和尿液共同孵育来研究体外生物降解性。溶菌酶、血浆和尿液均可加速Chi或FTC-Chi的降解。通过凝胶色谱法检测分子量。降解产物显示分子量相当小，且不含大分子的FTC-Chi。在给小鼠腹腔注射后1、14和24小时，对FTC-Chi的体内分布和尿排泄情况进行了研究。FTC-Chi快速进入肾脏和尿液，几乎不分布于肝脏、脾脏、腹腔积液和血浆中。14小时后，大部分FTC-Chi排泄到尿液中，排泄出的FTC-Chi的分子量与长时间体外孵育得到的产物的分子量一样小。因此，Chi被认为具有高度生物降解性且易于经尿液排泄，此外还表明其在体内不存在蓄积问题；然而，与此同时，发现Chi不能作为在体内具有长时间滞留性的聚合物载体发挥作用。
