甲氨喋呤-乳糖酰基壳聚糖的制备及其体外实验

Preparation and in vitro Experimental Study of Methotrexate-Lactosyl-Chitosan Conjugate

制备了不同乳糖酰基取代度的N-乳糖酰基壳聚糖(LCH),并通过红外光谱(IR)及核磁共振氢谱(1H NMR)对其进行了结构表征.体外放射性配基竞争结合实验结果显示,当乳糖酰基取代度为15·5%～38·9%时,LCH对肝实质细胞膜表面去唾液酸糖蛋白受体(ASGPR)具有特异亲和性,即具有潜在的肝靶向性.将甲氨喋呤(MTX)与壳聚糖以酰胺键偶联,制备MTX-壳聚糖(MTX-CH),再与乳糖酸反应生成目标产物MTX-乳糖酰基壳聚糖(MTX-LCH),并通过紫外分光光度法(UV)检测MTX的取代度为5·6%,乳糖酰基取代度为33·8%.溶解性实验结果显示,MTX-LCH溶于pH=1～14的水溶液;体外释放实验结果表明,MTX-LCH性质稳定,能明显延缓MTX的释放.

N-Lactosyl-chitosan（LCH） with different degrees of substitution（DS） of lactosyl group was synthe-sized and characterized with Fourier transform infrared （FTIR） and proton nuclear magnetic resonance （^1H NMR）. The result of radioactive experiment in vitro shows that LCH was a specific ligand for asialoglyco-protein receptor（ASGPR） when the DS of lactosyl group ranged from 15. 5% to 38.9%, which indicates LCH could be used as a novel kind of hepatic targeting carrier. Methotrexate-lactosyl-chitosan （MTX-LCH） was prepared via the following synthetic route： MTX was firstly coupled with chitosan, and then reacted with lacto-bionic acid to produce MTX-LCH. The DS of MTX moiety of MTX-LCH was determined via ultraviolet （UV） spectroscopy to be 5.6%, and the DS of lactosyl group to be 33.8%. MTX-LCH was water-soluble in the pH range of 1-14. The dynamic dialysis study shows that MTX-LCH was stable, and the release of MTX was very slow. These results provided a reference for the further study of liver-targeting polymeric prodrugs.