目的 研究酪蛋白和鱼精蛋白对酶降解胰岛素（INS）的保护作用及对大鼠灌胃给予INS溶液和微球后降血糖作用的影响。方法 采用：HPI止法测定α-糜蛋白酶和胰蛋白酶溶液中INS的残余量+考察酪蛋白和鱼精蛋白对体外酶陴解INS的保护作用；制各INS溶液及肠溶傲球。在促吸荆N-[8-（2-羟基苯甲酰幕）氮基]辛酸钠（SNAC）存在下，太鼠灌胃给药研究酷蛋白和鱼精蛋白单独腰合并使用对INS溶液和徽球降血糖作用的影响。结果 酪蛋白对α-糜蛋白酶体外降解INS有较好的抑制作用，鱼精蛋白不能抑制α-靡蛋白酶对INS的降解，但对胰蛋白酶降解INS的抑制作用忧于酪蛋白。鱼精蛋白和酪蛋白均可增加I№溶液和肠溶微球的降血糖作用，两者台用嫂果更佳。在SNAC、鱼精蛋白和酪蛋白存在下。INS肠溶豫球比INS籍液有更强而持久的降血糖作用。结论 酪蛋白和鱼精蛋白可通过竞争性与酶结音机制增加INS在肠道消化酶中的稳定性。对INS口服吸收有利。

目的：制备新型的两亲性N-辛基-N-PEG化壳聚糖衍生物。方法：以天然聚合物壳聚糖为原料，其2-NH-与辛醛形成Schiff's碱，用KBH4还原得到N-辛基壳聚糖，然后在其剩余2-NH-与MeO-PEG-CHO反应，再用KBH4还原制备了N-辛基-N-PEG化壳聚糖衍生物，结构经FTIR、13CNMR、1HNMR得到了表征。用DSC实验对其物理性质进行了分析。结果与结论：制得了新型的辛基、PEG取代度分别为36，64%的两亲性N-辛基-N-PEG化壳聚糖衍生物，有望作为难溶性药物增溶的载体。

The aim of this study was to design and characterize lectin-modified liposomes containing insulin and to evaluate the potential of these modified colloidal carriers for oral administration of peptide and protein drugs. Wheat germ agglutinin (WGA), tomato lectin (TL), or Ulex europaeus agglutinin 1 (UEA1) were conjugated by coupling their amino groups to carbodiimideactivated carboxylic groups of N-glutaryl-phosphatidylethanolamine (N-glut-PE). Insulin liposomes dispersions were prepared by the reverse-phase evaporation technique and modified with the lectin-N-glut-PE conjugates. Lectin-modified liposomes were characterized according to particles size, zeta potential and entrapment efficiency. The hypoglycemic effect indicated by pharmacological bioavailability of insulin liposomes modified with WGA, TL and UEA1 were 21.40, 16.71 and 8.38% in diabetic mice as comparison with abdominal cavity injection of insulin, respectively. After oral administration of the insulin liposomes modified with WGA, TL and UEA1 to rats, the relative pharmacological bioavailabilities were 8.47, 7.29 and 4.85%, the relative bioavailability were 9.12, 7.89 and 5.37% in comparison with subcutaneous injection of insulin, respectively. In the two cases, no remarkable hypoglycemic effects were observed with the conventional insulin liposomes. These results confirmed that lectin-modified liposomes promote the oral absorption of insulin due to the specific-site combination on GI cell membrane.