Synthesis and characterisation of mucoadhesive thiolated polymers
Synthesis and characterisation of mucoadhesive thiolated polymers
复制标题
DOI：
10.1016/s0378-5173(99)00387-7
复制
发表时间：
2000-01-25
影响因子：
5.8
通讯作者：
Steininger, S
中科院分区：
文献类型：
--
作者：
Bernkop-Schnürch, A;Steininger, S
本研究考察了影响黏液黏附性能的各种因素，这些因素能够与黏液糖蛋白的硫醇亚结构形成共价键。因此，在碳二亚胺的介导下，l -半胱氨酸与多酚（PCP）和羧甲基纤维素（CMC）共价结合。所得聚合物偶联物每克分别显示12.3和22.3 μ mol巯基。半胱氨酸固定对CMC片的肿胀行为无明显影响，而PCP对CMC片的肿胀行为有显著改善（P < 0.05）。对pH值分别为3、5和7的未改性和硫化聚合物进行的拉伸研究表明，只有当聚合物的pH值为5时，由于巯基的共价连接，总粘附功才能显著提高。这些结果与本文描述的一种新的黏附测试系统很好地一致，同时考虑到递送系统的内聚性。研究结果为改善巯基化聚合物的粘接性能提供了有益的基础信息。(C) 2000 Elsevier Science B.V.版权所有
This study examined various factors influencing the mucoadhesive properties of thiolated polymers (thiomers), which are capable of forming covalent bonds with thiol sub-structures of the mucus glycoprotein. Mediated by a carbodiimide, L-cysteine was therefore covalently bound to polycarbophil (PCP) and to carboxymethylcellulose (CMC). The resulting polymer conjugates displayed 12.3 and 22.3 mu mol thiol groups per gram, respectively. Whereas the swelling behaviour of tablets based on CMC was not markedly influenced by the immobilisation of cysteine, it was improved significantly (P < 0.05) in case of PCP. Tensile studies carried out with the unmodified and thiolated polymers of pH 3, 5 and 7, respectively, revealed that only if the polymer displays a pH-value of 5, the total work of adhesion can be improved significantly due to the covalent attachment of thiol groups. These results were in good agreement with a new mucoadhesion test system described here taking also the cohesiveness of the delivery system into account. The results represent helpful basic information in order to improve the mucoadhesive properties of thiolated polymers. (C) 2000 Elsevier Science B.V. All rights reserved.