Influence of amino acids, buffers, and pH on the γ-irradiation-induced degradation of alginates
Influence of amino acids, buffers, and pH on the γ-irradiation-induced degradation of alginates
复制标题
氨基酸、缓冲液和 pH 对 γ 辐照诱导的海藻酸盐降解的影响
DOI：
10.1021/bm501386n
复制
发表时间：
2014
影响因子：
6.2
通讯作者：
B. E. Christensen
中科院分区：
文献类型：
--
作者：
A.-S. T. Ulset;H. Mori;M. Ø. Dalheim;M. Hara;B. E. Christensen
基于藻酸盐的生物材料和医疗器械通常在干燥状态或凝胶（水合）状态下接受 γ 辐射作为灭菌手段。在此过程中，藻酸盐链以剂量依赖性方式随机降解，改变藻酸盐的材料特性。使用 SEC-MALLS 监测分子量分布的变化并确定降解的伪一级速率常数表明，添加自由基清除氨基酸（例如组氨酸和苯丙氨酸）可显着保护藻酸盐免受降解。 Tris 缓冲液 (0.5 M) 对降解速率有类似的影响，但醋酸盐、柠檬酸盐或磷酸盐缓冲液则没有。 pH值本身的变化对藻酸盐降解速率和氨基酸的保护作用仅产生边际影响。与之前的报道相反，海藻酸盐的化学成分（M/G 分布），包括均聚物甘露糖醛，在高达 10 kGy 的照射后没有改变。
Alginate-based biomaterials and medical devices are commonly subjected to γ-irradiation as a means of sterilization, either in the dry state or the gel (hydrated) state. In this process the alginate chains degrade randomly in a dose-dependent manner, altering alginates’ material properties. The addition of free radical scavenging amino acids such as histidine and phenylalanine protects the alginate significantly against degradation, as shown by monitoring changes in the molecular weight distributions using SEC-MALLS and determining the pseudo first order rate constants of degradation. Tris buffer (0.5 M), but not acetate, citrate, or phosphate buffers had a similar effect on the degradation rate. Changes in pH itself had only marginal effects on the rate of alginate degradation and on the protective effect of amino acids. Contrary to previous reports, the chemical composition (M/G profile) of the alginates, including homopolymeric mannuronan, was unaltered following irradiation up to 10 kGy.