水溶性低分子量壳聚糖辐射保护作用的研究

Radiation protective property of water-soluble chitosan with low-molecular weight

为研究水溶性低分子量壳聚糖(β-1,4-2-氨基-2-脱氧-D-葡聚糖;Chitosan,CTS)的辐射保护作用,通过强碱洗脱法和乙酸-H2O2氧化降解法制备水溶性低分子量壳聚糖,采用四甲基偶氮噻唑蓝(MTT)法和流式细胞分析法分别检测低分子量壳聚糖对60Coγ射线照射后大鼠正常肝细胞(BRL)的存活率、细胞凋亡和细胞周期的影响,评价水溶性低分子量壳聚糖的辐射保护作用。结果表明,成功地制备了水溶性低分子量壳聚糖,壳聚糖的脱乙酰度由原来的79.3%提高到94.1%,乙酸-H2O2法降解120min,壳聚糖的分子量由原来的8.50×105下降到3.26×103。低分子量壳聚糖(LMWC)对4Gy60Coγ射线照射后的BRL细胞具有良好的辐射保护作用,表现为照后细胞存活率明显升高,SubG1峰显著降低。50μg/mL的CTS使4Gy60Coγ照射后48hBRL细胞的存活率由66.5%±0.19%提高到了87.5%±0.16%(p<0.05);照后24h的SubG1峰由51.9%±2.1%降至16.9%±1.3%(p<0.05)。表明制备的水溶性低分子量壳聚糖对BRL细胞有较好的辐射保护作用。

In order to investigate the radioprotection property of water-soluble chitosan with low-molecular weight, sodium hydroxide eluting and oxidation degradation of chitosan with H2O2 under HAc condition were used to prepare water-soluble low-molecular weight chitosan.MTT assay and flow cytometry （FCM） assay were performed to evaluate the cell survival rate, apoptosis and cell cycle alteration, respectively, after γ-rays irradiation.The results show that water-soluble low-molecular weight chitosan was successfully prepared, and the degree of deacetylation （D.D） of chitosan was increased from 79.3% to 94.1% while the molecular weight was decreased from 8.50×10^5 to 3.26×10^3 after treatment for 120 min.Low-molecular weight chitosan （LMWC） has good radio-protection effect to BRL cells from radiation damage induced by 4 Gy 60↑Co γ-rays in evidence of higher survival rate and lower SubG1 peek of the cells.After treatment with 50 μg/mL of LMWC, survival rate of BRL cells increased from 66.5%±0.19% to 87.5%±0.16% at 48 h （p〈0.05）, the peak of SubG1 decreased from 51.9%±2.1% to 16.9%±1.3% at 24 h after 4 Gy 60↑Co γ-irradiation （p〈0.05）.The results indicate that low molecular weight has excellent radio-protection effect to normal rat liver cell line （BRL）.