Chondroitinase ABC I (cABC I) has received notable attention in treatment of spinal cord injuries and its application as therapeutics has been limited due to low thermal stability at physiological temperature. In this study, cABC I enzyme was immobilized on the dextran-coated Fe3O4 nanoparticles through physical adsorption to improve the thermal stability. The nanoparticles were characterized using XRD, SEM, VSM, and FTIR analyses. Response surface methodology and central composite design were employed to assess factors affecting the activity of immobilized cABC I. Experimental results showed that pH 6.3, temperature 24 °C, enzyme/support mass ratio 1.27, and incubation time 5.7 h were the optimal immobilization conditions. It was found that thermal stability of immobilized cABC I was significantly improved. In-vitro cABC I release was studied under pH 7.5 and temperature 37 °C and the results indicated that 70 % release occurred after 9 h and the release mechanism was first-order kinetic model.

中文翻译：

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软骨素酶ABC I固定在葡聚糖包被的Fe3O4纳米颗粒上的检测及其体外释放。

软骨素酶ABC I（cABC I）在治疗脊髓损伤方面受到了广泛关注，由于在生理温度下的热稳定性低，其作为治疗剂的应用受到限制。在这项研究中，通过物理吸附将cABC I酶固定在葡聚糖包覆的Fe3O4纳米颗粒上，以提高其热稳定性。使用XRD，SEM，VSM和FTIR分析对纳米颗粒进行表征。响应面法和中心复合材料设计用于评估影响固定化cABC I活性的因素。实验结果表明，pH 6.3，温度24°C，酶/载体质量比1.27和孵育时间5.7 h是最佳固定化条件。发现固定化的cABC I的热稳定性显着提高。