In this work, hydrogels composed of cellulose nanofibril (CNF) and sodium alginate (SA) were prepared as a pH-responsive release system by controlling the amount of CNF and SA. Scanning electron microscopy, thermogravimetric analysis, and swelling rate methods were used to characterize. The results showed that when the mass ratio of CNF to SA was 2:1, CNF/SA hydrogels with better morphology were obtained. Due to the deprotonation or protonation of calcium alginate, as the pH changing from 1.5 to 11.0, the swelling ratio increased from 7 times to 19 times compared with its dry weight. The drug release behaviors of the CNF/SA hydrogels using ibuprofen (IBU) as a model drug were investigated in vitro. The release of IBU was faster in alkaline conditions and slower in acidic conditions. The drug release mechanism under pH stimulation could be interpreted by the Fickian diffusion and erosion effect based on Korsmeyer-Peppas model.

中文翻译：

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用于药物释放的pH响应性纤维素纳米原纤维/海藻酸钠基水凝胶的制备

在这项工作中，通过控制 CNF 和 SA 的量，制备了由纤维素纳米纤维 (CNF) 和海藻酸钠 (SA) 组成的水凝胶作为 pH 响应释放系统。使用扫描电子显微镜、热重分析和溶胀率方法来表征。结果表明，当CNF与SA的质量比为2:1时，得到的CNF/SA水凝胶具有更好的形态。由于海藻酸钙的去质子化或质子化作用，随着pH值从1.5变为11.0，溶胀比与其干重相比从7倍增加到19倍。体外研究了以布洛芬 (IBU) 为模型药物的 CNF/SA 水凝胶的药物释放行为。IBU 的释放在碱性条件下较快，在酸性条件下较慢。