Istanbul Technical University, Department of Chemistry, Soft Materials Research Laboratory, 34469, Maslak, Istanbul, Turkey.
Soft Matter. 2022 Sep 28;18(37):7181-7200. doi: 10.1039/d2sm00938b.
A series of semi-interpenetrating polymer network (semi-IPN) hydrogels based on acrylamide (AAm) and itaconic acid (ITA) was prepared in the presence of different amounts of the natural polymer gelatin (GLN). The semi-IPNs were synthesized by simultaneous polymerization using ,'-methylene bisacrylamide as a crosslinking agent. A pH-sensitive system was obtained by adding 2 mol% ITA as an anionic comonomer. The effect of GLN content by changing the amine/carboxyl functional groups and incorporating carboxyl groups of ITA in semi-IPN on the swelling, elasticity and physical properties of the hydrogels was investigated. The presence of GLN improved the thermal stability, and the GLN-containing semi-IPNs exhibited a higher degradation temperature compared to the GLN-free copolymers. The addition of a small amount of GLN could effectively increase the swelling of the semi-IPNs in water. By employing the GLN-containing semi-IPN as a model system, the solvent/matrix interactions were demonstrated to reveal the effect of solvent structure on the swelling-shrinkage response. The addition of GLN improved the pH-sensitivity of the semi-IPN gels, resulting in a clear response to pH change by action of NH and COOH of GLN and additional COOH groups from ITA. The mechanical performance of the copolymer network was improved by entangling PAAm/ITA chains with GLN, which acted as a reinforcement node. In terms of the effect of Hofmeister anions on the swelling behavior, the anion effect became more pronounced with salt concentration. The affinity of semi-IPNs towards the cationic dyes methylene blue and malachite green was tested and the dependence of the adsorption process on the initial dye concentration, contact time and GLN content was determined. This method presents a simple and efficient approach for the design of chemically crosslinked protein-based gels for drug delivery applications.
一系列基于丙烯酰胺（AAm）和衣康酸（ITA）的半互穿聚合物网络（semi-IPN）水凝胶是在不同量天然聚合物明胶（GLN）存在的情况下制备的。半互穿网络是通过使用亚甲基双丙烯酰胺作为交联剂同时聚合合成的。通过添加 2mol%ITA 作为阴离子共聚单体，得到 pH 敏感体系。通过改变胺/羧基官能团和引入 ITA 的羧基来改变 GLN 含量对半互穿网络的溶胀、弹性和物理性能的影响进行了研究。GLN 的存在提高了热稳定性，含 GLN 的半互穿网络表现出比无 GLN 的共聚物更高的降解温度。少量 GLN 的添加可以有效地增加半互穿网络在水中的溶胀。通过采用含 GLN 的半互穿网络作为模型体系，证明了溶剂/基质相互作用揭示了溶剂结构对溶胀-收缩响应的影响。GLN 的添加提高了半互穿网络凝胶的 pH 敏感性，导致 GLN 的 NH 和 COOH 以及 ITA 的额外 COOH 基团的作用下对 pH 变化的响应更加明显。GLN 与 PAAm/ITA 链缠结，充当增强节点，从而改善了共聚物网络的机械性能。就阴离子对溶胀行为的影响而言，随着盐浓度的增加，阴离子效应变得更加明显。测试了半互穿网络对阳离子染料亚甲基蓝和孔雀石绿的吸附性能，并确定了吸附过程对初始染料浓度、接触时间和 GLN 含量的依赖性。该方法为用于药物输送应用的化学交联蛋白基凝胶的设计提供了一种简单有效的方法。
