Using osmotic deswelling of microgel particles to control the mechanical properties of pH-responsive hydrogel composites
Using osmotic deswelling of microgel particles to control the mechanical properties of pH-responsive hydrogel composites
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DOI：
10.1039/c1jm13395k
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发表时间：
2011-11
影响因子：
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通讯作者：
Sarah Lally;Ruixue Liu;Chonlakan Supasuteekul;B. Saunders;T. Freemont
中科院分区：
文献类型：
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作者：
Sarah Lally;Ruixue Liu;Chonlakan Supasuteekul;B. Saunders;T. Freemont
通过合理设计水凝胶复合材料的成分来调整其机械性能的能力，为再生医学应用提供先进的水凝胶具有良好的潜力。在这项研究中，我们研究了一种新的ph响应型水凝胶复合材料的形态和力学性能。将交联单体(X)添加到ph响应型聚（EA/MAA/BDD）（丙烯酸乙酯、甲基丙烯酸和丁二醇二丙烯酸酯）MG颗粒的浓缩分散体中制备。这些MG/X分散体形成物理凝胶。然后将分散体聚合成含有MG的ph响应水凝胶复合材料，这里称为MG/H-X。pH超过6.0时，MG颗粒剧烈膨胀。添加的交联单体为乙二醇二甲基丙烯酸酯（EGD）或聚乙二醇二甲基丙烯酸酯（PEGD）。后者的分子量在330 ~ 750 g/mol之间。如果X的分子量为330 g/mol或更高，MG颗粒发生渗透溶胀。这强烈地影响了MG/X分散体的凝胶行为和化学交联MG/H-X水凝胶复合材料的机械性能。对于这些新的水凝胶复合材料，X以两种方式起作用；它通过渗透溶胀来指导MG颗粒的形态，也提供了交联的来源。水凝胶复合材料的存储模量在五个数量级范围内可调。MG/H-X水凝胶复合材料具有ph依赖性的膨胀性能和力学性能。也可以用聚（EA/MAA/EGD）和聚（EA/MAA/PEGD550）微凝胶制备水凝胶复合材料。这里介绍的简单方法应该能够构建广泛的ph响应水凝胶复合材料，其中含有微凝胶，其形态可以在MG颗粒的长度尺度上进行调整，即大约100到500纳米。
The ability to tune the mechanical properties of hydrogel composites through the rational design of their constituents has excellent potential for providing advanced hydrogels for regenerative medicine applications. In this study we investigate the morphology and mechanical properties of a new family of pH-responsive hydrogel composites. They were prepared by adding crosslinking monomers (X) to concentrated dispersions of pH-responsive poly(EA/MAA/BDD) (ethylacrylate, methacrylic acid and butanediol diacrylate) MG particles. These MG/X dispersions formed physical gels. The dispersions were then polymerised to give pH-responsive hydrogel composites containing MGs, which are termed here as MG/H-X. The MG particles swelled strongly when the pH exceeded 6.0. The added crosslinking monomers were either ethyleneglycol dimethacrylate (EGD) or poly(ethylene glycol) dimethacrylate (PEGD). The latter had molecular weights in the range of 330 to 750 g/mol. If X had a molecular weight of 330 g/mol, or more, osmotic deswelling of the MG particles occurred. This strongly affected both the gelation behaviour of the MG/X dispersions and the mechanical properties of the chemically crosslinked MG/H-X hydrogel composites. For these new hydrogel composites X acted in two ways; it directed the morphology through osmotic deswelling of the MG particles and also provided a source of crosslinking. The storage modulus of the hydrogel composites was tuneable over a range of five orders of magnitude. The MG/H-X hydrogel composites showed pH-dependent swelling and mechanical properties. The hydrogel composites could also be prepared using poly(EA/MAA/EGD) and poly(EA/MAA/PEGD550) microgels. The simple method introduced here should enable construction of a wide range of pH-responsive hydrogel composites containing microgels with morphologies that can be tuned at the length scale of the MG particles, i.e., about 100 to 500 nm.