Thermo-Responsive Nanocomposite Hydrogels Based on PEG-b-PLGA Diblock Copolymer and Laponite
Thermo-Responsive Nanocomposite Hydrogels Based on PEG-b-PLGA Diblock Copolymer and Laponite
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DOI：
10.3390/polym11020250
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发表时间：
2019-02-01
期刊：
影响因子：
5
通讯作者：
Koizumi, Satoshi
中科院分区：
文献类型：
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作者：
Maeda, Tomoki;Kitagawa, Midori;Koizumi, Satoshi
聚（乙二醇）-b-聚（D，L-丙交酯-共-乙交酯）（PEG-b-PLGA）二嵌段共聚物被广泛认为是用于生物医学应用的聚合物表面活性剂，并且与被称为胶凝剂的PLGA-b-PEG-b-PLGA三嵌段共聚物相比，在水中表现出高溶解度。为了克服基于PLGA-b-PEG-b-PLGA的温度响应性水凝胶由于在水中的低溶解度而在制备中的困难，尝试通过向PEG-b-PLGA溶液中添加合成锂皂石来制备在水中具有高溶解度的基于PEG-b-PLGA的温度响应性水凝胶。详细地，在水中具有高溶解度的PEG-b-PLGA（即，高PEG/PLGA比率）。然后，通过混合PEG-b-PLGA溶液和合成锂皂石悬浮液来制备基于PEG-b-PLGA和合成锂皂石的纳米复合材料溶液（合成锂皂石/PEG-b-PLGA纳米复合材料）。通过试管倒置法和动态力学分析（DMA），发现使用PEG-b-PLGA（通常称为高分子表面活性剂）可以得到温度响应性水凝胶，并且凝胶化温度在生理温度附近，可以通过改变溶液组成来调节。小角中子散射（SANS）结构分析表明，PEG-b-PLGA存在于合成锂皂石片晶表面，且PEG-b-PLGA在合成锂皂石片晶表面具有温敏性，可引发合成锂皂石网络的温敏连接。
Poly(ethylene glycol)-b-poly(D,L-lactide-co-glycolide) (PEG-b-PLGA) diblock copolymers are widely known as polymeric surfactants for biomedical applications, and exhibit high solubility in water compared to PLGA-b-PEG-b-PLGA triblock copolymers known as gelation agents. In order to overcome the difficulties in the preparation of thermo-responsive hydrogels based on PLGA-b-PEG-b-PLGA due to the low solubility in water, the fabrication of thermo-responsive hydrogels based on PEG-b-PLGA with high solubility in water was attempted by adding laponite to the PEG-b-PLGA solution. In detail, PEG-b-PLGA with high solubility in water (i.e., high PEG/PLGA ratio) were synthesized. Then, the nanocomposite solution based on PEG-b-PLGA and laponite (laponite/PEG-b-PLGA nanocomposite) was fabricated by mixing the PEG-b-PLGA solutions and the laponite suspensions. By using the test tube inversion method and dynamic mechanical analysis (DMA), it was found that thermo-responsive hydrogels could be obtained by using PEG-b-PLGA, generally known as polymeric surfactants, and that the gelation temperature was around the physiological temperature and could be regulated by changing the solution composition. Furthermore, from the structural analysis by small angle neutron scattering (SANS), PEG-b-PLGA was confirmed to be on the surface of the laponite platelets, and the thermosensitive PEG-b-PLGA on the laponite surface could trigger the thermo-responsive connection of the preformed laponite network.