Injectable hydrogel as stem cell scaffolds from the thermosensitive terpolymer of NIPAAm/AAc/HEMAPCL
Injectable hydrogel as stem cell scaffolds from the thermosensitive terpolymer of NIPAAm/AAc/HEMAPCL
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由 NIPAAm/AAc/HEMAPCL 热敏三元聚合物制成的可注射水凝胶作为干细胞支架
DOI：
10.2147/ijn.s32645
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发表时间：
2012-01-01
影响因子：
8
通讯作者：
Lang, Meidong
中科院分区：
文献类型：
--
作者：
Lian, Sheng;Xiao, Yan;Lang, Meidong
以N-异丙基丙烯酰胺(NIPAAm)、丙烯酸(AAc)和大分子单体甲基丙烯酸羟乙酯-聚己内酯(HEMAPCL)为原料，通过自由基聚合法合成了一系列可生物降解的温敏共聚物。用质子核磁共振波谱确证了所得三元共聚物的结构和组成，用凝胶渗透色谱测定了它们的相对分子质量。将共聚物溶解在不同浓度的磷酸盐缓冲盐水(PBS)溶液中，制备水凝胶。用差示扫描量热法、紫外可见光谱仪和旋转流变仪分别测定了水凝胶的低临界溶解温度(LCST)、浊点和流变性。结果表明，随着NIPAAm含量的增加，水凝胶的LcST显著增加，且AAc/HEMAPCL比值越大，水凝胶的储能系数、含水率和可注性越好。将共聚物溶液保持在37℃下形成水凝胶，形成的水凝胶在PBS溶液中降解2周，失重率小于20%。用扫描电子显微镜对水凝胶的形态进行了研究。将NIPAAm/AAc/HEMAPCL摩尔比为88：9.6：2.4的共聚物与I型胶原生物偶联，以提高其生物相容性。研究了含和不含胶原蛋白的水凝胶的体外细胞毒性。
A series of biodegradable thermosensitive copolymers was synthesized by free radical polymerization with N-isopropylacrylamide (NIPAAm), acrylic acid (AAc) and macromer 2-hydroxylethyl methacrylate-poly(epsilon-caprolactone) (HEMAPCL). The structure and composition of the obtained terpolymers were confirmed by proton nuclear magnetic resonance spectroscopy, while their molecular weight was measured using gel permeation chromatography. The copolymers were dissolved in phosphate-buffered saline (PBS) solution (pH = 7.4) with different concentrations to prepare hydrogels. The lower critical solution temperature (LCST), cloud point, and rheological property of the hydrogels were determined by differential scanning calorimetry, ultraviolet-visible spectrometry, and rotational rheometry, respectively. It was found that LCST of the hydrogel increased significantly with the increasing NIPAAm content, and hydrogel with higher AAc/HEMAPCL ratio exhibited better storage modulus, water content, and injectability. The hydrogels were formed by maintaining the copolymer solution at 37 degrees C. The degradation experiment on the formed hydrogels was conducted in PBS solution for 2 weeks and demonstrated a less than 20% weight loss. Scanning electron microscopy was also used to study the morphology of the hydrogel. The copolymer with NIPAAm/AAc/HEMAPCL ratio of 88:9.6:2.4 was bioconjugated with type I collagen for the purpose of biocompatibility enhancement. In-vitro cytotoxicity of the hydrogels both with and without collagen was also addressed.