Li Xian, Fan Daidi
Shaanxi Key Laboratory of Degradable Biomedical Materials, Shaanxi R&D Center of Biomaterials and Fermentation Engineering, Biotech. & Biomed. Research Institute, School of Chemical Engineering, Northwest University, 229 Taibai North Road, Xi'an, Shaanxi 710069, China.
Clinical Medical Research Center of the Affiliated Hospital, Inner Mongolia Medical University, 1 Tong Dao Street, Hohhot 010050, Inner Mongolia Autonomous Region, China.
ACS Biomater Sci Eng. 2019 Jul 8;5(7):3523-3536. doi: 10.1021/acsbiomaterials.9b00393. Epub 2019 Jun 25.
For the first time, collagen-based hydrogels were fabricated in the presence of a biocompatible ionic liquid, 1-ethyl-3-methylimidazolium acetate ([EMIM] [Ac]), by a simple biopolymer cross-linking process facilitated by the strong catalytic hydrolysis of microbial transglutaminase (MTGase). Phosphate buffer solution (PBS)-encapsulated human-like collagen (HLC) or fish bone collagen (FBC) for the composite hydrogels was simply prepared by the codissolution of biopolymers in [EMIM] [Ac] or, in the absence of the ionic liquid, by the dispersion of MTGase in the biopolymer solution, leading to the formation of MTGase-aided hydrogels (Gel1 and Gel4) and [EMIM] [Ac]/MTGase-aided hydrogels (Gel2, Gel3, and Gel5). The effects of different contents of [EMIM] [Ac] and collagens of different origins (HLC and FBC) during fabrication on a range of structural and material characteristics, including the synthesis mechanism, three-dimensional structure, swelling behavior, mechanical strength, enzymatic hydrolysis rate, cytotoxicity, fibroblast cell proliferation rate, inhibition of cancer cells and cell adhesion, and histocompatibility, were investigated. Surprisingly, fabrication with [EMIM] [Ac] had significant effects on the structure and properties of the collagen/MTGase-based hydrogels. In other words, [EMIM] [Ac] changed the underlying mechanism responsible for the advantageous properties of the hydrogels by changing the three-dimensional structure of HLC or FBC, which improved their effects on fibroblast proliferation (3T3-L1 and L929 cells) and their inhibition of cancer cells (HepG2 and MKN45 cells). The use of the ionic liquid also imbued the hydrogels with degradation resistance and anti-inflammatory properties after subcutaneous injection into mice (). The catalytic hydrolysis by MTGase and the [EMIM] [Ac] content were the major factors that influenced the properties of the collagen. This result suggests the potential application of ionic liquid-enzymatic hydrolysis in the fabrication of collagen hydrogels in circumstances where the control of the properties by an ionic liquid is desirable. Therefore, [EMIM] [Ac] could be a promising solvent for the development of collagen into smart biomaterials with controlled biodegradation rates that can meet the needs of specific potential applications, such as tissue engineering and cancer therapy.
首次在生物相容性离子液体1-乙基-3-甲基咪唑醋酸盐（[EMIM][Ac]）存在的情况下，通过微生物转谷氨酰胺酶（MTGase）的强催化水解促进的简单生物聚合物交联过程，制备了基于胶原蛋白的水凝胶。用于复合水凝胶的磷酸盐缓冲溶液（PBS）包封的类人胶原蛋白（HLC）或鱼骨胶原蛋白（FBC），可通过在[EMIM][Ac]中共同溶解生物聚合物，或在不存在离子液体的情况下，通过将MTGase分散在生物聚合物溶液中来简单制备，从而形成MTGase辅助水凝胶（Gel1和Gel4）以及[EMIM][Ac]/MTGase辅助水凝胶（Gel2、Gel3和Gel5）。研究了在制备过程中不同含量的[EMIM][Ac]和不同来源的胶原蛋白（HLC和FBC）对一系列结构和材料特性的影响，包括合成机制、三维结构、溶胀行为、机械强度、酶促水解速率、细胞毒性、成纤维细胞增殖率、对癌细胞的抑制作用、细胞粘附以及组织相容性。令人惊讶的是，用[EMIM][Ac]进行制备对基于胶原蛋白/MTGase的水凝胶的结构和性能有显著影响。换句话说，[EMIM][Ac]通过改变HLC或FBC的三维结构，改变了导致水凝胶具有有利特性的潜在机制，这提高了它们对成纤维细胞增殖（3T3-L1和L929细胞）的影响以及对癌细胞（HepG2和MKN45细胞）的抑制作用。在皮下注射到小鼠体内后，离子液体的使用还赋予了水凝胶抗降解性和抗炎特性。MTGase的催化水解和[EMIM][Ac]的含量是影响胶原蛋白性能的主要因素。这一结果表明，在需要通过离子液体控制性能的情况下，离子液体 - 酶促水解在胶原蛋白水凝胶制备中具有潜在应用。因此，[EMIM][Ac]可能是一种有前途的溶剂，可用于将胶原蛋白开发成具有可控生物降解速率的智能生物材料，以满足特定潜在应用的需求，如组织工程和癌症治疗。
