Sakai Shinji, Moriyama Kousuke, Kawakami Koei
a Division of Chemical Engineering, Department of Materials Engineering, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama-cho, Toyonaka, Osaka 560-8531, Japan.
J Biomater Sci Polym Ed. 2011;22(9):1147-56. doi: 10.1163/092050610X500589.
A variety of cross-linking methods is used for obtaining gelatin gels having a tolerance to thermo-reversible gel-sol transition at physiological temperature. In this paper, we investigated the applicability of horseradish peroxidase-catalyzed cross-linking of tyrosine residues originally contained in native gelatin molecules for preparing such gelatin gels. The gelatin gels obtained through exposure to the enzymatic reaction showed a higher resistance to thermo-reversibility at 37°C than gels obtained through a thermally-induced gelation alone. In addition, the resistance property to thermo-reversible gel-sol transition was tunable by controlling enzymatic reaction conditions: higher peroxidase concentration and thermally-induced pre-gelation accomplished by cooling the gelatin solution prior to the enzymatic reaction produced gels with higher resistance to thermo-reversibility. Fibroblast cells enclosed in the gelatin gels obtained through the enzymatic reaction with thermally-induced pre-gelation showed 93% viability. These results demonstrate the feasibility of peroxidase-catalyzed reaction for obtaining gelatin gels having a tolerance to thermo-reversible gel-to-sol transition at physiological temperature toward applications in biomedical and biopharmaceutical fields.
为了获得在生理温度下对热可逆凝胶 - 溶胶转变具有耐受性的明胶凝胶，人们使用了多种交联方法。在本文中，我们研究了辣根过氧化物酶催化天然明胶分子中原本含有的酪氨酸残基进行交联，用于制备此类明胶凝胶的适用性。通过酶促反应获得的明胶凝胶在37°C时比仅通过热诱导凝胶化获得的凝胶表现出更高的抗热可逆性。此外，通过控制酶促反应条件可以调节对热可逆凝胶 - 溶胶转变的抗性：更高的过氧化物酶浓度以及在酶促反应之前通过冷却明胶溶液实现的热诱导预凝胶化产生了具有更高抗热可逆性的凝胶。包裹在通过热诱导预凝胶化的酶促反应获得的明胶凝胶中的成纤维细胞显示出93%的活力。这些结果证明了过氧化物酶催化反应在获得对生理温度下热可逆凝胶 - 溶胶转变具有耐受性的明胶凝胶方面的可行性，可用于生物医学和生物制药领域。
