Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL 60208, USA.
Biomaterials. 2010 Oct;31(28):7288-97. doi: 10.1016/j.biomaterials.2010.06.003. Epub 2010 Jul 6.
Biomaterials that mimic the extracellular matrix in both modularity and crosslinking chemistry have the potential to recapitulate the instructive signals that ultimately control cell fate. Toward this goal, modular protein polymer-based hydrogels were created through genetic engineering and enzymatic crosslinking. Animal derived tissue transglutaminase (tTG) and recombinant human transglutaminase (hTG) enzymes were used for coupling two classes of protein polymers containing either lysine or glutamine, which have the recognition substrates for enzymatic crosslinking evenly spaced along the protein backbone. Utilizing tTG under physiological conditions, complete crosslinking occurred within 2 min, as determined by particle tracking microrheology. Hydrogel composition impacted the elastic storage modulus of the gel over 4-fold and also influenced microstructure and degree of swelling, but did not appreciably effect degradation by plasmin. Mouse 3T3 and primary human fibroblasts were cultured in both 2- and 3-dimensions without a decrease in cell viability and displayed spreading in 2D. The properties, which are controlled through the specific nature of the protein polymer precursors, render these gels valuable for in situ therapies. Furthermore, the modular hydrogel composition allows tailoring of mechanical and physical properties for specific tissue engineering applications.
具有类似细胞外基质的结构和交联化学性质的生物材料具有重现最终控制细胞命运的指导信号的潜力。为此，通过遗传工程和酶交联方法构建了基于模块化蛋白质聚合物的水凝胶。使用动物来源的组织转谷氨酰胺酶（tTG）和重组人转谷氨酰胺酶（hTG）酶来偶联两类含有赖氨酸或谷氨酸的蛋白质聚合物，这些聚合物的酶交联识别底物均匀分布在蛋白质主链上。在生理条件下使用 tTG，通过粒子跟踪微流变学确定完全交联在 2 分钟内发生。水凝胶组成使凝胶的弹性储能模量增加了 4 倍以上，并且还影响了微结构和溶胀程度，但对纤溶酶的降解没有明显影响。鼠 3T3 和原代人成纤维细胞在 2 维和 3 维培养中均未降低细胞活力，并在 2D 中显示出扩展。这些特性可通过蛋白质聚合物前体的特定性质进行控制，使这些水凝胶非常适合原位治疗。此外，模块化水凝胶组成允许针对特定组织工程应用定制机械和物理性能。
