CBMA (Centre of Molecular and Environmental Biology), Department of Biology, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
Biomed Mater. 2013 Dec;8(6):065009. doi: 10.1088/1748-6041/8/6/065009. Epub 2013 Nov 28.
Protein-based polymers are present in a wide variety of organisms fulfilling structural and mechanical roles. Advances in protein engineering and recombinant DNA technology allow the design and production of recombinant protein-based polymers (rPBPs) with an absolute control of its composition. Although the application of recombinant proteins as biomaterials is still an emerging technology, the possibilities are limitless and far superior to natural or synthetic materials, as the complexity of the structural design can be fully customized. In this work, we report the electrospinning of two new genetically engineered silk-elastin-like proteins (SELPs) consisting of alternate silk- and elastin-like blocks. Electrospinning was performed with formic acid and aqueous solutions at different concentrations without addition of further agents. The size and morphology of the electrospun structures was characterized by scanning electron microscopy showing its dependence on the concentration and solvent used. Treatment with methanol-saturated air was employed to stabilize the structure and promote water insolubility through a time-dependent conversion of random coils into β-sheets (FTIR). The resultant methanol-treated electrospun mats were characterized for swelling degree (570-720%), water vapour transmission rate (1083 g/m(2)/day) and mechanical properties (modulus of elasticity ∼126 MPa). Furthermore, the methanol-treated SELP fibre mats showed no cytotoxicity and were able to support adhesion and proliferation of normal human skin fibroblasts. Adhesion was characterized by a filopodia-mediated mechanism. These results demonstrate that SELP fibre mats can provide promising solutions for the development of novel biomaterials suitable for tissue engineering applications.
蛋白质基聚合物存在于各种生物体中，具有结构和机械功能。蛋白质工程和重组 DNA 技术的进步允许设计和生产具有组成绝对控制的重组蛋白基聚合物（rPBPs）。尽管重组蛋白作为生物材料的应用仍然是一项新兴技术，但可能性是无限的，远远优于天然或合成材料，因为结构设计的复杂性可以完全定制。在这项工作中，我们报告了两种新型基因工程丝弹性蛋白样蛋白（SELPs）的静电纺丝，它们由交替的丝和弹性蛋白样结构组成。在不添加其他试剂的情况下，使用甲酸和不同浓度的水溶液进行静电纺丝。扫描电子显微镜观察到，静电纺丝结构的大小和形态与其浓度和所用溶剂有关。用甲醇饱和空气处理可通过无规卷曲向 β-折叠（FTIR）的时间依赖性转化来稳定结构并提高水不溶性。对甲醇处理后的静电纺丝垫进行了溶胀度（570-720%）、水蒸气透过率（1083g/m 2 /天）和机械性能（弹性模量约 126MPa）的表征。此外，甲醇处理的 SELP 纤维垫无细胞毒性，能够支持正常人皮肤成纤维细胞的黏附和增殖。黏附通过丝状伪足介导的机制进行了表征。这些结果表明，SELP 纤维垫可为开发适合组织工程应用的新型生物材料提供有前途的解决方案。
