Włodarczyk-Biegun Małgorzata K, Slingerland Cornelis J, Werten Marc W T, van Hees Ilse A, de Wolf Frits A, de Vries Renko, Stuart Martien A Cohen, Kamperman Marleen
Physical Chemistry and Soft Matter, Wageningen University and Research , Wageningen, The Netherlands.
Wageningen UR Food and Biobased Research, Wageningen, The Netherlands.
Biomacromolecules. 2016 Jun 13;17(6):2063-72. doi: 10.1021/acs.biomac.6b00276. Epub 2016 May 23.
Nature shows excellent control over the mechanics of fibrous hydrogels by assembling protein fibers into bundles of well-defined dimensions. Yet, obtaining artificial materials displaying controlled bundling remains a challenge. Here, we developed genetically engineered protein-based polymers functionalized with heparin-binding KRSR domains and show controlled bundling using heparin as a binder. The protein polymer forms fibers upon increasing the pH to physiological values and at higher concentrations fibrous gels. We show that addition of heparin to the protein polymer with incorporated KRSR domains, induces bundling, which results in faster gel formation and stiffer gels. The interactions are expected to be primarily electrostatic and fiber bundling has an optimum when the positive charges of KRSR are approximately in balance with the negative charges of the heparin. Our study suggests that, generally, a straightforward method to control the properties of fibrous gels is to prepare a fiber former with specific binding domains and then simply adding an appropriate amount of binder.
自然界通过将蛋白质纤维组装成尺寸明确的束状结构，对纤维状水凝胶的力学性能表现出卓越的控制能力。然而，获得具有可控束状结构的人工材料仍然是一项挑战。在此，我们开发了用肝素结合KRSR结构域功能化的基于蛋白质的基因工程聚合物，并展示了使用肝素作为粘合剂的可控束状结构。当将pH值提高到生理值时，蛋白质聚合物形成纤维，在更高浓度下形成纤维凝胶。我们表明，向含有KRSR结构域的蛋白质聚合物中添加肝素会诱导束状结构的形成，这会导致更快的凝胶形成和更硬的凝胶。预计这些相互作用主要是静电作用，当KRSR的正电荷与肝素的负电荷大致平衡时，纤维束状结构达到最佳状态。我们的研究表明，一般来说，控制纤维凝胶性质的一种直接方法是制备具有特定结合结构域的成纤材料，然后简单地添加适量的粘合剂。
