Interaction of Ferromagnetic Shape Memory Alloys and RGD Peptides for Mechanical Coupling to Cells: from Ab Initio Calculations to Cell Studies

摘要

Due to their magneto-mechanical coupling and biocompatibility, Fe-Pd based ferromagnetic shape memory alloys are a highly promising materials class for application as contact-less magneto-mechanical transducers in biomedical environments. For use in cell and tissue actuators or strain sensors, sufficient adhesion to mediate strains clearly constitutes a prerequisite. As the RGD sequence is the most important binding motif for mammalian cells, which they express to facilitate adhesion, the potential of RGD coatings to achieve this goal is explored. Employing large-scale density functional theory calculations the physics of bonding between RGD and Fe-Pd surfaces, which is characterized by coordinate bonds of O and N atoms to Fe, accompanied by electrostatic contributions, is clarified. Theoretical predictions on adhesion, that are confirmed experimentally, suggest RGD as suitable strain mediator to Fe-Pd surfaces. On the cell side, favorable adhesion properties of RGD-coated Fe-Pd are manifested in cell morphology and spreading behavior. Demonstrating that the adhesion forces between RGD and Fe-Pd exceed those exerted by cells to the RGD coating, as well as traction forces acting onto integrin bonds, the findings pave the way for novel type of applications as cell and tissue actuator or sensor within the areas of tissue engineering and regenerative medicine.