Ultrasound stimulated piezoelectric antibacterial silk composite films guiding differentiation of mesenchymal stem cells

Smart materials for tissue engineering have been in extensive use for few decades now. This work delves into the exploration of ultrasound-stimulated piezoelectric and antibacterial silk-based composite films as a pioneering strategy to guide the differentiation of human mesenchymal stem cells into osteogenic lineage without the application of any exogenous growth factors. The study evaluates the biocompatibility and antibacterial attributes of these films, which incorporates Barium Titanate nanoparticles (BTNPs) along with Zinc Oxide nanoparticles for obtaining high piezo modulated stimuli response and antibacterial properties. Further, to enhance the piezoelectric capability, a novel calcium doped Barium Titanate (BCTs) nanoparticles were synthesized and incorporated in silk based films with ZnO. The choice of using calcium as a doping material allows to increase its piezoelectric potential and retain its biocompatibility. The results reveal that, under the influence of ultrasound stimulation, these composite films respond to mechanical cues like low frequency ultrasound stimulations to facilitate lineage-specific differentiation of the seeded human mesenchymal stem cells. Ultrasound stimulations being wireless avoid complicated wired electric circuits and are also known to activate calcium channels in the cells which aids osteogenesis. Significantly, our findings exhibit the profound potential of these films to exploit the piezoelectric properties of BCTs, effectively enhancing the differentiation trajectories of stem cells. Furthermore, their demonstrated antibacterial capacities underscore their pivotal role in infection prevention, an important facet in the domains of tissue engineering and medical implantation. This study strongly suggests the utility of ultrasound-stimulated silk-based composite films in advancing the frontiers of regenerative medicine and tissue engineering.