PLLA scaffolds with controlled surface potential and piezoelectricity for enhancing cell adhesion in tissue engineering

The effect of the surface potential of biomaterials on cell attachment and development in regenerative medicine is still an unexplored area driving many regeneration processes, especially in piezoelectric bone tissue. Within this study, we electrospun poly(L-lactide) scaffolds constructed of fibers with either higher (-600 mV) or lower (-300 mV) surface potential, which is controlled by applied voltage polarity during their production. Interest-ingly, this way, the piezoelectric performance of PLLA fibers can be enhanced. The direct measurement of the PLLA fiber surface potential using Kelvin probe force microscopy (KPFM) showed a good correlation with the zeta potential analysis. The piezoelectricity of PLLA fibers was verified with piezoresponse force microscopy (PFM), indicating that it can be enhanced by applying the positive voltage polarity to the nozzle during elec-trospinning. Importantly, the cell adhesion assay showed a significant effect of the higher surface potential of PLLA fibers on osteoblasts behavior and creating a favorable bioelectric microenvironment. We observed enhanced initial adhesion of cells in the first 5 h with no additional effect of surface potential on proliferation, morphology, or collagen production. It was demonstrated that electrospun PLLA fibers with tunable surface potential and piezoelectricity are excellent for constructing bone tissue engineering scaffolds.