Surface modification of nanofibrous polyethersulfone scaffolds with fluorapatite nanoparticles toward improved stem cell behavior and osteogenic activity in vitro

Abstract

Nanofibrous polyethersulfone (PESf) scaffolds were fabricated by the electrospinning method. The fabricated scaffolds were surface-modified by fluorapatite nanoparticles (FAn) synthesized using Reline deep eutectic solvent (DES). The effect of surface modification on microstructure, wettability, porosity, biodegradation, and absorption of the scaffolds was investigated. Results confirmed the formation of nanofibers with narrow width between 250 and 600 nm and length of a few tens of microns which was roughened by nanoscale spherical FA particles having a particle size in the range of 40–60 nm. Surface modification of PES by FA nanoparticles led to a significant increase in hydrophilicity, roughness, porosity, and biodegradation which in turn resulted in improvement of viability, growth, proliferation, and differentiation of human bone marrow mesenchymal stem cells (hBMMSCs) assessed by MTT, calcium content (biomineralization), alkaline phosphatase (ALP) activity, alizarin red, and acridine orange staining tests. Gene expression test represented a significant increase in expression of ALP, OCN, RUNX-2, ONN, and COL-I in differentiated stem cells which was attributed to the changes in surface topography and releasing bioactive calcium and fluoride ions made by the inclusion of FA nanoparticles. In conclusion, the nanoscale FA particles in the nanofibrous PES scaffolds provided multiple avenues to engineer PES by modification of surface characteristics for favorable cell-surface interactions, biocalcification, and osteogenesis.