Surface modification of titanium implants via electrospinning of sericin and Equisetum arvense enhances the osteogenic differentiation of stem cells

Abstract

Titanium-based biomaterials are among the most extensively used implants in orthopedics and dentistry. However, their poor osteoconductivity and osteoinductivity are the main challenges for researchers, so the existence of other components with the aim of overcoming the mentioned deficiencies could be desirable. In the present research, a bioactive nanofibrous coating of polyvinyl alcohol-sericin, containing different amounts of Equisetum arvense (EA) was obtained by electrospinning process. This method was performed to mimic the bone extracellular matrix structure and also to improve the osseointegration performance of Ti-based materials. Furthermore, the effect of EA on the morphology, structure, adhesive strength, bioactivity and biological properties of titanium plates was assessed. Increasing the EA content does not affect the fiber diameter. Coral-like apatite layers were successfully deposited on all samples after 7 d of soaking in the simulated body fluid. The crystallinity degree of the deposited apatite layer decreased with the addition of EA – as indicated by XRD analysis. Increasing EA content enhanced the adhesive strength, EA and silicon ions release and the amounts of deposited apatite layer. Moreover, EA enhanced the attachment, proliferation and differentiation of the Human Adipose-Derived Stem cells (hADSCs) indicated by ALP activity and calcium deposition assays and mRNA expressions of different genes such as Runx2, Col I and OPN. Overall, the addition of EA into the polyvinyl alcohol-sericin nanofibrous coatings not only enhanced titanium bioactivity but also improved the osteoinductivity, which are important factors in increasing osseointegration of Ti-based implants.