Potential use of a bone tissue engineering scaffold based on electrospun poly (ɛ-caprolactone) - poly (vinyl alcohol) hybrid nanofibers containing modified cockle shell nanopowder

Today, the construction of scaffolds promoting the differentiation of stem cells is an intelligent innovation that accelerates the differentiation toward the target tissue. The use of calcium and phosphate compounds is capable of elevating the precision and efficiency of the osteogenic differentiation of stem cells. In this research, osteoconductive electrospun poly (ɛ-caprolactone) (PCL) - poly (vinyl alcohol) (PVA) hybrid nanofibrous scaffolds containing modified cockle shell (CS) nanopowder were prepared and investigated. In this regard, the modified CS nanopowder was prepared by grinding and modifying with phosphoric acid, and it was then added to PVA nanofibers at different weight percentages. Based on the SEM images, the optimum content of the modified CS nanopowder was set at 7 wt. %, since reaching the threshold of agglomeration restricted this incorporation. In the second step, the PVA-CS7 nanofibrous sample was hybridized with different PCL ratios. Concerning the hydrophilicity and mechanical strength, the sample named PCL50-PVA50-CS7 was ultimately selected as the optimized and suitable candidate scaffold for bone tissue application. The accelerated hydrolytic degradation of the sample was also studied by FTIR and SEM analyses, and the results confirmed that the mineral deposits of CS are available approximately 7 days for mesenchymal stem cells. Moreover, Alizarin red staining illustrated that the presence of CS in the PCL50-PVA50-CS7 hybrid nanofibrous scaffold may potentially lead to an increase in calcium deposits with high precipitates, authenticating the differentiation of stem cells towards osteogenic cells.