Surface-mineralized polymeric nanofiber for the population and osteogenic stimulation of rat bone-marrow stromal cells

Nanofibrous biomaterials made of degradable polymers, including poly(ɛ-caprolactone) (PCL), are considered as a potential substrate for populating and differentiating tissue cells. The surface modification of biomaterials is of utmost importance in regulating cell functions. This study examined the effects of an apatite-mineralization of the PCL nanofiber surface on the growth behavior and osteogenic differentiation of rat bone-marrow stromal cells (rBMSCs). BMSCs isolated from adult rats were seeded on the PCL nanofiber with mineralization (PCLnf-M) and without it as a control (PCLnf), and cultured for up to 28 days. Initially (for 1 h), the cells adhered better on the PCLnf-M than on the control, showing favorable cell affinity to the mineralized nanofibrous surface. The secretion of collagen by the cells was shown to increase with culturing time on both types of the nanofiber. The cell viability was similar at day 7 but was higher on the control at a prolonged period of day 14. However, the alkaline phosphatase (AP) activity was noticed to significantly higher level on the PCLnf-M than on the control at days 14 and 28. Overall, the surface-mineralized PCL nanofibrous substrate was shown to support the adhesion and growth of BMSCs and to stimulate the differentiation into an osteogenic lineage. This type of nanofibrous sheet is considered to be useful as a matrix for the regeneration and engineering of skeletal tissues.