Bioactive polymeric scaffolds for osteochondral tissue engineering: in vitro evaluation of the effect of culture media on bone marrow stromal cells

Abstract

The goal of this study was to determine the efficacy of the bioactive scaffold system to initiate bone marrow stromal cell (BMSC) differentiation into osteogenic and chondrogenic lineages in various culture media compositions. In the biphasic polymeric scaffolds, the chondrogenic layer contained aligned polycaprolactone nanofibers embedded with chondroitin sulfate and hyaluronic acid, while osteogenic layer carried nano‐hydroxyapatite. Many studies for in vitro testing of osteochondral scaffolds incorporate the use of complicated bioreactors or growth factors for the formation of cartilage and bone tissue, thus true efficacy of the scaffold system cannot be determined. The present study compared the effect of several media compositions consisting of osteogenic, chondrogenic components, and control basal media. Scaffolds seeded with BMSCs following 28 days in vitro culture in different induction and basal media were evaluated for osteogenic and chondrogenic markers such as aggrecan, collagen type II, bone sialoprotein, alkaline phosphatase (ALP), and runt‐related transcription factor 2 (Runx‐2). Cartilage scaffold layer of the biphasic scaffold resulted in the expression of chondrogenic markers such as aggrecan and collagen type II by BMSCs in control and induction media compositions. The bone scaffold layer supported the expression of osteogenic markers such as ALP and Runx‐2 by BMSCs in control and induction media compositions. The cartilage scaffold layer under the osteogenic induction media encouraged the growth of hypertrophic cartilage as marked by the positive expression of Runx‐2. Expression of collagen type II and aggrecan on the cartilage layer in basal media was confirmed by immunostaining. These studies suggest that the bioactive scaffolds were able to support the osteogenic and chondrogenic phenotype development in the absence of growth factors and induction media. Copyright © 2015 John Wiley & Sons, Ltd.