Effects of aligned PLGA/SrCSH composite scaffolds on in vitro growth and osteogenic differentiation of human mesenchymal stem cells

Abstract

Strontium (Sr) has important functions in bone remodeling. Incorporating strontium‐doped α‐calcium sulfate hemihydrate (SrCSH) into poly(lactic‐co‐glycolic acid) (PLGA) fibrous scaffolds were expected to increase its bio‐activity and provide a potential material for bone tissue engineering. In the present study, Sr‐containing aligned PLGA/SrCSH fibrous scaffolds similar to the architecture of natural bone were prepared via wet spinning. CCK‐8 assay revealed that Sr‐containing scaffolds possessed better bioactivity and supported favorable cell growth effectively. The aligned PLGA/SrCSH fibers exerted a contact effect on cell attachment, inducing regular cell alignment and influencing a series of cell behaviors. Releasing of high concentration Sr from a‐PLGA/SrCSH scaffolds could induce high expression levels of BMP‐2, increase ALP activity and upregulate RUNX‐2 expression, and further promote the expressions of COL‐I and OCN and the maximum mineralization. This study demonstrated that Sr and ordered structure in a‐PLGA/SrCSH fibrous scaffolds could synergistically enhance the osteogenic differentiation of umbilical cord mesenchymal stem cells (UCMSCs) by regulating cell arrangement and expressions of osteogenic genes.