Evaluation of in vitro and in vivo osteogenic differentiation of nano-hydroxyapatite/chitosan/poly(lactide-co-glycolide) scaffolds with human umbilical cord mesenchymal stem cells.

We aimed to evaluate the feasibility of the application of the nano-hydroxyapatite/chitosan/poly(lactide-co-glycolide) (nHA/CS/PLGA) scaffold seeded with human umbilical cord mesenchymal stem cells (hUCMSCs) in bone tissue engineering. We prepared the nHA/CS/PLGA, nHA/PLGA, CS/PLGA, and PLGA scaffolds, and tested their mechanical strength. We analyzed the surface antigen markers of hUCMSCs to determine their capability to differentiate into osteoblasts, chondrocytes, and adipocytes. The growth of hUCMSCs on the four types of scaffold was assayed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay (MTT assay) and observed using scanning electron microscopy (SEM). Quantitative analysis of alkaline phosphatase (ALP) activity and osteocalcin (OCN) content, as well as the semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) was performed. After 21 days, the subcutaneous implantations of the scaffolds samples seeded with hUCMSCs into nude mice were analyzed using immunohistochemical staining. The results showed that the mechanical strength of the nHA/CS/PLGA scaffold was enhanced. Furthermore, the nHA/CS/PLGA scaffolds were the most suitable for the adhesion, proliferation, and osteogenic differentiation of hUCMSCs in vitro and nude mouse subcutaneous implantation. The enhanced osteogenic inductivity of the nHA/CS/PLGA scaffolds for hUCMSCs might result from the addition of nHA and CS.