The study of bone formation of hUCMSCs compounded with β-TCP biological ceramic in vitro and in vivo

PURPOSE: To observe the osteogenesis of the construct combining human umbilical cord mesenchymal stem cells (hUCMSCs) with scaffold β-TCP biological ceramic both in vitro and in vivo.

METHODS: A composite was constructed combining hUCMSCs with β-TCP.The cellular capability of adhesion and growth on scaffold were investigated visually by scanning electron microscopy (SEM), specific immunofluorescence staining, MTT and ALP. The constructs were implanted in nude mice for osteogenic potential. The animals were divided into 3 groups: Group 1 (pure β-TCP), Group 2 (the construct combining hUCMSCs with scaffold β-TCP was induced to bone in vitro for 2 weeks), Group 3 (simple implantation of the hUCMSCs which was induced to bone in vitro for 2 weeks). 2 months after implantation, the specimens were harvested for gross observation, radiographic examination and histological observation. SPSS 16.0 software package was used for statistical analysis through repeated measures analysis of variances.

RESULTS: Cells can be seen attached in the scaffold after 4 hours of the implantation of HUCMSCs, a large number of cells reproduce in the scaffold after 1 week. After 2 months of implantation in the nude mice, the group of hUCMSCs and β-TCP incubation had the highest radiodensity. 2 months after implantation, the group of hUCMSCs and β-TCP had irregular new bone and vascular formation, β-TCP group had no obvious new bone and blood vessel formation. 2 months after implantation, hUCMSCs and β-TCP group had a lot of collagen formation, while β-TCP group had no obvious formation of collagen by using masson staining. 2 months after implantation, hUCMSCs and β-TCP group had a large number of osteoid formation, while β-TCP group had no obvious formation of osteoid by using VG staining.

CONCLUSIONS: hUCMSCs and β-TCP have good biocompatibility, the formation of new bone and blood vessels can be seen after 2 months of implantation of the construct into mice.