Differentiation of rabbit bone mesenchymal stem cells into endothelial cells in vitro and promotion of defective bone regeneration in vivo.
Tissue engineering strategies often fail to regenerate bones because of inadequate vascularization, especially in the reconstruction of large segmental bone defects. Large volumes of vascular endothelial cells (ECs) that functionally interact with osteoblasts during osteogenesis are difficult to obtain. In this study, we simulated bone healing by co-culturing differentiated ECs and mesenchymal stem cells (MSCs) either on a culture plate or on a polylactide glycolic acid (PLGA) scaffold in vitro. We also evaluated the effect of osteogenesis in repairing rabbit mandible defects in vivo. In this study, MSCs were separated from rabbit as the seed cells. After passage, the MSCs were cultured in an EC-conditioned medium to differentiate into ECs. Immunohistochemical staining analysis with CD34 showed that the induced cells had the characteristics of ECs and MSC. The induced ECs were co-cultured in vitro, and the induction of MSCs to osteoblast served as the control. Alkaline phosphatase (ALP) and alizarin red (AZR) staining experiments were performed, and the Coomassie brilliant blue total protein and ALP activity were measured. The MSCs proliferated and differentiated into osteoblast-like cells through direct contact between the derived ECs and MSCs. The co-cultured cells were seeded on PLGA scaffold to repair 1 cm mandible defects in the rabbit. The effectiveness of the repairs was assessed through soft X-ray and histological analyses. The main findings indicated that MSCs survived well on the scaffold and that the scaffold is biocompatible and noncytotoxic. The results demonstrated that the co-cultured MSC-derived ECs improved MSC osteogenesis and promoted new bone formation. This study may serve as a basis for the use of in vitro co-culturing techniques as an improvisation to bone tissue engineering for the repair of large bone defects.
Department of Oral Pathology, School of Stomatology, Jilin University, Changchun, 130021, People's Republic of China, liujinzhong920@163.com.
Jinzhong
J
Liu
Chao
C
Liu
Bin
B
Sun
Ce
C
Shi
Chunyan
C
Qiao
Xiaoliang
X
Ke
Shutai
S
Liu
Xia
X
Liu
Hongchen
H
Sun
D000818:Animals; D001861:Bone Regeneration / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D018920:Coculture Techniques; D042783:Endothelial Cells / Q000166:cytology* / Q000187:drug effects; D019344:Lactic Acid / Q000494:pharmacology; D008334:Mandible / Q000166:cytology* / Q000502:physiology*; D008422:Materials Testing; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000187:drug effects; D010012:Osteogenesis / Q000187:drug effects; D011100:Polyglycolic Acid / Q000494:pharmacology; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011817:Rabbits; D023822:Tissue Engineering
D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid