title: In vitro and in vivo effects of rat kidney vascular endothelial cells on osteogenesis of rat bone marrow mesenchymal stem cells growing on polylactide-glycoli acid (PLGA) scaffolds.
abstract: It is well established that vascularization is critical for osteogenesis. However, adequate vascularization also remains one of the major challenges in tissue engineering of bone. This problem is further accentuated in regeneration of large volume of tissue. Although a complex process, vascularization involves reciprocal regulation and functional interaction between endothelial and osteoblast-like cells during osteogenesis. This prompted us to investigate the possibility of producing bone tissue both in vitro and ectopically in vivo using vascular endothelial cells because we hypothesized that the direct contact or interaction between vascular endothelial cells and bone marrow mesenchymal stem cells are of benefit to osteogenesis in vitro and in vivo. For that purpose we co-cultured rat bone marrow mesenchymal stem cells (MSC) and kidney vascular endothelial cells (VEC) with polylactide-glycolic acid scaffolds. In vitro experiments using alkaline phosphatase and osteocalcin assays demonstrated the proliferation and differentiation of MSC into osteoblast-like cells, especially the direct contact between VEC and MSC. In addition, histochemical analysis with CD31 and von-Willebrand factor staining showed that VEC retained their endothelial characteristics. In vivo implantation of MSC and VEC co-cultures into rat's muscle resulted in pre-vascular network-like structure established by the VEC in the PLGA. These structures developed into vascularized tissue, and increased the amount and size of the new bone compared to the control group (p < 0.05). These results suggest that the vascular endothelial cells could efficiently stimulate the in vitro proliferation and differentiation of osteoblast-like cells and promote osteogenesis in vivo by the direct contact or interaction with the MSC. This technique for optimal regeneration of bone should be further investigated.
authors.affiliation: Department of Oral Pathology, School of Stomatology, JiLin University, ChangChun 130041, PR China. hcsun@jlu.edu.cn
authors.forename: Hongchen
authors.initials: H
authors.lastname: Sun
authors.forename: Zhe
authors.initials: Z
authors.lastname: Qu
authors.forename: Ying
authors.initials: Y
authors.lastname: Guo
authors.forename: Guangxiang
authors.initials: G
authors.lastname: Zang
authors.forename: Bai
authors.initials: B
authors.lastname: Yang
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D001854:Bone Marrow Cells / Q000378:metabolism*; D018929:Cell Culture Techniques / Q000295:instrumentation; D002454:Cell Differentiation; D049109:Cell Proliferation; D018920:Coculture Techniques; D042783:Endothelial Cells / Q000166:cytology; D004730:Endothelium, Vascular / Q000166:cytology* / Q000378:metabolism; D007668:Kidney / Q000378:metabolism*; D019344:Lactic Acid / Q000737:chemistry*; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D008954:Models, Biological; D010006:Osteoblasts / Q000378:metabolism; D015675:Osteocalcin / Q000378:metabolism; D010012:Osteogenesis; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000096:biosynthesis; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000737:chemistry*; D051381:Rats; D023822:Tissue Engineering / Q000295:instrumentation / Q000379:methods
chemical_list: D019408:Platelet Endothelial Cell Adhesion Molecule-1; D011108:Polymers; D015675:Osteocalcin; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D000469:Alkaline Phosphatase