title: Repair of bone defect by using vascular bundle implantation combined with Runx II gene-transfected adipose-derived stem cells and a biodegradable matrix.
abstract: A large hurdle in orthopedics today is the difficulty of dealing with the non-union of fractured bones. We therefore evaluated the effects of runt-related transcription factor II (Runx II), a factor used to create gene-modified tissue-engineered bone, combined with vascular bundle implantation for repairing segmental bone defects. Adenovirus Runx II gene (Ad-Runx II)-modified rabbit adipose-derived stem cells (ADSCs) were seeded onto polylactic acid/polycaprolacton (PLA/PCL) scaffolds to construct gene-modified tissue-engineered bone. The following four methods were used for repair in rabbit radial-defect (1.5 cm long) models: gene-modified tissue-engineered bone with vascular bundle (Group A), gene-modified tissue-engineered bone (Group B), non-gene-modified tissue-engineered bone with vascular bundle (Group C), and PLA/PCL scaffolds only (Group D). X-ray, histological examination, biomechanics analysis, and micro-angiography were conducted 4, 8, and 12 weeks later to determine angiogenesis and osteogenesis. The volume and speed of production of newly formed bones in Group A were significantly superior to those in other groups, and de-novo vascular network circulation from the vessel bundle through newly formed bone tissue was observed, with the defect being completely repaired. Group B showed a slightly better effect in terms of speed and quality of bone formation than Group C, whereas the bone defect in Group D was replaced by fibrous tissue. The maximal anti-bending strength in Group A was significantly higher than that in the other groups. Runx II gene therapy combined with vascular bundle implantation thus displays excellent abilities for osteoinduction and vascularization and is a promising method for the treatment of bone non-union and defect.
authors.affiliation: Department of Plastic and Reconstructive Surgery, Ninth People's Hospital, Medical School of Shanghai, Jiao Tong University, Shanghai, People's Republic of China.
authors.forename: Dong
authors.initials: D
authors.lastname: Han
authors.forename: Jianjun
authors.initials: J
authors.lastname: Li
mesh_terms: D000273:Adipose Tissue / Q000166:cytology*; D000818:Animals; D001672:Biocompatible Materials / Q000494:pharmacology*; D001696:Biomechanical Phenomena / Q000187:drug effects; D001808:Blood Vessels / Q000187:drug effects / Q000637:transplantation*; D002470:Cell Survival / Q000187:drug effects; D024042:Collagen Type I / Q000378:metabolism; D050659:Core Binding Factor Alpha 1 Subunit / Q000235:genetics*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D055806:Microvessels / Q000166:cytology; D010012:Osteogenesis / Q000187:drug effects; D011817:Rabbits; D011859:Radiography; D011884:Radius / Q000000981:diagnostic imaging / Q000187:drug effects / Q000473:pathology* / Q000648:ultrastructure; D033581:Stem Cell Transplantation; D013234:Stem Cells / Q000378:metabolism*; D023822:Tissue Engineering; D054457:Tissue Scaffolds / Q000737:chemistry; D014162:Transfection; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D014945:Wound Healing / Q000187:drug effects
chemical_list: D001672:Biocompatible Materials; D024042:Collagen Type I; D050659:Core Binding Factor Alpha 1 Subunit; D042461:Vascular Endothelial Growth Factor A