Adenovirus-mediated transfer of VEGF into marrow stromal cells combined with PLGA/TCP scaffold increases vascularization and promotes bone repair in vivo.
BACKGROUND
Large osseous defect remains a serious clinical problem due to the lack of sufficient blood supply and it has been proposed that this situation can be relieved by accelerating the formation of new vessels in the process of bone defect repair. The aim of this study was to develop a new type of artificial bone by transferring the VEGF gene into marrow stromal cells (MSCs) and seeding them into a porous scaffold.


METHODS
An adenovirus vector was employed to transfer the VEGF gene into MSCs and expression of the exogenous gene was confirmed by ELISA. Next the transduced cells were seeded into a collagen I modified PLGA/TCP scaffold. The constructed new complex artificial bone was then assessed for biocompatibility in vitro and blood vessel formation and bone formation in vivo.


RESULTS
We found that adenovirus mediated VEGF gene transfer into MSCs sustained VEGF expression in MSCs for 3 weeks. Porous scaffold PLGA/TCP made by rapid prototyping technology exhibited improved biocompatibility resulting from crosslinking with collagen I. Furthermore, the in vivo study showed that large amounts of blood vessels were detected histologically 1 week after artificial bone implantation, and significant bone formation was detected 8 weeks after implantation.


CONCLUSIONS
Our findings suggest that gene transfer of VEGF into MSCs combined with PLGA/TCP scaffold enhances bone repair in vivo by promoting vascularization.
Department of Orthopaedics and Traumatology, Xijing Hospital, Fourth Military Medical University, Xi'an, PR China.
Chunguang
C
Duan
Department of Orthopaedics and Traumatology, Xijing Hospital, Fourth Military Medical University, Xi'an, PR China.
Jian
J
Liu
Department of Orthopaedics and Traumatology, Xijing Hospital, Fourth Military Medical University, Xi'an, PR China.
Zhi
Z
Yuan
Department of Orthopaedics and Traumatology, Xijing Hospital, Fourth Military Medical University, Xi'an, PR China.
Guolin
G
Meng
Department of Ophthalmology, Xijing Hospital, Fourth Military Medical University, Xi'an, PR China.
Xiumei
X
Yang
Department of Orthopaedics and Traumatology, Xijing Hospital, Fourth Military Medical University, Xi'an, PR China.
Shuaijun
S
Jia
Department of Orthopaedics and Traumatology, Xijing Hospital, Fourth Military Medical University, Xi'an, PR China.
Jinkang
J
Zhang
Department of Orthopaedics and Traumatology, Xijing Hospital, Fourth Military Medical University, Xi'an, PR China.
Shi
S
Chen
artificial bone; gene transfer; poly-(DL-lactic-co-glycolic acid)/tricalcium phosphate; vascular endothelial growth factor