Geiger Florian, Beverungen Mirjam, Lorenz Helga, Wieland Julia, Fehr Michael, Kasten Philip
Division of Experimental Orthopedics, Orthopedic University Hospital of Heidelberg, Heidelberg 69118, Germany.
University of Veterinary Medicine Hannover, Hannover 30559, Germany.
J Funct Biomater. 2012 Apr 19;3(2):313-26. doi: 10.3390/jfb3020313.
VEGF (vascular endothelial growth factor) promotes vascularization and remodeling of bone substitutes. The aim of this study was to examine the effect of distinct resorbable ceramic carriers on bone forming capacities of VEGF transfected bone marrow stromal cells (BMSC). A critical size defect of the radius in rabbits was filled either by a low surface scaffold called beta-TCP (tricalciumphsphate) or the high surface scaffold CDHA (calcium deficient hydroxy-apatite) loaded with autologous BMSC, which were either transfected with a control plasmid or a plasmid coding for phVEGF165. They were compared to unloaded scaffolds. Thus, six treatment groups (n = 6 in each group) were followed by X-ray over 16 weeks. After probe retrieval, the volume of new bone was measured by micro-CT scans and vascularization was assessed in histology. While only minor bone formation was found in both carriers when implanted alone, BMSC led to increased osteogenesis in both carriers. VEGF promoted vascularization of the scaffolds significantly in contrast to BMSC alone. Bone formation was increased in the beta-TCP group, whereas it was inhibited in the CDHA group that showed faster scaffold degradation. The results indicate that the interaction of VEGF transfected BMSC with resorbable ceramic carrier influences the ability to promote bone healing.
血管内皮生长因子（VEGF）可促进骨替代物的血管化和重塑。本研究旨在考察不同的可吸收陶瓷载体对VEGF转染的骨髓基质细胞（BMSC）成骨能力的影响。将兔桡骨的临界尺寸缺损用低表面支架β-磷酸三钙（β-TCP）或高表面支架缺钙羟基磷灰石（CDHA）填充，两种支架均负载自体BMSC，这些BMSC分别用对照质粒或编码phVEGF165的质粒转染。将它们与未负载的支架进行比较。因此，六个治疗组（每组n = 6）在16周内接受X射线检查。取出探针后，通过显微CT扫描测量新骨体积，并在组织学上评估血管化情况。单独植入时，两种载体中均仅发现少量骨形成，而BMSC可导致两种载体中的成骨增加。与单独的BMSC相比，VEGF显著促进了支架的血管化。β-TCP组的骨形成增加，而在支架降解更快的CDHA组中骨形成受到抑制。结果表明，VEGF转染的BMSC与可吸收陶瓷载体的相互作用会影响促进骨愈合的能力。
