Innesto osseo omologo vascolarizzato e trapianto di cellule nucleate midollari per migliorare l’angiogenesi nella riparazione di lesioni ossee critiche: studio su animale

Abstract

Autologous bone grafting is a standard procedure for the clinical repair of skeletal defects, and good results have been obtained. Autologous vascularized bone grafting and allografts are often used, presenting several drawbacks. On the other side, several studies in literature reported the ability of bone marrow derived cells to promote neo-vascularization thanks to specific GF, hematopoietic and nesenchymal stem cells. In this scenario a new procedure was developed, consisting in an allogenic bone graft transplantation in a critical size defect in rabbit radius, plus a deviation at its inside of the median artery and vein with a supplement of autologous bone marrow concentrate on a collagen scaffold. Twenty-four rabbits were were operated with different experimental and control procedures. For each group, 3 experimental times: 8, 4 and 2 weeks. An in vitro evaluation of bone marrow concentrate was performed and at the time of sacrifice histological and histomorphometrical assessment were performed with immunohistochemical assays for VEGF, CD31 e CD146 to highlight the presence of vessels and endothelial cells. Micro-CT Analysis with quantitative bone evaluation was performed. The bone marrow concentrate showed a marked capability to differentiate into osteogenic, chondrogenic and agipogenic lineages. No complications were reported. The bone grafts showed only a partial integration, mainly at the extremities in the group with vascular and bone marrow concentrate supplement. Immunohistochemistry showed an interesting higher VEGF expression in the same group. Micro CT analysis showed a higher remodeling activities in the groups treated with vascular supplement, with an area of integration at the extremities increasing with the extension of the sacrifice time. The present study suggests that the vascular and marrow cells supplement may positively influence the neoangiogenesis and the neovascularization of the homologous bone graft