An experimental study of vascularization monitoring of tissue engineered bone in the rhesus / 中华创伤骨科杂志

ABSTRACT

Objective To compare four methods of monitoring vascularization of tissue engineered bone in the rhesus so as to find our the best. Methods Twenty-five lower limbs of 13 rhesuses were used in this study to make models of tibial diaphyseal defect of 20mm which were to be fixed with an AO reconstruction plate of 7 holes. The monkeys were randomly divided into five groups according to defect filling materials group A?-tricalcium phosphate (?-TCP) and bone marrow stromal cells (BMSCs) and blood vessel bundles; group B?-TCP and blood vessel bundles; group C?-TCP and BMSCs; group D?-TCP; group E blank. Perfusion weighted MR imaging (PWMR), X-ray, radionuclide imaging and histological examinations were carried out at weeks 4, 8, 12 postop- eratively. The maximum slope rates of the single intensity-time curve (SS_(max)) and values of baseline (Sl_(?))were calculated at the same time points. Transmittances of the X-ray films were assessed. Ratios between isotope counts in region of interest (ROI) were calculated. Chinese ink perfusion and calculation of blood vessel areas were done for histological examinations, Results Compared with other groups, the SS_(max) in group A was the highest at weeks 4, 8, 12 postoperatively. In group A, the SS_(max) at week eight was significantly higher than that at week four (P= 0. 003), and the SS_(max) and transmittance of X-ray were negatively related at week 12 after operation (rs=-0. 892, P=0. 042), but the SS_(max) and blood vessel area were positively related (rs=0. 894, P=0.041)Conclusions PWMR can be a sensitive, quantitative, noninvasive and non-radiant method to monitor vascularization of tissue engineered bone, because SS_(max) of the single intensity-time curve of PWMR can reflect the most accurately the process of vascularization of tissue engineered bone.