NEOVASCULARIZATION AND FIBROBLAST BEHAVIOR UNDER THE INFLUENCE OF ANDROGENS IN THE TISSUE-IMPLANT RESPONSE

摘要

Fibroblasts and blood vessels are critical components in the biocompatibility and functionality of implantable ceramic materialsused in drug delivery applications. The purpose of this study was to examine the correlation of fibroblasts andneovascularization by further defining their presence, relationship, and correlation in the fibrous tissue capsules of tricalciumphosphate (TCP) ceramic drug delivery systems. Sixteen animals in four experimental groups were implanted with one TCPbioceramic each. Group I animals were implanted with a TCP ceramic not containing a biologic (control group). Group IIanimals received the testosterone loaded TCP ceramic (T-TCP). Group III animals were implanted with the dihydrotestosteroneloaded ceramic (D-TCP). Group IV animals received the androstenedione ceramic (A-TCP). At 90 days post-implantation, theanimals were euthanized. Implants and fibrous tissue capsules were collected. Determination of fibroblast/fibrocytepopulations and neovascularity was conducted microscopically following H&E staining and aided by Image Pro digital analysissoftware. Androgens have varying effects on vascularity and fibroblast populations (ANOVA, p<0.05). Overall, fibroblastcounts were highly and significantly correlated with vascularity (p<0.001), particularly in T-TCP, D-TCP, and A-TCP groups.Correlations for control group was not statistically significant. Statistically significant differences were noted between D-TCPand control, T-TCP, and A-TCP groups (Bonferroni LSD, p<0.001). These findings suggest that presence of fibroblasts is bedirectly related to neovascularity and can be significantly influenced in the presence of exogenous androgens.