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

摘要

Macrophages and blood vessels are critical components in the biocompatibility and functionality of implantable ceramicmaterials used in drug delivery applications. The purpose of this study was to examine the correlation of macrophage andneovascularization by further defining their presence, relationship, and correlation in the fibrous tissue capsule of calciumphosphate (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. Group Ⅲ animals were implanted with the dihydrotestosterone loadedceramic. Group Ⅳ animals received the androstenedione ceramic. At 90 days post-implantation, the animals were euthanized.Implants and fibrous tissue capsules were collected. Determination of macrophage populations and neovascularity wasconducted microscopically following H&E staining and aided by ImagePro digital analysis software. Androgens have varyingeffects on vascularity and macrophage populations. Overall, macrophage counts were highly and significantly correlated withvascularity (p<0.05), particularly in Groups Ⅱ, Ⅲ, and IV. Correlations for Group Ⅰ was not statistically significant. Thesefindings suggest that presence of macrophages is be directly related to neovascularity, especially in the presence of exogenousandrogens.