Morphometric analysis of the hormonal effect on tissue-implant response associated with TCP bioceramic implants.

Recent studies in our laboratory have demonstrated the need for an experiment comparing the effect of steroid hormones on the cellular composition of the fibrous tissue capsules surrounding tricalcium phosphate (TCP) bioceramics. The effect of steroid hormones on inflammatory cells has been widely reported in the scientific literature. The purpose of this research is to contribute to the development of a long-term ceramic drug delivery system with human and veterinary applications. This study contributes information on the composition of fibrous tissue capsules surrounding hormone loaded TCP bioceramic implants at 90 days post-implantation. The data obtained in this study was gathered using protocols developed from ImagePro software. Sixteen animals in four experimental groups were implanted with one TCP bioceramic each. Group I animals were implanted with a sham TCP ceramic not containing a steroid hormone (control group). Group II animals received the testosterone loaded TCP ceramic. Group III animals were implanted with the dihydrotestosterone loaded ceramic. Group IV animals received the androstenedione ceramic. At 90 days post-implantation, the animals were euthanized. The implants and fibrous tissue capsules surrounding them were then extracted. The fibrous tissue capsules were evaluated microscopically using ImagePro software following routine II&E staining, modified Papanicolau, and Masson's trichrome. The research variables comparing the hormonal effects on fibrous tissue composition obtained by digital analysis were as follows: thickness of the fibrous tissue, quantification of macrophages, neutrophils, fibroblasts, vascularity, and area occupied by collagen. The results of this study support several conclusions. All three of the hormones in this study, particularly androstenedione, have significant affects on the thickness and cellular composition of the fibrous tissue capsules when compared to the control group. Digital analysis software enables more accurate and reproducible results to be obtained when specific procedures are followed.