Department of Diagnostic and Clinical Health Sciences, SHRP, UMC
Title: Histopathological evaluation of fibrous tissue surrounding bioceramic delivery systems in sheep and rodent models
Biography: Hamed A. Benghuzzi
The major challenges faces vast majority of orthopedic and dental implants are: (i) biocompatibility, (ii) resorbability and (iii) maintenance of mechanical strength. Several studies conducted in our laboratories have documented the effectiveness of various ceramic drug delivery systems (CDDS) in regulating fertility in females as well as males. It was observed that the mode of sustained delivery of reproductive hormones from CDDS was governed and regulated by the development of capsular tissue surrounding the implantable CDDS. This investigation was specifically designed to correlate the thickness of fibrous capsule and the various histopathological components that are seen in the fibrous capsule surrounding ALCAP, HA, and TCP ceramics at the S/C and I/P implantation sites in small (rats) and large (sheep) animals. Male albino rats and castrated adult rams were utilized for these studies. All experimental animals were implanted either S/C or I/P with ALCAP, HA, and TCP ceramics delivery devises loaded with 40 mg testosterone. At 90 days post- implantation, the animals in all groups were euthanized and the fibrous tissue surrounding the ceramic devices and internal organs were harvested. After routine histological processing, sections of tissue were stained with hematoxylin and eosin as well as special stains and evaluated using light microscopy. Analysis of the data revealed the followings: 1) development of fibrous tissue around the implants did not show any significant difference in small or large animals, 2) capsular tissues retrieved from S/C site induced less fibrous tissue formation compared to I/P site in both models, 3) the presence of proinflammatory cells such as macrophages, neutrophils, fibroblasts, and vascularity, was found to be statistically different among the S/C implanted CDDS groups (p<0.01) compared to I/P implantation site, and 4) regardless of animal model, the ease of fibrous capsule thickness were ALCAP> HA>TCP, respectively. Results from these studies provided very important outcomes in which can be utilized to predict the longevity of the physical strength of CDDS and the duration of delivery profiles. The clinical impact of this investigation stems in the ability to develop biocompatible and effective delivery systems that ultimately will lead to fertility regulation.