Comparison of subcutaneous inflammatory response to commercial and engineered zinc hydroxyapatite implants in rabbits

Abstract

Hydroxyapatite (HA) is widely used as a biomaterial for bone repair and metallic prostheses coating. The main limitations of the current commercial synthetic hydroxyapatite compounds include high cost and decreased availability, especially for veterinary medicine purposes. Additionally, it is thought that HA biocompatibility and bioactivity could be enhanced by the addition of metal compounds. The objective of this work was to compare the subcutaneous tissue response of commercial and engineered hydroxyapatite obtained from the bovine femur diaphysis mixed with different concentrations of hexa-hydrated Zinc Nitrate in rabbits. Twenty-Five New Zealand female rabbits were used. Five treatments were done according to HA composition (commercial HA, no Zn-HA, 0.1M Zn, 0.2M Zn, and 0.3M Zn). Each treatment was evaluated at five time-points (8, 15, 30, 60 and 90 days postimplantation). Histopathologic analysis was performed to assess inflammation by polymorphonuclear cells infiltration, neovascularization, and fibrosis. Results obtained in this work suggest that general inflammation decreased after 60 days of implantation regardless of Zn concentration. Fibrosis score was increased in the commercial HP compared to control and Zn-hydrated HA. This paper shows that bovine hydroxyapatite is a biocompatible material regardless of nitrate Zinc concentration and has the same properties of commercial hydroxyapatite.

Biocompatibility and biodegradation analysis of Nile Tilapia gelatin and apatite membranes

“…Intense and mixed infl ammatory infi ltrate at 1 week for all materials, with the exuberant presence of polymorphonuclear cells and lymphocytes, was also reported by Jardelino et al (2012) when they tested the biocompatibility of an alginate-capsule alloplastic membrane. Muñoz, Cardona-Ramirez and Silva (2019) reported an initial increase in polymorphonuclear cells for a bovine hydroxyapatite-zinc xenograft. Based on these fi ndings, the expected presence of these cells is confi rmed, which appear in the fi rst days after the surgical implant and tend to gradually decrease in 3 weeks until practically disappearing in 9 weeks (FRANZ et al, 2011).…”