In VitroCytokine Expression andIn VivoHealing and Inflammatory Response to a Collagen-Coated Synthetic Bone Filler

Abstract

The goal of the present work was to investigate the relationship betweenin vivohealing and inflammatory response andin vitrocytokine expression by macrophages of a synthetic bone filler (25% hydroxylapatite-75%β-tricalcium phosphate) bearing a surface nanolayer of collagen. A clinically accepted, state-of-the-art xenograft material was used as a “negative control,” that is, as a material that provides the correct clinical response for the intended use.In vitrodata show that both materials exert a very low stimulation of proinflammatory cytokines by macrophages, and this was confirmed by the very mild inflammatory response detected inin vivotests of local response in a rabbit model. Also,in vitrofindings suggest a different mechanism of healing for the test and the control material, with a higher regenerative activity for the synthetic, resorbable filler, as confirmed byin vivoobservation and literature reports. Thus, the simplein vitromodel adopted provides a reasonable forecast ofin vivoresults, suggesting that new product development can be guided byin vitrotuning of cell-materials interactions.