(543i) Composites Biointerfaces for an in Vitro cellular Study

The research area of implant improvement by surface functionalization when correlated with biological response is of major interest in the biomedical field. Based on the fact that the inflammatory response is directly involved in the ultimate response of the implant within the body; it is essential to study the macrophage-material interactions. Within this context; in this study we investigated the composite material-macrophage cell interactions and the inflammatory response to these composites that contained amorphous hydroxyapatite (HA), Lactoferrin (Lf) and the polyethylenglycol polycaprolactone (PEG-PCL) copolymer. The composite materials are obtained by the Matrix Assisted Pulsed Laser Evaporation (MAPLE) technique and the triple module target system; using a pulsed Nd: YAG laser system (Continuum Company;266 nm; 6 ns pulse duration; 10 Hz repetition rate; fluence of 450 mJ/cm²). The in vitro study included proliferation and metabolic activity of the cells assessed by the quantitative colorimetric MTS assay. Pro-TNF-α and anti-inflammatory IL-10 cytokine secretion in the presence and absence of the inflammatory stimuli (bacterial endotoxin; LPS), was measured using an ELISA method. The different cellular activation depended on the physical-chemical characteristics of the coatings that was observed by Atomic Force Microscopy and Scanning electron Microscopy. Copolymer-HA-Lf coatings led to low levels of pro-inflammatory TNF-α; increased levels of anti-inflammatory IL-10 and a polarization of THP-1 cells towards an M2 pro-reparative phenotype in the presence of LPS. These findings could have important potential for the development of composite coatings in implant applications.