Analysis of the Expression and Activity of Cyclooxygenases COX-1 and COX-2 in THP-1 Monocytes and Macrophages Cultured with Xenogenic Collagen Matrices Biofunctionalized with the Injectable Platelet-Rich Fibrin

Xenogenic collagen matrices are used in clinical practice for soft tissue augmentation around teeth and implants, either alone or biofunctionalized with injectable platelet-rich fibrin (iPRF). Their direct interaction with inflammatory cells may influence both healing and destructive inflammation processes. Therefore, expression of cyclooxygenases (COX-1 and COX-2) and prostanoids (PGE2 and TXB2) was studied in THP-1 monocyte/macrophage cultures exposed to porcine collagen matrices (a non-cross-linked monolayer scaffold composed of collagen type I, collagen type III, and elastin (MLCM), a bilayer scaffold made of collagen types I and III (BLCM), and a volume-stable cross-linked monolayer scaffold (VSCM)). The study showed that VSCM and MLCM significantly reduced PGE2 concentrations in THP-1 monocyte cultures. iPRF further reduced PGE2 concentrations when exposed to MLCM. In contrast, incubation of THP-1 monocytes with VSCM and BLCM resulted in a significant increase in TXB2 concentrations compared with control conditions. Incubation of macrophages with MLCM, VSCM, and BLCM increased PGE2 concentrations, with VSCM and BLCM additionally increasing TXB2 concentrations. iPRF in macrophage cultures with VSCM and BLCM also resulted in increased PGE2 and TXB2 concentrations compared with control conditions. Confocal microscopy revealed no visible differences in COX-1 immunoexpression in monocytes and macrophages cultured with collagen matrices, either with or without iPFR. Weak positive COX-2 immunofluorescence was observed in monocytes, while moderate positive immunofluorescence was detected in macrophages. In conclusion, it can be suggested that the studied collagen matrices interact with monocytes/macrophages, with MLCM exhibiting the highest compatibility.