Macrophage activity modulation via synergistic effect of a porous substrate and low-field laser therapy

Purpose: The aim of this study was to investigate the effect of substrate - polycaprolactone (PCL)-based porous membrane modified with rosmarinic acid (RA), (PCL-RA) and to determine the optimal values of low field laser irradiation (LLLT) as stimulators of biological response of RAW 264.7 macrophages. Methods: The porous polymer membrane was obtained by the phase inversion method, the addition of rosmarinic acid was 1%wt. The reference material was pure polymer membrane. RAW 264.7 were deposited on the material and then irradiated with a laser with a wavelength of 808 nm, a power of 100 mW, an irradiation dose of 2 J/cm2/cell well, applied continuously (C), (100/2/C) or pulsed (I), (100/2/I). Results: Macrophage irradiation resulted in an increase in their adhesion. Modifying the PCL membranes with rosmarinic acid had no effect on cell viability on day 3 of the cell culture. Irradiation of macrophages cultured on PCL-RA material increased their viability. Irradiation of macrophages cultured on PCL-RA material decreased macrophage secretion of NO and protein and the increase in TNF and MCP-1 secretion was only transient on day 3 of culture. Conclusions: Macrophage irradiation had a positive effect on macrophage attachment. Modification of PCL membranes with rosmarinic acid influenced the biological activity of macrophages. Culture of macrophages on rosmarinic acid-modified PCL membranes and simultaneous irradiation of LLLT cells resulted in anti-inflammatory effects.