Detection of Changes in Macrophage Polarization as a Result of 5-Aminolevulinic Acid Photodynamic Therapy Using Fluorescence-Lifetime Imaging Microscopy

Non-invasive detection of polarized macrophages in tumors is an urgent task terms combined antitumor therapy. By analyzing the fluorescence lifetime metabolic cofactors—the reduced form nicotinamide adenine dinucleotide (NADH) and flavins—differences cellular metabolism normal tissue, tumor, inflammatory anti-inflammatory were demonstrated. In this work we studied changes polarization obtained from THP-1 monocytes response to photodynamic therapy with 5-aminolevulinic acid (ALA–PDT). Moderate ALA–PDT vitro led M0 towards M1 polarization, wherein M2 died replaced by non-polarized cells. The interstitial distribution after was a mouse tumor model grafted Lewis lung carcinoma. ALA–PDT, there increase fraction node. Metabolic fluorescence-lifetime imaging microscopy (FLIM) performed for cryosections. It shown that analysis phasor diagrams NADH, flavins, 5-ALA-induced protoporphyrin IX (PpIX) helps determine change different modes PDT at tissue levels. These data can be used post-surgery inspection.