Noninvasive Markers of Macrophage Polarization via Multimodal Nonlinear Optical Microscopy

Tumor associated macrophages (TAMs) are pivotal in the tumor microenvironment, influencing angiogenesis, metastasis, and immunosuppression. This study explores macrophage polarization using a noninvasive, label free multimodal nonlinear optical approach, combining Stimulated Raman Scattering and Two-Photon Excited Fluorescence microscopy. By investigating murine TAMs, we identify distinct polarization states (M0, M1, and M2) through marker free vibrational and autofluorescence signatures. Our findings highlight lipidome and metabolic alterations as key indicators of macrophage phenotypes. This method advances our understanding of TAM biochemistry and offers potential pathways for novel macrophage targeted cancer therapies.