Mid-infrared optoacoustic microscopy with label-free chemical contrast in living cells and tissues

Abstract

17We developed mid-infrared optoacoustic microscopy (MiROM), a bond-18 selective imaging modality that overcomes water/tissue opacity and depth 19 limitations of mid-infrared sensing allowing uncompromised live-20 cell/thick-tissue mid-infrared microscopy with up to three orders of 21 magnitude higher sensitivity than other vibrational imaging modalities; 22 such as Raman. We showcase the functional label-free biomolecular 23 imaging capabilities of MiROM by monitoring the spatiotemporal 24 dynamics of lipids and proteins during lipolysis in living adipocytes. Since 25MiROM, contrary to Raman modalities, is not only able to detect lipids and 26 proteins, but also important metabolites such as glucose without the need 27

Emerging Technologies to Image Tissue Metabolism

“…A similar approach, using deuterated amino acids, was applied for monitoring the synthesis of proteins in living HeLa, HEK293T, and neuron-like N2A cells (Wei et al, 2013). Beyond the use of isotopic labeling, it recently became possible to directly monitor lipid/protein dynamics during lipolysis in brown and white adipocytes in a label-free manner using a combination of mid-infrared excitation and optoacoustic detection (Pleitez et al, 2018). Vibrational microscopy has also been used to observe metabolic activity in small-animal models.…”

Greasing the Wheels of Lipid Biology with Chemical Tools

“…Other promising modern, nonfluorescent imaging techniques include mid-infrared optoacoustic microscopy (MiROM), which is a bond vibrational imaging modality similar to SRS that allows for higher sensitivity and deeper tissue penetration by limiting the effect of the ubiquitous water found in biological samples. MiROM was recently used to monitor the dynamics of lipids and proteins in live, label-free mode in adipocytes [66].…”