Apro, A. | Search bioRxiv

bioRxiv2026

Vibrational optoacoustic detection of lipid-membrane dynamics enables label-free imaging of cell membrane potential

Current technologies to monitor membrane potential are either highly invasive and perturb the integrity of the membrane, use labels that compromise biological behavior, or are limited in sensitivity and do not enable simultaneous monitoring of multiple cells and cell populations. Here, we present Mid-IR Assessment of Conformation in Lipids by Ensemble Sensing (MIRACLES) that, by detection of molecular vibration of lipid acyl chains under cell-membranes electric field dynamics, achieves highly sensitive label-free imaging of membrane potential dynamics in living cells. MIRACLES leverages lipid conformational changes within the plasma membrane as intrinsic indicator for cell membrane depolarization and hyperpolarization. As proof-of-concept, we apply MIRACLES to monitor membrane depolarization during glucose stimulated insulin secretion in {beta}-cells at single-cell level and achieve assessment of {beta}-cell functionality in real time. These results highlight the potential of mid-IR optoacoustic as a powerful tool for indirect, label-free potential assessment of cellular metabolic activities.

bioengineering↗

bioRxiv2024

Oxygen carrying nanoemulsions and respiratory hyperoxia eliminate tumor hypoxia-induced suppression and improve cancer immunotherapy

Hypoxia-HIF-1-driven immunosuppressive transcription and cAMP-elevating signaling through A2A-adenosine receptors (A2AR) represent a major tumor-protecting pathway that enables immune evasion. Recent promising clinical outcomes due to the blockade of the adenosine-generating enzyme CD73 and A2AR in patients refractory to all other therapies have confirmed the importance of targeting hypoxia-adenosinergic signaling. We report a novel and feasible approach to target the upstream stage of hypoxia-adenosinergic immunosuppression using an oxygen-carrying nanoemulsion (perfluorocarbon blood substitute). It is shown that oxygenation agent therapy i) eliminates tumor hypoxia, ii) improves efficacy of endogenously developed and adoptively transferred T cells, and thereby iii) promotes regression of tumors in different anatomical locations. We show that both T cells and NK cells avoid hypoxic tumor areas and that reversal of hypoxia by oxygenation agent therapy increases intratumoral infiltration of activated T cells and NK cells due to re-programming of the tumor microenvironment (TME). Thus, repurposing oxygenation agents in combination with supplemental oxygen may improve current cancer immunotherapies by preventing hypoxia-adenosinergic suppression, promoting immune cell infiltration and enhancing effector responses. These data also suggest that pretreating patients with oxygenation agent therapy may reprogram the TME from immune-suppressive to immune-permissive prior to adoptive cell therapy, or other forms of immunotherapy. SummaryOxygen delivering nanoemulsions and respiratory hyperoxia address limitations of blood vessel-mediated tumor oxygenation and promote anti-tumor immune responses to enhance immunotherapy.

immunology↗