Double Emulsion Droplets as Osmotic Pressure Sensors in Living Cells and Tissues

Background

Osmotic pressure has an important impact on cell behavior, tissue homeostasis, and even cancer progression, making it a crucial topic for many life science applications. Skincare, for example, relies strongly on water content of the tissue, which is directly related to osmolarity. Osmotic pressure is also an important indicator of hemodynamic disorders, kidney disease, and the evolution of tumors. However, quantifying osmotic pressure in living cells and tissues is extraordinarily difficult and not possible inside 3D multicellular systems, such as living embryos, tissues, organs, and organoids, without considerably perturbing the system. Direct in vivo and in situ measurements of osmotic pressure would unlock critical data on fundamental cellular and developmental processes and help understand multiple disease processes.

Description

Researchers at the University of California, Santa Barbara have developed a technology that non-invasively measures osmotic pressure in situ and in vivo within 3D living cells and tissues. Key to the invention are double emulsion droplets (generated using microfluidics) composed of an aqueous core with calibrated osmolarity surrounded by an oil layer. The oil layer acts as a semi-permeable membrane that enables the transport of water molecules exclusively. When the osmolarity between the aqueous core and the surrounding environment is different, water molecules exit or enter the core through the oil layer resulting in changes to the droplet volume, which provides a direct readout of osmotic pressure in the living system. The droplets are inserted using fine glass capillaries and the osmotic pressure measurement is precisely localized at the droplet, allowing for direct, absolute measurements of osmotic pressure in living cells and in the extracellular spaces of living tissues.

Advantages

  • Non-invasive measurements of osmotic pressure in situ and in vivo within 3D living cells and tissues
  • Direct, spatially-localized and time-dependent measurement of osmotic pressure

Applications

  • Biotech
    • Skincare
    • Diagnostics
  • Pharmaceuticals
    • Drug delivery