Our Technology

Oxygen Imaging

O2M’s core technology is inversion recovery pulsed electron paramagnetic resonance oxygen imaging (EPROI) invented by O2M’s co-founders.

EPROI is a noninvasive oxygen mapping technology.

It measures the relaxation maps of a water-soluble, oxygen-reporting trityl molecule (OX063 or its deuterated version OX071, also known as OX063-D24) that distributes in a body upon injection. Oxygen concentration is linearly related to trityl relaxation rates.

Tissue oxygen maps obtained using our technology can be used to develop enhanced therapies.

The examples include but are not limited to:

  • Cancer research, diagnostics, and treatment
  • Assessment of therapy outcome
  • Development of artificial cell replacement devices
  • Drug development
  • Vitality probing of artificial cell replacement devices

Electron Paramagnetic Resonance

  • Zeeman effect - splitting of magnetic particle energy levels into several states in the presence of a static magnetic field
  • The transition between these states results in absorption or emission of power 
  • The transition can be excited using oscillating magnetic field with particular  frequency – magnetic resonance
low freq epr plot

How EPROI is Different from MRI

our tech- mri vs eproi

Magnetic Field vs Penetration Depth in EPROI

frequency - our tech

EPROI Spin Probes

Trityl OX063/OX071

The oxygen imaging using EPROI requires contrast agent, trityl OX063 or its deuterated version OX071. OX071 has many unbeatable qualities:

  • Stable radicals 
  • Water soluble and non-toxic 
  • Single EPR line
  • High SNR at physiologic settings
  • Trityl is added in vitro (0.5 mM – 1 mM concentration)
  • Trityl is injected systematically via I.V. or I.P. route in animals (150 µL – 300 µL of 72 mM stock solution). In tumors, trityl can also be injected via intra-tumoral injections
  • Fast clearance from animals (10 – 30 min). No adverse effect reported from hundreds of animals imaged

Ball-and-stick model of OX-071³⁻. Carbon atoms are depicted in grey, hydrogen in white, deuterium in green, oxygen in red, and sulfur in gold.

Applications of Our Tech


Tumor Hypoxia

Spatial heterogeneity in tumor hypoxia is the most important factor in regulating tumor growth, development, aggressiveness, metastasis, and effective treatment outcome. It has been known that most tumors are often characterized by hypoxia or low oxygen levels (pO₂ < 10 torr/mmHg). An accurate oxygen concentration is needed for Oxygen Guided Radiation Therapy (OGRT) to reduce the overall radiation dose. O2M's patented technology has been shown to be highly effective in measuring tiny voxels of hypoxic tumor. 

Read more here, here, here, and here.


Type 1 Diabetes (T1D)

T1D mellitus is an autoimmune disorder in which the body’s immune response destroys the insulin-producing islet cells. Islet transplantation therapy has shown significant promise; however, the lack of oxygen supply to the highly metabolic islet cells is the major contributing factor to the failure of cell transplantation devices. Backed by JDRF, O2M team is helping researchers optimize islet cell replacement devices.

Read more here and here.

tissue graft

Biomaterials Assessment

Oxygen affects cell proliferation, differentiation, metabolism and apoptosis. Biomaterials have different oxygen diffusion profile based on their treatment. Oxygen monitoring in biomaterials and artificial tissues will avert hypoxia induced cell death, control cell differentiation, and overall improve the graft quality.

Read more here, here, here, here, and here.

Recent Publications Featuring O2M™

  • In Vivo pO2 pO2 Assessment in Subcutaneous and Intraperitoneal Sites Using Imaging of Solid Oxygen Probe

    Tissue Engineering Part C: Methods, 2022

  • Amniotic growth factors enhanced human pre-adipocyte cell viability and differentiation under hypoxia

    Journal of Biomedical Materials Research, 2022

  • A Bioinspired Scaffold for Rapid Oxygenation of Cell Encapsulation

    Nature Communications, 2021

  • An Inverse-Breathing Encapsulation System for Cell Delivery

    Science Advances, 2021

  • EPR Everywhere

    Applied Magnetic Resonance, 2021

  • Cyclic Hypoxia: An Update on Its Characteristics, Methods to Measure It and Biological Implications in Cancer

    Cancer, 2020

  • Abstract 1646: Preclinical Oxygen Imager for Cancer Oxygenation Studies

    Cancer Research, 2020

For a full list of our publications, see our Publications page

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