Hypoxia is a condition that drives a lack of responses to a wide array of cancer therapies. Tumor hypoxia causes resistance to many cancer therapies, including radiotherapy and chemotherapy. Methods that increase tumor oxygen pressures, such as hyperbaric oxygen therapy and microbubble infusion, are utilized to improve the responses to current standard-of-care treatments. However, key obstacles remain, particularly the delivery of oxygen at the appropriate dose and with optimal pharmacokinetics.
In a new study, scientists at the University of Iowa used GeMs to deliver high oxygen levels directly into tumors. Inspired by the foam on top of lattes, gummy bears, and Pop Rocks candies, scientists are creating new, biocompatible materials- called gas-entrapping materials, or GeMs, that may improve the effectiveness of chemotherapy and radiation for treating cancers. Â
GeMs can considerably raise the oxygen levels within solid tumors, according to a recent study, making the cancer cells more susceptible to radiation or chemotherapy. Additionally, the elevated oxygen levels appeared to enhance immunological reactivity, which is essential for eliciting an immune response to immunotherapy.
Byrne, UI assistant professor of radiation oncology and a member of Holden Comprehensive Cancer Center at the UI, said, “We’ve known for a long time that if you increase the amount of oxygen within a tumor, you can make it more responsive to radiation, certain chemotherapies, and even potentially immunotherapies.”
“However, the challenge has been delivering an effective dose of oxygen in a safe, controlled fashion.”
“These GeMs are very simple, with just three ingredients: the gas, the foaming agents, and the thickening agent. We use several unique, custom-built pressurized systems to incorporate high concentrations of gas into small volumes of these biocompatible materials, which can be injected or implanted into tissues and allow for prolonged, controlled release of the gas.”
Scientists created GeMs using a whipping siphon but reverse-engineered them to accept various gases, including oxygen. They used safe, low-cost components in many processed foods to make the GeMs.
The amount of each component can be changed to regulate how much oxygen is released from the component. Byrne argues that the GeMs’ translatability for cancer treatment is probably quite high because they are made with safe and ingestible components.
The capability to implant or inject GeMs right into the tumor is an additional benefit. The capacity to deliver high medication concentrations with few adverse effects inside the tumor has led to the rise of the intratumoral delivery of cancer medicines over the past ten years. The foams can be injected into challenging tumor locations to treat or remove surgically.
Study first author Bi, a research scientist in Byrne’s lab, said, “One of the aspects of this project that excited me was the combination of cancer biology principles with material science to create something that can be impactful.”
Journal Reference:
- Jianling Bi, Emily Witt, et al. Low-Cost, High-Pressure-Synthesized Oxygen-Entrapping Materials to Improve Treatment of Solid Tumors. Advanced Science. DOI: 10.1002/advs.202205995