A cancer treatment inspired by the foam on top of your overly complicated iced coffee

While cancer therapies won’t be delivered through the foam on top of your hot chocolate anytime soon, researchers are creating new, biocompatible foamy materials that might help improve the effectiveness of chemotherapy and radiation for treating cancers.

Known as gas-entrapping materials, or GeMs, they’re designed to carry high concentrations of therapeutic gases directly into tissues, including tumours, and can be formulated into foams, solids, or hydrogels.

Now researchers have used GeMs to deliver high levels of oxygen directly into tumours and showed that this improved the effectiveness of standard chemotherapy and radiation treatments. They injected the substances into mice models of prostate cancer and a type of sarcoma.

The foam GeMs were created using a whipping siphon – essentially the same device baristas use to make foams on hot chocolate and frozen coffee drinks – reverse engineered to infuse various gases (including oxygen) instead of nitrous oxide.

Graphical abstract
Schematic diagram illustrating how O2-GeMs are fabricated and incorporated into clinically relevant therapies for treatment-refractory tumors. Credit: Bi et al. 2023

Injection or implantation of GeMs significantly increased the oxygen levels within the solid tumours, combating tumour hypoxia – a reduction of oxygen transport in the microenvironment of solid tumours that correlates with poor outcomes in human patients.

The GeMs also changed the composition of immune cells inside the tumours by increasing immune reactivity, which is key to generating a response to immunotherapy.

The foams, in particular, can be injected into areas of the tumour that are harder to treat or remove by surgery. 

Read more: Could a carbon monoxide foam therapeutic help fight inflammation?

“We’ve known for a long time that if you increase the amount of oxygen within a tumour you can make it more responsive to radiation, certain chemotherapies, and even potentially immunotherapies,” says James Byrne, Assistant Professor of radiation oncology at the University of Iowa (UI) in the US, and senior author of the study.

“However, the challenge has been how to deliver 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,” says Byrne, who also is a UI assistant professor of biomedical engineering.

A gloved hand releases foam out of a siphon
James Byrne demonstrates use of a whipping siphon to dispense gas-entrapping foam in his lab on Friday, Jan. 27, 2023. A paper published in February 2023 in Advanced Science (IF 17.5) focused on the use of molecular gastronomical techniques to create novel materials for the treatment for cancer. Credit: University of Iowa Health Care

“We use several unique, custom-built pressurised 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.” 

They used safe, low-cost ingredients found in many processed foods to make the GeMs, which Byrne says means it’s extremely likely they will translate well for cancer care. By varying the quantities of each component they were able to control the release of oxygen from the final material.

“One of the aspects of this project that really excited me was the combination of cancer biology principles with material science, to create something that can be really impactful,” concludes study first author Dr Jianling Bi, a research scientist in Byrne’s lab.

Details are in in a new study in Advanced Science.

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