New 'smart' nanoparticles help the immune system better attack tumors
· Medical Xpressedited by Gaby Clark, reviewed by Robert Egan
Gaby Clark
Scientific Editor
Meet our editorial team
Behind our editorial process
Robert Egan
Senior Editor
Meet our editorial team
Behind our editorial process Editors' notes
This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility:
fact-checked
peer-reviewed publication
trusted source
proofread
The GIST Add as preferred source
Adelaide University researchers have developed a new way to use mRNA technology to reprogram tumor-supporting immune cells and strengthen the body's anticancer immune response.
The scientific team, spanning engineering, biomedical, oncology and immunology experts, has developed tiny, targeted particles that could help the immune system fight cancer by reprogramming immune cells within the tumor environment.
The findings have been published in Science Advances today.
Turning macrophages inside tumors
The new approach uses lipid nanoparticles—the same delivery technology used to deliver mRNA in COVID-19 vaccines—to target a type of immune cell that can help tumors evade the body's defenses.
In animal experiments, the nanoparticles were designed to find tumor-associated macrophages, or TAMs, which are large white blood cells commonly found in tumors.
Rather than attacking these cells, the researchers effectively reprogrammed them so they became less suppressive and helped attract cancer-fighting T cells into the tumor.
Lead researcher Professor Chunxia Zhao from Adelaide University's School of Chemical Engineering said the research tackles a major challenge in cancer immunotherapy—getting immune cells into tumors and keeping them active.
"One of the biggest challenges in cancer immunotherapy is that the immune system may be capable of attacking a tumor, but the tumor environment can stop those immune cells from doing their job," Zhao said.
"Our approach is designed to change that environment from within the tumor. By specifically targeting tumor-associated macrophages, we can deliver the treatment where it is needed and encourage the immune system's cancer-fighting T cells to enter the tumor and become more active."
Two-part payload inside cells
The nanoparticles were coated with an antibody that recognizes a protein called TREM2, which is highly expressed on tumor-associated macrophages.
Once inside the macrophages, the particles delivered two key ingredients: an mRNA molecule carrying instructions to produce a chemical signal called CXCL9 and a compound called Resiquimod that helps switch the macrophages away from their immune-suppressing behavior.
CXCL9 acts like a chemical beacon, helping attract cancer-fighting CD8+ T cells into the tumor.
In mouse experiments, treatment reduced the proportion of immune-suppressing macrophages by more than 60% and increased CXCL9 levels in tumors fourfold. The researchers also observed greater numbers and activity of cancer-fighting T cells and a moderate reduction in tumor growth.
Checkpoint drugs added mixed results
When the treatment was combined with existing immune checkpoint-blocking drugs targeting PD-L1 and CTLA-4, the researchers saw further increases in cancer-fighting T cells and the development of central memory T cells, which could help the immune system remember and respond to cancer in the future. However, the combination did not produce additional tumor-growth inhibition in this particular mouse model.
Zhao said the findings could open a new avenue for improving immunotherapy for solid cancers, where the tumor environment can prevent immune treatments from working effectively.
"This is an important proof of concept that we can use mRNA and nanoparticle technology to reprogram the immune environment of a tumor.
"There is still significant work to do before this approach could be considered for patients, but these results provide an encouraging foundation for developing more targeted cancer immunotherapies."
The research was led by Adelaide University researchers in collaboration with SA Pathology and the Royal Adelaide Hospital.
Publication details
Rui Chen et al, Targeting tumour-associated macrophages using mRNA lipid nanoparticles for cytotoxic T lymphocyte-mediated cancer immunotherapy, Science Advances (2026). DOI: 10.1126/sciadv.aed9568. www.science.org/doi/10.1126/sciadv.aed9568
Journal information: Science Advances
Key medical concepts
Tumor-Associated MacrophagesTREM2 protein, human
Clinical categories
OncologyAllergy and immunology Provided by University of Adelaide Who's behind this story?
Gaby Clark
MA in English, copy editor since 2021 with experience in higher education and health content. Dedicated to trustworthy science news. Full profile →
Robert Egan
Bachelor's in mathematical biology, Master's in creative writing. Well-traveled with unique perspectives on science and language. Full profile →
Citation: New 'smart' nanoparticles help the immune system better attack tumors (2026, September 11) retrieved 11 September 2026 from https://medicalxpress.com/news/2026-09-smart-nanoparticles-immune-tumors.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.