RNA medicine shows promise for training the body to recognize tumors and eliminate them, but a better delivery system is needed to activate the immune cells within the body and generate an anti-tumor response. With backing from the National Institutes of Health, materials scientist Hai-Quan Mao is part of a Johns Hopkins University team working to create more potent mRNA-based immunotherapies to target solid tumors and metastatic cancers.
Mao, Jordan Green, Jonathan Schneck, and Lei Zheng from the School of Medicine are working to develop biodegradable mRNA nanoparticles to target circulating monocytes, which are white blood cells in the bloodstream, to improve mRNA therapies. It's one of several ways Mao is adding his materials science expertise to collaborations addressing health challenges including cancer, malaria, and nerve and tissue damage.
"With the support of the NIH, our team collaborates closely with clinicians and physician-scientists to design patient-centric solutions that address urgent medical challenges," Mao said. "By harnessing the power of materials science, we are developing innovative biomaterials—such as nanoparticles, hydrogels, and composite systems—that can enhance healing, improve immune therapies, and ultimately transform patient care."
A professor in the Department of Materials Science and Engineering at the university's Whiting School of Engineering and director of the Johns Hopkins Institute for NanoBioTechnology, Mao is also a key member of the NIH-funded Johns Hopkins Center for Translational Immunoengineering.
NIH-funded projects led by Mao include a collaboration with Sami Tuffaha, an associate professor of plastic and reconstructive surgery at the Johns Hopkins School of Medicine, to develop nanoparticles to aid persistent nerve regeneration and improve functional recoveries for patients suffering from peripheral nerve injuries, and with Sashank Reddy—also an associate professor of plastic and reconstructive surgery and associate director of the INBT—to develop a nanofiber-hydrogel composite to promote vascularized soft tissue regeneration that could be used for facial reconstruction and to address tissue loss after cancer surgery.
Through an NIH-funded partnership with the University of Washington and the University of South Florida, Mao is also working to better understand, treat, and prevent infectious diseases such as malaria. In 2023, there were more than 150 million infections globally, leading to more than 600,000 deaths.
"We seek to improve defense against malaria by generating liver-resident T cells, which block the parasite lifecycle in the patient's liver," Mao said. This strategy will help improve the potency to stop the spread of malaria and provide protection for people in endemic and non-endemic regions.
Mao acknowledges and credits the NIH for enabling these and countless other advances in medical research.
"The NIH has supported large-scale studies like these for generations and has been critical to research that directly impacts our health today," he said. "Continued funding from the NIH is critical to solve complex health challenges we are facing globally."

Image caption: Hai-Quan Mao and team
Image credit: Will Kirk / Johns Hopkins University