Researchers at Nanyang Technological University developed peptide microdroplets that deliver siRNA into T cells and colorectal cancer cells to suppress PD-1 and PD-L1 production. In mouse models of microsatellite-stable (MSS) colorectal cancer, which accounts for about 85% of CRCs and generally responds poorly to checkpoint inhibitors, the dual-siRNA approach reduced tumor growth by about 67%, comparable to the antibody combination used as a benchmark.
The approach could potentially offer a lower-cost alternative to monoclonal antibody immunotherapy; researchers estimate manufacturing costs could be 5–10 times lower if the technology translates successfully to treatment. However, this remains an early preclinical finding: the team plans larger animal studies to assess safety, dosing, and durability of the gene-silencing effect.