“This technique creates a steady, sustained release of antibodies directly into the tumor site; it is an efficient approach with enhanced retention of anti-PD-1 antibodies in the tumor microenvironment,” says Zhen Gu, an assistant professor in the biomedical engineering program and senior author of the paper.
The researchers tested the technique against melanoma in a mouse model. The microneedle patch loaded with anti-PD-1 nanoparticles was compared to treatment by injecting anti-PD-1 antibodies directly into the bloodstream and to injecting anti-PD-1 nanoparticles directly into the tumor.
“After 40 days, 40 percent of the mice who were treated using the microneedle patch survived and had no detectable remaining melanoma – compared to a zero percent survival rate for the control groups,” said Yanqi Ye, a Ph.D. student in Gu’s lab and co-lead author of the paper.
The researchers also created a drug cocktail, consisting of anti-PD-1 antibodies and another antibody called anti-CTLA-4 – which also helps T cells attack the cancer cells.
“Using a combination of anti-PD-1 and anti-CTLA-4 in the microneedle patch, 70 percent of the mice survived and had no detectable melanoma after 40 days,” Wang said.
“Because of the sustained and localized release manner, mediated by microneedles, we are able to achieve desirable therapeutic effects with a relatively low dosage, which reduces the risk of auto-immune disorders,” Gu said.
“We’re excited about this technique, and are seeking funding to pursue further studies and potential clinical translation,” Gu added.