Shelf-stable mRNA delivery system targets bladder cancer cells without immune response

Published, peer-reviewed research shows a patent-pending, virus-mimicking platform technology developed at Purdue University improves upon traditional methods of targeting bladder cancer cells with messenger RNA (mRNA) therapies.

The study, published in the Proceedings of the National Academy of Sciences, highlights compelling features of the therapy-delivering system with respect to size, targetability, encapsulation efficiency, complex stability, gene expression and “green” manufacturability.

David Thompson led the team conducting research about layer-by-layer elastin-like polypeptide nucleic acid nanoparticle (LENN). He is a professor in the James Tarpo Jr. and Margaret Tarpo Department of Chemistry and a member of the Purdue Institute for Cancer Research and the Purdue Institute for Drug Discovery. Saloni Darji, a commercialization postdoctoral research associate, is the paper’s lead author.

“We have validated that the LENN system can be freeze-dried and stored for several days as a powder and retain full biological activity after rehydration,” Thompson said. “We also confirmed that this biomanufacturable system homes to the target tissue and neither alters the natural entry pathway to those tumors nor triggers an immune response. LENN traffics to the cancer cells then releases the mRNA within the cells, leading to expression of the protein encoded by the mRNA.

“These results could address challenges faced by lipid nanoparticle delivery systems, which must be continuously stored as liquids below minus 45 degrees Celsius to maintain their activity,” he said. “Additionally, LENN system components are products of biological expression that enable a readily manufacturable delivery system.”

Lyophilization and entry pathways

LENN particles mimic the multilayer structure of viruses to deliver nucleic acid-based therapies to targeted cells. It comprises two protective layers: an inner shell that condenses the therapies and an outer shell that protects it from degradation and evasion of the immune system.

To assess the stability of the freeze-dried formulations, Darji said concentrated formulations of LENN samples were diluted and initially frozen at minus 20 degrees C, followed by cooling to minus 80 C and lyophilization overnight. The lyophilized powders were stored at minus 20 C for three days.

“Sample rehydration was performed and formulations tested for structural integrity and encapsulation efficiency compared to fresh samples,” she said. “These samples retained their functionality even after lyophilization, making them a promising mRNA vector system for therapeutic applications that require long-term storage.”

Darji said the research into LENN’s effects on entry pathways was conducted on bladder cancer cells because bladder cancer poses significant targeting and delivery challenges.

“LENN can target the mRNA to a specific cell type based on that cell’s surface information,” she said. “In the case of bladder cancer cells, LENN targets a specific cell surface receptor already present on the tumor cell. The LENN system targets it and enters through the natural pathway.”

Thompson said the next phases of this project will focus on upscaling the system to support further preclinical evaluation.

“This includes efficacy and safety studies in the mouse model of bladder cancer in collaboration with Bennett Elzey in the Department of Comparative Pathobiology and the Purdue Institute for Cancer Research,” he said.