A Rationally Optimized Nanoparticle System for the Delivery of RNA Interference Therapeutics into Pancreatic Tumors in Vivo

• Published in: Biomacromolecules Vol. 17; no. 7; pp. 2337 - 2351
• Main Authors: Teo, Joann, McCarroll, Joshua A, Boyer, Cyrille, Youkhana, Janet, Sagnella, Sharon M, Duong, Hien T. T, Liu, Jie, Sharbeen, George, Goldstein, David, Davis, Thomas P, Kavallaris, Maria, Phillips, Phoebe A
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 11.07.2016
• Subjects: Animals; Cell Survival - drug effects; Drug Delivery Systems; Humans; Methacrylates - chemistry; Mice; Mice, Inbred BALB C; Mice, Nude; Nanoparticles - administration & dosage; Nanoparticles - chemistry; Nylons - chemistry; Pancreatic Neoplasms - drug therapy; Pancreatic Neoplasms - genetics; Pancreatic Neoplasms - pathology; Polymers - chemistry; RNA, Small Interfering - administration & dosage; RNA, Small Interfering - genetics; Tubulin - chemistry; Tubulin - genetics; Tubulin - metabolism; Tumor Cells, Cultured; Xenograft Model Antitumor Assays
• ISSN: 1525-7797; 1526-4602
• DOI: 10.1021/acs.biomac.6b00185

Pancreatic cancer is a devastating disease with a dismal prognosis. Short-interfering RNA (siRNA)-based therapeutics hold promise for the treatment of cancer. However, development of efficient and safe delivery vehicles for siRNA remains a challenge. Here, we describe the synthesis and physicochemical characterization of star polymers (star 1, star 2, star 3) using reversible addition–fragmentation chain transfer polymerization (RAFT) for the delivery of siRNA to pancreatic cancer cells. These star polymers were designed to contain different lengths of cationic poly­(dimethylaminoethyl methacrylate) (PDMAEMA) side-arms and varied amounts of poly­[oligo­(ethylene glycol) methyl ether methacrylate] (POEGMA). We showed that star-POEGMA polymers could readily self-assemble with siRNA to form nanoparticles. The star-POEGMA polymers were nontoxic to normal cells and delivered siRNA with high efficiency to pancreatic cancer cells to silence a gene (TUBB3/βIII-tubulin) which is currently undruggable using chemical agents, and is involved in regulating tumor growth and metastases. Notably, systemic administration of star-POEGMA-siRNA resulted in high accumulation of siRNA to orthotopic pancreatic tumors in mice and silenced βIII-tubulin expression by 80% at the gene and protein levels in pancreatic tumors. Together, these novel findings provide strong rationale for the use of star-POEGMA polymers as delivery vehicles for siRNA to pancreatic tumors.