Dual Tumor-Targeting Nanocarrier System for siRNA Delivery Based on pRNA and Modified Chitosan

Abstract

Highly specific and efficient delivery of siRNA is still unsatisfactory. Herein, a dual tumor-targeting siRNA delivery system combining pRNA dimers with chitosan nanoparticles (CNPPs) was designed to improve the specificity and efficiency of siRNA delivery. In this dual delivery system, folate-conjugated and PEGylated chitosan nanoparticles encapsulating pRNA dimers were used as the first class of delivery system and would selectively deliver intact pRNA dimers near or into target cells. pRNA dimers simultaneously carrying siRNA and targeting aptamer, the second class of delivery system, would specifically deliver siRNA into the target cells via aptamer-mediated endocytosis or proper particle size. To certify the delivering efficiency of this dual system, CNPPs, pRNA dimers alone, chitosan nanoparticles containing siRNA with folate conjugation and PEGylation (CNPS), and chitosan nanoparticles containing pRNA dimers alone (CN) were first prepared. Then, we observed that treatment with CNPPs resulted in increased cellular uptake, higher cell apoptosis, stronger cell cytotoxicity, and more efficacious gene silencing compared to the other three formulations. Higher accumulation of siRNA in the tumor site, stronger tumor inhibition, and longer circulating time were also observed with CNPPs compared to other formulations. In conclusion, this dual nanocarrier system showed high targeting and favorable therapeutic efficacy both in vitro and in vivo. Thereby, a new approach is provided in this study for specific and efficient delivery of siRNA, which lays a foundation for the development of pRNA hexamers, which can simultaneously carry six different substances.

Anti-c-myc RNAi-Based Onconanotherapeutics

“…Other organic anti- c-myc nano delivery systems reported are often complex polymer- and peptide-based nanocomposites. Folate-targeted, pegylated chitosan nanoparticles were used to encapsulate anti- c-myc siRNA associated with packaging RNA, to give a dual-targeting anti-tumor system that improved cellular uptake, gene silencing, and cancer cell death [ 67 ]. As a further example, Raichur et al [ 68 ] used a layer-by-layer approach to associate anti- c-myc siRNA with poly(lactic-co-glycolic acid) hollow nanoparticles.…”

Nanocomposites as biomolecules delivery agents in nanomedicine

“…Aptamers are also considered as highly specific and efficient delivery agents for siRNA. A dual tumor-targeting siRNA delivery system combining pRNA dimers with chitosan nanoparticles was designed by Li et al [159]. In this nanovehicle, folate-conjugated and PEGylated chitosan nanoparticles encapsulating pRNA dimers were used.…”

“…Both in vitro treatment of MCF-7 cells and in vivo treatment of MCF-7 tumor-bearing mice with aptamer-decorated chitosan NPs resulted in increased cellular uptake, stronger cell cytotoxicity, higher cell apoptosis, and more efficacious gene silencing. Higher accumulation of siRNA in the tumor site, stronger tumor inhibition, and longer circulating time were also observed [159] by using this nanocarrier. To deliver P-gp-targeted siRNA into breast cancer cells, Powell et al constructed aptamer-functionalized nanoliposomes.…”

Aptamers as Delivery Agents of siRNA and Chimeric Formulations for the Treatment of Cancer

“…The pRNA-siRNA-aptamer was encapsulated in folate and PEG functionalized chitosan nanoparticles. In that study, the aptamer used was FB4 for a transferrin domain, and the siRNA was c-myc [33]. Wu et al demonstrated that functionalized cationic nanobubbles decorated with PSMA aptamers are able to carry and deliver FoxM1 siRNA to prostate cancer positive cells and xenographic tumors [34].…”