Protection and Systemic Translocation of siRNA Following Oral Administration of Chitosan/siRNA Nanoparticles

Abstract

Harnessing the RNA interference pathway offers a new therapeutic modality; however, solutions to overcome biological barriers to small interfering RNA (siRNA) delivery are required for clinical translation. This work demonstrates, by direct northern and quantitative PCR (qPCR) detection, stability, gastrointestinal (GI) deposition, and translocation into peripheral tissue of nonmodified siRNA after oral gavage of chitosan/siRNA nanoparticles in mice. In contrast to naked siRNA, retained structural integrity and deposition in the stomach, proximal and distal small intestine, and colon was observed at 1 and 5 hours for siRNA within nanoparticles. Furthermore, histological detection of fluorescent siRNA at the apical regions of the intestinal epithelium suggests mucoadhesion provided by chitosan. Detection of intact siRNA in the liver, spleen, and kidney was observed 1 hour after oral gavage, with an organ distribution pattern influenced by nanoparticle N:P ratio that could reflect differences in particle stability. This proof-of-concept work presents an oral delivery platform that could have the potential to treat local and systemic disorders by siRNA.

Optimization of multifunctional chitosan–siRNA nanoparticles for oral delivery applications, targeting TNF-α silencing in rats

“…[8,10,13,[21][22][23]25,38,39]. MTC conjugates were rationally designed in our previous investigation and were demonstrated to overcome the intestinal absorption barrier as well as the transfection barrier in macrophages [13].…”

“…Efforts have been made to deliver therapeutic siRNA to rats via multiple administration routes such as circumferential perfusion to the adventitia of carotid artery after ballon angioplasty, intraparenchymal central nervous system infusion, and intra-articular injection [18][19][20]. We and other groups have reported successful oral siRNA delivery to mice for the treatment of liver cancer, acute hepatic injury, and bowel inflammation [10,13,[21][22][23][24][25][26]. However, to our knowledge, successful siRNA delivery to rats via oral administration is still lacking in the literature because NPs possessing high siRNA delivery efficiency in mice might behave differently when applied to rats.…”

F1-ATP synthaseα-subunit: a potential target for RNAi-mediated pest management ofLocusta migratoria manilensis

“…35,36 Direct feeding of dsRNA is another way to interfere with insect gene expression. Although previous attempts to use RNAi by direct feeding of dsRNA failed in L. migratoria and S. gregaria owing to dsRNA degradation by RNase in the gut, 37,38 chitosan/siRNA nanoparticles have been shown to protect siRNA against degradation in the stomach, small intestine and colon and to reduce the expression of the target gene in mice when administered orally, 39,40 and feeding with chitosan/dsRNA nanoparticles has also been successful in mosquitoes. 41 Therefore, future research should explore effective delivery systems for overcoming this barrier.…”

In-vitro assessment of cytotoxicity of halloysite nanotubes against HepG2, HCT116 and human peripheral blood lymphocytes

“…In this study, halloysite nanotubes have been characterized for size distribution (length, diameter, and aspect ratio) before being evaluated in-vitro of their cytotoxic potential at high doses against two model cell lines (colorectal carcinoma cells HCT116; and hepatocellular carcinoma cells HepG2) [21,22] which represent the earliest entry point and the first accumulating organ, respectively, for xenobiotics and nanoparticles en-route to systemic circulation after oral delivery [23,24]. Moreover, cytogenetic toxicity of halloysite nanotubes has also been estimated in this study for the first time by in-vitro mitotic index assay using peripheral blood human lymphocytes cultures [25].…”