ABSTRACT
PURPOSE: Development of efficient in vivo delivery nanodevices remains a major challenge to achieve clinical application of siRNA. The present study refers to the conception of core-shell nanoparticles aiming to make possible intravenous administration of chemically unmodified siRNA oriented towards the junction oncogene of the papillary thyroid carcinoma. METHODS: Nanoparticles were prepared by redox radical emulsion polymerization of isobutylcyanoacrylate and isohexylcyanoacrylate with chitosan. The loading of the nanoparticles with siRNA was achieved by adsorption. The biological activity of the siRNA-loaded nanoparticles was assessed on mice bearing a papillary thyroid carcinoma after intratumoral and intravenous administration. RESULTS: Chitosan-coated nanoparticles with a diameter of 60 nm were obtained by adding 3% pluronic in the preparation medium. siRNA were associated with the nanoparticles by surface adsorption. In vivo, the antisense siRNA associated with the nanoparticles lead to a strong antitumoral activity. The tumor growth was almost stopped after intravenous injection of the antisense siRNA-loaded nanoparticles, while in all control experiments, the tumor size was increased by at least 10 times. CONCLUSION: This work showed that poly(alkylcyanoacrylate) nanoparticles coated with chitosan are suitable carriers to achieve in vivo delivery of active siRNA to tumor including after systemic administration.
Subject(s)
Carcinoma, Papillary/drug therapy , Chitosan/chemistry , Nanoparticles/chemistry , RNA, Small Interfering/administration & dosage , RNA, Small Interfering/therapeutic use , Thyroid Neoplasms/drug therapy , Animals , Carcinoma, Papillary/pathology , Cell Line, Tumor , Cell Survival/drug effects , Humans , Mice , Mice, Nude , Nanoparticles/ultrastructure , Particle Size , Thyroid Neoplasms/pathologyABSTRACT
Delivery is a very important concern for therapeutic applications of siRNA. In this study, we have used chitosan-coated poly(isobutylcyanoacrylate) nanoparticles to deliver siRNA with a complementary sequence to the fusion oncogene ret/PTC1. By screening the mRNA junction we have selected a potent siRNA sequence able to inhibit this oncogene in a model of Papillary Thyroid Carcinoma cells. This siRNA sequence has then been validated by a shRNA approach using the same sequence. Furthermore, the high ret/PTC1 inhibition has triggered a phenotypic reversion of the transformed cells. We have designed well-defined chitosan decorated nanoparticles and succeeded to reduce their size. They have allowed to protect ret/PTC1 siRNA from in vivo degradation and leading to significant tumour growth inhibition after intratumoral administration.
