Fluorescently-labelled PLGA from PolySciTech used in development of siRNA delivery spheroplexes for ulcerative colitis treatment

 

siRNA is short snippets of RNA that bind to transcribed messenger RNA and prevent it from being translated into a protein. This allows siRNA to “silence” select genetic expression and prevent the formation of proteins which may be pathological in nature. Recently, researchers at Universidade Federal de Minas Gerais (Brazil), PSL University, Sorbonne Université, Université de Lyon, and INSERM (France), used fluorescent PLGA-FPR648 (cat# AV008) from PolySciTech Division of Akina, Inc. (www.polyscitech.com) to create siRNA loaded spheroplexes. The Fluorescent polymer allowed for tracking of the nanoparticles for research applications. This research holds promise to improve siRNA delivery for gene therapy as ulcerative colitis treatment. Read More: Arruda, D.C., Lachagès, A.M., Demory, H., Escriou, G., Lai-Kuen, R., Dugas, P.Y., Hoffmann, C., Bessoles, S., Sarrabayrouse, G., Malachias, A. and Finet, S., 2022. Spheroplexes: Hybrid PLGA-cationic lipid nanoparticles, for in vitro and oral delivery of siRNA. Journal of Controlled Release, 350, pp.228-243. https://www.sciencedirect.com/science/article/pii/S0168365922005351


“Highlights: Spheroplexes (Sphx) were developed by a modified nanoprecipitation method using siRNA lipoplexes as starting nanoparticles. Sphx were spherical nanoparticles with surface characteristics similar to those of lipoplexes. Sphx were very stable particles and more efficient than siRNA lipoplexes for the in vitro delivery of siRNA. Sphx were uptake by macrophages/monocytes at the colon with nearly no toxicity after oral administration. The oral delivery of TNF-α siRNAs Sphx to mice with ulcerative colitis reduced the level of TNF-α and signs of lesions. Abstract: Vectorized small interfering RNAs (siRNAs) are widely used to induce gene silencing. Among the delivery systems used, lipid-based particles are the most effective. Our objective was the development of novel lipid-polymer hybrid nanoparticles, from lipoplexes (complexes of cationic lipid and siRNAs), and poly (lactic-co-glycolic acid) (PLGA), using a simple modified nanoprecipitation method. Due to their morphology, we called these hybrid nanoparticles Spheroplexes. We elucidated their structure using several physico-chemical techniques and showed that they are composed of a hydrophobic PLGA matrix, surrounded by a lipid envelope adopting a lamellar structure, in which the siRNA is complexed, and they retain surface characteristics identical to the starting nanoparticles, i.e. lipoplexes siRNA. We analyzed the composition of the particle population and determined the final percentage of spheroplexes within this population, 80 to 85% depending on the preparation conditions, using fluorescent markers and the ability of flow cytometry to detect nanometric particles (approximately 200 nm). Finally, we showed that spheroplexes are very stable particles and more efficient than siRNA lipoplexes for the delivery of siRNA to cultured cells. We administered spheroplexes contain siRNAs targeting TNF-α to mice with ulcerative colitis induced by dextran sulfate and our results indicate a disease regression effect with a response probably mediated by their uptake by macrophages / monocytes at the level of lamina propria of the colon. The efficacy of decreased level of TNF-α in vivo seemed to be an association of spheroplexes polymer-lipid composition and the specific siRNA. These results demonstrate that spheroplexes are a promising hybrid nanoparticle for the oral delivery of siRNA to the colon. Keywords: RNA interference Lipoplexes Hybrid nanoparticle Delivery system Biodegradable polymer Oral delivery”