(414a) siRNA Liposome by SCF Technology | AIChE

(414a) siRNA Liposome by SCF Technology

Authors 

Thakur, R. - Presenter, Novartis Pharma AG


Short interference RNA (now on siRNA) is a new area of biological therapeutics for gene targeting. A major issue associated with gene therapy is delivery of therapeutically active siRNA, which are the mediators of RNAi-induced specific mRNA (messenger RNA) degradation, into target tissue/cell in vivo. One of the most desirable approach is based on delivery systems like liposomes. Lipid based drug delivery system is gaining lot of importance due to self assembling nature of these molecules. Also, lipids can accommodate hydrophilic as well as hydrophobic molecules which give great advantage for sensitive oligonucleotides such as proteins, RNA, siRNA, ds-RNA, antisense etc. There are various methods discussed in literature for liposome formulation such as thin film method using evaporation, sonication method as well as ethanol injection method. However, these techniques suffer from different disadvantages, such as multi-step process, scalability, reproducibility and broad particle size distribution along with others. In this work, Supercritical fluid (SCF) is used for siRNA-lipid nanoparticles formulation. SCF based process is a one step process for siRNA lipoplex formulation with controllable particle size and can be operated at mild conditions. In this process, lipid or mixture of lipids is solubilized in supercritical CO2 with or without co-solvents and then depressurized jet stream coming out of nozzle mixes with aqueous jet stream of siRNA solution. In current work, nozzle is used to create high velocity stream for better mixing prior to mixing with each other. This work is a first ever attempt to produce nanometer lipid vesicles containing siRNA using SCF method. The major advantage of using this technique is control on the particle size with one step process. This successful attempt is highly encouraging for delivery issues related with siRNA. The size of siRNA-lipid nanoparticles obtained after processing was < 350 nm. Encapsulation of siRNA in lipid bilayers were analyzed using gel electrophoresis. This process can also be used to encapsulate liposome with polymers like PLGA and PEG. These polymers can either be present in aqueous solution or SCF-lipid solution.