Archana M Raichur is currently pursuing her Doctoral course final year in Toyo University, Japan under Prof. D. Sakthikumar. She is completed her Masters in Philosophy with Distinction from University of Pune, India in Medical Sciences and currently working on Gene therapy Research using Nanotechnology. She has chosen this area of Research as this subject has created a new horizon in Interdisciplinary Sciences.


Unexpurgated and site targeted delivery of small interfering RNA (siRNA) that can silence the expression of disease related genes is still a great challenge in nano-gene delivery field.siRNA cellular/nuclear uptake,intracellular transport and endosomal release could critically contribute in improvement of delivery methods and development in RNAi therapeutics.Delivery approaches using non-viral agents like metal nanoparticles,magnetic nanoparticles,polymeric nano-particles,liposomes are widely used for gene knockdown in RNA interference.However the key challenge of complete delivery of siRNA, biodegradability of nanoparticles and their toxicity still exists and creates hindrance in gene delivery. Here we use hollow; nearly mono-dispersed and FDA approved (polymer; poly D,L-lactide-co-glycolic. 50:50) PLGA nanoparticles as carriers for siRNA delivery. We conjugated cell penetrating peptides(CPPs) and custom designed peptide nucleic acids (PNAs) using layer by layer technique on surface of nanoparticles with complete encapsulation of siRNA for site directed oncogene knockdown in cancer cells (neuroblastoma and carcinoma) resulting in apoptosis induced effect.The CPP-PNA-PLGA nano-capsules-siRNA nanoparticles were selectively uptaken into cells via endocytosis resulting in enhanced gene silencing compared to naked siRNA (72nMol siRNA was used). Silencing studies were conducted using RT-Real time PCR and apoptosis studies were carried on using flow cytometry.PLGA-HNPswere characterized using Scanning and Transmission Electron Microscopy, Dynamic Light Scattering and Zeta potential analysis. The cell proliferation and viability assays confirmed that there is 97% of reduction in cell dividing activity. Confocal analysis confirms the delivery and uptake of HNPs inside the nucleus of the cancer cells.We found that the usage of PLGA HNPs using CPPs and PNAs could delivery almost 100% of siRNA safely inside the nucleus resulting in site targeted gene silencing in cancer cells.