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https://ptsldigital.ukm.my/jspui/handle/123456789/485665| Title: | Physico-chemical and biological characteristics of siRNA-and DsiNA-loaded polycationic nanoparticulate systems |
| Authors: | Maria (P65168) |
| Supervisor: | Haliza Katas, Assoc Prof Dr. |
| Keywords: | Dicer-substrate small interfering RNA (DsiRNA) small interfering RNA (siRNA) Dissertations, Academic -- Malaysia |
| Issue Date: | 17-Feb-2015 |
| Description: | Dicer-substrate small interfering RNA (DsiRNA) has gained much attention owing to its greater potency and efficacy over small interfering RNA (siRNA). Similar to siRNA, the use of DsiRNA is limited by its rapid degradation in vitro and in vivo. The main objective of the study was to develop and comparatively characterise polycationic nanopaticles based on chitosan (CS) and Tat-peptide (Tat) as carriers for DsiRNA and siRNA. CS nanoparticles were successfully prepared by two methods of ionic cross linking, namely, simple complexation and ionic gelation. DsiRNA-Tat complexes were prepared by simple complexation method only. Their biological activities were then determined in 3D cell culture to mimic the tumour in vivo. The mean particle size of DsiRNA-loaded CS nanoparticles were ranged from 125 ± 20 to 335 ± 30 nm, while simple complexation yielded DsiRNA-CS complexes with the size that ranged from 270 ± 25 to 730 ± 50 nm. Both methods produced nanoparticles/complexes with a high positive zeta potential (+40 ± 5 to +65 ± 6 mV). Transmission electron microscopy (TEM) micrographs revealed spherical and irregular morphology of DsiRNA-CS nanoparticles and DsiRNA-CS complexes, respectively. In addition, ATR-FTIR spectroscopy confirmed the presence of DsiRNA in the CS nanoparticles/complexes. Both nanoparticles and complexes were able to strongly bind and completely encapsulate DsiRNA. They also exhibited sustained release of DsiRNA at 37 °C for 15 days. DsiRNA-CS nanoparticles/complexes showed relatively low and concentration-dependent cytotoxicity in human colorectal adenocarcinoma and Chinese hamster lung fibroblast cell lines. DsiRNA-CS nanoparticles showed a better stability than the complexes when stored at 4° and 25°C. On the other hand, DsiRNA-Tat complexes had particles size and surface charge in the range of 176 ± 8.6 to 458 ±14.7 nm and +27.1 ±3.6 to +38.1 ±0.9 mV, respectively. DsiRNA bound strongly to Tat, forming stable complexes with loading efficiency of more than 86%. These complexes were non-cytotoxic as percent of cell viability of ˃90% was observed on Chinese hamster lung fibroblast cells. Moreover, DsiRNA-loaded CS nanoparticles and DsiRNA-Tat complexes significantly knocked down the expression of target gene when exposed to multicellular layers of 3D cell culture. Thus, it is anticipated that CS and Tat are promising vectors for DsiRNA delivery due to properties such as good stability, safe, and cost-effective.,Ijazah Doktor Falsafah |
| Pages: | 209 |
| Call Number: | QV20.5.M332p 2015 9 |
| Publisher: | UKM, Kuala Lumpur |
| Appears in Collections: | Faculty of Pharmacy / Fakulti Farmasi |
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