| Summary: | Understanding the role of lipids in drug transport is critical in ocular drug delivery to overcome the challenges in treating diseases affecting the posterior segment of the eye. In this study, liposomes are fabricated from various forms of lipids such as the neutral and the charged ones. The neutral liposomes are selected for the quantification of liposomes via trans-scleral liposomal experiments. This group of liposomes are divided into two broad categories- Saturated lipids and unsaturated lipids. The aim of this study is to explore the role of lipids interaction on transport across the sclera and to understand the differences between the two types of lipids saturation in terms of lipid packing and membrane fluidity. Various methods were adopted to quantify liposomes before the trans-scleral experiment was set up. These include Stewart assay and Phospholipid assay. Liposomes made from unsaturated lipids, in this case, 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) showed significantly high potential in transport across the sclera. This, however, was not the case for liposomes made from saturated lipids like 1,2-Dimyristoyl-sn-glyceo-3-phosphocholine (DMPC). Parafilms were used as sealants to prevent leakage in a control set up loaded with liposomes in the donor chamber, which mimicked a trans-scleral static set up to prove its feasibility. The sizes of the samples collected from the receiver chamber of the control set up were measured and found to correspond to that of the sample solution drawn from the buffer, in this case, deionised (DI) water. This proves the feasibility of the static set up as the sizes further confirmed that liposomes did not pass through from the donor to the receiver chamber when parafilms were used. Parallel to the trans-scleral study, the effect of storage on the stability of Lucentis was also explored. This study was done over a period of 10 weeks to investigate the protein activity upon prolonged storage at room temperature. ELISA and microBCA tests were carried out and results proved that degradation of Lucentis occurred over the 10 weeks of incubation. This study is useful future work on encapsulation of Lucentis within nanoparticles for treatment of eye diseases such as the Age-related Macular Degeneration. The novelty of this study is based on the quantification of liposomes which is largely unexplored as yet. Numerous challenges have to be overcome before trans-scleral delivery can be considered as an ideal treatment for patients suffering from diseases affecting the posterior segment of the eye.
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