Preparation of Alginate Encapsulating Nanoliposomes for Drug Delivery

Nanomedicine field focuses on the development of nanoscale carriers that can effectively deliver therapeutics to the diseased sites. One of the most promising drug carriers developed to date are the nanoliposomes. Nanoliposomes are accepted in our bodies due to their lipid bilayer structure, which mimics the outer membrane of cells. However, nanoliposomes lack physical stability that limits their success. In contrast, polymeric nanoparticles such as hydrogels have excellent stability and offer tunable mechanical properties. By combining nanoliposomes and polymeric nanoparticles, the hydrogel encapsulated liposomes provide more stability and adjustable mechanical properties for successful drug delivery. In this study, I focus on alginate that is a natural hydrogel and can be crosslinked by calcium ions. I prepare hydrogel encapsulated nanoliposomes using the method of lipid film dehydration and rehydration with the alginic acid solution. Then, I utilize freeze-thaw process and extrusion to form unilamellar vesicles from multilamellar vesicles and adjust their size. Later, the solution is dialyzed to remove non-encapsulated alginate, and then calcium chloride solution is added to the system. The calcium ions diffuse through the lipid membrane and crosslink the alginate. I will study size distribution and zeta potential of these nanoliposomes using dynamic light scattering and laser doppler electrophoresis. Also, I will investigate the mechanical elasticity of alginate hydrogel, using a rheometer instrument, as a function of calcium concentration. This will allow us to control the mechanical properties of hydrogel-filled liposomes, as an important factor for their delivery performance.