Lipids are the major architectural components of cell membranes and are crucial to membrane functions. The amphiphilic nature of lipids allows them to self-assemble into a condensed phase in an aqueous environment, a property has been exploited extensively in biophysical studies. Giant unilamellar vesicles (GUVs) are one model membrane system that has been used for this purpose. The diameters of GUVs range from 10-100 microns, comparable to the size of a cell. These structures have been utilized as microreactors and for entrapping biological macromolecules. A key limitation in using GUVs composed of natural lipids for technological applications is their inherent instability. The goal of this study is to enhance the GUV stability while maintaining the inherent impermeability of the membrane and the bioactivity of incorporated proteins. Two basic strategies are being investigated. In the first, we have prepared GUVs from synthetic lipids functionalized with dienoyl groups that can be cross-linked by UV irradiation. The poly(GUVs) thus formed are very robust, resistant to both surfactant dissolution and drying/rehydration. In the second, we have incorporated hydrophobic methacrylate monomers and crosslinkers into the hydrophobic core of the bilayer by partitioning, and used a photoinitiator to form poly(methacrylate) network in the bilayer. Optimizing the polymerization conditions has resulted in formation of stabilized GUVs. A detailed comparison of the two strategies will be presented.