Executive Summary : | Phase separation in an aqueous two-phase system (ATPS) is a common and exciting phenomenon. ATPS offers a low-cost and efficient route to separate complex proteins and biomaterials on a large scale. This aqueous-based formulation also provides an exciting avenue to produce next-generation low-calorie-based food products to curb chronic disorders like diabetes, obesity, etc. We propose a water-in-water (w/w) emulsion-based template route, a representative system of ATPS, to produce nano-capsules (drug carriers). Unlike o/w or w/o, the proposed template lacks oil and associated deleterious effects. Therefore, it is suitable to encapsulate an oil-sensitive drug. However, it is challenging to stabilize w/w emulsions owing to its unique challenges, such as ultralow interfacial tension and large interfacial zone thickness. The way to tackle these issues will be to use larger-sized particles as the stabilizing agent. Nevertheless, it has remained an unresolved puzzle due to swift sedimentation due to gravity and the rapid solvent exchange due to more significant interstitial sites offered by the larger-sized particles. Therefore, it is imperative to devise a suitable strategy to resolve the issues. We want to employ oppositely charged PEC-based biopolymer nanoparticles for stabilizing ATPS via self-assembly. It is envisaged that the self-assembly route would promote irreversible adsorption at the interface by inducing the formation of 2D and 3D aggregates of varying sizes and shapes via heteroaggregation during emulsifications. The interplay of size and shape directly correlates with Gibbs detachment energy. We aspire to develop a phase diagram to probe the influence of polymers’ and particles’ composition on the evolution of microstructure induced by particle assemblies at the interface. Since the complexation of PEC via self-assembly will lead to aggregates with different net charges, 1) positive clusters, 2) negative clusters, and 3) neutral clusters, it is possible to control the aggregate size and contact angle by tuning the parameter ‘M (ratio of wt. fraction of positively charged to negatively charged nanoparticles)’. Furthermore, a systematic study will be carried out to probe the role of emulsifying devices with and without premixed conditions on the quality of emulsion products. The preliminary studies suggest that it is possible to produce nano-emulsions using the two-step emulsification methodology proposed in the experimental scheme. The nano-emulsion route offers better control over tuneability in size, loading efficiencies, and permeability. Since the delivery of any bioactive compound to the target sites is affected by the size of the carriers, the proposed mechanistic route of w/w emulsion-based nanoencapsulation has tremendous potential to improve bioavailability and controlled release to a more significant extent. |