Finding efficient edible delivery carriers is important to the bioavailability of bioactives, but more importantly is to understand mechanistically their formation and conditions that can lead to the optimal encapsulation and stability. Two exciting technologies that still have many unknowns are the fabrication of polyelectrolyte complexes (PECs) and hollow cylindrical polyelectrolyte complex (PEC) particles. Fabrication of these edible particles results in a repertoire of flexible carriers with controlled surface properties that enable their tailored use with a variety of bioactive compounds. This study focused on understanding the effect of charge ratio, order of addition and resulting thermodynamics of interaction on the formation and properties of PECs from sodium alginate and chitosan. The second part of the study evaluates the conditions influencing the interaction of the biopolymers and the manufacturing steps that allow the formation of edible cylindrical hollow nanotubes (NTs) using chitosan (CHI)/α-lactalbumin (LAC), and BSA/κ-carrageenan (CAR). Dynamic light scattering (DLS) and isothermal titration calorimetry (ITC) were used to study the ability of the polyelectrolytes to interact and form spherical and tubular nanoparticles. ITC indicated that electrostatic interactions were the controlling driving force for the formation of PECs as well as hollow tubular nanoparticles. The formation of PECs was optimal at pH 4 and ITC results showed that stoichiometry and enthalpy of reactions were strongly affected by the order of addition and influenced the average particle size and zeta potential of PECs. The optimal fabrication of the hollow cylindrical particles were found to be pH 7 for CHI/LAC and pH 4 for BSA/CAR. Curcumin encapsulation was studied at concentrations of 10, 15 and 20μg/ml. These edible delivery carriers can enhance the encapsulation and bioavailability of poorly water-soluble bioactives such as curcumin, and their fabrication and stability at different pHs expands the repertoire of applications where these carriers can be used.

Mechanistic understanding of the formation of edible spherical and tubular nanoparticles: Insights of the thermodynamics of interaction

256th National Meeting (2018)

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