Enthalpy and structural characteristics of polyelectrolyte chitosan and xanthan gum-based capsule formation in aqueous solutions

The isothermal titration calorimetry (ITC) method has been applied to determine the optimal concentration conditions for obtaining stable shells of nano- and microcapsules for the delivery of biologically active substances and active fragments of biopolymers. Specifically, ITC was used to study intermolecular interactions in aqueous solutions of xanthan gum (XG) and chitosan (Chit). The enthalpy parameters of the interaction between Chit and XG in aqueous solution were calculated. Based on the ITC data, the optimal concentrations of these substances for forming a stable nanocapsule shell have been identified. A template method for producing nanocapsules containing L-tyrosine as the active core was tested. It was found that the shape and size of the template play a crucial role in forming the nanocapsule shell.