Co-Assembled Nanogels of Tannic Acid and Biocompatible Random Copolymers for Potential Ovalbumin Delivery

This study investigates the efficacy of co-assembled, physically cross-linked nanocarriers comprising tannic acid (TA) and a P(DMAEMA-co-OEGMA) random/statistical double-hydrophilic copolymer for ovalbumin (OVA) encapsulation. TA-based nanocarriers, prepared at varying TA molar ratios (10% w/v and 20% w/v), exhibited nanoaggregates of different sizes, as revealed by dynamic light scattering, with Nanocarrier 1 system showing populations of 11 and 109 nm, while Nanocarrier 2 formed a single population of 75 nm in size. Notably, both colloidal systems demonstrated stability under thermal treatment and resilience to changes in salt concentrations higher than 0.15 M, but disassembly phenomena in basic media. Utilizing these nanocarriers for OVA loading via electrostatic interactions revealed strong positive charges (~30 mV) for all protein-loaded nanocarrier cases. In particular, they demonstrated sizes within the desired range (Rh = 96–118 nm) and considerable stability over 20 days and in the presence of serum proteins. Overall, this study underscores the importance of physical cross-linking as a viable strategy for the formation of tunable nanometric hydrocolloids for effective protein encapsulation, with significant implications for drug delivery systems.