Formation of self-assembled polyelectrolyte complex derived from BSA and nanogels: a study to optimize processing parameters and preserve protein integrity.

OBJECTIVE

The aim of this work was to identify, optimize, and use nondestructive process to develop nano-formulation using polyelectrolyte complexation (PEC) between polymeric nanocarrier and bovine serum albumin.

SIGNIFICANCE: Proteins are mostly degraded during preparation and loading into nano-carriers which hinders success in protein delivery.

METHOD: Herein, novel PEC consisting of model protein BSA and nanogels (NGs), were prepared to form self-assembled polyelectrolyte nanocomplexes (BSA/NGs-PEC). The BSA/NGs-PEC were obtained by mixing BSA and nanogels at various weight ratios (1:2, 1:4, 1:5, 1:6, 1:8, 1:10), pH values of solution (1.2, 4.0, 6.0), incubation time (2, 4, 6, 8 h), and stirring rate (without, 100, 200 rpm). The prepared PEC were evaluated for particle size (PS), polydispersity index (PDI), zeta potential (ZP), and percentage of complexation efficiency (%CE). To study insights into structural integrity and biological activity, the SDS-PAGE and esterase activity assay was performed on BSA released from final optimized formulation.

RESULTS

The optimized parameters were BSA/nanogels mixing ratios at 1:8, pH of complex-forming medium at 4.0, incubation time of 6 h, and stirring rate at 100 rpm. The SDS-PAGE and esterase activity assay revealed that the primary structure and bioactivity, respectively, of BSA was still intact.

CONCLUSION

The results suggest that current scheme for optimization has considerable potential for creating protein-based delivery system by using PEC via electrostatic interaction.