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

Abstract

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.