Towards rational design of porous nanostructured biopolymeric microparticles for biomacromolecules separation: A case study of intraparticle diffusion facilitation and BSA adsorption on agarose microspheres.

Abstract Synthesis and employing advanced materials for emerging applications is of great challenge for the scientific community. Recombinant proteins production and purification is one of the fastest growing fields in the global economy. In this regard, it is essential to fabricate biocompatible low-cost materials with high specificity to enhance purification efficiency. This requires the regulation of mass transfer based on the protein molecular size and interactions with the matrix interface; thus, needs synthesizing novel materials with tuned porosity. In this study, we proposed rational alteration in porous structure of biopolymeric microspheres using appropriate-sized porogen to facilitate intraparticle molecular diffusion. The tailored porous nanostructures, which were generated by phase separation in the polymer blend of agarose and polyethylene glycol, were analyzed with optical and scanning electron microscopy, Fourier transform infrared spectroscopy, water diffusion, and albumin adsorption. The well-tuned beads possessed highly porous structures with dominant mesopores owing to PEG phase migration out of the network. The high speed homogenizer caused an uncommon dense morphology with interwoven two-type porosity. Optimally tuned mesoporous beads with considerably high specific surface area exhibited dramatically fast and enhanced intraparticle diffusion of both water and protein molecules. Thus, the introduced porosity modification is a promising design for enhancing mass transfer in the bio-separation process. Finally, useful insights for developing future smart hydrogel microparticles with tuned porous network for biomolecules purification are provided by the conducted experiments. Graphical abstract Unlabelled Image Highlights • A rational strategy is introduced to tune the nanostructure of agarose microspheres • Small mesopores (<20nm); thus, the highest surface area are achieved by PEG removal • High shear mixing leads to smaller beads and increased physical cross-link density • Engineered mesoporous beads show remarkable intraparticle molecular diffusion • Highly enhanced protein adsorption rate and capacity validated our proposal [ABSTRACT FROM AUTHOR]