Impact of adjustable swelling dynamics on the structural integrity of sunflower pollen microgels

Pollen is a renewable biomaterial found in seed-bearing plants, and the biocompatibility of pollen microgels is a key factor driving their use in drug delivery, biosensor development, and wound care applications. Herein, the microgel was synthesized from sunflower bee pollen by using a cost-effective process, and to examine its structural integrity under adverse acidic and alkaline conditions, digital microscopy and dynamic image particle analysis were carried out. Swelling dynamics of pollen microgels were regulated by varying pH conditions, and adding aqueous KOH to the solution, and the influence of swelling-deswelling on bulk rheology and local elastic properties were experimentally investigated and theoretically interpreted by using the Ross-Minton equation for the suspension viscosity. The present findings reveal how pollen microgels can be adapted to acidic to alkaline environments in order to modify mechanical and rheological properties.