Silk fibroin supraparticles created by the evaporation of colloidal Ouzo droplets

Abstract

Due to its high biocompatibility and biodegradability, supraparticles made from silk fibroin - produced from Bombyx mori (B. mori) cocoons - can find various applications in biomedical fields. The evaporation of Ouzo droplets by not requiring energy nor a surfactant is an environmentally friendly, easy, and cost-effective strategy to fabricate three-dimensional supraparticles, tackling the so-called "coffee ring effect"associated with droplet evaporation. Silk fibroins are dissolved into quaternary droplets, comprised of ultrapure water, ethanol, trans-anethole oil, and formic acid. The Ouzo droplet is able to form an oil ring that facilitates the droplet contraction to create a three-dimensional supraparticle. Using the Ouzo effect to fabricate these particles from silk fibroin results in consistent macro-porous structures with a high porosity.