Biomimetic Fabrication of Silica Microcapsules Using Bifunctional Peptides

Microcapsules have a wide range of applications in various fields due to their unique core-shell structures and high volume-to-surface area ratio. However, existing fabrication methods often rely on toxic chemicals or harsh conditions. A new biomimetic approach for fabricating silica microcapsules via biosilicification is developed, using a nature-inspired bifunctional peptide as both a surfactant and catalyst. This method eliminates the need for high temperatures, extreme pH, and toxic chemicals. The study evaluated the performance of different peptide surfactant formulations for emulsion-template stabilization and silicification, identifying AM1 as the most effective. Using a microfluidic device, AM1 efficiently generated uniform oil-in-water micro-sized emulsion templates due to its excellent surface activity, and the formation of a metal-peptide crosslinking network around the droplets. AM1 also induced controlled silicification at the water-oil interface, producing core-shell silica microcapsules at neutral pH, thus the formation of microcapsules. Additionally, the microcapsules exhibited excellent stability, controlled degradation profiles, and superior dye retention capabilities. This new method represents a significant advancement in the development of safe, effective, and eco-friendly microcapsules for diverse applications while providing deeper insights into the mechanisms and properties of bifunctional peptides.