Ultrafast and one-step coating sporopollenin exine capsules with metal-phenolic networks for bio-composite applications

Sporopollenin exine capsules (SECs), extracted from plant pollen grains, are becoming increasingly popular as natural microcapsules for a broad spectrum of bio-composite applications due to their plentiful supply, resilience to chemicals and physical stress, unique species-specific designs, exceptional consistency in structure, and significant internal volume. However, SECs have a relatively bioinert interface hindering their application in biomaterials. Thus, surface modification is an efficient strategy to convert SECs into biocompatible materials better for biological applications. Previous approaches predominantly depend on labor-intensive, multi-stage procedures that are time-consuming. Herein, we report an ultrafast, one-step, and effective modification strategy to render SECs biocompatibility by coating them with ferric ions and tannic acids, which endow them with a better cell adhesion property. In summary, our results show that this ultrafast and one-step biocompatibility strategy enhances the functional characteristics of SECs and holds wide-ranging implications for bio-composite applications..