Sporopollenin exine capsules with polypeptide multilayer films promoting cell adhesion

Sporopollenin exine capsules (SECs), extracted from plant pollen, are emerging as attractive and natural microcapsules for a wide range of bio-composite applications due to their abundant availability, chemical and mechanical robustness, species-specific architectural features, striking structural uniformity, and large inner cavity. However, SECs have a predominantly hydrophobic interface hindering their application in biomaterials. Thus, developing robust surface functionalization strategies to increase their hydrophilicity would open the door to interfacing microcapsules with cells. Herein, we create SECs with increased surface hydrophilicity coated by polypeptide multilayer films using layer-by-layer (LbL) self-assembly technology. Furthermore, human bone marrow-derived stem cells adhere more to these LbL-treated SECs acting as seed cells for tissue engineering. In summary, our findings demonstrate that LbL modification of SECs improves their functional properties and has broad implications across bio-composite applications.

Automated summary

Sporopollenin exine capsules (SECs) extracted from plant pollen are promising microcapsules for various bio-composite applications, but their hydrophobic interface hinders their use in biomaterials. This study demonstrates that surface functionalization of SECs with polypeptide multilayer films using layer-by-layer self-assembly technology improves their hydrophilicity, enabling better interaction with cells.