Amyloid fibrils creating a novel platform constructing network nanostructures for co-encapsulation of iron and vitamin D3

Both iron and vitamin are essential to health management but there is yet to establish a co-encapsulation strategy toward a simultaneous supplementation. In this study, the authors assemble protein fibrils tailoring network nanostructures carrying both Fe(III) and vitamin D 3 (VD 3 ). The protein fibrils are constructed by acid-heat treatment to induce amyloid fibrillation of panda bean protein isolates (PDPIs), while concomitant treatment with Fe(III) enables the formation of iron-fortified fibrils (Fe@PFs). Furthermore, the Fe@PFs actively react with eugenol containing VD 3 , forming fibril network nanostructures loaded with both Fe(III) and VD 3 (Fe&VD 3 @net-PFs). The Fe&VD 3 @net-PFs realize solubilization of VD 3 and effectively extend the lifetime of VD 3 when subjected to UV irradiation or long-term storage. Importantly, the material mechanics and structure properties are highly dependent on the levels of Fe(III) contained in the delivery system, enabling regulatory release profiles of both iron and VD 3 pivotal to their bioactivities during oral administration. This study would pave the path for rationally developing protein-based nanostructures toward the co-delivery of multiple bioactives.