In vivo biosynthesis of nutritional holoferritin nanoparticles: Preparation, characterization, iron content analysis,...

Natural holoferritin, containing average 2000 Fe³⁺/ferritin, has been considered as promising iron supplementary in food and medical science. However, the low extraction yields highly limited its practical application. Herein, we provided a facile strategy for holoferritin preparation through in vivo microorganism-directed biosynthesis, and the structure, iron content, and the composition of iron core have been investigated. The results revealed that in vivo biosynthesized holoferritin possesses great monodispersity and water-solubility. In addition, the in vivo biosynthesized holoferritin contains a comparative iron content as compared to natural holoferritin, giving the ratio of ∼ 2500 iron/ferritin. Besides, the composition of iron core has been identified as ferrihydrite and FeOOH, and three steps might be involved in iron core formation. This work highlighted that the microorganism-directed biosynthesis could be an efficient strategy for preparation of holoferritin, which might be beneficial for its practical application for iron supplementation.