Ferritin is a globular hollow protein that acts as the major iron storage protein across living organisms. The 8 nm-diameter internal cavity of ferritin has been used as a nanoreactor for the synthesis of various metallic nanoparticles different to iron oxides. For this purpose, ferritin is incubated in solution with metallic ions that enter the cavity through its natural channels. Then, these ions are subjected to a reduction step to obtain highly monodisperse metallic nanoparticles, with enhanced stability and biocompatibility provided by the ferritin structure. Potential biomedical applications of ferritin-nanoparticle complex will require the use of human ferritin to provide a safer and low-risk alternative for the delivery of metallic nanoparticles into the body. However, most of the reported protocols for metallic nanoparticles synthesis uses horse spleen ferritin as nanocontainer. Previous studies have acknowledged technical difficulties with recombinant human ferritin during the synthesis of metallic nanoparticles, like protein precipitation, which is translated into low recovery yields. In this study, we tested a novel photochemical reduction method for silver nanoparticle synthesis in human recombinant ferritin and compared it with the traditional chemical reduction method. The results show that photoreduction of silver ions inside ferritin cavity provides a universal method for silver nanoparticle synthesis in both recombinant human ferritin homopolymers (Light and Heavy ferritin). Additionally, we report important parameters that account for the efficiency of the method, such as ferritin recovery yield (~60%) and ferritin‑silver nanoparticle yield (34% for H-ferritin and 17% for L-ferritin).

铁蛋白是一种球形空心蛋白，在整个生物体中充当主要的铁存储蛋白。铁蛋白的8纳米直径内腔已被用作纳米反应器，用于合成各种不同于氧化铁的金属纳米粒子。为此，将铁蛋白在溶液中与通过其自然通道进入空腔的金属离子一起孵育。然后，将这些离子进行还原步骤以获得高度单分散的金属纳米粒子，并具有铁蛋白结构提供的增强的稳定性和生物相容性。铁蛋白-纳米颗粒复合物的潜在生物医学应用将需要使用人铁蛋白来提供将金属纳米颗粒递送到体内的更安全且低风险的替代方法。然而，金属纳米颗粒合成的大多数已报告方案都使用马脾铁蛋白作为纳米容器。先前的研究已经确认了重组人类铁蛋白在金属纳米颗粒合成过程中的技术难题，例如蛋白质沉淀，这转化为低回收率。在这项研究中，我们测试了一种用于人类重组铁蛋白中银纳米粒子合成的新型光化学还原方法，并将其与传统化学还原方法进行了比较。结果表明，铁蛋白腔内银离子的光还原为两种重组人铁蛋白均聚物（轻铁蛋白和重铁蛋白）中的银纳米粒子合成提供了一种通用方法。此外，我们报告了说明该方法效率的重要参数，