Green fabrication of nanoscale materials is highly desirable because of associated adverse effects with conventional nanomaterial biomedical applications. Moreover, the higher selective nature of the blood-brain barrier (BBB) limits the brain ailments treatment through conventional chemotherapy, thus providing room for nanotechnology-based modalities for BBB traversing. In this contribution, we have biosynthesized gold nanoparticles from the HAuCl₄ solution in the aged cells culture medium. This approach is highly facile without any other chemical utilization. The cell culture medium age and cell number can tune the Au nanoparticles (AuNPs) size from 2 to several hundred nm. The 24 h MTT assay and cell uptake studies in vitro and murine models' vital organs (liver, kidney, spleen, lung, and heart) study up to 48 h demonstrated that biosynthesized AuNPs were biocompatible and BBB amenable. Interestingly, the transferrin and cell culture medium isolated proteins were found factors responsible for HAuCl₄ solution biomineralization and size control. Moreover, the protein corona on biosynthesized AuNPs could help them traverse BBB both in vitro and in vivo, suggesting their potential applications for brain disease theranostics. In conclusion, the biosynthesis of AuNPs from aged cells medium is highly facile, green, and biocompatible for brain disease theranostics.

由于与常规纳米材料生物医学应用相关的不利影响，绿色制备纳米级材料是非常需要的。此外，血脑屏障（BBB）的较高选择性限制了通过常规化学疗法治疗脑部疾病的能力，从而为基于纳米技术的BBB穿越方式提供了空间。在这项贡献中，我们在老化的细胞培养基中从HAuCl ₄溶液中生物合成了金纳米颗粒。这种方法非常简便，无需任何其他化学方法的利用。细胞培养基的年龄和细胞数可以将Au纳米颗粒（AuNPs）的大小从2纳米调整到数百纳米。体外24小时MTT分析和细胞摄取研究和小鼠模型的重要器官（肝脏，肾脏，脾脏，肺和心脏）长达48小时的研究表明，生物合成的AuNP具有生物相容性，并且BBB适合。有趣的是，发现转铁蛋白和细胞培养基中分离出的蛋白质是造成HAuCl ₄溶液生物矿化和尺寸控制的因素。此外，在生物合成金纳米粒子的蛋白质冠可以帮助他们穿越BBB都在体外和体内，这表明他们的脑部疾病治疗诊断潜在的应用。总之，从衰老的细胞培养基中合成AuNPs高度容易，绿色且对脑部疾病诊断学具有生物相容性。