Synthesis of Ultrathin Biotite Nanosheets as an Intelligent Theranostic Platform for Combination Cancer Therapy

• Published in: Advanced science 2019-10, Vol.6 (19), p.1901211-n/a
• Main Authors: Ji, Xiaoyuan, Kang, Yong, Ouyang, Jiang, Chen, Yunhan, Artzi, Dolev, Zeng, Xiaobin, Xiao, Yuling, Feng, Chan, Qi, Baowen, Kim, Na Yoon, Saw, Phei Er, Kong, Na, Farokhzad, Omid C., Tao, Wei
• Format: Article
• Language: English
• Subjects: 2D nanosheets; Biocompatibility; biotite; Cancer therapies; combination cancer therapy; Communication; Communications; Hypoxia; Light; Polyethylene glycol; reactive oxygen species; Womens health
• ISSN: 2198-3844; 2198-3844
• DOI: 10.1002/advs.201901211

Biotite, also called black mica (BM), is a group of sheet silicate minerals with great potential in various fields. However, synthesis of high‐quality BM nanosheets (NSs) remains a huge challenge. Here, an exfoliation approach is provided that combines calcination, n‐butyllithium exchange and intercalation, and liquid exfoliating processes for the high‐yield synthesis of ultrathin BM NSs. Due to the presence of MgO, Fe2O3, and FeO in these NSs, PEGylated BM can be engineered as an intelligent theranostic platform with the following unique features: i) Fe3+ can damage the tumor microenvironment (TME) through glutathione consumption and O2 production; ii) Generated O2 can be further catalyzed by MgO with oxygen vacancy to generate ·O2−; iii) The Fe2+‐catalyzed Fenton reaction can produce ·OH by disproportionation reactions of H2O2 in the TME; iv) Reactions in (i) and (iii) circularly regenerate Fe2+ and Fe3+ for continuous consumption of glutathione and H2O2 and constant production of ·OH and O2; v) The NSs can be triggered by a 650 nm laser to generate ·O2− from O2 as well as by an 808 nm laser to generate local hyperthermia; and vi) The fluorescent, photoacoustic, and photothermal imaging capabilities of the engineered NSs allow for multimodal imaging‐guided breast cancer treatment. 2D black mica (BM)‐based nanosheets (NSs) are fabricated through an exfoliation approach that combines grinding, calcination, n‐butyllithium exchange and intercalation, and liquid exfoliating processes. The nanoplatform based on PEGylated BM NSs exhibits multiple features, such as tumor microenvironment modulation, efficient reactive oxygen species production and photothermal conversion, high tumor site accumulation, good biocompatibility, and multimodal imaging‐guided breast cancer treatment.