Source: School of Pharmaceutical Sciences (Shenzhen)
Written by: School of Pharmaceutical Sciences (Shenzhen)
Edited by: Wang Dongmei

As a novel 2D material, black phosphorus nanosheets (BP NSs) are considered as a promising candidate for drug delivery platform for synergistic chemo/photothermal therapy. However, the lack of water- and air-stability under ambient conditions hinders its potential biomedical applications. Very recently, some efforts have been made to improve the stability of BP NSs, including ligand surface coordination, covalent aryl diazonium functionalization and capping layer protection. Unfortunately, most of these strategies are not suitable for the drug delivery systems.

Prof. Lin Mei’s group from the Institute of Pharmaceutics, School of Pharmaceutical Sciences (Shenzhen) at Sun Yat-sen University reported a mussel-inspired biomimetics polydopamine (PDA) modification strategy to enhance the stability of BP NSs. PDA coating could isolate the interior BP NS from oxygen and water and thus to improve its stability. Besides, PDA also has strong NIR absorbility and high photothermal conversion efficiency. Therefore, the modification of PDA layer could further improve the photothermal performance of BP NSs. Moreover, Mei and co-workers employed this PDA-modified nanocapsule as a co-delivery platform for combined gene, chemo, and photothermal therapy against multidrug-resistant cancer. The enhanced tumor therapy effect is demonstrated by both in vitro and in vivo studies. This work has been published in Advanced Science (Xiaowei Zeng, Miaomiao Luo, Gan Liu, Xusheng Wang, Wei Tao, Yaoxin Lin, Xiaoyuan Ji, Lin Nie, and Lin Mei* Adv Sci. DOI: 10.1002/advs.201800510). The title is "Polydopamine-Modified Black Phosphorous Nanocapsule with Enhanced Stability and Photothermal Performance for Tumor Multimodal Treatments”. The first author of this paper is Xiaowei Zeng, and the corresponding author is Lin Mei.

This work was supported by the National Natural Science Foundation of China, the Natural Science Foundation of Guangdong Province, Science and Technology Planning Project of Guangdong Province and Science, Technology & Innovation Commission of Shenzhen Municipality.
Before this, Prof. Mei’s group cooperated with Prof. Jinjun Shi (Harvard Medical School) and Prof. Han Zhang (Shenzhen University) to develop a novel top-down approach to fabricate ultrathin boron nanosheets (B NSs). This smart top-down approach was achieved through coupling thermal oxidation etching and liquid exfoliation technologies to prepare B NSs with controlled nanoscale thickness. Based on the PEGylated B NSs, a new photonic drug delivery platform was developed, which exhibits multiple promising features for cancer therapy and imaging, including: i) efficient NIR-light-to-heat conversion with a high photothermal conversion efficiency of 42.5%, ii) high drug-loading capacity and triggered drug release by NIR light and moderate acidic pH, iii) strong accumulation at tumor sites, iv) multimodal imaging properties (photoacoustic, photothermal, and fluorescence imaging), and v) complete tumor ablation and excellent biocompatibility. As far as it is known, this is the first report on the top-down fabrication of ultrathin 2D B NSs by the combined thermal oxidation etching and liquid exfoliation, as well as their application as a multimodal imaging guided drug delivery platform. The results were published online in Advanced Materials (IF: 21.95) by "A Novel top-down Synthesis of Ultrathin 2D Boron Nanosheets for Multimodal image-guided Cancer Therapy" on July 18, 2018. The first author of this work is Xiaoyuan Ji from School of Pharmaceutical Sciences (Shenzhen), Sun Yat-sen University.

Link to the papers:
https://onlinelibrary.wiley.com/doi/10.1002/advs.201800510
https://onlinelibrary.wiley.com/doi/10.1002/adma.201803031