Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei 10607, Taiwan.
Nanoscale. 2019 May 30;11(21):10393-10401. doi: 10.1039/c8nr09537j.
The new concept of modifying and tailoring the properties of existing two-dimensional (2D) nanomaterials by invoking the assembly of supramolecular networks upon association with a adenine-functionalized macromer (A-PPG) has significant potential to facilitate the development of highly water-dispersible few-layered 2D nanosheets. In this study, we propose that water-soluble A-PPG directly self-assembles into a long-period stacking-ordered lamellar structure over the surface of hexagonal boron nitride (BN) in aqueous solution, due to the efficient non-covalent interactions between A-PPG and BN nanosheets. The layer number of BN nanosheets can be easily tuned by altering the mass ratio of the A-PPG and BN blend, and the resulting exfoliated nanosheets also exhibit excellent temperature/pH-responsive behavior, biocompatibility and extremely high drug-loading capacity (up to 36.2%), features that are highly desirable yet exceedingly rare in traditional 2D nanomaterials. Importantly, in vitro drug release studies showed the drug-loaded nanosheets function as a stable nanocarrier with excellent stability and drug entrapment under normal physiological conditions. Increasing the environmental temperature to 40 °C or decreasing the pH to 5.5 triggered rapid release of the encapsulated drug from the drug-loaded nanosheets, suggesting this newly developed material has potential as a novel multi-responsive 2D nanocarrier to safely deliver drugs and effectively facilitate controlled drug release under specific microenvironmental conditions. This study provides new insight towards the promising application of this system in controlled release drug delivery systems.
通过与腺嘌呤功能化大分子（A-PPG）缔合，赋予现有二维（2D）纳米材料特性的新构想，通过超分子网络的组装来修饰和定制其特性，这为开发高度水分散的少层 2D 纳米片具有重要意义。在这项研究中，我们提出水溶性 A-PPG 由于 A-PPG 和 BN 纳米片之间的有效非共价相互作用，直接在水溶液中自组装成六方氮化硼（BN）表面的长周期有序层状结构。BN 纳米片的层数可以通过改变 A-PPG 和 BN 混合物的质量比轻松调节，所得剥离纳米片还表现出出色的温度/pH 响应行为、生物相容性和极高的载药能力（高达 36.2%），这些特性在传统的 2D 纳米材料中非常理想但极为罕见。重要的是，体外药物释放研究表明，负载药物的纳米片作为一种稳定的纳米载体，在正常生理条件下具有出色的稳定性和药物包封能力。将环境温度升高到 40°C 或降低 pH 值至 5.5 会触发负载药物的纳米片中包封药物的快速释放，这表明这种新开发的材料具有作为新型多响应 2D 纳米载体的潜力，可安全输送药物并在特定的微环境条件下有效促进药物控制释放。这项研究为该系统在控释药物输送系统中的应用提供了新的思路。
