基于二维黑磷的可控降解近红外光热转换材料

Nanomaterials with strong near-infrared absorption and high photothermal conversion ability have shown great application potential in many areas including cancer treatment. However, the current photothermal conversion nanomaterials generally have poor biodegradability and would stay in the body for a long period of time accentuating the risk of deleterious effects, which limit their clinic applications. This project plans to develop a kind of biodegradable photothermal conversion nanomaterial based on black phosphorus, a newly developed two-dimensional semiconductor. It has been found that black phosphorus have high photothermal conversion ability, and can degrade into nontoxic phosphate and phosphonate in aqueous media. However, their photothermal applications still suffer from rapid degradation of their optical properties during circulation in the body. Based on these facts, we first explore the synthesis strategy to control the thickness and lateral size of black phosphorus, and improve their near-infrared photothermal conversion performances. Secondly, we study the biodegradation behavior and photothermal cancer therapy based on black phosphorus. Surface coordination and polymer encapsulation are suggested to control the degradation rate of black phosphorus in physiological mediums. By using the black phosphorus after such treatments, we want to achieve not only the stable optical performance and tumor accumulation for highly efficient photothermal cancer therapy, but also ensuring that the materials can be discharged harmlessly from the body after completion of the therapeutic functions. The successful development of such biodegradable photothermal conversion nanomaterials would promote the clinic photothermal applications, and provide guidance for the development of biomedical materials in the future.

光热转换材料是指一类能将近红外光高效地转换成热能的材料，在肿瘤光热治疗等领域展现出巨大的应用潜力。然而，目前纳米光热转换材料大都在体内无法降解，因而存在潜在的生物安全性问题，限制了其临床应用。本项目拟基于黑磷，这一新型二维半导体，发展一种可控降解光热转换材料。申请人近期研究发现，黑磷具有很好的近红外光热转换性能，并可降解为安全的小分子产物，但其在生理环境中降解过快会导致光学性能的快速下降，影响治疗效果。基于此，本项目首先研究控制黑磷厚度和片层大小的方法，优化其光热性能；随后开展黑磷在生理环境中降解行为和光热治疗应用研究。通过表面配位化学修饰、聚合物包裹等手段控制黑磷的降解速度，既实现其在治疗过程中性能的稳定和有效的肿瘤富集，以高效地杀灭肿瘤，又可在治疗结束后安全地降解代谢出体外。这种新型可控降解光热转换材料的研发，将有助于推动光热技术的临床应用，并为今后纳米生物医用材料的研发提供借鉴。

本项目基于黑磷发展出多种可控降解光热转换材料，并研究其在肿瘤治疗、药物递送以及光催化等领域的应用前景。在前期研究中，项目负责人发现，黑磷具有很好的近红外光热转换性能，在生理环境中可被氧化降解成磷酸根离子或亚磷酸根离子等安全的小分子产物，但其降解过快会导致光学性能的快速下降，影响治疗效果。因此，本项目首先从黑磷的制备工艺出发，通过控制黑磷厚度和片层大小的方法，优化其光热性能，随后开展黑磷在生理环境中降解行为和光热治疗应用等研究。申请人团队通过表面配位化学修饰、聚合物包裹等手段控制黑磷的降解速度，既实现其在治疗过程中性能的稳定和有效的肿瘤富集，保证高效地肿瘤杀灭，又可在治疗结束后安全地缓慢降解代谢出体外。这种新型可控降解光热转换材料的研发，推动了光热技术在肿瘤治疗、生物医用材料等领域的临床应用，并为今后纳米生物医用材料的研发提供借鉴和参考。依托上述成果，本项目共发表SCI论文29篇，申请了6项中国发明专利和1项PCT国际发明专利，其中3项获得授权。