单相介孔稀土上转换纳米发光材料的制备及其在药物缓释和光动力学诊疗方面的应用

Lanthanide doped up-conversion materials have some novel properties by comparing with organic dyes and quantum dots, such as, high stability, low inherent toxicity, sharp line emissions and low background signals in biological environment under near infrared excitation present in the transmission window of biological tissues. In this project, one new wet chemical method will be developed to prepare a series of single phase and mesoporous rare earth oxide and rare earth fluoride with highly efficient up-conversion luminescence, and control their size, structure, porosity and optical properties by varying synthetic conditions. Various characterized methods will be used to study the structure, luminescence properties and growth mechanism of mesoporous structure. Applications in drug delivery of aforementioned mesoporous up-conversion materials will be explored to get high loading efficiency for different ionic types of drug, smart release in cells by monitoring the up-conversion emissions; Applications in photodynamic therapy will be explored to get high loading efficiency for phtosensitizers of reactive oxygen, to increase the efficiencies of energy transfer and application of up-converted energy by loading one or two kinds of phtosensitizers, increasing accordingly the quantum yield of reactive oxygen (e.g. 1O2) of killing cancer cells. Single phase and multifunctional materials combining mesoporosity and up-conversion luminescence are expected to be obtained upon performing this project, which will strongly advance the development of pharmacology as well as medical diagnosis and therapeutics.

镧系稀土上转换发光材料由于其较高的稳定性，低毒性，线状发射，近红外激发光位于生物组织透射窗口及较低的生物背景信号等独特优势成为继有机染料，量子点之后一理想生物材料引起了材料学，生命科学等各领域的极大关注。本项目拟采用湿化学方法合成一系列具有高效上转换发光性能的单相介孔稀土氧化物/氟化物纳米材料，通过改变合成条件对材料的结构，尺寸，孔径大小，光学性质进行调控。采用各种表征手段研究其结构，组成，光学性质并对介孔结构的形成机理进行探讨；探索应用该材料负载药物分子，拟实现不同离子类型药物的高负载及释放过程的上转换荧光监控。探索该材料于光动力学诊疗的应用，拟实现对单种或两种光敏剂的高负载与可靠束缚，提高近红外激发下对光敏剂的能量传递效率和能量利用率，从而产生高的活性氧效率，杀灭癌细胞。本项目将获得集介孔结构与上转化发光于一体的纯相多功能材料，推动药物学和医学治疗诊断学的发展。

本项目深入研究了稀土上转换发光材料的合成及其在药物缓释及光动力学诊疗方面的应用。在项目进行期间，我们采用溶剂热方法通过改变合成条件对材料的结构，尺寸，孔径大小，光学性质进行了调控，在100℃的低温条件下获得了集介孔结构与上转换发光于一体的六角相NaYF4:Yb3+,Er3+纳米微球材料，从基础研究的角度，利用各种表征手段研究了材料的组成，结构，表面物理化学性质及发光性质，并对介孔结构的形成机理进行了探讨。药物缓释实验中，实现了所选模拟药物阿霉素（DOX）在介孔材料中的高负载及缓慢释放。光动力学诊疗实验中，通过将光敏剂负载在上转换发光材料NaYF4:Yb3+,Er3+纳米微球的介孔孔道中，在980nm激发下，通过能量传递过程，产生了可用于杀死癌细胞的单态氧。经过三年的执行，我们基本总体完成了预期目标，发表SCI论文7篇，EI论文3篇。本项目为药物学和医学治疗诊断学领域提供更具实用价值的功能材料，为实际应用奠定基础。