基于氮化碳类纳米材料的长寿命发光生物成像分析

In recent years, carbon nitride nanoparticles (CNPs), one of novel long-persistent luminescent materials with high fluorescence efficiency, can be directly chemical modified and conjugated with ligands, such as antibodies, proteins and peptides, to effectively attract and specifically bind with targeting tumor markers. The background arising from self-absorption-induced fluorescence and scattering would be even avoided by taking full advantage of long-persistent luminescent property of CNPs, giving rise to a significant enhancement of the sensitivity of bio-imaging. Additionally, CNPs, consisting only of carbon and nitrogen, are free of potential health and safety risks caused by harmful or toxic heavy metals. As a result, the biological compatibility of bio-markers would be considerably improved. In this project, novel synthetic methods of carbon nitride based nano-sized long-persistent luminescent materials will be investigated to obtain nanoparticles with high luminescence efficiency and long persistence. Then, luminescence imaging probes aiming at tumor markers of breast cancer will be prepared via direct chemical modification, and analytical method based on luminescence imaging and with high sensitivity and specificity toward tumor markers of breast cancer will thus be developed. Moreover, a probe targeting RGD, which has a strong affinity for integrin αvβ3 on the surface membrane of breast cancer cells, will be designed to further construct an analytical platform for luminescence imaging and tracing breast cancer cells in vivo. This project will pioneer new approaches for luminescence imaging tumor markers.

氮化碳纳米粒子是最新发现的具有高发光效率的长寿命发光材料，可直接修饰并与目标配体如抗体、蛋白质和多肽相连，实现对肿瘤标记物的特异性结合；其长寿命发光特性可有效避免内源性吸收产生的荧光或散射背景，大大提升生物成像灵敏度；碳氮构成避免了有毒有害重金属元素带来的潜在毒害，提高生物标记物的生物相容性。本项目中拟通过新型的氮化碳类纳米长寿命发光材料合成方法研究，获得具有高发光效率和寿命的纳米粒子，通过直接化学修饰等手段制备针对乳腺癌肿瘤细胞标志物的发光成像探针，建立乳腺癌肿瘤标志物的高灵敏特异性检测和发光成像分析方法，并通过对乳腺癌细胞膜的表面αvβ3整合素分子高亲和作用的RGD靶向标记探针，进一步建立对生物体内乳腺癌细胞的示踪成像分析方法，为现有肿瘤标记物发光成像分析研究提供新的途径。

构建高灵敏度和高选择性的发光生物探针，是实现直观生物成像分析的重要条件之一，是获得生物体中不同生理及病理动态变化过程本质认识的重要手段之一，可为生物医学和临床诊断等相关研究提供新手段新途径。本项目围绕发光探针设计及其生物成像开展了深入研究，主要完成了如下工作：高发光效率长寿命发光探针和近红外发光纳米探针设计合成及其在裸鼠肿瘤细胞的靶向成像分析；新型双光子荧光探针及多功能发光探针的设计合成及其生物体活性氧小分子的示踪成像分析；基于黑磷和硅基的化学发光纳米探针及其对活性氧小分子的识别方法构建。研究结果包括：（1）我们设计合成了基于共振能量转移长寿命发光探针、近红外长寿命发光探针实现对小鼠肿瘤细胞的成像分析，并应用于小鼠体内诊疗一体方法的构建；（2）成功设计合成了几种以有机小分子萘、荧光素及金属铱配合物为母体的反应型荧光和化学发光探针，利用发光探针与目标物的特异性反应来调节发光强度或者波长变化实现对ONOO-和HOCl两种ROS的检测与成像，并深入讨论了两种ROS在疾病模型中的作用；（3）开展了黑磷和硅基等非金属纳米探针的绿色合成方法研究，将合成的纳米材料引入化学发光，构建一系列新的发光体系，成功实现活性氧小分子的高选择性识别，并深入研究其传感识别原理，有望用于生命体中内在活性氧的检测。本研究结果为推动发光生物成像研究具有积极意义。