量子点在肿瘤研究中的应用

量子点是指半径小于或接近于激子玻尔半径的半导体纳米晶粒。量子点发射荧光的可调节性强,通过改变粒子半径的大小可获得从紫外到近红外范围内任意点的光谱,且Stokes位移大。其荧光强度高而稳定,单一量子点表现出的荧光亮度和持续时间是普通有机荧光染料的10～20倍。被适当外壳包裹修饰的量子点在短时间内,对细胞的生长、发育、信号转导以及迁移等生理活动无影响。随着光学标记技术和成像技术的不断发展,现有的许多传统、常规的生物医学方法在微观上直接、实时研究生物分子的相互作用以及在临床肿瘤疾病早期诊断上都存在较大的局限性。量子点的发明及其在生物医学领域的应用,尤其是将其作为特异性标记物应用于前列腺癌、乳腺癌、子宫颈癌、皮肤基底细胞癌、肝癌、黑色素瘤等肿瘤的示踪和靶向研究中具有很大的实用价值。当前的研究主要集中在通过细胞组织等有形载体显示特定的肿瘤标志物或分子相互作用．下一步的发展方向之一就是开发这种高灵敏标记技术用于血清或其他体液成分中肿瘤分子的标记与成像,提高早期诊断率。

Quantum dots and their applications in cancer research

Quantum dots are semiconductor nanocrystals with physical dimensions smaller than the exciton Bohr radius. As their fluorescence emissions are size-tunable, we can acquire any spectrum from ultraviolet (UV) to near-infrared by changing the particles' radiuses. The large Stokes shifts of quantum dots can be used to further improve detection sensitivity. The luminescence intensity is high and stable. Single quantum dots have longer excited state lifetimes, and they appear 10-20 times brighter than organic fluorescent dyes. And they have good biocompatibility because quantum dots with appropriate shells don't interfere with physiological processes, such as growth, development, signaling and motility. With the development of optical labeling and imaging technology, many present conventional biomedical methods have limitations in microcosmic direct real-time researches of bio-molecular interactions and early diagnosis of malignant tumors. The invention of quantum dots and their biomedical applications make them as good markers for tumor cell tracing and targeting in cancer research, such as prostate cancer, mammary cancer, cervical cancer, basal cell carcinoma, liver cancer, and melanoma. The current research is focused on tumor markers imaging and molecular interaction based on tangible carriers such as cells and tissues. The next research orientation would be to tap the potential of this highly sensitive technology to image tumor biomarkers in serum and other body fluids, so as to increase the early diagnosis rate of malignant tumors.