恶性肿瘤荧光成像的研究进展

Advances in fluorescence imaging of malignant tumors

恶性肿瘤是威胁人类健康的常见疾病,早期诊断并完整切除可显著改善恶性肿瘤患者的预后。目前,临床上用于恶性肿瘤检查的影像学技术多存在灵敏度和时空分辨率差、成像扫描时间长等问题,无法对其行早期诊断,也难以满足手术导航的要求。作为一种具有优异成像特性的新型成像技术,荧光成像能够对生物组织器官的结构和功能进行实时成像,即通过设计高灵敏度、高选择性和特异性的荧光探针,实现对恶性肿瘤的精准检测;其灵敏度主要取决于探针的荧光基团,选择性和特异性则取决于探针是否采取有效的靶向策略。研究显示,发射波长在近红外窗口内的近红外荧光团,尤其在近红外第二窗口内的荧光团,其光学性质优异,可有效提升恶性肿瘤荧光成像的灵敏度;同时,基于恶性肿瘤独特的结构和代谢特性,各种靶向策略也已被开发出来用于设计“常亮”型荧光探针和“激活”型荧光探针,以显著提高恶性肿瘤荧光成像的选择性和特异性。基于此,该文对新近开发的近红外荧光团以及荧光探针靶向恶性肿瘤的策略进行综述。

Malignant tumors are common diseases that threaten human health.Early diagnosis and complete resection can significantly improve the prognosis of patients with malignant tumors.At present,the imaging techniques used clinically for malignant tumor detection have problems such as poor sensitivity and temporal-spatial resolution,long scanning time,etc.,which cannot achieve early diagnosis and meet the requirements of surgical navigation.As a new imaging technology with excellent imaging characteristics,fluorescence imaging can perform real-time imaging of the structure and function of biological tissues and organs.It can realize the accurate detection of malignant tumors by designing fluorescent probes with high sensitivity,high selectivity and specificity.The sensitivity of fluorescence imaging mainly depends on the fluorophore of the probe,and the selectivity and specificity mainly depend on whether the probe adopts an effective targeting strategy.Studies have shown that near infrared fluorophores with emission wavelengths in the near infrared window,especially those in the near infraredⅡwindow,have excellent optical properties,which can effectively improve the sensitivity of fluorescence imaging of malignant tumors;at the same time,based on the unique structure and metabolic features of malignant tumors,various targeting strategies have been developed to design"always-on"fluorescent probes and"turn-on"fluorescent probes,which significantly improved the selectivity and specificity of fluorescent imaging of malignant tumors.In this paper,the newly developed near infrared fluorophores and the strategies of fluorescent probes targeting malignant tumors are reviewed.