为解决体内肿瘤取样体外良恶性识别易导致扩散和并发症等问题，利用良恶性细胞表面电荷性质显著差异的特点，依据稀土离子对X-射线强的衰减能力和将近红外光上转换为不同波长可见发光可分别用于发光生物探针和能量传递供体的特性与过渡族离子发光性质易受微环境干扰的特性，合成具有X-射线计算机断层扫描成像（CT）功能的发光上转换(NaYF4:Er,Yb)核/下转换（NaYF4: Yb,Cr）壳复合纳米发光生物传探针（CUNBP），研究CUNBP结构、界面和表面与核内Er离子上转换发光和壳内Cr离子发光的关系、CUNBP的CT和上转换发光活体成像和受癌细胞表面电荷影响的Cr离子光谱行为、CUNBP生物安全性。重点解决CUNBP发光效率和解析Cr离子光谱线形与微环境生物信息的关系。为建立集CT/发光癌细胞成像定位引导的良恶肿瘤细胞活体光谱识别多功能于一体的新技术和新方法提供新型多功能纳米生物探针和理论依据。

Current in vitro identification methodologies of benign or malignant tumors suffer from cancer transformation and complication, etc. due to the in vivo tumor sampling approach. To circumvent these drawbakcs, in this project, we shall develp and validate a new identification approach based on a novel dual model imaging nanoprobe of which NaYF4:Er,Yb is taken as core and NaYF4:Yb,Cr as shell, termed as CUNBP. This approach takes the advantage of (1) the remarkable difference in the structure and charge properties between benign and malignant tumor cells, and (2) the strong adsorption of rare earth ions on X-ray, upconversion of near infrared photons into visible high energy photons of different wavelengths which can be used as bioprobes and the energy donors, respectively, together with the fact that the luminescence properties of rare earth ions in nanoparticles are subject to their local environment. In this design, identification of benign or malignant tumors is via dual-mode imaging of enhanced X-ray Computed Tomography (CT) and near infrared upconversion luminescence imaging. For this purpose of the identification, the following issues will be addressed in the project, including (1) the effects of nanoconstruct with core/shell, interface, surface of CUNBP on the properties of upconversion luminescence of trivalent Er ions in core and downconversion luminescence of Cr ions in shell, (2) in vivo behaviour of the dual-mode bioimaging of enhanced CT of trivalent Yb ions and upconversion photons of CUNBP for identification of benign and malignant tumor cells, and (3) effects of CUNBP on bio-safety of mouse model. Two key questions are expected to be answered, i.e. the relationship between the spectral change and the properties of the surface structure a nd charges of benign and malignant tumor cells, and how to improve the upconversion luminescence. This innovation nano-bioprobe platform, i.e. CUNBP, and theoretical foundation shall be provided to develop a novel CUNBP with multi-functions of the dual-mode imaging of enhanced CT of Yb ions and near infrared photons, and in vivo and in situ identification of benign and malignant tumor cells.