光动力疗法是临床治疗肿瘤的新型疗法，目前临床应用主要受限于静脉给药难（光疗药物绝大多数属于脂溶性化合物）、治疗光源组织穿透深度浅和可到达肿瘤细胞内部的光剂量不足等问题。本项目拟运用具有良好生理相容性且对pH敏感的纳米磷酸钙来分层负载生物发光系统及光疗药物，该治疗体系不仅实现了在血液中的有效传输和在EPR效应作用下实现肿瘤组织部位的靶向富集，而且在肿瘤细胞内涵体内的酸性作用下，触发生物发光共振能量转移，使体系能自敏化光疗药物，发挥抗肿瘤活性。通过探讨和分析该体系的构建条件及结构对血液中的传输性能、肿瘤组织部位的摄取率、生物发光共振能量转移敏化光敏药物的效率和抗肿瘤细胞的活性等的影响规律，优化该体系构建条件，获得具有自主知识产权、适用于体内实体肿瘤治疗的新型光动力治疗体系，同时建立利用生物发光共振能量转移原理来构建光动力治疗体系的新方法。以期推动光动力疗法在实体肿瘤治疗领域中的临床应用进程。

Photodynamic therapy is a new type of therapy in clinical treatment of tumors, the clinical application of main current is limited by intravenous dosing difficult (phototherapy drugs most belong to the fat-soluble compounds), treatment source tissue penetration depth is shallow and can be reached such problems as insufficient light dose within the tumor cells.This project intends to use with good biological compatibility and sensitive to pH nano calcium phosphate of layered load bioluminescent system and phototherapy drugs, the treatment system not only implements the effective transmission in the blood and in the EPR effect under the action of tumor tissue targeting enrichment, and the connotation of the tumor cells under the action of acid in the body, triggering bioluminescent resonance energy Photodynamic therapy (PDT) utilizes a combination of photosensitizers (PSs) and specific light sources for the treatment of various diseases. The use of PDT as a treatment modality is gradually gaining acceptance but it is not widely used in solid tumor treatment for several reasons, including the hydrophobic property of PSs, the penetration depth limitation and the inadequate light dose inside cancer cells. This project intends to use calcium phosphate nanoparticles, with good biological compatibility and pH sensitive property, to encapsulate bioluminescence system and PSs in separate part of nanoparticle. Such complex can be delivered in the blood and targeted to tumor tissue because of the enhanced permeability and retention effect (EPR). After entrapped inside cancer cells, calcium phosphate nanoparticles can be destroyed in the acid environment inside endosome, which triggering bioluminescent resonance energy transfer (BRET) and sensitizing PSs, simultaneously. The reactive oxygen species generated by the sensitized PSs can destroy the membrane of endosome to release bioluminescence system and PSs into cytoplasm to show PDT activity. By analyzing the relationship between the structure of drug delivery system and the delivery performance in the blood, tumor tissue uptake rate, BRET efficiency and anti-cancer activity, the ideal self-illuminate PDT system can be selected to be used in solid tumor treatment. Furthermore, a new method of photodynamic therapy system based on BRET principle can be built. Above research can promote the clinical application in solid tumor treatment by PDT.