Visualising the intracellular environment during normal cell function and photodynamic therapy using advanced imaging techniques

光动力疗法（PDT）是治疗各种癌症（特别是肺癌、头颈癌和非黑色素瘤皮肤癌）和治疗称为急性黄斑变性（AMD）的疾病的已建立的方法，所述急性黄斑变性是老年人中法律的失明的主要来源。它基于优先定位在癌组织中的敏化剂分子的光活化，其产生细胞毒性物质，例如单线态氧，其杀死靶区域中的周围细胞。为了充分理解PDT机制，关键是能够可视化细胞内致敏剂和细胞毒性物质的定位。该提案旨在使用先进的成像技术，荧光，拉曼和二次谐波产生成像的组合，以可视化正常细胞功能和PDT诱导的细胞死亡期间的单个细胞内事件。我们将利用共轭卟啉二聚体的高双光子吸收（TPA）横截面用于TPA PDT和TPA细胞内成像，以获得高图像分辨率、更深的组织穿透和精确的光应用，从而有利于治疗诸如AMD的疾病，其中焦点外损伤应最小化。将筛选一系列敏化剂的生物物理性质、细胞定位和体外PDT作用，以揭示体内测试的最佳候选物。我们将结合联合收割机成像结果的敏化剂与单线态氧，细胞毒性物种负责细胞死亡，这将为我们提供的PDT机制在细胞内的洞察力。这是一个跨学科的项目，涉及分子设计，合成，光物理，光化学，成像，光谱和细胞生物学。

Photodynamic Therapy (PDT) is an established method to treat the variety of cancers (particularly lung, head, neck and non-melanoma skin cancer) and for treating the disease known as acute macular degeneration (AMD) which is a main source of legal blindness in old people. It is based on the light activation of the sensitizer molecules preferentially localised in the cancerous tissues, which produce cytotoxic species such as singlet oxygen, which kill surrounding cells in the target areas. For full understanding of PDT mechanism it is crucial to be able to visualise the localisation of both the sensitiser and cytotoxic species within cells. This proposal seeks to use advanced imaging techniques, the combination of fluorescence, Raman and second harmonic generation imaging to visualise individual intracellular events during normal cell function and PDT-induced cell death. We will take advantage of high two-photon absorption (TPA) cross sections of conjugated porphyrin dimers for TPA PDT and TPA intracellular imaging for high image resolution, deeper tissue penetration and precise application of light for the benefit of treatments of diseases such as AMD, where out of focus damage should be minimised. Series of sensitisers would be screened for photophysical properties, cell localisation and PDT action in vitro to reveal the best candidates for in vivo testing. We will combine imaging results for the sensitisers with that of singlet oxygen, the cytotoxic species responsible for cell death, which would provide us with the insight of the PDT mechanism in cellulo. This is an interdisciplinary project involving molecular design, synthesis, photophysics, photochemistry, imaging, spectroscopy and cell biology.