Although photodynamic therapy (PDT) has been accepted as a reliable and minimal invasive clinical treatment for cancers, the treatment efficacy is hampered by limitations in cancer cell recognition, molecular imaging, in situ monitoring and depth of light penetration. In light of these challenges, increasing attention is being directed to two-photon absorption photodynamic therapy (TPA-PDT) since near-infrared (NIR) photons can penetrate deeper into tissue and re-emit energy sharply without it being absorbed by the cell. Several TPA-PDT photosensitisers have been reported in the literature, but only very few of those compounds are cancer cell-specific. The invention introduces a novel and smart TPA-PDT agent called gadolinium porphyrinate (Gd-N) comprising formula (I). Their comprehensive studies have shown that Gd-N injected into the blood stream can recognise cancer cells and through photoexcitation inhibit the growth of cancer cells. Gd-N can serve as a blueprint for the development of practical next-generation smart PDT agents with the use of lanthanide porphyrinates for locating, imaging, tracking and obliterating cancer cells. Another embodiment of this invention provides a new generation of PDT agents based on porphyrin-lanthanide complexes (formula II)) with specific functional groups which are conjugated with integrinαβ3 isoform-specific peptides. The porphyrin-lanthanide complexes are able to significantly interrupt bladder cancer tumour growth that specific binds to "integrinαβ3 isoform" with responsive emission for imaging.
The technology provides a reliable and minimally invasive clinical treatment for cancers. The technology is tumour cell-specific and in a way that can provide an in situ monitoring for the development of the tumour, which provide crucial information to clinical doctor during diagnostic and treatment. Moreover, it also provides mean of cancer therapy as it can inhibit the growth of the tumour cells.
Beneficial from its specificity and sensitivity, the two-photon absorption photodynamic therapy (TPA-PDT) agents in our technology can be used for in vivo detection of tumour by locating, imaging, tracking and obliterating the cancer cells. Moreover, it also provide a mean of cancer therapy as the agent can inhibit the growth of tumour cells.