π-extended porphyrin-based near-infrared photosensitizers for mitochondria-targeted photodynamic therapy

Near-infrared (NIR) photosensitizers have great potential to develop various fields of photochemistry, such as photodynamic therapy (PDT) and photocatalysts. Organelle-targeted PDT using NIR light attracts considerable attention to high-efficiency phototherapy. Although drug delivery system (DDS) carriers are often combined with NIR photosensitizers for effective PDT, the systematic correlations between the cargo and DDS carriers are still unclear. In this study, we develop NIR-photosensitizers from a pi-extended porphyrin-type sensitizer (rTPA) that allows us to modify the structure and properties with a one-touch operation for the systematic study. Single-step amidations give five rTPA derivatives readily, facilitating comprehensive information about the properties according to their molecular structure and electric charge of the photosensitizer and DDS carriers prepared using a microfluidic device. One of the combinations, rTPA-NH2@MP, demonstrates the highest ability among the derivatives to kill pancreatic cancer cells, which are known to be highly lethal. The present study provides a guideline for inventing effective DDS-based NIR-PDT compounds for future photodrugs.