pyropheophorbide a + polyethylene glycol + folic acid

pyropheophorbide a + polyethylene glycol + folic acid is a targeted photosensitizer conjugate developed for photodynamic therapy (PDT), especially for cancers that overexpress folate receptor alpha such as ovarian cancer[1][4][7]. Pyropheophorbide a acts as a photosensitizer generating reactive oxygen species upon light irradiation, leading to tumor cell death (mainly via apoptosis)[2][4]. Polyethylene glycol acts as a hydrophilic linker, improving water solubility, stability, and tumor accumulation through the enhanced permeability and retention (EPR) effect[1][2][4][6]. Folic acid enables selective targeting of cancer cells by binding to surface folate receptors highly expressed in many epithelial cancers[1][4][7]. The conjugate allows for improved tumor delivery, selectivity, and efficient PDT-induced cytotoxicity, with reduced systemic toxicity and cutaneous phototoxicity compared to unconjugated photosensitizers[1][4].