Porphyrin–Camptothecin (CPT) Grafted Polyoxazoline Amphiphiles for Tumor Photodynamic–Chemotherapy Combination Treatment

Porphyrin-based photosensitizers are extensively utilized in the realm of photodynamic therapy, capitalizing on their advantageous optical, chemical, and electronic properties. Nonetheless, their application is often constrained by their pronounced hydrophobicity. Structures with a high load capacity and excellent biocompatibility are preferred options to circumvent this obstacle. Herein, we constructed a novel porphyrin–camptothecin (CPT) polymer, which is composed of amphiphilic oxazoline segments, and the drug monomers containing disulfide bonds are modified on the hydrophobic chain of polyoxazoline. The polyoxazoline–porphyrin–CPT (OPC) polymer can self-assemble into nanoparticles in the aqueous phase, possesses excellent stability, and generates abundant singlet oxygen (¹O₂) under laser irradiation. Additionally, the OPC nanoparticles exhibit satisfactory biocompatibility and high light toxicity against 4T1 cells. In the microenvironment of the tumor, drugs were released from the OPC nanoparticles owing to the high concentration of GSH, causing direct damage to the tumor cell, achieving the combination of photo-chemotherapy. The findings of this research indicate that polyoxazoline porphyrin demonstrates adaptability as a nanoplatform for cancer treatment.