A Paclitaxel Prodrug Activatable by Irradiation in a Hypoxic Microenvironment.

The innate hypoxic microenvironment of most solid tumors has a major influence on tumor growth, invasiveness, and distant metastasis. Here, a hypoxia-activated self-immolative prodrug of paclitaxel (PTX2 -Azo) was synthesized and encapsulated by a peptide copolymer decorated with the photosensitizer chlorin e6 (Ce6) to prepare light-boosted PTX nanoparticle (Ce6/PTX2 -Azo NP). In this nanoparticle, PTX2 -Azo prevents premature drug leakage and realizes specific release in hypoxic tumor microenvironment and the photosensitizer Ce6 not only efficiently generates singlet oxygen under light irradiation but also acts as a positive amplifier to promote the release of PTX. The combination of photodynamic therapy (PDT) and chemotherapy results in excellent antitumor efficacy, demonstrating the great potential for synergistic cancer therapy.