An Oxygen-Enriched Photodynamic Nanospray for Postsurgical Tumor Regression.

Postoperative local recurrence and metastasis are non-negligible challenges in clinical cancer treatment. Photodynamic therapy (PDT) has presented a great potential in preventing cancer recurrence owing to its noninvasiveness and high specificity for local irradiation of tumor sites. However, the application of conventional PDT is often limited by insufficient oxygen supply, making it difficult to achieve high PDT efficacy. Herein, we combined liposomes with photosensitizer indocyanine green (ICG) and perfluorooctyl bromide (PFOB) to develop a new oxygen-enriched photodynamic nanospray (Lip-PFOB-ICG) for cancer postoperative treatment. The Lip-PFOB-ICG not only has good biocompatibility but also enhanced the PDT effect under near-infrared light. More importantly, PFOB can continuously absorb oxygen, thus improving the collision energy transfer between the ICG photosensitizer and oxygen, and significantly inhibit local tumor recurrence in the subcutaneous tumor recurrence model. This oxygen-enriched photodynamic nanospray strategy may open up new avenues for effective postoperative cancer therapy in the clinic.