Natural pollen extract for photothermal therapy

Herein, we discovered that the sunflower sporopollenin exine capsule (SEC) is an effective photothermal agent. In vitro study finds that the spikes on the surface of the sunflower SEC and its structural integrity are the two key factors to determine the photothermal effect. In vivo melanoma mouse model proves that the sunflower SEC can effectively inhibit tumor growth by inducing cell apoptosis and reducing cell proliferation through the near-infra red light triggered photothermal therapy. The in vivo biosafety of the SEC is also validated. In consideration of its safety, uniform size distribution and abundant availability, the sunflower SEC will be a promising photothermal agent candidate for clinical translational application.