Near-infrared laser light mediated cancer therapy by photothermal effect of Fe3O4 magnetic nanoparticles.

The photothermal effect of Fe3O4 magnetic nanoparticles is investigated for cancer therapy both in vitro and in vivo experiments. Heat is found to be rapidly generated by red and near-infrared (NIR) range laser irradiation of Fe3O4 nanoparticles with spherical, hexagonal and wire-like shapes. These Fe3O4 nanoparticles are coated with carboxyl-terminated poly (ethylene glycol)-phospholipid for enhanced dispersion in water. The surface-functionalized Fe3O4 nanoparticles can be taken up by esophageal cancer cells and do not obviously affect the cell structure and viability. Upon irradiation at 808 nm however, the esophageal cancer cell viability is effectively suppressed, and the cellular organelles are obviously damaged when incubated with the NIR laser activated Fe3O4 nanoparticles. Mouse esophageal tumor growth was found to be significantly inhibited by the photothermal effect of Fe3O4 nanoparticles, resulting in effective tumor reduction. A morphological examination revealed that after a photothermal therapy, the tumor tissue structure exhibited discontinuation, the cells were significantly shriveled and some cells have finally disintegrated.

Bovine serum albumin nanospheres synchronously encapsulating "gold selenium/gold" nanoparticles and photosensitizer for high-efficiency cancer phototherapy.

Gold nanostructures have generated significant attention in biomedical areas because of their major role in cancer photothermal therapeutics. In order to conveniently combine gold nanostructures and drugs into one nanocomposite, Au2Se/Au core-shell nanostructures with strong near-infrared-absorbing properties were synthesized using a simple method and embedded inside bovine serum albumin (BSA) nanospheres by using a spray dryer equipped with an ultrasonic atomizer followed by thermal denaturation. The nanospheres with narrow size distribution mainly ranging from 450 to 600 nm were obtained. The Au2Se/Au-loaded BSA nanospheres (1 mg) adsorbed at least 0.01 mg of water-insoluble zinc phthalocyanine (ZnPc) photosensitizer. After irradiation with a 655-nm laser (20 min), the temperature of the Au2Se/Au-loaded BSA nanospheres [200 µL, 2 mg/mL, BSA/Au2Se/Au 10:1 (w/w)] increased by over 20 °C from the initial temperature of 24.82 ± 0.15 °C, and the release of ZnPc was improved compared with a corresponding sample without irradiation. After being incubated with cancer cells (human esophageal carcinoma Eca-109), the nanospheres exhibited photothermal and photodynamic therapy with a synergistic effect upon laser irradiation. This work provides novel Au2Se/Au-loaded polymer nanospheres prepared by a high-efficiency strategy for incorporating drugs for improving the efficiency in killing cancer cells.