title: Photothermally enhanced drug delivery by ultrasmall multifunctional FeCo/graphitic shell nanocrystals.
abstract: FeCo/graphitic carbon shell (FeCo/GC) nanocrystals (∼4-5 nm in diameter) with ultrahigh magnetization are synthesized, functionalized, and developed into multifunctional biocompatible materials. We demonstrate the ability of this material to serve as an integrated system for combined drug delivery, near-infrared (NIR) photothermal therapy, and magnetic resonance imaging (MRI) in vitro. We show highly efficient loading of doxorubicin (DOX) by π-stacking on the graphitic shell to afford FeCo/GC-DOX complexes and pH sensitive DOX release from the particles. We observe enhanced intracellular drug delivery by FeCo/GC-DOX under 20 min of NIR laser (808 nm) induced hyperthermia to 43 °C, resulting in a significant increase of FeCo/GC-DOX toxicity toward breast cancer cells. The synergistic cancer cell killing by FeCo/GC-DOX drug delivery under photothermal heating is due to a ∼two-fold enhancement of cancer cell uptake of FeCo/GC-DOX complex and the increased DOX toxicity under the 43 °C hyperthermic condition. The combination of synergistic NIR photothermally enhanced drug delivery and MRI with the FeCo/GC nanocrystals could lead to a powerful multimodal system for biomedical detection and therapy.
authors.affiliation: Department of Chemistry, Stanford University, Stanford, California 94305, USA.
authors.forename: Sarah P
authors.initials: SP
authors.lastname: Sherlock
authors.forename: Scott M
authors.initials: SM
authors.lastname: Tabakman
authors.forename: Liming
authors.initials: L
authors.lastname: Xie
authors.forename: Hongjie
authors.initials: H
authors.lastname: Dai
mesh_terms: D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D003035:Cobalt / Q000737:chemistry*; D004317:Doxorubicin / Q000737:chemistry / Q000378:metabolism; D004337:Drug Carriers / Q000737:chemistry* / Q000633:toxicity; D006108:Graphite / Q000737:chemistry*; D006801:Humans; D007501:Iron / Q000737:chemistry*; D008027:Light; D057054:Molecular Imaging; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size
chemical_list: D004337:Drug Carriers; D003035:Cobalt; D006108:Graphite; D004317:Doxorubicin; D007501:Iron