Nanotechnology-based photothermal therapy has emerged as a promising treatment for cancer during the past decade. However, heterogeneous laser heating and limited light penetration can lead to incomplete tumor cell eradication. Here, we developed a method to overcome these limitations by combining chemotherapy with photothermal therapy using paclitaxel-loaded gold nanorods. Paclitaxel was loaded to gold nanorods with high density (2.0 × 10(4) paclitaxel per gold nanorod) via nonspecific adsorption, followed by stabilization with poly(ethylene glycol) linked with 11-mercaptoundecanoic acid. Paclitaxel was entrapped in the hydrophobic pocket of the polymeric monolayer on the surface of gold nanorods, which allows direct cellular delivery of the hydrophobic drugs via the lipophilic plasma membrane. Highly efficient drug release was demonstrated in a cell membrane mimicking two-phase solution. Combined photothermal therapy and chemotherapy with the paclitaxel-loaded gold nanorods was shown to be highly effective in killing head and neck cancer cells and lung cancer cells, superior to photothermal therapy or chemotherapy alone due to a synergistic effect. The paclitaxel-gold nanorod enabled photothermal chemotherapy has the potential of preventing tumor reoccurrence and metastasis and may have an important impact on the treatment of head and neck cancer and other malignancies in the clinic.

We present the synthesis and application of a new type of dual magnetic and plasmonic nanostructures for magnetic-field-guided drug delivery and combined photothermal and photodynamic cancer therapy. Near-infrared-absorbing gold nanopopcorns containing a self-assembled iron oxide cluster core were prepared via a seed-mediated growth method. The hybrid nanostructures are superparamagnetic and show great photothermal conversion efficiency (η=61%) under near-infrared irradiation. Compact and stable nanocomplexes for photothermal-photodynamic therapy were formed by coating the nanoparticles with near-infrared-absorbing photosensitizer silicon 2,3-naphthalocyannie dihydroxide and stabilization with poly(ethylene glycol) linked with 11-mercaptoundecanoic acid. The nanocomplex showed enhanced release and cellular uptake of the photosensitizer with the use of a gradient magnetic field. In vitro studies using two different cell lines showed that the dual mode photothermal and photodynamic therapy with the assistance of magnetic-field-guided drug delivery dramatically improved the therapeutic efficacy of cancer cells as compared to the combination treatment without using a magnetic field and the two treatments alone. The "three-in-one" nanocomplex has the potential to carry therapeutic agents deep into a tumor through magnetic manipulation and to completely eradicate tumors by subsequent photothermal and photodynamic therapies without systemic toxicity.

Magnetic-plasmonic core-shell nanomaterials offer a wide range of applications across science, engineering and biomedical disciplines. However, the ability to synthesize and understand magnetic-plasmonic core-shell nanoparticles with tunable sizes and shapes remains very limited. This work reports experimental and computational studies on the synthesis and properties of iron oxide-gold core-shell nanoparticles of three different shapes (sphere, popcorn and star) with controllable sizes (70 to 250 nm). The nanoparticles were synthesized via a seed-mediated growth method in which newly formed gold atoms were added onto gold-seeded iron oxide octahedrons to form gold shell. The evolution of the shell into different shapes was found to occur after the coalescence of gold seeds, which was achieved by controlling the amount of additive (silver nitrate) and reducing agent (ascorbic acid) in the growth solution. First principles calculation, together with experimental results, elucidated the intimate roles of thermodynamic and kinetic parameters in the shape-controlled synthesis. Both discrete dipole approximation calculation and experimental results showed that the nanopopcorns and nanostars exhibited red-shifted plasmon resonance compared with the nanospheres, with the nanostars giving multispectral feature. This research has made a great step further in manipulating and understanding magnetic-plasmonic hybrid nanostructures and will make important impact in many different fields.

Circulating tumor cells (CTCs) are a hallmark of invasive behavior of cancer, responsible for the development of metastasis. Their detection and analysis have significant impacts in cancer biology and clinical practice. However, CTCs are rare events and contain heterogeneous subpopulations, requiring highly sensitive and specific techniques to identify and capture CTCs with high efficiency. Nanotechnology shows strong promises for CTC enrichment and detection owning to the unique structural and functional properties of nanoscale materials. In this review, we discuss the CTC enrichment and detection technologies based on a variety of functional nanosystems and nanostructured substrates, with the goal to highlight the role of nanotechnology in the advancement of basic and clinical CTC research.

The growth mechanism of magnetic nanoparticles (NPs) in the presence of graphite oxide (GO) has been investigated by varying the iron precursor dosage and reaction time (product donated as MP/GO). The synthesized magnetic NPs were anchored on the GO sheets due to the abundant oxygen-containing functionalities on the GO sheets such as carboxyl, hydroxyl and epoxy functional groups. The introduced NPs changed the intrinsic functionalities and lattice structure of the basal GO as indicated by FT-IR, Raman and XRD analysis, and this effect was enhanced by increasing the amount of iron precursor. Uniform distribution of NPs within the basal GO sheets and an increased particle size from 19.5 to 25.4, 31.5 and 85.4 nm were observed using scanning electron microscope (SEM) and transmission electron microscope (TEM) when increasing the weight ratio of GO to iron precursor from 10 : 1, to 5 : 1, 1 : 1 and 1 : 5, respectively. An aggregation of NPs was observed when increasing the iron precursor dosage or prolonging the reaction time from 1 to 8 h. Most functionalities were removed and the magnetic NPs were partially converted to iron upon thermal treatment under a reducing condition. The GO and MP/GO nanocomposites reacted for one and two hours (denoted as MP/GO 1 -1 h and MP/GO 1 -2 h) were converted from insulator to semiconductor after the annealing treatment as annealed GO (A-GO, 8.86 S cm À1 ), annealed MP/GO 1 -1 h (A-MP/GO 1 -1 h, 7.48 Â 10 À2 S cm À1 ) and annealed MP/GO 1 -2 h (A-MP/GO 1 -2 h, 7.58 Â 10 À2 S cm À1 ). The saturation magnetization was also enhanced significantly after the annealing treatment, increased from almost 0 to 26.7 and 83.6 emu g À1 for A-MP/GO 1 -1 h and A-MP/GO 1 -2 h, respectively.