Recent years have witnessed many breakthroughs in research on graphene (the first two-dimensional atomic crystal) as well as a significant advance in the mass production of this material. This one-atom-thick fabric of carbon uniquely combines extreme mechanical strength, exceptionally high electronic and thermal conductivities, impermeability to gases, as well as many other supreme properties, all of which make it highly attractive for numerous applications. Here we review recent progress in graphene research and in the development of production methods, and critically analyse the feasibility of various graphene applications.

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A roadmap for graphene

Nanotechnology has the potential to revolutionize cancer diagnosis and therapy. Advances in protein engineering and materials science have contributed to novel nanoscale targeting approaches that may bring new hope to cancer patients. Several therapeutic nanocarriers have been approved for clinical use. However, to date, there are only a few clinically approved nanocarriers that incorporate molecules to selectively bind and target cancer cells. This review examines some of the approved formulations and discusses the challenges in translating basic research to the clinic. We detail the arsenal of nanocarriers and molecules available for selective tumour targeting, and emphasize the challenges in cancer treatment.

Nanocarriers as an emerging platform for cancer therapy

Nanocrystals are fundamental to modern science and technology. Mastery over the shape of a nanocrystal enables control of its properties and enhancement of its usefulness for a given application. Our aim is to present a comprehensive review of current research activities that center on the shape-controlled synthesis of metal nanocrystals. We begin with a brief introduction to nucleation and growth within the context of metal nanocrystal synthesis, followed by a discussion of the possible shapes that a metal nanocrystal might take under different conditions. We then focus on a variety of experimental parameters that have been explored to manipulate the nucleation and growth of metal nanocrystals in solution-phase syntheses in an effort to generate specific shapes. We then elaborate on these approaches by selecting examples in which there is already reasonable understanding for the observed shape control or at least the protocols have proven to be reproducible and controllable. Finally, we highlight a number of applications that have been enabled and/or enhanced by the shape-controlled synthesis of metal nanocrystals. We conclude this article with personal perspectives on the directions toward which future research in this field might take.

Shape‐Controlled Synthesis of Metal Nanocrystals: Simple Chemistry Meets Complex Physics?

We investigated the intracellular uptake of different sized and shaped colloidal gold nanoparticles. We showed that kinetics and saturation concentrations are highly dependent upon the physical dimensions of the nanoparticles (e.g., uptake half-life of 14, 50, and 74 nm nanoparticles is 2.10, 1.90, and 2.24 h, respectively). The findings from this study will have implications in the chemical design of nanostructures for biomedical applications (e.g., tuning intracellular delivery rates and amounts by nanoscale dimensions and engineering complex, multifunctional nanostructures for imaging and therapeutics).

Determining the size and shape dependence of gold nanoparticle uptake into mammalian cells.

The selection of nanoparticles for achieving efficient contrast for biological and cell imaging applications, as well as for photothermal therapeutic applications, is based on the optical properties of the nanoparticles. We use Mie theory and discrete dipole approximation method to calculate absorption and scattering efficiencies and optical resonance wavelengths for three commonly used classes of nanoparticles:  gold nanospheres, silica−gold nanoshells, and gold nanorods. The calculated spectra clearly reflect the well-known dependence of nanoparticle optical properties viz. the resonance wavelength, the extinction cross-section, and the ratio of scattering to absorption, on the nanoparticle dimensions. A systematic quantitative study of the various trends is presented. By increasing the size of gold nanospheres from 20 to 80 nm, the magnitude of extinction as well as the relative contribution of scattering to the extinction rapidly increases. Gold nanospheres in the size range commonly employed (∼40 nm)...

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Calculated Absorption and Scattering Properties of Gold Nanoparticles of Different Size, Shape, and Composition: Applications in Biological Imaging and Biomedicine

Using an acousto-optic modulator that froze beam positions on frames captured by an ordinary CCD camera, we were able to calibrate the Lissajous scanning pattern on a fiber-optic nonlinear endomicroscope quickly and precisely.

Lissajous Scanning Fiber-optic Nonlinear Endomicroscope with Precise Position Calibration

Summary form only given. Optical coherence tomography (OCT) is an emerging technique for micron-scale cross-sectional imaging of biological tissue. High resolution detection of reflected or backscattering light is performed using low coherence interferometry. High nonlinearity, air-silica microstructure fibers or tapered fibers can generate an extremely broadband continuum using low energy femtosecond pulses. This is achieved by the anomalous dispersion characteristics of the fibers which shift the zero dispersion wavelength to shorter wavelengths and small core diameters which provide a tight mode confinement. We recently demonstrated ultrahigh resolution OCT using an air-silica microstructure fiber as light source in the spectral region between 1.2 /spl mu/m and 1.5 /spl mu/m with an axial resolution of 2.5 /spl mu/m at 1.3 /spl mu/m center wavelength. In this paper we demonstrate an extension of this method to broadband spectroscopically resolved OCT imaging.

Imaging water absorption wrth spectroscopie optical coherence tomography

We report an all-fiber-optic approach for beam delivery, collection, scanning and dispersion management in a microendoscope for nonlinear optical imaging. Preliminary result of ex vivo rat tail tendon imaging is presented.

Flexible Scanning MicroEndoscope for Two-photon Fluorescence and SHG Imaging

Temporal characterization of bone regeneration induced by angiogenic and osteoinductive hydrogel scaffolds

We show that spectral-domain optical coherence tomography can monitor blood flow in and around the wound bed during the cutaneous wound healing process in a mouse model.

Xingde Li

Papers

Lissajous Scanning Fiber-optic Nonlinear Endomicroscope with Precise Position Calibration

Imaging water absorption wrth spectroscopie optical coherence tomography

Flexible Scanning MicroEndoscope for Two-photon Fluorescence and SHG Imaging

Temporal characterization of bone regeneration induced by angiogenic and osteoinductive hydrogel scaffolds

Functional assessment of cutaneous wound healing using spectral-domain optical doppler tomography