Image-guided drug delivery of nanotheranostics for targeted lung cancer therapy.

Enormous efforts have been made to integrate various therapeutic interventions into multifunctional nanoplatforms, resulting in the advance of nanomedicine. Image-guided drug delivery plays a pivotal role in this field by providing specific targeting as well as image navigation for disease prognosis. Methods: We demonstrate image-guided surgery and drug delivery for the treatment of lung cancer using nanotheranostic H-dots loaded with gefitinib and genistein. Results: The surgical margin for lung tumors is determined by image guidance for precise tumor resection, while targeted anti-cancer drugs function simultaneously for synergistic combination therapy. Compared to conventional chemotherapies, H-dot complexes could improve the therapeutic efficacy of drugs while reducing the risk of adverse effects and drug resistance owing to their ideal biodistribution profiles, high targetability, low nonspecific tissue uptake, and fast renal excretion. Conclusions: These H-dot complexes have unlocked a unique framework for integrating multiple therapeutic and diagnostic modalities into one nanoplatform.

Injectable Thermosensitive Hydrogels for a Sustained Release of Iron Nanochelators.

Deferoxamine (DFO) is an FDA-approved iron-chelating agent which shows good therapeutic efficacy, however, its short blood half-life presents challenges such as the need for repeated injections or continuous infusions. Considering the lifelong need of chelating agents for iron overload patients, a sustained-release formulation that can reduce the number of chelator administrations is essential. Here, injectable hydrogel formulations prepared by integrating crosslinked hyaluronic acid into Pluronic F127 for an extended release of DFO nanochelators are reported. The subcutaneously injected hydrogel shows a thermosensitive sol-gel transition at physiological body temperature and provides a prolonged release of renal clearable nanochelators over 2 weeks, resulting in a half-life 47-fold longer than that of the nanochelator alone. In addition, no chronic toxicity of the nanochelator-loaded hydrogel is confirmed by biochemical and histological analyses. This injectable hydrogel formulation with DFO nanochelators has the potential to be a promising formulation for the treatment of iron overload disorders.

Nondestructive Characterizations of Au-Catalyzed GaAs Nanowires on GaAs(111)B Substrates via Identifications of 1st Order Optical Phonon Modes Using µ-Raman Spectroscopy.

We report the relation between the catalyst patterning conditions and the intensity of the 1st order Raman active modes in Au-catalyzed GaAs nanowire bundles. We fabricated e-beam lithographically Au-patterned GaAs(111)B substrates by varying the patterning conditions (e-beam dose rate, dot-size and interdot-spacings), and grew GaAs nanowires via vapor-liquid-solid process using a solid-source molecular beam epitaxy. To understand the effects of the substrate preparation conditions and resulting morphologies on the optical characteristics of 1st order transverse optical and longitudinal optical phonon modes of GaAs, we characterized the nanowire bundles using complementary µ-Raman spectroscopy and scanning electron microscopy as a function of the e-beam dose rate (145-595 µC/cm²), inter-dot spacing (100 and 150 nm) and pattern size (100 and 150 nm). Ensembles of single crystalline GaAs nanowires covered with different Au-thickness exhibit a downshift and asymmetric broadening of the 1st order transverse optical and longitudinal optical phonon peaks relative to GaAs bulk modes. We also showed that the sensitivity of a downshift and broadening of Raman spectra are directly related to morphological and surface coverage variations in as-grown nanowires. We observed clear increases of the transverse optical and longitudinal optical intensity as well as the relatively higher peak shift and broadening of Raman spectra from the 100 nm patterning in response to the dose rate change. Strong dependence of Raman spectra of the nanowire bundles on the e-beam dose rate changes are attributed to the variations in spatial density, size, shape and random growth orientation of the wires. We have shown that the identification of the changes in GaAs longitudinal optical and Arsenic anti-site peaks is good indicators to characterize the quality of as-grown GaAs nanowires. Our finding confirms the utilization of Raman spectroscopy as a powerful tool for characterizing chemical, structural, and morphological information of as-grown nanowires within the supporting substrate.

Effects of Density and Diameter on Surface Optical Phonon Modes in GaAs Nanowire Bundles.

We report the systematic investigation of the surface optical phonon modes in Au-catalyzed GaAs nanowires grown on an Au pre-patterned GaAs(111)B substrate using µ-Raman spectroscopy. We employed electron-beam dose rate as a control parameter during the substrate patterning step for adjusting the nanowire base diameter and coverage, which are independent from the nanowire growth conditions. We have experimentally studied the effect of the fill factor and average diameter on the surface optical phonon modes and explained the red-shift and broadening of the surface optical phonon frequencies by employing the dielectric continuum model. The surface optical phonon mode shift is exhibited to be sensitive to fill factor, rather than base diameter. The decrease in the average diameter from 280 nm to 180 nm results in the asymmetric broadening and red-shift of the surface optical phonon frequency (~1.83 cm-1) but the theoretical calculation from the isolated single nanowire-based dielectric continuum model cannot solely explain the behaviors of the surface optical phonon mode. In contrast, the change in the fill factor from 0.01 to 0.83 results in a shift of the surface optical phonon frequency (~6.5 cm-1) from the GaAs bulk value. The red-shift and asymmetric broadening of the surface optical phonons, in an agreement with the Maxwell-Garnett approximation, are consequences of dipolar interaction of randomly aligned neighboring nanowires and the polar nature of GaAs nanowire bundles. This work suggests the pre-patterning parameter dependent surface optical phonon characteristics of GaAs nanowire bundles which are of great importance in the nondestructive characterization of low-dimensional opto-electronic materials and devices.

Micro-Raman Spectroscopy in Self-Catalyzed Indium Phosphide Nanostructures: Morphology and Substrate Effects.

We report the effect of morphology and substrate of self-catalyzed indium phosphide (InP) nanostructures on phonon vibration modes. Using liquid indium as a catalyst, we grew self-catalyzed InP nanocones and nanopillars on single crystal substrates of InP(111)B, Si(111), and Si(100) via metal-organic chemical vapor epitaxy. Due to crystal symmetry breaking in one-dimensional nanostructure, longitudinal-optical (LO) and transverse-optical (TO) phonon modes are clearly resolved with the strong anisotropic behavior. Broadening and downshift of LO phonon modes are found to be sensitive to the morphology (i.e., aspect ratio and surface-to-volume ratio) and crystal structure (i.e., Wurtzite and Zinc Blende) of the as-grown nanostructures. This work demonstrated that Raman spectroscopy provides statistical insights on the quality of as-grown nanostructures (i.e., growth orientation, crystal structures, and the presence of structural defects) without destroying samples.

Thermal evolution characterizatics of atomic layer deposition prepared TiO2 interfacial layer by synchrotron radiation X-ray scattering.

TiO2 thin film prepared by the atomic layer deposition (ALD) with supplies of Ti(O-i-Pr)4 and H2O have been analyzed using the difference X-ray reflectivity (DXRR). The thickness of buried interfacial layer (IL) embedded in between Si-substrate and TiO2 layer was characterized as a function of temperatures of 20, 300, and 500 degrees C mounted on an in-situ hot stage The growth rate of TiO2 film was estimated to be 0.5 nm/cycle at the temperature of 150 degrees C. It was identified that the interfacial layer of the treated thin film was disappeared at a certain temperature rise. Furthermore, we found that the crystalline structure of TiO2 film was varied depending on not only the growth temperature but also the post thermal treatment of the samples. Since the synchrotron radiation X-ray scattering measurement allow us to investigate the atomic structure evolution in the range of a few nanometer thick, nondestructively, in this letter we report its characteristics of the thermal evolution of the TiO2 interfacial layer that is the crucial step for progress in microelectronics and nanotechnology.

E-beam deposited Ag-nanoparticles plasmonic organic solar cell and its absorption enhancement analysis using FDTD-based cylindrical nano-particle optical model.

We report the plasmon-assisted photocurrent enhancement in Ag-nanoparticles (Ag-NPs) embedded PEDOT:PSS/P3HT:PCBM organic solar cells, and systematically investigate the causes of the improved optical absorption based on a cylindrical Ag-NPs optical model which is simulated with a 3-Dimensional finite difference time domain (FDTD) method. The proposed cylindrical Ag-NPs optical model is able to explain the optical absorption enhancement by the localized surface plasmon resonance (LSPR) modes, and to provide a further understanding of Ag-NPs shape parameters which play an important role to determine the broadband absorption phenomena in plasmonic organic solar cells. A significant increase in the power conversion efficiency (PCE) of the plasmonic solar cell was experimentally observed and compared with that of the solar cells without Ag-NPs. Finally, our conclusion was made after briefly discussing the electrical effects of the fabricated plasmonic organic solar cells.

Reduction of scattering loss of silicon slot waveguides by RCA smoothing.

Because of stronger optical confinement density, silicon slot waveguides tend to have higher scattering loss than normal ridge waveguides with same sidewall roughness. A wet chemical process is found to be highly effective in reducing the surface roughness and scattering loss. A reduction in scattering loss by 10.2 dB/cm for TE and 8.5 dB/cm for TM polarizations has been achieved.

A review of 1985 Volvo Award winner in clinical science: objective assessment of spine function following industrial injury: a prospective study with comparison group and 1-year follow-up.

It is now 2 decades since Mayer et al published their Volvo Award-winning paper entitled "Objective assessment of spine function following industrial injury: a prospective study with comparison group and one-year follow-up." Their landmark paper reported that return to work rates of patients that underwent a "functional restoration" treatment program were double that of a comparative group of patients that were denied treatment by their insurers. These results were considered extraordinary and inspired both debate and enthusiasm. Our goal is to review this landmark study, report on its strengths and weaknesses, and review the studies that have attempted to replicate this work in other settings. We also highlight its contribution to our current knowledge about the treatment of back pain and disability. The major weaknesses of the paper of Mayer et al are the possibility of selection bias in the development of their cohort of patients and the lack of a true randomized controlled study design. These factors may have inflated the rates of return to work. Regardless, their reported results were robust, and cannot be easily dismissed. During the last 20 years, this treatment model has received considerable study worldwide, and it is generally agreed that it is superior to standard care for reducing work absence in patients with chronic low back pain. Additionally, the concepts underlying functional restoration have been found to be highly relevant to patients with chronic low back pain, medical providers, and disability systems and continue to gain acceptance and integration into the care of patients throughout the industrialized world.