Small-cell lung cancer, a highly malignant form of lung cancer, often responds to first-line treatments but relapses in most cases with resistance to further treatments. We tested zinc oxide (ZnO) nanoparticles against small-cell lung cancer and other cancer cell lines, in light of reported anticancer effects in vitro. Because of a strong safety record, ZnO nanoparticles are frequently used in biomedical research, including in cellular imaging and drug delivery, and have been used for many years in several commercial products such as skin care agents. Strikingly, ZnO nanoparticles were genotoxic against small-cell lung cancer cells, resulting in low viability, even in cells orthotopically grafted onto mouse models. However, the nanoparticles were less cytotoxic against normal lung-derived cells and did not elicit observable adverse effects after intravenous administration. ZnO nanoparticles were also found to induce highly reactive oxygen species and DNA leakage from nuclei. This study is the first comprehensive evaluation of the anticancer effects of ZnO nanoparticles in vitro and in vivo and highlights new therapeutic opportunities against small-cell lung cancer.

Raman spectroscopy is commonly used in chemistry to identify molecular structure. This technique is a nondestructive analysis and needs no sample preparation. Recently, Raman spectroscopy has been shown to be effective as a multipurpose analytical method for forensic applications. In the present study, blood identification and discrimination between human and nonhuman blood were performed by a portable Raman spectrometer, which can be used at a crime scene. To identify the blood and to discriminate between human and nonhuman blood, Raman spectra of bloodstains from 11 species (human, rat, mouse, cow, horse, sheep, pig, rabbit, cat, dog, and chicken) were taken using a portable Raman spectrometer. Raman peaks for blood (742, 1001, 1123, 1247, 1341, 1368, 1446, 1576, and 1619 cm) could be observed by the portable Raman spectrometer in all 11 species, and the human bloodstain could be distinguished from the nonhuman ones by using a principal component analysis. This analysis can be performed on a bloodstain sample of at least 3 months old. The portable Raman spectrometer can be used at a crime scene, and this analysis is useful for forensic examination.

Hydrogen related local vibrational modes (LVMs) of ZnO nanoparticles have been studied using Fourier transform infrared spectroscopy and Raman spectroscopy in as prepared and high temperature annealed samples. The obtained experimental results confirm the presence of cationic vacancies (VZn) in addition to unintentional hydrogen doping and their complex defects such as VZn–Hi and VZn–HO. After high temperature annealing, hydrogen related LVMs and multiphonon modes disappear. The presence of these complex defects determines the nonradiative and multiphonon recombination processes in the band gap of ZnO due to carrier trapping at deep levels.

ZnO nanoparticles were prepared by using a gas evaporation method. As ZnO is a luminescent and less toxic material, it can be useful in imaging applications. The nanoparticles prepared in our laboratory showed intense exciton emission in the UV‐blue region. They were processed and surface treated to be compatible for bio‐conjugation. We were able to prepare good dispersions and water‐soluble ZnO nanoparticles from our experiments. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

The defect and impurity states in ZnO nanocrystals synthesized using the plasma arc technique can be modified to optimize the nonlinear optical properties for optoelectronic and biophotonic applications. Highly efficient second harmonic signals over a wide range of near-infrared wavelengths, spanning from 735 nm-980 nm, has been observed and can be used in biological imaging. The use of further high energy excitation ranging from 700 nm-755 nm leads to two-photon absorption and yields broadband two photon emission extending from the 370 nm-450 nm wavelength regime which can be useful for therapeutic applications.