Computational characterization of reflectance confocal microscopy features reveals potential for automated photoageing assessment.

Skin photoageing results from a combination of factors including ultraviolet (sun) exposure, leading to significant changes in skin morphology and composition. Conventional methods assessing the degree of photoageing, in particular histopathological assessment involve an invasive multistep process. Advances in microscopy have enabled a shift towards non-invasive in vivo microscopy techniques such as reflectance confocal microscopy (RCM) in this context.

A modular design of low-background bioassays based on a high-affinity molecular pair barstar:barnase.

High-affinity molecular pairs provide a convenient and flexible modular base for the design of molecular probes and protein/antigen assays. Specificity and sensitivity performance indicators of a bioassay critically depend on the dissociation constant (K(D)) of the molecular pair, with avidin:biotin being the state-of-the-art molecular pair (K(D) ∼ 1 fM) used almost universally for applications in the fields of nanotechnology and proteomics. In this paper, we present an alternative high-affinity protein pair, barstar:barnase (K(D) ∼ 10 fM), which addresses several shortfalls of the avidin:biotin system, including non-negligible background due to the non-specific binding.

Characterization of optical properties of ZnO nanoparticles for quantitative imaging of transdermal transport.

Widespread applications of ZnO nanoparticles (NP) in sun-blocking cosmetic products have raised safety concerns related to their potential transdermal penetration and resultant cytotoxicity. Nonlinear optical microscopy provides means for high-contrast imaging of ZnO NPs lending in vitro and in vivo assessment of the nanoparticle uptake in skin, provided their nonlinear optical properties are characterized. We report on this characterization using ZnO NP commercial product, Zinclear, mean-sized 21 nm.

Scar tissue classification using nonlinear optical microscopy and discriminant analysis.

This paper addresses the scar tissue maturation process that occurs stepwise, and calls for reliable classification. The structure of collagen imaged by nonlinear optical microscopy (NLOM) in post-burn hypertrophic and mature scar, as well as in normal skin, appeared to distinguish these maturation steps. However, it was a discrimination analysis, demonstrated here, that automated and quantified the scar tissue maturation process.

Pharmacological characterization of a recombinant, fluorescent somatostatin receptor agonist.

Somatostatin (SST) is a peptide neurotransmitter/hormone found in several mammalian tissue types. Apart from its natural importance, labeled SST/analogues are utilized in clinical applications such as targeting/diagnosis of neuroendocrine tumors. We report on the development and characterization of a novel, recombinant, fluorescent somatostatin analogue that has potential to elucidate somatostatin-activated cell signaling.

Sculpted substrates for SERS.

Sculpted SERS-active substrates are prepared by assembling a closed packed monolayer of uniform polystyrene colloidal particles (diameter 350 to 800 nm) onto an evaporated gold surface and then electrodepositing gold through this template to produce films with controlled thicknesses, measured as fractions of the sphere diameter, d. The resulting surfaces consist of a regular hexagonal array of interconnected spherical cross-section dishes. The role of localised plasmons in determining the SERS enhancement factor obtained for benzene thiol adsorbed onto the surfaces is then investigated by correlation of the UV-visible reflectance spectra, 400 to 900 nm, measured at the same positions on the substrate surfaces, with the SERS spectra.

Angle-resolved surface-enhanced Raman scattering on metallic nanostructured plasmonic crystals.

Surface-enhanced Raman scattering is an ideal tool for identifying molecules from the "fingerprint" of their molecular bonds; unfortunately, this process lacks a full microscopic understanding and, practically, is plagued with irreproducibility. Using nanostructured metal surfaces, we demonstrate strong correlations between plasmon resonances and Raman enhancements. Evidence for simultaneous ingoing and outgoing resonances in wavelength and angle sheds new light on the Raman enhancement process, allowing optimization of a new generation of reproducible Raman substrates.