Deagglomeration of DNA nanomedicine carriers using controlled ultrasonication.

Control over the agglomeration state of manufactured particle systems for drug and oligonucleotide intracellular delivery is paramount to ensure reproducible and scalable therapeutic efficacy. Ultrasonication is a well-established mechanism for the deagglomeration of bulk powders in dispersion. Its use in manufacturing requires strict control of the uniformity and reproducibility of the cavitation field within the sample volume to minimise within-batch and batch-to-batch variability.

Composition, thickness, and homogeneity of the coating of core-shell nanoparticles-possibilities, limits, and challenges of X-ray photoelectron spectroscopy.

Core-shell nanoparticles have attracted much attention in recent years due to their unique properties and their increasing importance in many technological and consumer products. However, the chemistry of nanoparticles is still rarely investigated in comparison to their size and morphology. In this review, the possibilities, limits, and challenges of X-ray photoelectron spectroscopy (XPS) for obtaining more insights into the composition, thickness, and homogeneity of nanoparticle coatings are discussed with four examples: CdSe/CdS quantum dots with a thick coating and a small core; NaYF-based upconverting nanoparticles with a large Yb-doped core and a thin Er-doped coating; and two types of polymer nanoparticles with a poly(tetrafluoroethylene) core with either a poly(methyl methacrylate) or polystyrene coating.

Exposure of mass-selected bimetallic Pt-Ti nanoalloys to oxygen explored using scanning transmission electron microscopy and density functional theory.

The response of nanoparticles to exposure to ambient conditions and especially oxidation is fundamental to the application of nanotechnology. Bimetallic platinum-titanium nanoparticles of selected mass, 30 kDa and 90 kDa, were produced using a magnetron sputtering gas condensation cluster source and deposited onto amorphous carbon TEM grids. The nanoparticles were analysed with a C-corrected Scanning Transmission Electron Microscope (STEM) in High Angle Annular Dark Field (HAADF) mode.

Analysis of protein coatings on gold nanoparticles by XPS and liquid-based particle sizing techniques.

The precise use of nanoparticles in technological applications requires control over their surface properties. This implies the ability to quantitatively describe, for example, molecular coatings in terms of their thickness, areal mass, or number of molecules. Here, the authors describe two different approaches to the measurement of these parameters by using gold nanoparticles ranging in diameter from 10 to 80 nm and coated with three different proteins: immunoglobulin G, bovine serum albumin, and a peptide.

Depth resolution, angle dependence, and the sputtering yield of Irganox 1010 by coronene primary ions.

A study is reported of the depth resolution and angle dependence of sputtering yields using the reference organic material, Irganox 1010, for a new coronene(+) depth profiling ion source at 8 and 16 keV beam energies. This source provides excellent depth profiles as shown by 8.5 nm marker layers of Irganox 3114.

Chemical and biological characterisation of a sensor surface for bioprocess monitoring.

This paper describes the step-wise fabrication and characterisation of a multi-layer dual polarization interferometry (DPI) based biosensor utilising Protein G (ProG) as the bio-recognition layer for the detection of a fragment antibody (Fab'). The biosensor is capable of monitoring the concentration of Fab' product within the extracellular medium of a fed-batch fermentation after leakage from Escherichia coli (E.coli).

Simplifying the delivery of melanocytes and keratinocytes for the treatment of vitiligo using a chemically defined carrier dressing.

Obtaining pigmentary function in autologous skin grafts is a current challenge for burn surgeons as is developing reliable robust grafting strategies for patients with vitiligo and piebaldism. In this paper, we present the development of a simple methodology for delivering cultured keratinocytes and melanocytes to the patient that is of low risk for the patient but also user friendly for the surgeon. In this study, we examined the ability of keratinocytes and melanocytes to transfer from potential cell carriers under different media conditions to an in vitro human wound bed model.

The effect of positive ion energy on plasma polymerization: a comparison between acrylic and propionic acids.

Using a novel RF biasing technique, the energy of positive ions at a depositing substrate is controlled, independently of other parameters. Under bias conditions which gave the maximum and minimum ion energies, plasmas of propionic and acrylic acid were investigated using mass spectrometry, an ion flux probe, quartz crystal microbalance, and X-ray photoelectron spectroscopy (XPS). For both compounds investigated, the ion energy affects the deposition rate but leaves the neutral gas-phase chemistry and positive ion fluxes unchanged.

A chemically defined surface for the co-culture of melanocytes and keratinocytes.

Patients with stable vitiligo can be helped surgically using transplantation of autologous cultured melanocytes, but there is a need for a culture methodology that is free from xenobiotic agents and for a simple way of delivering cultured melanocytes to the patient to achieve pigmentation with good wound healing. The aim of this study was to develop a chemically defined surface, suitable for the co-culture of melanocytes and keratinocytes which could be used in the future for the treatment vitiligo patients to achieve both restoration of pigmentation and good wound healing. Two keratinocyte growth media and two melanocyte growth media were compared; two of these were serum free.