PlasmaChem (Germany)

The electroless copper plating of textiles, which have been previously printed with a catalyst, is a promising method to selectively metallise them to produce high-reliability e-textiles, sensors and wearable electronics with wide-ranging applications in high-value sectors such as healthcare, sport, and the military. In this study, polyester textiles were ink-jet printed using differing numbers of printing cycles and printing directions with a functionalised copper–silver nanoparticle catalyst, followed by electroless copper plating. The catalyst was characterised using Transmission Electron Microscopy (TEM) and Ultraviolet/Visible (UV/Vis) spectroscopy. The electroless copper coatings were characterised by copper mass gain, visual appearance and electrical resistance in addition to their morphology and the plating coverage of the fibres using Scanning Electron Microscopy (SEM). Stiffness, laundering durability and colour fastness of the textiles were also analysed using a stiffness tester and Launder Ometer, respectively. The results indicated that in order to provide a metallised pattern with the desired conductivity, stiffness and laundering durability for e-textiles, the printing design, printing direction and the number of printing cycles of the catalyst should be carefully optimised considering the textile’s structure. Achieving a highly conductive complete copper coating, together with an almost identical and sufficiently low stiffness on both sides of the textile can be considered as useful indicators to judge the suitability of the process.

The nanodiamonds (NDs) have attracted much attention in biomedical applications due to their excellent magnetic and optical properties. However, comprehensive study of different surfacemodified NDs on toxicity and differentiation of mesenchymal stem cells are very deficient. In this study, three types of NDs, i.e., ND-COOH, ND-NH+₃ and ND-PEG were co-cultured with rat bone mesenchymal stem cells (MSCs) to assess their biosafety and effects on differentiation. In a dry state, they had a similar diameter of about 6-7 nm, and aggregated into ˜100 nm (hydrodynamic size) in cell culture medium. Co-culture with MSCs showed that the ND-COOH and ND-PEG had lower cytotoxicity than ND-NH+₃. Alkaline comet assay showed slight genotoxicity for all the NDs regardless of their surface coatings. The reactive oxygen species (ROS) test showed that the cytotoxicity and genotoxicity of NDs may be attributed to the NDs-mediated intracellular oxidative stress. All the NDs did not show significant impact on the osteogenic differentiation of MSCs, whereas the ND-COOH and ND-PEG slightly impaired the adipogenic differentiation. Taken together, these findings provide some momentous implications for the design of surface chemical structures of NDs for their applications in biological field.

Drug delivery monitoring and trackingin the human body are twoof the biggest challenges in targeted therapy to be addressed by nanomedicine.The ability of imaging drugs and micro-/nanoengineered drug carriersand of visualizing their interactions at the cellular interface ina label-free manner is crucial in providing the ability of trackingtheir cellular pathways and will help understand their biologicalimpact, allowing thus to improve the therapeutic efficacy. We presenta fast, label-free technique to achieve high-resolution imaging atthe mid-infrared (MIR) spectrum that provides chemical information.Using our custom-made benchtop infrared microscope using a high-repetition-ratepulsed laser (80 MHz, 40 ps), we were able to acquire images withsubwavelength resolution (0.8 × λ) at very high speeds.As a proof-of-concept, we embarked on the investigation of nanoengineeredpolyelectrolyte capsules (NPCs) containing the anticancer drug, docetaxel.These NPCs were synthesized using a layer-by-layer approach builtupon a calcium carbonate (CaCO3) core, which was then removedaway with ethylenediaminetetraacetic acid. The obtained MIR imagesshow that NPCs are attached to the cell membrane, which is a goodstep toward an efficient drug delivery. This has been confirmed byboth three-dimensional confocal fluorescence and stimulated emissiondepletion microscopy. Coupled with additional instrumentation anddata processing advancements, this setup is capable of video-rateimaging speeds and will be significantly complementing current super-resolutionmicroscopy techniques while providing an unperturbed view into livingcells.

The electronic properties of graphenes depend sensitively on their deformation, and therefore strain engineered graphene electronics is envisioned. In order to deform graphenes locally, we have mechanically exfoliated single and few layer graphenes onto atomically flat mica surfaces covered with isolated double stranded plasmid DNA rings. Using scanning force microscopy in both contact and intermittent contact modes, we find that the graphenes replicate the topography of the underlying DNA with high precision. The availability of macromolecules of different topologies, e.g., programmable DNA patterns, render this approach promising for new graphene based device designs. On the other hand, the encapsulation of single macromolecules offers new prospects for analytical scanning probe microscopy techniques.

Ultrasound has been used to trigger release of encapsulated material from polyelectrolyte multilayer capsules. Sonication was found to destroy both plain and nanoparticle-modified capsules. Cavitation occurs through the collapse of generated microbubbles and the resulting shear forces should cause the destruction of the polyelectrolyte capsules. Application in catalysis is demonstrated in this paper, while further potential usage of ultrasound triggered release is anticipated in bio-medical applications.