Spatial Control of Neuronal Adhesion on Diamond-Like Carbon

This study reports a route to spatial control of neuronal adhesion onto Diamond-Like Carbon (DLC) by surface functionalisation by poly (oligo-ethyleneglycol methacrylate) (pOEGMA) and consequent laser ablation to produce cell adhesive tracks. DLC can be deposited as a tough and low friction coating on implantable devices and surgical instruments and has favourable properties for use as a biomaterial. The pOEGMA surface coating renders the DLC surface antifouling and the laser ablation creates graphitised tracks on the surface. The surfaces were coated with laminin, which adhered preferentially to the ablation tracks. The patterned surfaces were investigated for neuronal cell growth with NG108-15 cells for short term culture and rat neural stem cells for longer term culture. The cells initially adhered highly selectively to the ablation tracks while longer term cell culture revealed a more uniform cell coverage of the surface.

Electron-Beam-Induced Grafting of Chitosan onto HDPE/ATZ Composites for Biomedical Applications

The surface functionalisation of high-density polyethylene (HDPE) and HDPE/alumina-toughened zirconia (ATZ) surfaces with chitosan via electron-beam (EB) irradiation technique was exploited for preparing materials suitable for biomedical purposes. ATR–FTIR analysis and wettability measurements were employed for monitoring the surface changes after both irradiation and chitosan grafting reaction. Interestingly, the presence of ATZ loadings beyond 2 wt% influenced both the EB irradiation process and the chitosan functionalisation reaction, decreasing the oxidation of the surface and the chitosan grafting. The EB irradiation induced an increase in Young’s modulus and a decrease in the elongation at the break of all analysed systems, whereas the tensile strength was not affected in a relevant way. Biological assays indicated that electrostatic interactions between the negative charges of the surface of cell membranes and the –NH3+ sites on chitosan chains promoted cell adhesion, while some oxidised species produced during the irradiation process are thought to cause a detrimental effect on the cell viability.

Carbon-Based Coatings in Medical Textiles Surface Functionalisation: An Overview

The COVID-19 pandemic has further highlighted the need for antimicrobial surfaces, especially those used in a healthcare environment. Textiles are the most difficult surfaces to modify since their typical use is in direct human body contact and, consequently, some aspects need to be improved, such as wear time and filtration efficiency, antibacterial and anti-viral capacity, or hydrophobicity. To this end, several techniques can be used for the surface modification of tissues, being magnetron sputtering (MS) one of [hose that have been growing in the last years to meet the antimicrobial objective. The current state of the art available on textile functionalisation techniques, the improvements obtained by using MS, and the potential of diamond-like-carbon (DLC) coatings on fabrics for medical applications will be discussed in this review in order to contribute to a higher knowledge of functionalized textiles themes.

Pool boiling performance of laser-textured surfaces with time-dependent wettability

In last years, the direct laser texturing proved as environmentally friendly, scalable, flexible and efficient approach for surface functionalisation by creating appropriate surface features for enhanced boiling performance. When metal surface is laser-processed in open (oxygen-containing) atmosphere, it oxidizes and becomes (super)hydrophilic. However, it is well known that the wettability transition towards (super)hydrophobic state occur, if such a surface is exposed to the presence of hydrophobic contaminants. When water is used as a working fluid, this wettability transition can have a significant effect on nucleate boiling performance, which is investigated in this work.

Development of next generation nanomedicine-based approaches for the treatment of cancer: we've barely scratched the surface

Interest in nanomedicines has grown rapidly over the past two decades, owing to the promising therapeutic applications they may provide, particularly for the treatment of cancer. Personalised medicine and ‘smart’ actively targeted nanoparticles represent an opportunity to deliver therapies directly to cancer cells and provide sustained drug release, in turn providing overall lower off-target toxicity and increased therapeutic efficacy. However, the successful translation of nanomedicines from encouraging pre-clinical findings to the clinic has, to date, proven arduous. In this review, we will discuss the use of nanomedicines for the treatment of cancer, with a specific focus on the use of polymeric and lipid nanoparticle delivery systems. In particular, we examine approaches exploring the surface functionalisation of nanomedicines to elicit active targeting and therapeutic effects as well as challenges and future directions for nanoparticles in cancer treatment.

Preparation of oleylethylene glycol-sreptavidin surfaces for SPR v2

Surface plasmon resonance uses gold surfaces for sensing. Manufacturers provide a range of pre-functionalised surfaces, but these are often prone to non-specific binding problems. In other surface science sensing techniques a range of surface functionalisation approaches have been described. Here, the preparation of a self-assembled monolayer (SAM) of a thiolated oleyl ethylene glycol, incorporating a defined mole % of biotinylated ligands , on a gold surface is described. This allows the formation of a streptavidin layer on the SAM with control over the average surface coverage of streptavidin. Biotinylated ligands can then be immobilised on the streptavidin. Such surfaces have proved to be very resistant to non-specific binding and they are easily implemented on the sensor surfaces of commercial (surface plasmon resonance) SPR instruments. This is adapted from a published method: Migliorini, E. et al. Well-defined biomimetic surfaces to characterize glycosaminoglycan-mediated interactions on the molecular, supramolecular and cellular levels. Biomaterials (2014) doi:10.1016/j.biomaterials.2014.07.017.

Preparation of binary nanofluid with heat transfer additives by particle surface functionalisation

Current binary nanofluid synthesis methods with heat transfer additives lack an understanding of the chemistry of the nanoparticle-additive-base fluid interaction, which plays a significant role in the adsorption of the surfactant on the nanoparticle surface. Consequently, this leads to the formation of aggregates within the nanofluid after a couple of days, affecting the stability of the colloidal suspension. Here, a lithium bromide-alumina salt-based nanofluid is proposed following a newly developed synthesis method including particle surface functionalisation. The new procedure developed allows the initial preparation of the nanoparticles with the surfactant as the first step (surface functionalisation) and then the preparation of the base fluid with a dispersion stabilising agent (Gum Arabic) separately. This is then followed by the dispersion of the prepared alumina nanoparticles into the base fluid, by stirring and ultrasonication to produce the final nanofluid, lithium bromide-water (LiBr-H2O)-alumina nanofluid. Until now, proper procedures have not been reported for the nanofluid synthesis combining surfactant and dispersant and the chemistry of nanoparticles-surfactant-base fluid interaction, which was thoroughly investigated in the new approach. The fluid prepared by both the conventional and new procedures was characterised and analysed simultaneously. A thermal conductivity enhancement of 3% was achieved by using the surface functionalisation method, with greater particle concentration distribution (number of particles in suspension) of 22.7% over the conventional procedure. It also achieved a 5% decrease in dynamic viscosity. On the other hand, a Mouromtseff number value between 0.7 and 1.8 was obtained for the fluid at 293 K and 373 K temperature range, indicating a strong heat transfer capability. It was apparent from the particle size and concentration distribution analysis conducted that this procedure produced a more stable nanofluid with a high distribution of nanoparticles within the fluid. This allows high improvement of thermal properties of the fluid. Graphical abstract Graphical abstract of a new procedure for nanofluid synthesis with heat transfer additives using the two-step method

Bioactive Plasma Coatings on Orthodontic Brackets: In Vitro Metal Ion Release and Cytotoxicity

The metal ion release characteristics and biocompatibility of meta-based materials are key factors that influence their use in orthodontics. Although stainless steel-based alloys have gained much interest and use due to their mechanical properties and cost, they are prone to localised attack after prolonged exposure to the hostile oral environment. Metal ions may induce cellular toxicity at high dosages. To circumvent these issues, orthodontic brackets were coated with a functional nano-thin layer of plasma polymer and further immobilised with enantiomers of tryptophan. Analysis of the physicochemical properties confirmed the presence of functional coatings on the surface of the brackets. The quantification of metal ion release using mass spectrometry proved that plasma functionalisation could minimise metal ion release from orthodontic brackets. Furthermore, the biocompatibility of the brackets has been improved after functionalisation. These findings demonstrate that plasma polymer facilitated surface functionalisation of orthodontic brackets is a promising approach to reducing metal toxicity without impacting their bulk properties.

Biofunctionalisation of Gallium Arsenide with Neutravidin

<div>We report a study presenting a physicochemical surface characterisation of the GaAs surface along the functionalisation with a high-affinity bioconjugation pair widely explored in the life</div><div>sciences: biotin and neutravidin. Combined X-ray photoelectron spectroscopy (XPS), wettability measurements and spectroscopic ellipsometry were used for a reliable characterisation of the surface functionalisation process. The results suggest that a film with a thickness lower than 10nm was formed, with a neutravidin to biotin ratio of 1:25 on the GaAs surface. Reduction of non-specific binding of the protein to the surface was achieved by optimising the protein buffer and rinsing steps. This study shows the feasibility of using GaAs as a platform for specific biomolecular recognition, paving the way to a new generation of optoelectronic biosensors.</div>

Biofunctionalisation of Gallium Arsenide with Neutravidin

<div>We report a study presenting a physicochemical surface characterisation of the GaAs surface along the functionalisation with a high-affinity bioconjugation pair widely explored in the life</div><div>sciences: biotin and neutravidin. Combined X-ray photoelectron spectroscopy (XPS), wettability measurements and spectroscopic ellipsometry were used for a reliable characterisation of the surface functionalisation process. The results suggest that a film with a thickness lower than 10nm was formed, with a neutravidin to biotin ratio of 1:25 on the GaAs surface. Reduction of non-specific binding of the protein to the surface was achieved by optimising the protein buffer and rinsing steps. This study shows the feasibility of using GaAs as a platform for specific biomolecular recognition, paving the way to a new generation of optoelectronic biosensors.</div>