Increasing Antibiotic Susceptibility: The Use of Cationic Gold Nanoparticles in Gram-Negative Bacterial Membrane Models.

Antibiotic resistance will be one of the most prominent challenges to health-care systems in the coming decades, with the OECD predicting that up to 2.4 million deaths will be caused between 2015 and 2050 by drug-resistant bacterial infections in first-world countries alone, with infections costing health-care systems billions of dollars each year. Developing new methods to increase bacterial susceptibility toward drugs is an important step in treating resistant infections. Here, the synergistic effects of gold nanoparticles and the antibiotic drug colistin sulfate have been examined. A tethered lipid bilayer membrane was used to mimic a Gram-negative bacterial cell membrane. Exposing the membrane to gold nanoparticles prior to adding the antibiotic significantly increased the effect of the antibiotic on the membrane. Cationic gold nanoparticles could thus be used to enhance bacterial susceptibility to antibiotics, leading to a more potent treatment.

A tethered bilayer lipid membrane that mimics microbial membranes.

A model membrane system has been developed, which mimics the outer membrane of Gram negative bacteria. The structure is based on a tethered monolayer which has been fused with vesicles containing lipopolysaccharide molecules. The effect of the composition of the monolayer and the lipids in the outer layer on the structural and electrical properties of the membrane has been investigated. By using electrochemical impedance spectroscopy as well as neutron scattering techniques, it could be shown that a relatively high tethering density and a small amount of diluting lipids in the outer membrane leaflet leads to the formation of a stable solid supported membrane. The influence of divalent ions on the membrane stability has been probed as well as the interaction of the bilayer with the antibiotic colistin. A number of different architectures were developed, suited to both the study of bacterial membrane proteins and the screening of antimicrobial activity of potential drug candidates.

Artistic and Health Professionals' Perceptions of Training Load Practices in Pre-Professional and Professional Ballet and Contemporary Dance: A Cross-Sectional Survey.

This study aimed to investigate the perceptions of training load practices of dance artistic and health professionals. Artistic staff and health professionals with experience in dance were invited to participate in a cross-sectional survey study relating to training load practices in pre-professional and professional, ballet and contemporary dance. The survey was developed from previous investigations in soccer and consisted of multiple-choice, Likert scale, and free-text responses. Responses to closed questions were reported by percentage and 95% confidence intervals (95% CI). Thematic analysis was performed by two independent assessors of free-text responses. There were six artistic staff and 18 health professional participants. Artistic staff were perceived to be "mostly/completely responsible" for planning training (artistic staff: 100%, 95% CI: 61%, 100%; health professionals: 94%, 95% CI: 76%, 100%), with health professionals "mostly/completely responsible" at times of injury (artistic staff: 83%, 95% CI: 41%, 99%; health professionals: 95% CI: 61%, 96%). Both groups reported using individual modification to manage training loads and recognized the benefits of rest. Artistic staff recognized the need to modify training when injured, in line with experience levels, workload, age, and general health. Both groups "agree/strongly agree" that monitoring would be or is useful (artistic staff: 83%, 95% CI: 41%, 99%; health professionals: 95% CI: 61%, 96%). This investigation provides insight into the perceptions of artistic staff and health professionals with experience in dance toward training practices. Artistic staff and health professionals need to work together and adapt monitoring practices to their context to support artistic staff in planning training. The findings guide the implementation of these interventions by understanding potential barriers to their effectiveness that may potentially reduce injury.

Biomedical applications of polyelectrolyte coated spherical gold nanoparticles.

Surface modified gold nanoparticles are becoming more and more popular for use in biomaterials due to the possibility for specific targeting and increased biocompatibility. This review provides a summary of the recent literature surrounding polyelectrolyte coatings on spherical gold nanoparticles and their potential biomedical applications. The synthesis and layer-by layer coating approach are briefly discussed together with common characterisation methods. The potential applications and recent developments in drug delivery, gene therapy, photothermal therapy and imaging are summarized as well as the effects on cellular uptake and toxicity. Finally, the future outlook for polyelectrolyte coated gold nanoparticles is explored, focusing on their use in biomedicine.

Ballet and Contemporary Dance Injuries When Transitioning to Full-Time Training or Professional Level Dance: A Systematic Review.

This systematic review examines the relationship between injury and two stages of a dancer's career development: when transitioning to full-time training and to a professional dance company. The findings are discussed in relation to managing transitioning loads with regard to injury prevention. Six electronic databases (PubMed, Embase, CINAHL, SPORTDiscus, Scopus, and Performing Arts Periodicals Database) were searched from inception to July 2018, inclusive of English language peer reviewed studies investigating injury in pre-professional and professional ballet and contemporary dancers. Seventeen studies met the inclusion criteria. "Limited" evidence revealed that dancers transitioning to professional ballet had a significantly higher rate of time-loss injuries per exposure hour relative to established professionals, whereas transitioning professional contemporary dancers had a significantly lower rate of both medical-attention and time-loss injuries. "Limited" evidence also showed a decreased rate and trend toward lower prevalence rates for time-loss injuries per exposure hour for transitioning ballet students and an increased rate of medical-attention injury in a combined cohort of transitioning ballet and contemporary dance students. Thus, this review provides some evidence that injuries tend to occur as dancers are transitioning to full-time ballet or contemporary dance training or to professional careers.

Nanoparticles in an antibiotic-loaded nanomesh for drug delivery.

Antibiotic loaded nanomeshes were fabricated by electrospinning polycaprolactone, a biocompatible polymer, with 12.5% w/w Colistin, 1.4% w/w Vancomycin and either cationic or anionic gold nanoparticles in varying combinations. The resulting nanomeshes had different antibiotic release profiles, with citrate capped gold nanoparticles combined with Colistin having the highest sustained release over 14 days for a 4 mg, 1.5 cm2 nanomesh. The electrospinning parameters were optimised to ensure the spinning of a homogenous mesh and the addition of antibiotics was confirmed through 1H NMR and ATR-FTIR. This research, as a proof of concept, suggests an opportunity for fabricating nanomeshes which contain gold nanoparticles as a drug release mechanism for antibiotics.

Polyelectrolyte-Coated Gold Nanoparticles: The Effect of Salt and Polyelectrolyte Concentration on Colloidal Stability.

Gold nanoparticles are widely used in biomedical applications. Their ease of surface modification, biocompatibility and the presence of surface plasmons makes them ideal tools for a variety of investigations. Polyelectrolyte-coated gold nanoparticles are employed in areas such as imaging, drug delivery and gene therapy; however, it is not well understood how different factors such as the polyelectrolyte and salt concentration affect the coating on the nanoparticles and hence their performance. Here, these parameters were systematically varied and their effect on the stability of the colloidal nanoparticle suspension was monitored. An increase in the polyelectrolyte concentration from 0 to 30 mg/mL led to a red shift of the surface plasmon peak and an increase in the zeta potential. Concentrations between 5 mg/mL and 30 mg/mL resulted in the most stable systems, with 1 mg/mL being the most unstable. Stable nanoparticle suspensions were formed in salt concentrations below 50 mM, while higher concentrations caused colloidal instability and irreversible aggregation.