2,157 research outputs found
Biofilm Removal and Bacterial Re-Colonization Inhibition of a Novel Erythritol/Chlorhexidine Air-Polishing Powder on Titanium Disks
No full textAir-polishing with low abrasiveness powders is fast arising as a valid and mini-invasive instrument for the management of biofilm colonizing dental implants. In general, the reported advantage is the efficient removal of plaque with respect to the titanium integrity. In the present study, we evaluated the in situ plaque removal and the preventive efficacy in forestalling further infection of an innovative erythritol/chlorhexidine air-polishing powder and compared it with sodium bicarbonate. Accordingly, two peri-implantitis-linked biofilm formers, strains Staphylococcus aureus and Aggregatibacter actinomycetemcomitans, were selected and used to infect titanium disks before and after the air-polishing treatment to test its ability in biofilm removal and re-colonization inhibition, respectively. Biofilm cell numbers and viability were assayed by colony-forming unit (CFU) count and metabolic-colorimetric (2,3-Bis-(2-Methoxy-4-Nitro-5-Sulfophenyl)-2H-Tetrazolium-5-Carboxanilide) (XTT) assay. Results demonstrated that air-polishing performed with either sodium bicarbonate or erythritol/chlorhexidine was effective in reducing bacteria biofilm viability and number on pre-infected specimens, thus showing a similar ability in counteracting existing infection in situ; on the other hand, when air-polished pre-treated disks were infected, only erythritol/chlorhexidine powder showed higher post-treatment biofilm re-growth inhibition. Finally, surface analysis via mechanical profilometry failed to show an increase in titanium roughness, regardless of the powder selected, thus excluding any possible surface damage due to the use of either sodium bicarbonate or erythritol/chlorhexidine
"The love that made hell, paradise." Ouida re-writing the Paolo and Francesca theme in Held in Bondage
No full textThe bestselling Victorian author Ouida reveals in her novels, and, in particular, Held in Bondage, an extraordinary knowledge od Dante, by using characters and themes from the Commedia. The Paolo and Francesca theme actually constitutes part of the plot of the novel and is to be found in many of her other works, short stories and non-fiction writing
Nano-topography and functionalization with the synthetic peptoid GN2-Npm9 as a strategy for antibacterial and biocompatible titanium implants
No full textIn recent years, antimicrobial peptides (AMPs) have attracted great interest in scientific research, especially for biomedical applications such as drug delivery and orthopedic applications. Since they are readily degradable in the physiological environment, scientific research has recently been trying to make AMPs more stable. Peptoids are synthetic N-substituted glycine oligomers that mimic the structure of peptides. They have a structure that does not allow proteolytic degradation, which makes them more stable while maintaining microbial activity. This structure also brings many advantages to the molecule, such as greater diversity and specificity, making it more suitable for biological applications. For the first time, a synthesized peptoid (GN2-Npm9) was used to functionalize a nanometric chemically pre-treated (CT) titanium surface for bone-contact implant applications. A preliminary characterization of the functionalized surfaces was performed using the contact angle measurements and zeta potential titration curves. These preliminary analyses confirmed the presence of the peptoid and its adsorption on CT. The functionalized surface had a hydrophilic behaviour (contact angle = 30°) but the hydrophobic tryptophan-like residues were also exposed. An electrostatic interaction between the lysine residue of GN2-Npm9 and the surface allowed a chemisorption mechanism. The biological characterization of the CT_GN2-Nmp9 surfaces demonstrated the ability to prevent surface colonization and biofilm formation by the pathogens Escherichia coli and Staphylococcus epidermidis thus showing a broad-range activity. The cytocompatibility was confirmed by human mesenchymal stem cells. Finally, a bacteria-cells co-culture model was applied to demonstrate the selective bioactivity of the CT_GN2-Nmp9 surface that was able to preserve colonizing cells adhered to the device surface from bacterial infection
Stimulation of the Nonneuronal Cholinergic System by Highly Diluted Acetylcholine in Keratinocytes
No full textThe physiological effects of acetylcholine on keratinocytes depend on the presence of nicotinic and muscarinic receptors. The role of nonneuronal acetylcholine in keratinocytes could have important clinical implications for patients with various skin disorders such as nonhealing wounds. In order to evaluate the efficacy of highly diluted acetylcholine solutions obtained by sequential kinetic activation, we aimed to investigate the effects of these solutions on normal human keratinocytes. Two different concentrations (10 fg/mL and 1 pg/mL) and formulations (kinetically activated and nonkinetically activated) of acetylcholine were used to verify keratinocyte viability, proliferation, and migration and the intracellular pathways involved using MTT, crystal violet, wound healing, and Western blot compared to 147 ng/mL acetylcholine. The activated formulations (1 pg/mL and 10 fg/mL) revealed a significant capacity to increase migration, cell viability, and cell proliferation compared to 147 ng/mL acetylcholine, and these effects were more evident after a single administration. Sequential kinetic activation resulted in a statistically significant decrease in reactive oxygen species production accompanied by an increase in mitochondrial membrane potential and a decrease in oxygen consumption compared to 147 ng/mL acetylcholine. The M1 muscarinic receptor was involved in these effects. Finally, the involvement of ERK/mitogen-activated protein kinases (MAPK) and KI67 confirmed the effectiveness of the single treatment on cell proliferation. The intracellular pathways of calcium were investigated as well. Our results indicate for the first time that highly diluted and kinetically activated acetylcholine seems to play an active role in an in vitro model of wound healing. Moreover, the administration of acetylcholine within the physiological range may not only be effective but is also likely to be safe
HERStory Makers 2023: Francesca Fotheringham
No full textFrancesca Fotheringham is a postdoctoral research associate at the University of Edinburgh studying educational psychology with a focus on neurodiversity. She took part in HERStory Makers 2023.What is HERStory Makers?HERStory Makers is a social media competition for female-identifying early career researchers to share their research, their career journeys, and to inspire the next generation. Winners are selected by public vote. HERStory Makers is also part of EXPLORATHON, Scotland's contribution to European Researchers' Night.In 2022-23, EXPLORATHON Francescasupported by the Engineering & Physical Sciences Research Council [grant number EP/X020762/1].Author contributions to contentFrancesca conceived, planned, and recorded the video content. Kirsty Ross edited the video content to insert HERStory Maker credits, added subtitles, and reduce video length to below Twitter/X limit of 2 mins and 20 secs.</p
Hybrid polyurethane scaffolds interpenetrated with newly cross-linked gelatin for adipose tissue regeneration
No full textIn Vitro Reconstructed Human Epithelial Models for Microbial Infection Research: Why Do We Need them?
No full textIn the last 50 years, the Replacement, Reduction and Refinement principles have become a framework for conducting high quality
academic, pre-clinical, clinical and industrial research experimentation studies, in order to respond to the European Union legislative
demand of alternatives to animal-based experimentation, often difficult to translate to human applications, expensive and not
ethically approved.
Thanks to the improvement of cellular isolation protocols, culture and co-culture conditions, together with the increased clinical
demand, several novel in vitro three-dimensional tissue engineered human epithelial models, able to create sophisticate pre-clinical
tests and produce results more reliable than the traditional bi-dimensional flat cell culture systems, have been developing also for
microbial infection research purposes
Bifunctional mesoporous glasses for bone tissue engineering: Biological effects of doping with cerium and polyphenols in 2D and 3D in vitro models
No full textThis study evaluates the cytocompatibility of cerium-doped mesoporous bioactive glasses (Ce-MBGs) loaded with polyphenols (Ce-MBGs-Poly) for possible application in bone tissue engineering after tumour resection. We tested MBGs powders and pellets on 2D and 3D in vitro models using human bone marrow-derived mesenchymal stem cells (hMSCs), osteosarcoma cells (U2OS), and endothelial cells (EA.hy926). Promisingly, at a low concentration in culture medium, Poly-loaded MBGs powders containing 1.2 mol% of cerium inhibited U2OS metabolic activity, preserved hMSCs viability, and had no adverse effects on EA.hy926 migration. Moreover, the study discussed the possible interaction between cerium and Poly, influencing anti-cancer effects. In summary, this research provides insights into the complex interactions between Ce-MBGs, Poly, and various cell types in distinct 2D and 3D in vitro models, highlighting the potential of loaded Ce-MBGs for post-resection bone tissue engineering with a balance between pro-regenerative and anti-tumorigenic activities.This study evaluates the cytocompatibility of cerium-doped mesoporous bioactive glasses (Ce-MBGs) loaded with polyphenols (Ce-MBGs-Poly) for possible application in bone tissue engineering after tumour resection. We tested MBGs powders and pellets on 2D and 3D in vitro models using human bone marrow-derived mesenchymal stem cells (hMSCs), osteosarcoma cells (U2OS), and endothelial cells (EA.hy926). Promisingly, at a low concentration in culture medium, Poly-loaded MBGs powders containing 1.2 mol% of cerium inhibited U2OS metabolic activity, preserved hMSCs viability, and had no adverse effects on EA.hy926 migration. Moreover, the study discussed the possible interaction between cerium and Poly, influencing anti-cancer effects. In summary, this research provides insights into the complex interactions between Ce-MBGs, Poly, and various cell types in distinct 2D and 3D in vitro models, highlighting the potential of loaded Ce-MBGs for post-resection bone tissue engineering with a balance between pro-regenerative and anti-tumorigenic activities
Grafting of alpha-tocopheryl phosphate on chemically treated Ti-6Al-4V for antibacterial bone implants
No full textAlpha-tocopheryl phosphate ( tocopherol. Even if α α-TP) is the water-soluble form of the antioxidant and lipophilic molecule alpha- -TP’s antioxidant and antibacterial properties are known, it has never been exploited to prevent implantable materials against bacterial surface contamination, till now. Accordingly, the purpose of this work is to couple a chemically treated Ti6Al4V surface with α-TP conferring a local antibacterial activity preserving orthopaedic and dental prosthetic devices. The grafting of the α-TP molecule is explored both as a thin coating (3 logs (≈ 92%) in comparison to the uncoated controls. Contrarily, the phosphorylated groups were used to create the binding to the surface on the functionalized samples, as shown by the XPS analysis. The functionalized surface results in poor antibacterial properties (≈1 log reduction of viable colonies) and hydrophobic behaviour. Finally, the cytocompatibility evaluation towards human mesenchymal stem cells showed the coating treatment to be more cell’s friendly in comparison with the functionalization
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