Isopropyl alcohol 70% / Hydrogen peroxide 0.125% spray

BACKGROUND Surgical site infection (SSI) is a major concern in orthopaedic surgery procedures as they can have devastating consequences for patients and their outcomes. Many infection prevention measures are routinely taken in order to prevent infection during surgery, the main one being surgical skin preparation prior to any incision. AIM To investigate the efficacy of different perioperative surgical skin preparation products commonly used in orthopaedic surgery. METHODS Seven databases were searched from inception to January 25, 2025, using a combination of keywords and medical subject headings terms, specifically for studies comparing any two surgical skin preparation products used at any point prior to skin incision for orthopaedic procedures. Titles and abstracts were screened and full texts reviewed based on inclusion criteria. Data was extracted on study design, interventions, and outcomes from studies that met inclusion criteria. Meta-analysis was not completed due to heterogeneity. RESULTS Thirty-two studies met the inclusion criteria in this systematic review. In extremity fracture surgery, evidence was mixed on whether iodine or chlorhexidine-based solutions are more effective at preventing SSI. No significant difference was found between iodine and chlorhexidine-based solutions in total joint arthroplasty, spine surgery, foot and ankle surgery, or upper extremity surgery. No tested preparation method was superior in reducing positive Cutibacterium acnes culture rates in upper extremity (shoulder) surgery. Adding adjuncts to iodine and chlorhexidine methods, such as isopropyl alcohol, hydrogen peroxide, or benzoyl peroxide showed no significant changes to SSI or bacterial cultures. CONCLUSION Current literature shows no significant difference between chlorhexidine-based and iodine-based skin preparation solutions in orthopaedic extremity or spine surgery regarding SSI prevention or culture results. Likewise, adding other antiseptic agents provided no clear benefit. While skin antisepsis is important, many different factors contribute to SSI risk outside of the skin preparation solution.

Abstract licence: CC BY-NC

Candidozyma auris is an emerging multidrug-resistant yeast that readily contaminates healthcare environments, persisting on dry surfaces and enabling transmission and difficult-to-control outbreaks. A systematic review of environmental hygiene interventions targeting C. auris was conducted, focusing on efficacy against planktonic cells and surface-associated biofilms (including dry-surface biofilms, DSB where available). PubMed and Scopus were searched for English-language records published from 1 January 2017 to 30 September 2025, and study selection followed PRISMA 2020. Thirty-six studies from nine countries met the inclusion criteria. These were predominantly laboratory efficacy evaluations using carrier/suspension or quantitative surface methods reporting log10 Colony Forming Unit (CFU) reductions; only seven studies assessed biofilm-associated C. auris. Across clades I–IV, chlorine-based disinfectants and oxidizing chemistries (hydrogen peroxide/peracetic acid formulations) most consistently achieved high-level reductions (often ≥ 5 log10 CFU) under label-relevant conditions. In contrast, products containing only quaternary ammonium compounds (QACs) frequently underperformed and demonstrated greater variability. No-touch methods, particularly 254 nm ultraviolet-C light (UV-C), provided meaningful adjunctive reductions, but were highly dependent on dose delivery and geometry, and evidence for ozone-based approaches was mixed. Limited data on C. auris DSBs suggest planktonic testing may overestimate real-world conditions and underscore the importance of endpoints, such as transfer prevention and regrowth suppression.

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The reaction between hydrogen peroxide and ferrous EDTA generates an oxidizing intermediate (I1) which is not the hydroxyl radical. It oxidizes ferrocytochrome c and also reacts with hydrogen peroxide (k5 = 3.2 X 10(3) M-1 S-1) to form a second oxidizing transient (I2). I1 is not scavenged by t-butyl alcohol whereas I2 is. I1 is found to be significantly less reactive than the hydroxyl radical toward benzoate ion, t-butyl alcohol, acetate ion, arginine, and serine, but is scavenged by compounds with readily oxidizable functional groups such as ethanol and isopropyl alcohol. This indicates that I1 does not undergo the characteristic reactions of the hydroxyl radical but shows a pattern of reactivity more associated with a metal ion oxidant like a ferryl (FeO2+)-EDTA complex.

Abstract licence: CC BY

Additive manufacturing (AM), particularly fused deposition modeling (FDM) 3D printing, has emerged as a versatile and accessible technology for prototyping and functional part production across a wide range of industrial applications. One of the critical performance-limiting factors in AM is the chemical resistance of thermoplastic materials, which directly influences their structural integrity, durability, and suitability in chemically aggressive environments. This study systematically investigates the chemical resistance of eight different widely utilized FDM filaments-acrylonitrile butadiene styrene (ABS), acrylonitrile styrene acrylate (ASA), polyamide (PA, Nylon), polycarbonate (PC), polyethylene terephthalate glycol (PETG), polylactic acid (PLA), polypropylene (PP), and polyvinyl butyral (PVB)-by examining their tensile strength and impact resistance after immersion in representative chemical agents: distilled water, ethanol (99.5%), isopropyl alcohol (75% and 99%), acetic acid (8%), hydrochloric acid (37%), hydrogen peroxide (30%), and acetone (99.5%). Quantitative mechanical testing was conducted in accordance with ASTM D638 and ASTM D256 standards, and statistical variability was accounted for using triplicate measurements with standard deviation analysis. The results reveal that PP exhibits the highest chemical resilience, retaining over 97% of its mechanical properties even after 7 days of immersion in aggressive solvents like acetone. PETG and ASA also demonstrated quite successful stability (>90% retention) in mildly corrosive environments such as alcohols and weak acids. In contrast, PLA, due to its low crystallinity and polar ester backbone, and PVB, due to its high amorphous content, showed substantial degradation: tensile strength losses exceeding 70% and impact resistance dropping below 20% in acetone. Moderate resistance was observed in ABS and PC, which maintained structural properties in neutral or weakly reactive conditions but suffered mechanical deterioration (>50% loss) in solvent-rich media. A strong correlation (r > 0.95) between tensile and impact strength reduction was found for most materials, indicating that chemical attack affects both static and dynamic mechanical performance uniformly. The findings of this study provide a robust framework for selecting appropriate 3D printing materials in applications exposed to solvents, acids, or oxidizing agents. PP is recommended for harsh chemical environments; PETG and ASA are suitable for moderate exposure scenarios, whereas PLA and PVB should be limited to low-risk, esthetic, or disposable applications.

Abstract licence: CC BY

Colorimetric assays are a rapid, scalable technique well suited to enzyme activity screening. However, side reactions or chromogenic reagent instability can result in false positives or false negatives that compromise the accuracy of such assays. Here, we identify three classes of compounds incompatible with the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) colorimetric assay for galactose oxidase activity. Dark green ABTS·+ cationic radicals indicating enzyme activity can get quenched to yield colorless solutions or couple with substrates to form differently colored adducts, thus preventing accurate colorimetric measurements. These side reactions limit the utility of the ABTS assay and introduce uncertainty in the substrate scope to which it is applicable. We have investigated the underlying mechanisms behind these side reactions to conclude that free radical scavengers, phenols with electron-donating substituents, and β,γ-unsaturated aryl ketones are incompatible with the ABTS colorimetric assay. In search of a viable alternative, we developed an assay using 2,4-dinitrophenylhydrazine under neutral conditions with isopropyl alcohol as a solubilizing agent. The use of neutral conditions was found to be critical to avoid hydrolysis of hydrazone adducts, ensuring reproducible measurements. Our assay is compatible with free radical scavengers (R2 = 0.98), phenols with electron-donating substituents (R2 = 0.97), and β,γ-unsaturated aryl ketones (R2 = 0.88). This modified assay enables galactose oxidase activity screening across a broader substrate scope, thus facilitating enzyme use for more practical applications.

Abstract licence: CC BY-NC-ND

(1) Background: This article evaluates the influence of different dentin cleaning protocols and surface conditioning on the shear bond strength of resin composite to bovine dentin, with and without thermocycling. (2) Methods: 120 cubic alloy specimens were bonded to bovine dentin using a resin composite. Dentin surfaces were treated with one of four cleaning protocols (hydrogen peroxide, sodium hypochlorite, cleaning solvent (acetone, isopropyl alcohol, and di-isopropyl ether), or distilled water) and either subjected to total-etch conditioning (TE) or left unetched. Shear bond strength was measured after 24 hours of storage and after thermocycling (TC; ΔT=50 K). Statistical analysis was performed at a significance level of α=0.05. (2) Results: TC reduced the overall shear bond strength by approximately 40%. The highest median bond strength (3.45±1.82 MPa) was observed in specimens treated with sodium hypochlorite without total-etching. In contrast, the lowest values (1.37±1.20 MPa) were found in specimens cleaned with cleaning solvent before TE and TC. Thermocycling significantly increased the incidence of adhesive failures at the specimen–composite interface (p

Abstract licence: CC BY

The purpose of this research is to develop a highly efficient, atom-economical protocol for biomass valorization by targeting the challenging selective oxidation of levulinic acid into succinic acid. Addressing a long-standing challenge in biomass oxidation chemistry, this study outlines the design of an inorganic tungsten - oxygen rich dilacunary phosphotungstate anchored to zeolite HY, forming a redox-active heterogeneous catalyst. For the first time, complete selectivity toward succinic acid with a 42% yield was achieved using hydrogen peroxide as a green oxidant under mild, solvent-free conditions. The major innovation lies in utilizing the unique structural confinement and cooperative acidity of the faujasite supercages and phosphotungstates, which allowed the catalyst to significantly outperform the previously reported supports, opening new horizons towards dicarboxylic acid production. Comprehensive physicochemical characterization confirmed the successful incorporation of the active species and revealed the structural and acidic features responsible for catalytic performance. The reaction was carried out in a simple batch reactor, and systematic investigation of key reaction parameters enabled precise regulation of the reaction pathway, delivering a turnover number of 462. Mechanistic insights were gained through radical-scavenging and control experiments, elucidating the nature of the active oxidant and the reactive species involved. This highly controlled radical network precisely directs the oxidative cleavage at the C3-C4 bond of levulinic acid while completely suppressing over-oxidation pathways. The effectiveness of the developed system was highlighted through comparison with previously reported methods, and recycling experiments demonstrated catalyst stability up to 4 cycles. Overall, the developed methodology provides a blueprint for future inorganic materials design for the sustainable transformation of biomass-derived molecules into high-value chemical products.

Abstract licence: CC BY-NC

INTRODUCTION AND AIMS: This in vitro study evaluated how 3 sterilization methods-autoclaving, ethylene oxide (EO) gas, and hydrogen peroxide gas plasma-affect the mechanical, physical, and dimensional properties of 3-dimensional (3D) printed implant surgical guides. These techniques are widely used in dental practice but differ in mechanism and limitations. METHODS: Twenty specimens were fabricated using a digital light processing printer and divided into 4 groups (n = 5): non-sterilized control, autoclaving (121 °C, 15 minutes), EO gas (55 °C, 60 minutes), and hydrogen peroxide gas plasma (<57 °C, 18 minutes). Mechanical tests evaluated flexural strength, modulus, and Shore D hardness while translucency and dimensional stability were also assessed. Shape deviation and implant positioning accuracy were compared before and after sterilization. Data were analyzed with one-way analysis of variance and Tukey's post hoc test. RESULTS: All sterilized groups maintained internal fit deviations within clinically acceptable tolerance (±120 μm), showing no significant differences in overall dimensional accuracy. Implant placement precision was preserved, with implant-tooth distances ≥2 mm. EO sterilization significantly increased the flexural strength (122.49 ± 10.10 MPa) and modulus (3477 ± 161 MPa) compared with controls whereas autoclaving showed the lowest strength (92.40 ± 15.06 MPa). Shore D hardness exceeded 90 HS in all groups, with autoclaving producing the highest values. Only EO treatment significantly reduced translucency. CONCLUSION: Sterilization method influenced the mechanical and optical properties of 3D-printed surgical guides without compromising dimensional accuracy. CLINICAL RELEVANCE: The findings provide evidence-based guidance for clinicians to select sterilization protocols that preserve the functionality of 3D-printed surgical guides and ensure precision in implant placement.

Abstract licence: CC BY-NC-ND

The essential technique of Goldmann tonometry is thought to have a risk of nosocomial infection, and thus there has been pressure to use single-use tonometer tips or slower and more-costly methods of disinfection for reusable tips. Here we review the evidence of infection from tonometry and the evidence behind different disinfection methods. The only infection reported to be transmitted by tonometry is adenoviral epidemic keratoconjunctivitis, which is also transmitted without tonometry and is a relatively low-morbidity infection. More serious eye infections or systemic infections have never been reported to be attributed to tonometry or eye examination. The most popular, affordable, quick and sustainable method of disinfection, using alcohol swabs to wipe the tip, is the only economically justifiable method.

Abstract licence: CC BY