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Translational Vision Science &... Aug 2023To develop a feline model of acute Acanthamoeba keratitis using methods that replicate natural routes of infection transmission.
PURPOSE
To develop a feline model of acute Acanthamoeba keratitis using methods that replicate natural routes of infection transmission.
METHODS
Corneal Acanthamoeba castellanii inoculation was performed by three methods: topical inoculation with Acanthamoeba solution following corneal abrasion, placement of a contaminated contact lens for 7 days, and placement of a contaminated contact lens for 7 days following corneal abrasion. Sham inoculations with parasite-free medium and sterile contact lenses were also performed. Cats were monitored by ocular examination and in vivo corneal confocal microscopy for 21 days post-inoculation. Corneal samples were collected at intervals for microbiologic assessment, histopathology, and immunohistochemistry.
RESULTS
All cats in the corneal abrasion groups developed clinical keratitis. Clinical ocular disease was inconsistently detected in cats from the contaminated contact lens only group. Initial corneal lesions were characterized by multifocal epithelial leukocyte infiltrates. Ocular lesions progressed to corneal epithelial ulceration and diffuse stromal inflammation. After 14 days, corneal ulcerations resolved, and stromal inflammation consolidated into multifocal subepithelial and stromal infiltrates. Corneal amoebae were detected by culture, in vivo confocal microscopy, histopathology, and immunohistochemistry in cats with keratitis. Neutrophilic and lymphocytic keratoconjunctivitis with lymphoplasmacytic anterior uveitis were identified by histopathology. Coinfection with aerobic bacteria was detected in some, but not all, cats with keratitis. Ocular disease was not detected in the sham inoculation groups.
CONCLUSIONS
Feline Acanthamoeba keratitis is experimentally transmissible by contaminated contact lenses and topical inoculation following corneal epithelial trauma.
TRANSLATIONAL RELEVANCE
Experimentally induced acute Acanthamoeba keratitis in cats is clinically and histopathologically similar to its human counterpart.
Topics: Cats; Animals; Humans; Acanthamoeba Keratitis; Acanthamoeba castellanii; Cornea; Corneal Injuries; Inflammation
PubMed: 37566398
DOI: 10.1167/tvst.12.8.10 -
Advanced Drug Delivery Reviews Nov 2023Surfactants are a diverse group of compounds that share the capacity to adsorb at the boundary between distinct phases of matter. They are used as pharmaceutical... (Review)
Review
Surfactants are a diverse group of compounds that share the capacity to adsorb at the boundary between distinct phases of matter. They are used as pharmaceutical excipients, food additives, emulsifiers in cosmetics, and as household/industrial detergents. This review outlines the interaction of surfactant-type excipients present in oral pharmaceutical dosage forms with the intestinal epithelium of the gastrointestinal (GI) tract. Many surfactants permitted for human consumption in oral products reduce intestinal epithelial cell viability in vitro and alter barrier integrity in epithelial cell monolayers, isolated GI tissue mucosae, and in animal models. This suggests a degree of mis-match for predicting safety issues in humans from such models. Recent controversial preclinical research also infers that some widely used emulsifiers used in oral products may be linked to ulcerative colitis, some metabolic disorders, and cancers. We review a wide range of surfactant excipients in oral dosage forms regarding their interactions with the GI tract. Safety data is reviewed across in vitro, ex vivo, pre-clinical animal, and human studies. The factors that may mitigate against some of the potentially abrasive effects of surfactants on GI epithelia observed in pre-clinical studies are summarised. We conclude with a perspective on the overall safety of surfactants in oral pharmaceutical dosage forms, which has relevance for delivery system development.
Topics: Animals; Humans; Excipients; Drug Compounding; Pharmaceutical Preparations; Intestines; Surface-Active Agents
PubMed: 37739041
DOI: 10.1016/j.addr.2023.115086 -
Membranes Jun 2023Nowadays, membrane technology is an efficient process for separating compounds with minimal structural abrasion; however, the manufacture of membranes still has several...
Nowadays, membrane technology is an efficient process for separating compounds with minimal structural abrasion; however, the manufacture of membranes still has several drawbacks to being profitable and competitive commercially under an environmentally friendly approach. In this sense, this review focuses on bio-based polymeric membranes as an alternative to solve the environmental concern caused by the use of polymeric materials of fossil origin. The fabrication of bio-based polymeric membranes is explained through a general description of elements such as the selection of bio-based polymers, the preparation methods, the usefulness of additives, the search for green solvents, and the characterization of the membranes. The advantages and disadvantages of bio-based polymeric membranes are discussed, and the application of bio-based membranes to recover organic and inorganic contaminants is also discussed.
PubMed: 37504991
DOI: 10.3390/membranes13070625 -
Materials (Basel, Switzerland) Nov 2023The behaviour of geosynthetics can be affected by many agents, both in the short and long term. Mechanical damage caused by repeated loading or abrasion are examples of...
The behaviour of geosynthetics can be affected by many agents, both in the short and long term. Mechanical damage caused by repeated loading or abrasion are examples of agents that may induce undesirable changes in the properties of geosynthetics. The research conducted in this work complemented previous studies and consisted of submitting a geocomposite, isolated and successively, to two degradation tests: mechanical damage under repeated loading and abrasion. The geocomposite (a nonwoven geotextile reinforced with polyethylene terephthalate filaments) was tested on both sides (with or without filaments) and directions (machine and cross-machine). The impact of the degradation tests on the geocomposite was quantified by monitoring changes in its tensile and tearing behaviour. The results showed that, in most cases, the degradation tests caused the deterioration of the tensile and tearing behaviour of the geocomposite, affecting its reinforcement function. The decline in tensile strength correlated reasonably well with the decline in tearing strength. Changing the side and direction tested influenced, in some cases (those involving abrasion), the degradation experienced by the geocomposite. The reduction factors (referring to tensile and tearing strength) for the combined effect of the degradation agents tended to be lower when determined by using the common method (compared to those resulting directly from the successive exposure to both agents).
PubMed: 37959644
DOI: 10.3390/ma16217047 -
Polymers Sep 2023Aqueous polyurethane is an environmentally friendly, low-cost, high-performance resin with good abrasion resistance and strong adhesion. Cationic aqueous polyurethane is...
Aqueous polyurethane is an environmentally friendly, low-cost, high-performance resin with good abrasion resistance and strong adhesion. Cationic aqueous polyurethane is limited in cathodic electrophoretic coatings due to its complicated preparation process and its poor stability and single performance after emulsification and dispersion. The introduction of perfluoropolyether alcohol (PFPE-OH) and light curing technology can effectively improve the stability of aqueous polyurethane emulsions, and thus enhance the functionality of coating films. In this paper, a new UV-curable fluorinated polyurethane-based cathodic electrophoretic coating was prepared using cationic polyurethane as a precursor, introducing PFPE-OH capping, and grafting hydroxyethyl methacrylate (HEMA). The results showed that the presence of perfluoropolyether alcohol in the structure affected the variation of the moisture content of the paint film after flash evaporation. Based on the emulsion particle size and morphology tests, it can be assumed that the fluorinated cationic polyurethane emulsion is a core-shell structure with hydrophobic ends encapsulated in the polymer and hydrophilic ends on the outer surface. After abrasion testing and baking, the fluorine atoms of the coating were found to increase from 8.89% to 27.34%. The static contact angle of the coating to water was 104.6 ± 3°, and the water droplets rolled off without traces, indicating that the coating is hydrophobic. The coating has excellent thermal stability and tensile properties. The coating also passed the tests of impact resistance, flexibility, adhesion, and resistance to chemical corrosion in extreme environments. This study provides a new idea for the construction of a new and efficient cathodic electrophoretic coating system, and also provides more areas for the promotion of cationic polyurethane to practical applications.
PubMed: 37765579
DOI: 10.3390/polym15183725 -
Journal of Dentistry Jul 2024This laboratory study assessed the performance of a novel fluoride dentifrice containing micro-fibrillated cellulose (MFC) and entrapped silica. (Comparative Study)
Comparative Study
OBJECTIVES
This laboratory study assessed the performance of a novel fluoride dentifrice containing micro-fibrillated cellulose (MFC) and entrapped silica.
METHODS
Removal of extrinsic stains was assessed using the pellicle cleaning ratio (PCR) method, and radioactive dentin abrasivity (RDA) was measured, to calculate a cleaning efficiency index (CEI). Fluoride efficacy was evaluated using widely used remineralization and fluoride uptake methods. The test product (Protegera™) was compared to common dentifrices (Crest - Cavity Protection™ and ProHealth™, Sensodyne Pronamel™, Arm & Hammer™ Advanced Whitening, Crest ProHealth™, and Colgate Optic White™).
RESULTS
The PCR for the MFC dentifrice (141) was comparable to three known marketed stain-removing dentifrices (Arm & Hammer™ Advanced Whitening, Crest ProHealth™, and Colgate Optic White™) but it had a significantly lower RDA (88 ± 6) than 5 other products. This gave it the highest CEI of the tested products (2.0). In a 10-day pH cycling study, the fluoride efficacy of the MFC product was comparable to Sensodyne Pronamel and Crest Cavity Protection. The MFC dentifrice was superior for promoting fluoride uptake into incipient enamel lesions compared to the USP reference dentifrice.
CONCLUSION
The MFC dentifrice has low abrasion, but despite this, it is highly effective in removing stained pellicle. It also is an efficacious fluoride source when compared to relevant commercially available fluoride dentifrices with high dentin abrasivity.
CLINICAL SIGNIFICANCE
The addition of micro-fibrillated cellulose to a fluoride dentifrice gives a low abrasive product that can effectively remove external stains, and serve as an effective fluoride source. This combination of benefits seems well suited to enamel protection and caries prevention.
Topics: Dentifrices; Tooth Discoloration; Cellulose; Humans; Tooth Abrasion; Dentin; Tooth Remineralization; Cariostatic Agents; Dental Pellicle; Fluorides; Silicon Dioxide; Materials Testing; Dental Enamel; Hydrogen-Ion Concentration; Phosphates; Toothpastes
PubMed: 38714242
DOI: 10.1016/j.jdent.2024.105038 -
BMC Oral Health Sep 2023Hydrogen peroxide (HP) and citric acid (CA), key contributors to toothpaste acidity, can lead to dental loss. This study aimed to compare the amount of abrasion or loss...
BACKGROUND
Hydrogen peroxide (HP) and citric acid (CA), key contributors to toothpaste acidity, can lead to dental loss. This study aimed to compare the amount of abrasion or loss of dentin based on pH, buffering, and concentration of HP and CA in commercial and experimental toothpastes after toothbrushing or immersion.
METHODS
Bovine dentin specimens were randomly assigned to nine solutions. The prepared solutions included two commercial toothpastes (whitening toothpaste [WT] with HP and CA; conventional toothpaste [CT] without HP and CA), reference slurry (RS), two CA solutions (1.92%, CAS1; 0.001%, CAS2), basic solution (7.16% sodium phosphate dibasic [SPDS]), CA phosphate buffer solution (3.58% SPDS and 0.96% CA [CAPB]), HP solution (4%, HPS), and distilled water (DW). Dentin specimens were performed in two treatments: one with only abrasion (10,000 brushings) and one with only immersion (1 h). After treatments, the amount of dentin loss and surface images were measured and observed using noncontact profilometry. Data were analyzed using an one-way analysis of variance and the Tukey test as a post hoc analysis (p < 0.05).
RESULTS
WT with pH 5.0 had lower dentin abrasion than CT and RS after brushing but had higher dentin loss than both after immersion. The dentin surfaces of CAS1, CAPB, and WT were damaged after immersion, whereas HPS, CAS2, CT, SPDS, RS, and DW remained intact after soaking. CAS2 and HPS, which had a pH of 5.0 like WT, did not significantly differ from those of DW after brushing.
CONCLUSIONS
WT containing HP and CA did not cause significant dentin abrasion but may cause additional dentin loss even without brushing. After brushing or immersion, the CA concentration may affect the dentin surface more than the HP concentration included in WT. The amount of abrasion or loss of dentin after brushing or soaking can vary based on the composition, concentration, and buffer in the solution, even if the pH of the solution is similar to pH 5.0.
Topics: Humans; Animals; Cattle; Hydrogen Peroxide; Toothpastes; Citric Acid; Dentin
PubMed: 37658357
DOI: 10.1186/s12903-023-03319-x -
Heliyon Jul 2023Alkali-activated binders made from various waste products can appreciably reduce the emission of CO and enhance the waste recycling efficiency, thus making them viable...
Alkali-activated binders made from various waste products can appreciably reduce the emission of CO and enhance the waste recycling efficiency, thus making them viable substitutes to ordinary Portland cement (OPC)-based binders. Waste materials including fly ash (FA), palm oil fuel ash (POFA), and granulated blast furnace slag (GBFS) reveal favorable effects when applied to alkali-activated mortars (AAMs) that are mainly related to the high contents of silica, alumina, and calcium. Therefore, fifteen AAM mixes enclosing FA, POFA with high volume of GBFS were designed. The obtained GBFS/FA/POFA-based AAMs were subjected wet/dry and freeze/thaw cycles. The impact of various GBFS contents on the microstructures, freeze-thaw cycle, abrasion resistance, mechanical and durability features of the proposed AAMs were evaluated. The results showed that presence of Ca can significantly affect the AAMs durability features and long-term performance. The abrasion resistance of the AAMs was decreased with the decrease of CaO contents. Furthermore, the abrasion depth of 70% AAMs (0.8 mm) was lower in comparison to the mix made by replacing 50 wt% of FA with GBFS (1.4 mm). Generally, increase in the GBFS contents from 50 to 70% could largely impact the AAMs properties under aggressive environmental exposure. The expansion and physical impacts during the freezing-thawing cycles was argued to destroy the bonds in -S-H and paste-aggregates, causing the formation of large cracks. It is asserted that the AAM mixes made from FA, POFA and high volume of GBFS may offer definitive mechanical, durable, and environmental benefits with their enhanced performance under aggressive environments.
PubMed: 37539229
DOI: 10.1016/j.heliyon.2023.e17672 -
Annals of Medicine and Surgery (2012) Jan 2024A corneal abrasion is a flaw in the cornea's epithelial surface, which is located in the front of the eye. It causes recurrent erosions, corneal inflammation, and... (Review)
Review
BACKGROUND
A corneal abrasion is a flaw in the cornea's epithelial surface, which is located in the front of the eye. It causes recurrent erosions, corneal inflammation, and chronic corneal defects. In a context with limited resources, the goal of this review was to provide an evidence-based procedure for perioperative risk stratification, prevention, and management of corneal abrasion during non-ocular surgery.
METHODS
A medical search engines of PUBMED, GOOGLE SCHOLAR, COCHRANE REVIEW, and PUBMED CENTERAL to get access for current and updated evidence on procedures on risk stratification, prevention and management of corneal abrasion for non-ocular surgery. The authors formulate the key questions, scope, and articles written in English language, human study focuses on corneal abrasion, articles in the last 20 year was implemented to identify or filter high-level evidences were included. Reports contain corneal abrasion due to ocular surgery were excluded. All the research articles, which were identified from searches of electronic databases, were imported into Endnote software, duplicate were removed advanced search strategy of electronic sources from databases and websites was conducted using Boolean operators (cornea AND (abrasion OR injury OR laceration)) AND ("Perioperative Period" OR "general anesthesia"). Screening of literatures was conducted with proper appraisal checklist. This review was reported in accordance with preferred reporting items for systematic reviews and meta-analyses (PRISMA) 2020 statement.
RESULTS
From 8767 identified articles, two hundred articles were removed for duplication and 7720 studies were excluded, 1205 articles were retrieved and evaluated for eligibility. Finally, 24 were included in this systematic review. Advanced age, Prominent eyes, exophthalmus, ocular surface abnormalities (dry eye), expected duration of surgery (>1 h), the favourable position of the surgery, prone,Trendelenburg and lateral, risk of bleeding, surgical site of the surgery(head /neck) and diabetes mellitus were risk for corneal abrasion. The use of appropriate intervention with pharmacological and Non-pharmacological strategies minimizes the occurrence of perioperative corneal abrasion was crucial for the quality of care.
CONCLUSION
Preventing and managing corneal abrasion improves patients' quality of life. However, there was insufficient evidence to draw conclusions, and high-quality trials of multimodal interventions matched to risk stratification and prevention of corneal abrasion needed to provide robust evidence to guide prevention and management of perioperative corneal abrasion.
PubMed: 38222698
DOI: 10.1097/MS9.0000000000001566 -
ACS Omega Aug 2023The development of self-healing materials has gained significance in the medical field to enhance the longevity and reliability of medical devices and implants. Material... (Review)
Review
The development of self-healing materials has gained significance in the medical field to enhance the longevity and reliability of medical devices and implants. Material degradation caused by mechanical stress, environmental factors, and damage during use can lead to failure and necessitate manual inspection and maintenance. Self-healing materials, including polymers and elastomers, offer a promising solution by activating microdamage repair mechanisms. Polyurea coatings, known for their durability, flexibility, and versatility, have found widespread applications in various industries to prevent corrosion and abrasion and impact damage. This review focuses on the self-healing capability of polyurethane coatings and the efficacy of fabricated microcapsules. Experimental results elucidate the necessary conditions for achieving self-healing in polyurethane coatings encapsulated with suitable healing agents. These factors directly impact the self-healing potential of polyurea coatings and provide insights for medical device manufacturers seeking optimal coatings. The report also discusses challenges in fabrication and sample preparation, along with limitations of the project and recommendations for future research.
PubMed: 37546595
DOI: 10.1021/acsomega.3c02723