Background
Fusarium spp. has been considered as an onychomycosis agent, but little is known about the etiopathogenesis of fusarial onychomycosis; thus, the objective of this study was to characterize ...the fungal‐nail interaction and the consequences of the nail infection process by Fusarium oxysporum using the human nail, in an ex vivo model.
Methods
The kinetic of biofilm production and infection by F. oxysporum using the nail as the only nutritional source were evaluated by scanning electron microscopy, number of culturable cells, metabolic activity, characterization of extracellular matrix, spectroscopy and histopathology analyses.
Results
After evaluating the biofilm kinetic over 7 days using different parameters and techniques, it was possible to characterize the Fusarium‐nail interaction.
Conclusions
This study is a part of a big project aiming to clarify the fusarial pathogenesis and contributes to proving F. oxysporum is able to adapt, grow, develop, and form a biofilm on healthy human nails, which are crucial steps for the invasion process.
Fungal biofilms have been involved in the pathogenesis of onychomycosis, but the aspects contributing to this association need to be enlightened. This study aimed to investigate the ability of three ...different fungi to form biofilm on the nail. All evaluated fungi were able to grow on the nails, using them as the only nutritional source and formed a structure strongly suggestive of biofilms. However, their architecture and morphology were highly contrasting: Candida albicans showed dense growth, exhibited a well‐structured community and a large amount of extracellular matrix (ECM), and FTIR‐ATR spectroscopy reinforced these findings revealing components suggestive of the biofilm. For Fusarium oxysporum, these events were also observed, but in lower intensity. Furthermore, while Trichophyton rubrum presented a well‐organized architecture, the ECM was not visualized. We hypothesize that these findings are related to the symptomatology of onychomycosis. When it is caused by a non‐dermatophyte, it usually is accompanied with paronychia, pain, oedema, inflammation and few signals of keratolysis, while dermatophytes are more associated with intense onycholysis and absence of the inflammatory signals. Biofilm seems to be crucial for non‐dermatophytes to cause onychomycosis, but not for T. rubrum.
Current oral squamous cell carcinoma chemotherapies demonstrate off-target toxicity, which could be reduced by local delivery. Curcumin acts via many cellular targets to give anti-cancer properties; ...however the bioavailability is hindered by its physicochemical characteristics. The incorporation of curcumin into emulgel systems could be a promising approach for its solubilization and delivery. The aim of this work was to develop emulgel systems containing curcumin for the treatment of oral cancer. The emulgels containing curcumin were prepared with poloxamer 407, acrylic acid derivatives, oil phase (sesame oil or isopropyl myristate). The more stable system was evaluated for mechanical and rheological properties, as well as, the in vitro drug release profile, permeation and cytotoxic potential to oral mucosa models. The flow-throw system evidenced that the formulations could keep 5 min over porcine oral mucosa. Emulgel showed pseudoplastic behavior and a gelation temperature of 33 °C, which ensure their higher consistency. In addition, 70% of the incorporated curcumin was released within 24 h in an in vitro drug release study and could permeate porcine oral mucosa. Monolayers cultures and tissue-engineered models showed the selectivity of the drug and systems for tumor cells. The physicochemical properties, subsequent release and permeation of curcumin to selectivity kill cancer cells could be improved by the incorporation into emulgel systems.
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The photocatalyst composition affects the chemical–physical properties and directly impacts photocatalytic activity, both in the hydrogen production and degradation of organic contaminants. In this ...work, the influence of zeolitic structures NaA, NaY, and ZSM‐5 combined with a 10% active phase, TiO2 catalyst doped with 1% copper, and cobalt cocatalysts was tested to mineralize the reactive blue dye (CI250) and to produce hydrogen by photocatalysis under ultraviolet radiation. The band gap energy was affected mainly by the cocatalyst, while the Brunauer‐Emmett‐Teller method (BET) area was affected by the zeolite structure as well as the X‐ray diffraction (XRD). The most active catalyst was the Cu@TiO2/NaY, which promoted a hydrogen production rate of 240 μmolH2gcat−1 using 10% ethanol (v/v) aqueous solution as a sacrificial agent and mineralization of 53% of the organic dye, followed by the catalysts impregnated on ZSM‐5 zeolites, which had discolouration up to 50% and hydrogen evolution of 92.6 and 109.7 μmolH2gcat−1 for the catalyst doped with Cu and Co, respectively.
Electronic photo‐excitation scheme of the structured catalyst in solution.
Mucoadhesive nanostructured systems comprising poloxamer 407 and Carbopol 974P
have already demonstrated good mucoadhesion, as well as improved mechanical and rheological properties. Curcumin ...displays excellent biological activity, mainly in oral squamous cancer; however, its physicochemical characteristics hinder its application. Therefore, the aim of this study was to develop nanostructured formulations containing curcumin for oral cancer therapy. The photophysical interactions between curcumin and the formulations were elucidated by incorporation kinetics and location studies. They revealed that the drug was quickly incorporated and located in the hydrophobic portion of nanometer-sized polymeric micelles. Moreover, the systems displayed plastic behavior with rheopexy characteristics at 37 °C, viscoelastic properties and a gelation temperature of 36 °C, which ensures increased retention after application in the oral cavity. The mucoadhesion results confirmed the previous findings with the nanostructured systems showing a residence time of 20 min in porcine oral mucosa under flow system conditions. Curcumin was released after 8 h and could permeate through the porcine oral mucosa. Cytotoxicity testing revealed that the formulations were selective to cancer cells over healthy cells. Therefore, these systems could improve the physicochemical characteristics of curcumin by providing improved release and permeation, while selectivity targeting cancer cells.
Environmentally responsive systems composed of poloxamer 407 (P407) and different carbomers were investigated for eprinomectin delivery, as they can show improved properties for skin administration ...and permeation. Eprinomectin shows great efficacy against endo and ectoparasites, but its hydrophobicity is a challenge for the development of formulations. This work aimed to evaluate the influence of P407 amount, carbomer type and isopropyl alcohol (IA) concentration on sol-gel transition, compressional, rheological, drug release, bioadhesive and skin permeation properties of designed systems for topical administration of eprinomectin. Systems composed of different amounts of P407 and Carbomer 974P or 934P were proposed. The influence of IA amount and the eprinomectin presence was also investigated. Drug and IA reduced the structuring capacity and the compressional properties of systems. Preparations displayed bioadhesive force influenced by the carbomer type and drug presence. The higher P407 amount, the presence of C974P and the temperature increase enhanced the bioadhesiveness and structuring of systems. The selected formulations displayed drug release controlled by anomalous transport, and the formulations improved the bovine skin permeation of eprinomectin. P407 (17.5 %), 15 % IA, 0.3 % C974P and 0.5 % eprinomectin showed rendered an efficient system for controlled topical delivery and suggest it is worthy of in vivo evaluation.
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•Effect of polymer, alcohol and eprinomectin on physicochemical, drug release and skin permeation of responsive systems was evaluated.•Drug, isopropyl alcohol presence and the carbomers influenced the Tsol/gel, compressional, rheological and bioadhesive properties of systems.•17.5 % P407 and C974P or C934P resulted responsive and bioadhesive systems with controlled eprinomectin release and permeation.
Recently, the number of new cases of cutaneous leishmaniasis has been of concern among health agencies. Research that offers new therapeutic alternatives is advantageous, especially those that ...develop innovative drugs. Therefore, this paper presents the incorporation of
Ducke and chlorophyll extract into Pluronic
F127 and Carbopol gels, under optimized polymer quantities. The chlorophyll extract (rich in photosensitizing compounds) was obtained by continuous-flow pressurized liquid extraction (PLE), a clean, environmentally friendly method. The system aims to act as as a leishmanicidal, cicatrizant, and antibiotic agent, with reinforcement of the photodynamic therapy (PDT) action. Rheological and mechanical analyses, permeation studies and bioadhesiveness analyses on human skin, and PDT-mediated activation of
were performed. The emulgels showed gelation between 13° and 15 °C, besides pseudoplastic and viscoelastic properties. Furthermore, the systems showed transdermal potential, by releasing chlorophylls and
Ducke into the deep layers of human skin, with good bioadhesive performance. The application of PDT reduced three logarithmic colony-forming units of
bacteria. The results support the potential of the natural drug for future clinical trials in treating wounds and cutaneous leishmania.
Copaiba oil-resin (COR) extracted from
Ducke has been used as a natural chemotherapeutic agent for a wide range of therapeutic applications. This study presents an emulgel design with a high ...concentration of COR, designed to prevent and treat mastitis. The COR was stabilized in a gel matrix constituted by carbopol C934P and Pluronic
F127 (ECO formulation) ratios. The permeation study of ECO was accessed by Fourier transform infrared photoacoustic spectroscopy (FTIR-PAS). The results reveal a high capacity of ECO to permeate deep skin layers. Dairy cows with a history of mastitis were used as in vivo models and exposed to ECO treatment. Monitoring of the teat's inflammatory response showed that ECO effectively prevents mastitis. Furthermore, the ECO formulation was able to form a thin film gel on the application side, preventing fly proliferation and significantly reducing the pathogen load. This study reveals a drug that can used as an alternative application for mastitis in human or veterinary clinics.
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