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Introduction: Topical antifungals for toenail onychomycosis must penetrate the nail to deliver an inhibitory concentration of free drug to the site of infection. In two ex vivo experiments, we tested the ability of topical antifungals to inhibit growth of Trichophyton rubrum and Trichophyton mentagrophytes, the most common causative fungi in toenail onychomycosis., Methods: Seven topical antifungals were tested: three U.S. Food and Drug Administration-approved products indicated for onychomycosis (ciclopirox 8% lacquer; efinaconazole 10% solution; tavaborole 5% solution) and four over-the-counter (OTC) products for fungal infections (tolnaftate 1% and/or undecylenic acid 25% solutions). The ability to inhibit fungal growth was tested in the presence and absence of keratin. Products were applied either to human cadaverous nails or keratin-free cellulose disks prior to placement on an agar plate (radius: 85 mm) seeded with a clinical isolate of T. rubrum or T. mentagrophytes. After incubation, the zone of inhibition (ZI), defined as the radius of the area of no fungal growth, was recorded., Results: In the nail penetration assay, average ZIs for efinaconazole (T. rubrum: 82.1 mm; T. mentagrophytes: 63.8 mm) were significantly greater than those for tavaborole (63.5 mm; 39.1 mm), ciclopirox (7.4 mm; 3.6 mm) and all OTC products (range: 10.5-34.2 mm against both species; all P < 0.001). In the cellulose disk diffusion assay, efinaconazole and tavaborole demonstrated maximal antifungal activity against both species (ZIs = 85 mm); average ZIs against T. rubrum and T. mentagrophytes were smaller for ciclopirox (59.0 and 55.7 mm, respectively) and OTC products (range: 31.2-57.8 mm and 25.7-47.7 mm, respectively)., Conclusions: Among all antifungals tested, the ability to penetrate human toenails to inhibit growth of both T. rubrum and T. mentagrophytes was greatest for efinaconazole, followed by tavaborole. These results indicate superior transungual penetration of efinaconazole compared to the other antifungals, suggesting lower keratin binding in the nail., (© 2024. The Author(s).)

The control of Candida albicans biofilm formation on dentures made of poly(methyl methacrylate) (PMMA) is an important challenge due to the high resistance to antifungal drugs. Interestingly, the natural compounds undecylenic acid (UDA) and farnesol (FAR) both prevent C. albicans biofilm formation and could have a synergetic effect. We therefore modified PMMA with a combination of UDA and FAR (UDA+FAR), aiming to obtain the antifungal PMMA&#95;UDA+FAR composites. Equal concentrations of FAR and UDA were added to PMMA to reach 3%, 6%, and 9% in total of both compounds in composites. The physico-chemical properties of the composites were characterized by Fourier-transform infrared spectroscopy and water contact angle measurement. The antifungal activity of the composites was tested on both biofilm and planktonic cells with an XTT test 0 and 6 days after the composites' preparation. The effect of the UDA+FAR combination on C. albicans filamentation was studied in agar containing 0.0125% and 0.4% UDA+FAR after 24 h and 48 h of incubation. The results showed the presence of UDA and FAR on the composite and decreases in the water contact angle and metabolic activity of both the biofilm and planktonic cells at both time points at non-toxic UDA+FAR concentrations. Thus, the modification of PMMA with a combination of UDA+FAR reduces C. albicans biofilm formation on dentures and could be a promising anti- Candida strategy.

Membrane materials with osmium nanoparticles have been recently reported for bulk membranes and supported composite membrane systems. In the present paper, a catalytic material based on osmium dispersed in n-decanol (nD) or n-dodecanol (nDD) is presented, which also works as an emulsion membrane. The hydrogenation of p-nitrophenol (PNP) is carried out in a reaction and separation column in which an emulsion in the acid-receiving phase is dispersed in an osmium nanodispersion in n-alcohols. The variables of the PNP conversion process and p-aminophenol (PAP) transport are as follows: the nature of the membrane alcohol, the flow regime, the pH difference between the source and receiving phases and the number of operating cycles. The conversion results are in all cases better for nD than nDD. The counter-current flow regime is superior to the co-current flow. Increasing the pH difference between the source and receiving phases amplifies the process. The number of operating cycles is limited to five, after which the regeneration of the membrane dispersion is required. The apparent catalytic rate constant ( k app ) of the new catalytic material based on the emulsion membrane with the nanodispersion of osmium nanoparticles (0.1 × 10 -3 s -1 for n-dodecanol and 0.9 × 10 -3 s -1 for n-decanol) is lower by an order of magnitude compared to those based on adsorption on catalysts from the platinum metal group. The advantage of the tested membrane catalytic material is that it extracts p-aminophenol in the acid-receiving phase.

Undecylenic acid, a monounsaturated fatty acid, is currently in clinical use as a topical antifungal agent, however the potential for therapeutic application in other disease settings has not been investigated. In this study, we describe a novel platform for the solubilization of fatty acids using amino acids and utilize this approach to define a tumoricidal activity and underlying mechanism for undecylenic acid. We examined a novel formulation of undecylenic acid compounded with L-Arginine, called GS-1, that induced concentration-dependent tumor cell death, with undecylenic acid being the cytotoxic component. Further investigation revealed that GS-1-mediated cell death was caspase-dependent with a reduction in mitochondrial membrane potential, suggesting a pro-apoptotic mechanism of action. Additionally, GS-1 was found to localize intracellularly to lipid droplets. In contrast to previous studies where lipid droplets have been shown to be protective against fatty acid-induced cell death, we showed that lipid droplets could not protect against GS-1-induced cytotoxicity. We also found a role for Fatty Acid Transport Protein 2 (FATP2) in the uptake of this compound. Collectively, this study demonstrates that GS-1 has effective pro-apoptotic antitumor activity in vitro and, together with the novel platform of fatty acid solubilization, contributes to the re-emerging field of fatty acids as potential anti-cancer therapeutics.

Onychomycosis is a prominent fungal infection that causes discoloration, thickening, and mutilation leading to the separation of the nail from the nail bed. Treatment modalities for onychomycosis may include oral, topical, or combination therapy with antifungals and at times may require chemical or surgical intervention. The burden of side effects of antifungals is enormous, and therefore using molecular docking-based drug selection in context with the target keratin protein would ensure better disease management. Ciclopirox, Amorolfine HCl, Efinaconazole, Tioconazole, and Tavaborole were submitted for assessment, revealing that Amorolfine HCl is the best fit. Consequently, two formulations (Nail lacquer and nanoemulgel) were developed from Amorolfine HCl to validate the in silico screening outcomes. The formulations were further fortified with over-the-counter ingredients vis-a-vis with vitamin E in nail lacquer and undecylenic acid in nanoemulgel for their prominent roles in improving nail health. Both the formulations were systematically designed, optimized, and characterized. Amorolfine HCl containing nanoemulgel (NEG) was developed using undecylenic acid as an oil phase and thioglycolic acid as a penetration enhancer. The quality parameters evaluated were particle size, the zeta potential for nanoemulsion (NE) (78.04 ± 4.724 nm and -0.7mV, respectively), in vitro cumulative drug release (96.74% for NE and 88.54% for NEG), and transungual permeation (about 73.49% for NEG and 54.81% for NE). Nail lacquer was evaluated for the drying time, non-volatile content, and blush test. In vitro cumulative drug release of the developed nail lacquer and comparator marketed formulations were around 81.5% and 75%, respectively. Similarly, the transungual drug permeation was 6.32 μg/cm 2 and 5.89 μg/cm 2 , respectively, in 24 h. The in silico guided preparation of both formulations containing Amorolfine HCl and over the counter ingredients is amenable for therapeutic use against onychomycosis and will be evaluated in the in vivo model.

In this work, three new mixed-mode stationary phases were prepared, based on different ratio of N-vinyl pyrrolidone (NVP) copolymerized together with undecylenic acid (UA) on silica microspheres surface without silanization, which named Sil@NVPUA series. The combination of NVP and UA rendered the Sil@NVPUA suitable for reversed-phase liquid chromatography (RPLC) and hydrophilic interaction liquid chromatography (HILIC), and shown excellent methyl, planar, isomers and ion selectivity. Five types of model analytes including eight polycyclic aromatic hydrocarbons, six alkylbenzenes, eight nucleosides and nucleobases, seven ginsenosides and five oxazolidinones can be well separated on this stationary phase. The preparation method of NVP and UA modified silica-based stationary phase is simple, and it also provides a new idea for the design of synthetic polymers to develop mixed-mode chromatography., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021. Published by Elsevier B.V.)

We present the development of surfactant-free, silica-free and fully biobased oil-in-water antimicrobial Pickering emulsions, based on the self-assembly of β-cyclodextrin and phytoantimicrobial oils (terpinen-4-ol or carvacrol). Undecylenic acid (UA), derived from castor oil, can be used as bio-based drug to treat fungal infection, but is less effective than petroleum-based drugs as azole derivatives. To maximize its antifungal potential, we have incorporated UA in fully biobased Pickering emulsions. These emulsions are effective against fungi, Gram-positive and Gram-negative bacteria. The carvacrol emulsion charged with UA is +390 % and +165 % more potent against methicillin-resistant S. aureus (MRSA), compared to UA and azole-based commercial formulations. Moreover, this emulsion is up to +480 % more efficient that UA ointment against C. albicans. Finally, remarkable eradication of E. coli and MRSA biofilms was obtained with this environmental-friendly emulsion., (© 2021 Wiley-VCH GmbH.)

The synthesis of undecylenic acid partial esters can be performed at mild temperature with a classical esterification reaction catalyzed by dodecylbenzene sulfonic acid (DBSA). A semi-empirical molecular modeling on the different reaction intermediates indicates that DBSA can strongly decrease their heats of formation through hydrogen bonding. Diester formation seems to be thermodynamically favored with a selectivity for alpha, alpha, or alpha, beta forms that depend on the geometry of the catalyst-intermediate configuration. Triesters are not favored but a high selectivity for monoesters requires a kinetic control. Experimental approach, considering different DBSA concentrations and temperature partially confirms the theoretical predictions but surfactant properties of DBSA and monoesters may induce nonpredicted geometries. Global apparent activation energies are calculated, corresponding to the formation and hydrolysis of mono and diesters. If water trapping allows the decrease of hydrolysis reaction constants, the presence of water and subsequent phase separation may explain differences between theoretical and experimental results and could help increasing monoester selectivity., (© 2020 AOCS.)

Due to the growing issues with fungal infections, especially with Candida , there is still a need to develop novel anti- Candida materials. One of the known antifungal agents is undecylenic acid (UA), which still cannot be efficiently used due to its oily nature, and thus limited solubility. By taking advantage of the properties of UA, we developed an emulsion with hexagonal phase, i.e., hexosomes, whose structure and morphology was studied by small-angle X-ray scattering and cryo-electron microscopy, respectively. The presence of UA in the hexosome was confirmed by spectroscopy. Moreover, we studied the anti- Candida effect of hexosomes and their cytotoxicity toward human cells. The minimal inhibitory concentration for the 50% and 90% Candida -growth reduction was found at 0.01 and 0.16 wt % hexosomes, respectively (i.e., 2 and 32 pg hex / C.a. cell, respectively). The percentage of metabolically active Candida was reduced by 72-96% at hexosome concentrations of 1.0-8.2 pg hex / C.a. cell as compared to untreated Candida . Furthermore, at the same concentration range the embedded filamentation test after 24 and 48 h showed the inhibition of both the filamentation and growth of Candida , while the preliminary toxicity test showed that hexosomes were nontoxic for human cells. All these render the here-developed hexosomes with UA efficient and promising anti- Candida agents., Competing Interests: The authors declare no conflict of interest. The founding sponsors had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, and in the decision to publish the results.

Undecylenic acid (UA), known as antifungal agent, still cannot be used to efficiently modify commercial dental materials in such a way that this affects Candida . Actually, issues with Candida infections and fungal resistance compromise the use of Poly(methyl-methacrylate) (PMMA) as dental material. The challenge remains to turn PMMA into an antifugal material, which can ideally affect both sessile (attached) and planktonic (free-floating) Candida cells. We aimed to tackle this challenge by designing PMMA-UA composites with different UA concentrations (3-12%). We studied their physico-chemical properties, the antifungal effect on Candida and the cytotoxicity toward human cells. We found that UA changes the PMMA surface into a more hydrophilic one. Mainly, as-preparation composites with ≥6% UA reduced sessile Candida for >90%. After six days, the composites were still efficiently reducing the sessile Candida cells (for ~70% for composites with ≥6% UA). Similar results were recorded for planktonic Candida . Moreover, the inhibition zone increased along with the UA concentration. The antifungal effect of UA was also examined at the surface of an UA-loaded agar and the minimal inhibitory concentration (MIC90) was below the lowest-studied 0.0125% UA. Furthermore, the embedded filamentation test after 24 h and 48 h showed complete inhibition of the Candida growth at 0.4% UA., Competing Interests: The authors declare no conflict of interest.

The main objectives of the present study were to investigate the biocompatibility of polyelectrolyte-coated nanocapsules and to evaluate the neuroprotective action of the nanoencapsulated water-insoluble neuroprotective drug-undecylenic acid (UDA), in vitro. Core-shell nanocapsules were synthesized using nanoemulsification and the layer-by-layer (LbL) technique (by saturation method). The average size of synthesized nanocapsules was around 80 nm and the concentration was 2.5 × 10(10) particles/ml. Their zeta potential values ranged from less than -30 mV for the ones with external polyanion layers through -4 mV for the PEG-ylated layers to more than 30 mV for the polycation layers. Biocompatibility of synthesized nanocarriers was evaluated in the SH-SY5Y human neuroblastoma cell line using cell viability/toxicity assays (MTT reduction, LDH release). The results obtained showed that synthesized nanocapsules coated with PLL and PGA (also PEG-ylated) were non-toxic to SH-SY5Y cells, therefore, they were used as nanocarriers for UDA. Moreover, studies with ROD/FITC-labeled polyelectrolytes demonstrated approximately 20% cellular uptake of synthetized nanocapsules. Further studies showed that nanoencapsulated form of UDA was biocompatible and protected SH-SY5Y cells against the staurosporine-induced damage in lower concentrations than those of the same drug added directly to the culture medium. These data suggest that designed nanocapsules might serve as novel, promising delivery systems for neuroprotective agents., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Undecylenic acid in a dosage tolerated by most patients is of doubtful value in the treatment of psoriasis and neurodermatitis.Thirty-one patients were given the drug. Exudative dermatitis developed in one case, generalized pruritus in another. One patient may have had a cardiac accident attributable to the drug.