The increasing importance of novel deep eutectic solvents as potential effective antimicrobials and other medicinal properties.

With the rise of antibiotic resistance globally, coupled with evolving and emerging infectious diseases, there is an urgent need for the development of novel antimicrobials. Deep eutectic solvents (DES) are a new generation of eutectic mixtures that depict promising attributes with several biological implications. DES exhibit unique properties such as low toxicity, biodegradability, and high thermal stability. Herein, the antimicrobial properties of DES and their mechanisms of action against a range of microorganisms, including bacteria, amoebae, fungi, viruses, and anti-cancer properties are reviewed. Overall, DES represent a promising class of novel antimicrobial agents as well as possessing other important biological attributes, however, future studies on DES are needed to investigate their underlying antimicrobial mechanism, as well as their in vivo effects, for use in the clinic and public at large.

A novel montmorillonite clay-cetylpyridinium chloride complex as a potential antiamoebic composite material in contact lenses disinfection.

BACKGROUND: Acanthamoeba keratitis is a painful, sight-threatening infection. It is commonly associated with the use of contact lens. Several lines of evidence suggest inadequate contact lens solutions especially against the cyst forms of pathogenic Acanthamoeba, indicating the need to develop effective disinfectants. OBJECTIVE: In this work, the application and assessment of montmorillonite clay (Mt-clay), cetylpyridinium chloride (CPC) and cetylpyridinium chloride-montmorillonite clay complex (CPC-Mt) against keratitis-causing A. castellanii belonging to the T4 genotype was studied. METHODS: Adhesion to human cells and amoeba-mediated cytopathogenicity assays were conducted to determine the impact of Mt-clay, CPC and CPC-Mt complex on amoeba-mediated binding and host cell death. Furthermore, assays were also performed to determine inhibitory effects of Mt-clay, CPC and CPC-Mt complex on encystment and excystment. In addition, the cytotoxicity of Mt-clay, CPC and CPC-Mt complex against human cells was examined. RESULTS: The results revealed that CPC and CPC-Mt complex presented significant antiamoebic effects against A. castellanii at microgram dose. Also, the CPC and CPC-Mt complex inhibited amoebae binding to host cells. Furthermore, CPC and CPC-Mt complex, were found to inhibit the encystment and excystment processes. Finally, CPC and CPC-Mt complex showed minimal host cell cytotoxicity. These results show that CPC and CPC-Mt complex exhibit potent anti-acanthamoebic properties. CONCLUSION: Given the ease of usage, safety, cost-effectiveness and long-term stability, CPC and CPC-Mt complex can prove to be an excellent choice in the rational development of contact-lens disinfectants to eradicate pathogenic Acanthamoeba effectively.

Antibacterial effects of octadecyl trimethylammonium micelle-clay complex against bacterial eye pathogens: potential as a contact lens disinfectant.

AIM: In this study, we utilized a micelle-clay complex composed of the surfactant octadecyltrimethylammonium bromide and montmorillonite clay and evaluated its antibacterial effects. METHODS: Using Pseudomonas aeruginosa, Staphylococcus epidermidis, and Micrococcus luteus, bactericidal assays were performed to determine the effects of ODTMA-clay complex on the viability of bacterial pathogen at various doses and different intervals of time. Cytotoxicity assays were performed to investigate ODTMA-clay complex effects on human cells, as determined by release of intracellular lactate dehydrogenase. RESULTS: The results revealed that ODTMA-clay complex abolished bacterial viability at 100 µg/mL within 45 min against P. aeruginosa, S. epidermidis, and M. luteus. Cytotoxicity assays revealed that ODTMA-clay complex exhibited minimal toxicity of the human cells. CONCLUSION: Rapid and potent antibacterial effects of ODTMA micelle-clay complex were observed in vitro; however, research is needed to determine precise formulation of contact lens disinfectants comprising ODTMA micelle-clay complex. Additionally, studies should be conducted using in vivo models of keratitis, progressing to pre-clinical and clinical trials. ODTMA micelle-clay complex is an ideal candidate to be incorporated in a novel contact lens disinfectant given the cost-effectiveness and ease of application and can be incorporated as an effective preventative strategy.

Cationic Surfactant-Natural Clay Complex as a Novel Agent Against Acanthamoeba castellanii Belonging to the T4 Genotype.

BACKGROUND: Acanthamoeba is a protozoan pathogen that is widely distributed in the environment. Given the opportunity, it can cause a serious eye infection known as Acanthamoeba keratitis as well as a fatal brain infection known as granulomatous amoebic encephalitis. Inappropriate use of contact lenses can contribute to contracting Acanthamoeba keratitis, and contact lens disinfectants are not always effective in eradicating Acanthamoeba. Therefore, there is a need to develop novel antimicrobial agents with efficient antiamoebic properties. OBJECTIVE: In this study, we tested octadecyltrimethylammonium (ODTMA)-clay (montmorillonite) complex as a novel antiamoebic agent. METHODS: Using A. castellanii belonging to the T4 genotype of keratitis origin, amobicidal assays were performed to determine the effects of ODTMA-cay complex on the viability of parasites at various concentrations ranging from 10 to 100 µg. Adhesion and cytopathogenicity assays were performed to investigate ODTMA effects on A. castellanii-mediated binding and damage to human cells. Encystation and excystation assays were conducted to establish ODTMA-mediated inhibitory effects against the cyst stage of A. castellanii. RESULTS: Using cell survival assays, the results revealed that ODTMA-clay complex exhibited amobicidal activity against keratitis-causing A. castellanii in a dose-dependent manner. Pretreatment of A. castellanii with ODTMA-clay complex inhibited parasite adhesion to as well as parasite-mediated human cell damage. Using encystation and excystation assays, it was revealed that ODTMA-clay complex inhibited A. castellanii cysts at 100 µg (P<0.05). CONCLUSION: To the best of our knowledge, for the first time, it was shown that ODTMA-clay complex exhibited anti-Acanthamoebic activities. The possibility of adding ODTMA-clay in a contact lens cleaning solution to formulate effective disinfectants is discussed further.

Group Contribution Estimation of Ionic Liquid Melting Points: Critical Evaluation and Refinement of Existing Models.

While several group contribution method (GCM) models have been developed in recent years for the prediction of ionic liquid (IL) properties, some challenges exist in their effective application. Firstly, the models have been developed and tested based on different datasets; therefore, direct comparison based on reported statistical measures is not reliable. Secondly, many of the existing models are limited in the range of ILs for which they can be used due to the lack of functional group parameters. In this paper, we examine two of the most diverse GCMs for the estimation of IL melting point; a key property in the selection and design of ILs for materials and energy applications. A comprehensive database consisting of over 1300 data points for 933 unique ILs, has been compiled and used to critically evaluate the two GCMs. One of the GCMs has been refined by introducing new functional groups and reparametrized to give improved performance for melting point estimation over a wider range of ILs. This work will aid in the targeted design of ILs for materials and energy applications.

Stability and removal of spironolactone from wastewater.

Stability and removal of spironolactone (SP) from wastewater produced at Al-Quds University Campus were investigated. Kinetic studies on both pure water and wastewater coming from secondary treatment (activated sludge) demonstrated that the potassium-sparing diuretic (water pill), spironolactone, underwent degradation to its hydrolytic derivative, canrenone, in both media. The first-order hydrolysis rate of SP in activated sludge at 25°C (3.80 × 10(-5) s(-1)) was about 49-fold larger than in pure water (7.4 × 10(-7) s(-1)). The overall performance of the wastewater treatment plant (WWTP) installed in the University Campus was assessed showing that more than 90% of spiked SP was removed together with its newly identified metabolites. In order to look for a technology to supplement or replace ultra-filtration membranes, the effectiveness of adsorption and filtration by micelle-clay filters for removing SP was tested in comparison with activated charcoal. Batch adsorption in aqueous suspensions was well described by Langmuir isotherms, showing a better removal by the micelle-clay material. Filtration of SP water solutions by columns filled with a mixture of sand and a micelle-clay complex showed complete removal of the drug at concentrations higher than in sand/activated-charcoal filled filters.

Removal of amoxicillin and cefuroxime axetil by advanced membranes technology, activated carbon and micelle-clay complex.

Two antibacterials, amoxicillin trihydrate and cefuroxime axetil spiked into wastewater were completely removed by sequential wastewater treatment plant's membranes, which included activated sludge, ultrafiltration (hollow fibre and spiral wound membranes with 100 and 20 kDa cut-offs), activated carbon column and reverse osmosis. Adsorption isotherms in synthetic water which employed activated carbon and micelle-clay complex (octadecyltrimethylammonium-montmorillonite) as adsorbents fitted the Langmuir equation. Qmax of 100 and 90.9 mg g(-1), and K values of 0.158 and 0.229 L mg(-1) were obtained for amoxicillin trihydrate using activated carbon and micelle-clay complex, respectively. Filtration of antibacterials in the ppm range, which yielded variable degrees of removal depending on the volumes passed and flow rates, was simulated and capacities for the ppb range were estimated. Stability study in pure water and wastewater revealed that amoxicillin was totally stable for one month when kept at 37°C, whereas cefuroxime axetil underwent slow hydrolysis to cefuroxime.

Stability and removal of dexamethasone sodium phosphate from wastewater using modified clays.

Stability and removal of dexamethasone sodium phosphate (DSP) from wastewater produced at Al-Quds University Campus were investigated. Kinetic studies in both pure water and wastewater coming from secondary treatment (activated sludge) demonstrated that the anti-inflammatory DSP underwent degradation to its hydrolytic derivative, dexamethasone, in both media. The first-order hydrolysis rate of DSP in activated sludge at 25 degrees C (3.80 x 10(-6) s-1) was about 12-fold larger than in pure water (3.25 x 10(-7) s-1). The overall performance of the wastewater treatment plant (WWTP) installed in the University Campus was also assessed showing that 90% of spiked DSP was removed together with its newly identified metabolites by the ultra-filtration (UF) system, which consists of a UF hollow fibre (HF) with a 100-kDa cutoff membrane as the pre-polishing stage for the UF spiral wound with a 20-kDa cutoffmembrane. In testing other technologies, the effectiveness of adsorption and filtration by micelle-clay (MC) preparation for removing DSP was ascertained in comparison with activated charcoal. Batch adsorption in aqueous suspensions of the MC composite and activated carbon was well described by Langmuir isotherms showing the best results for MC material. Filtration of DSP water solutions demonstrated a significant advantage of columns filled in with a mixture of sand and MC complex in comparison with activated carbon/sand filters.

Phosphonium chloride-based deep eutectic solvents inhibit pathogenic Acanthamoeba castellanii belonging to the T4 genotype.

Herein, we investigated the anti-amoebic activity of phosphonium-chloride-based deep eutectic solvents against pathogenic Acanthamoeba castellanii of the T4 genotype. Deep eutectic solvents are ionic fluids composed of two or three substances, capable of self-association to form a eutectic mixture with a melting point lower than each substance. In this study, three distinct hydrophobic deep eutectic solvents were formulated, employing trihexyltetradecylphosphonium chloride as the hydrogen bond acceptor and aspirin, dodecanoic acid, and 4-tert-butylbenzoic acid as the hydrogen bond donors. Subsequently, all three deep eutectic solvents, denoted as DES1, DES2, DES3 formulations, underwent investigations comprising amoebicidal, adhesion, excystation, cytotoxicity, and cytopathogenicity assays. The findings revealed that DES2 was the most potent anti-amoebic agent, with a 94% elimination rate against the amoebae within 24 h at 30 °C. Adhesion assays revealed that deep eutectic solvents hindered amoebae adhesion to human brain endothelial cells, with DES2 exhibiting 88% reduction of adhesion. Notably, DES3 exhibited remarkable anti-excystation properties, preventing 94% of cysts from reverting to trophozoites. In cytopathogenicity experiments, deep eutectic solvent formulations and dodecanoic acid alone reduced amoebae-induced human brain endothelial cell death, with DES2 showing the highest effects. Lactate dehydrogenase assays revealed the minimal cytotoxicity of the tested deep eutectic solvents, with the exception of trihexyltetradecylphosphonium chloride, which exhibited 35% endothelial cell damage. These findings underscore the potential of specific deep eutectic solvents in combating pathogenic Acanthamoeba, presenting promising avenues for further research and development against free-living amoebae.

The Zanzibar Heart Survey: A special report from a humanitarian cardiology program at the Mnazi Mmoja referral hospital, Zanzibar, United Republic of Tanzania by Haukeland University Hospital in Bergen, Norway.

A Norwegian cardiology delegation comprised of Cardiologists and Researchers travelled voluntarily to Zanzibar to undertake 4 humanitarian missions in 2022. The principal aims of this were to: 1) Train local cardiologists in transthoracic echocardiography and perform echocardiographic screening in patients with cardiac symptoms who had not undergone any prior cardiac imaging, 2) Conduct a hypertension survey to improve awareness, treatment and control of hypertension and 3) Implant permanent pacemakers in patients with significant bradyarrhythmias for the first time in the Archipelago. The current report details our experience at the Mnazi Mmoja Referral Hospital. We describe the challenges in managing common cardiovascular conditions such as hypertension, cardiomyopathies, coronary artery disease and rhythm disturbances. Furthermore, we propose that improvement to care may be achieved by implementing systematic access to echocardiography and hypertension services to the island. In our survey, we found that hypertension and hypertension-mediated target organ damage were highly prevalent and hypertension was poorly controlled in Zanzibar. The common reasons for poor BP control were reported to be partly the issue of cost, affordability and availability of antihypertensive medications, and partly due to lack of awareness. Women were on average 10 years younger than men and were more likely to be obese, while men had higher burden of established cardiovascular disease (CAD, stroke, chronic kidney disease, and atrial fibrillation). Humanitarian healthcare missions by Western countries provide invaluable contributions to the healthcare of patients elsewhere in the world. Although their impact can be felt immediately, there is the propensity for these benefits to dissipate rapidly following the departure of visiting delegations. There is a need for more sustainable solutions whereby local healthcare systems are empowered to develop their own local capacities and initiate a system whereby local training can occur, the utilisation of facilities can be maximised and new skills can be transferred to health care practitioners to ensure universal access to diagnostics and treatments of cardiovascular diseases in Zanzibar. Our report indicates that measurable changes can be achieved in a relatively short time frame. These may in turn translate to improvements in access and quality of healthcare to the local population.

Removal of Cr(VI) from aqueous environments using micelle-clay adsorption.

Removal of Cr(VI) from aqueous solutions under different conditions was investigated using either clay (montmorillonite) or micelle-clay complex, the last obtained by adsorbing critical micelle concentration of octadecyltrimethylammonium ions onto montmorillonite. Batch experiments showed the effects of contact time, adsorbent dosage, and pH on the removal efficiency of Cr(VI) from aqueous solutions. Langmuir adsorption isotherm fitted the experimental data giving significant results. Filtration experiments using columns filled with micelle-clay complex mixed with sand were performed to assess Cr(VI) removal efficiency under continuous flow at different pH values. The micelle-clay complex used in this study was capable of removing Cr(VI) from aqueous solutions without any prior acidification of the sample. Results demonstrated that the removal effectiveness reached nearly 100% when using optimal conditions for both batch and continuous flow techniques.

Inland treatment of the brine generated from reverse osmosis advanced membrane wastewater treatment plant using epuvalisation system.

The reverse osmosis (RO) brine generated from the Al-Quds University wastewater treatment plant was treated using an epuvalisation system. The advanced integrated wastewater treatment plant included an activated sludge unit, two consecutive ultrafiltration (UF) membrane filters (20 kD and 100 kD cutoffs) followed by an activated carbon filter and a reverse osmosis membrane. The epuvalisation system consisted of salt tolerant plants grown in hydroponic channels under continuous water flowing in a closed loop system, and placed in a greenhouse at Al-Quds University. Sweet basil (Ocimum basilicum) plants were selected, and underwent two consecutive hydroponic flowing stages using different brine-concentrations: an adaptation stage, in which a 1:1 mixture of brine and fresh water was used; followed by a functioning stage, with 100% brine. A control treatment using fresh water was included as well. The experiment started in April and ended in June (2012). At the end of the experiment, analysis of the effluent brine showed a remarkable decrease of electroconductivity (EC), PO43-, chemical oxygen demand (COD) and K+ with a reduction of 60%, 74%, 70%, and 60%, respectively, as compared to the influent. The effluent of the control treatment showed 50%, 63%, 46%, and 90% reduction for the same parameters as compared to the influent. Plant growth parameters (plant height, fresh and dry weight) showed no significant difference between fresh water and brine treatments. Obtained results suggest that the epuvalisation system is a promising technique for inland brine treatment with added benefits. The increasing of channel number or closed loop time is estimated for enhancing the treatment process and increasing the nutrient uptake. Nevertheless, the epuvalisation technique is considered to be simple, efficient and low cost for inland RO brine treatment.

Efficiency of membrane technology, activated charcoal, and a micelle-clay complex for removal of the acidic pharmaceutical mefenamic acid.

The efficiency of sequential advanced membrane technology wastewater treatment plant towards removal of a widely used non-steroid anti-inflammatory drug (NSAID) mefenamic acid was investigated. The sequential system included activated sludge, ultrafiltration by hollow fibre membranes with 100 kDa cutoff, and spiral wound membranes with 20 kDa cutoff, activated carbon and a reverse osmosis (RO) unit. The performance of the integrated plant showed complete removal of mefenamic acid from spiked wastewater samples. The activated carbon column was the most effective component in removing mefenamic acid with a removal efficiency of 97.2%. Stability study of mefenamic acid in pure water and Al-Quds activated sludge revealed that the anti-inflammatory drug was resistant to degradation in both environments. Batch adsorption of mefenamic acid by activated charcoal and a composite micelle (otadecyltrimethylammonium (ODTMA)-clay (montmorillonite) was determined at 25.0°C. Langmuir isotherm was found to fit the data with Qmax of 90.9 mg g(-1) and 100.0 mg g(-1) for activated carbon and micelle-clay complex, respectively. Filtration experiment by micelle-clay columns mixed with sand in the mg L(-1) range revealed complete removal of the drug with much larger capacity than activated carbon column. The combined results demonstrated that an integration of a micelle-clay column in the plant system has a good potential to improve the removal efficiency of the plant towards NSAID drugs such as mefenamic acid.

Efficiency of advanced wastewater treatment plant system and laboratory-scale micelle-clay filtration for the removal of ibuprofen residues.

The efficiency of Al-Quds Waste Water Treatment Plant (WWTP), which includes sequential elements as activated sludge, ultrafiltration, activated carbon column and reverse osmosis, to remove spiked ibuprofen, a non steroid anti inflammatory drug (NSAID), was investigated. Kinetic studies in pure water and in the activated sludge indicated that the drug was stable during one month of observation. Besides, the overall performance of the integrated plant showed complete removal of ibuprofen from wastewater. Activated carbon column, which was the last element in the sequence before the reverse osmosis system, yielded 95.7% removal of ibuprofen. Batch adsorptions of the drug by using either activated charcoal or composite micelle-clay system were determined at 25°C and well described by Langmuir isotherms. Octadecyltrimethylammonium (ODTMA) bromide and montmorillonite were used to prepare the micelle-clay adsorbent, for which the adsorption kinetics are much faster than activated charcoal. Results suggest that integrating clay-micelle complex filters within the existing WWTP may be promising in improving removal efficiency of the NSAID.

Antiamoebic properties of Methyltrioctylammonium chloride based deep eutectic solvents.

PURPOSE: This aim of this study was to assess anti-parasitic properties of deep eutectic solvents against eye pathogen, Acanthamoeba, often associated with the use of contact lens. METHODS: Assays were performed to investigate the effects of various Methyltrioctylammonium chloride-based deep eutectic solvents on Acanthamoeba castellanii, comprising amoebicidal assays, encystment assays, excystment assays, cytotoxicity assays by measuring lactate dehydrogenase release from human cells, and cytopathogenicity assays to determine parasite-mediated host cell death. RESULTS: In a 2 h incubation period, DES-B, DES-C, DES-D, and DES-E exhibited up to 85 % amoebicidal activity at micromolar doses, which was enhanced further following 24 h incubation. When tested in encystment assays, selected deep eutectic solvents abolished cyst formation and were able to block excystment of A. castellanii. All solvents exhibited minimal human cell cytotoxicity except DES-D. Finally, all tested deep eutectic solvents inhibited amoeba-mediated cytopathogenicity, except DES-B. CONCLUSIONS: Deep eutectic solvents show potent antiamoebic effects. These findings are promising and could lead to the development of novel contact lens disinfectants, as well as opening several avenues to explore the molecular mechanisms, various doses and incubation periods, and use of different bases against Acanthamoeba castellanii.

A Two-Step Femtosecond Laser-Based Deposition of Robust Corrosion-Resistant Molybdenum Oxide Coating.

A two-step femtosecond-pulsed laser deposition (fs-PLD) process is reported for the rapid development of uniform, poreless, crack-free, and well-adhering amorphous coatings of source materials with a high melting point. The first step comprises a high-rate raw deposition of the source material via fs-PLD, followed by a second step of scanning the raw sample with fs laser pulses of optimized fluence and scan parameters. The technique is applied to develop substoichiometric molybdenum oxide (MoOx, x < 3) coatings on mild steel. The thickness of the layer was ~4.25 µm with roughness around 0.27 µm. Comprehensive surface characterization reveals highly uniform and relatively moderate roughness coatings, implying the potential of these films as robust corrosion-resistant coats. Corrosion measurements in an aqueous NaCl environment revealed that the coated mild steel samples possess an average corrosion inhibition efficiency of around 95% relative to polished mild steel.

Removal of diclofenac potassium from wastewater using clay-micelle complex.

The presence of an ionized carboxyl group in the widely used non-steroidal anti-inflammatory (NSAID) drug diclofenac potassium results in a high mobility of diclofenac and in its low sorption under conditions of slow sand filtration or subsoil passage. No diclofenac degradation was detected in pure water or sludge during one month. Tertiary treatments of wastewater indicated that the effective removal of diclofenac was by reverse osmosis, but the removal by activated carbon was less satisfactory. This study presents an efficient method for the removal of diclofenac from water by micelle-clay composites that are positively charged, have a large surface area and include large hydrophobic domains. Adsorption of diclofenac in dispersion by charcoal and a composite micelle (otadecyltrimethylammonium [ODTMA] and clay [montmorillonite]) was investigated. Analysis by the Langmuir isotherm revealed that charcoal had a somewhat larger number of adsorption sites than the composite, but the latter had a significantly larger binding affinity for diclofenac. Filtration experiments on a solution containing 300 ppm diclofenac demonstrated poor removal by activated carbon, in contrast to very efficient removal by micelle-clay filters. In the latter case the weight of removed diclofenac exceeded half that of ODTMA in the filter. Filtration of diclofenac solutions at concentrations of 8 and 80 ppb yielded almost complete removal at flow rates of 30 and 60 mL min(-1). One kilogram of ODTMA in the micelle-clay filter has been estimated to remove more than 99% of diclofenac from a solution of 100 ppb during passage of more than 100 m3.

Enhancing Gas Solubility in Water via Femtosecond Laser-Induced Plasma.

The generation of laser-induced plasma at the gas-liquid interface provides many fundamental and interesting scientific phenomena such as ionization, sharp explosion, shock wave radiation, bubble creation, and water splitting. However, despite the extensive research in this area, there is no reference on the effect of the surrounding environment on the chemical processes that occur during the laser-induced plasma-water interaction. In this work, we investigate the effect of the surrounding gas environment on femtosecond laser-induced plasma when generated at the pure water-gas interface. Ultrashort laser pulses were applied to water in the presence of air and N2 and Ar gas environments. Formation of a significant number of nitrate-based species in water was observed after exposure to femtosecond laser-induced plasma in air and N2 environments. The detected NO3 ions formed in the laser-treated water led to the appearance of an absorption peak in the UV range, a significant decrease in the water pH value, and a significant increase in water's electrical conductivity. All induced properties of water were stable for 3 months of monitoring after laser treatment. Our work shows that the generation of laser-induced plasma in water propagating into a gaseous medium facilitates the interaction between the two media, as a result of which the compositions of substances present in the gaseous medium can be dissolved in water without increasing the gas pressure. The presented approach may find applications in areas such as water purification, material synthesis, and environmental stewardship.

Primary Amoebic Meningoencephalitis: Potential Application of Ionic Liquids Against Brain-Eating Amoebae?

Naegleria fowleri, a well-known brain-eating amoeba, induces high mortality with no available effective treatment. Ionic liquids are compounds that contain a variety of cations and anions that can be tailored to specific applications. Based on the biological, chemical and physical properties of these ionic liquids, this work proposes the use of ionic liquids as novel anti-Naegleria fowleri biocides.

Antiamoebic properties of salicylic acid-based deep eutectic solvents for the development of contact lens disinfecting solutions against Acanthamoeba.

Acanthamoeba castellanii is a protist pathogen that can cause sight-threatening keratitis and a fatal infection of the central nervous system, known as granulomatous amoebic encephalitis. In this study, effects of five malonic acid and salicylic acid-based deep eutectic solvents (DES) on A. castellanii were investigated. These are salicylic acid-trioctylphosphine (DES 1), salicylic acid- trihexylamine (DES 2), salicylic acid-trioctylamine (DES 3), malonic acid-trioctylphosphine (DES 4) and malonic acid-trihexylamine (DES 5). The experiments were done by performing amoebicidal, encystment, excystment, cytopathogenicity, and cytotoxicity assays. At micromolar dosage, the solvents DES 2 and DES 3 displayed significant amoebicidal effects (P < 0.05), inhibited encystment and excystment, undermined the cell-mediated cytopathogenicity of A. castellanii, and also displayed minimal cytotoxicity to human cells. Conversely, the chemical components of these solvents: salicylic acid, trihexylamine, and trioctylamine showed minimal effects when tested individually. These results are very promising and to the best of our knowledge, are reported for the first time on the effects of deep eutectic solvents on amoebae. These results can be applied in the development of new formulations of novel contact lens disinfectants against Acanthamoeba castellanii.