Cationic surfactants are widely used as antimicrobial agents in various fields. However, the widespread use of cationic surfactants has caused huge accumulation in environment, triggering the ...emergence of bacterial resistance. Besides, owing to the strong cytotoxicity, most of the cationic surfactants are limited in practical applications. Therefore, constant attention has been paid on how to rationally design the surfactants for achieving highly efficient antimicrobial activity at lower doses but simultaneously presenting low toxic side effects. In this review, we mainly focus on recent advances in the key structural determinants of antibacterial activity and cytotoxicity of cationic surfactants, as well as the design strategies of effective antimicrobial surfactants with low cytotoxicity.
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•Key structural determinants of antimicrobial activity of cationic surfactants.•Key structural determinants of cytotoxicity of cationic surfactants.•Surfactant self-assemblies as antimicrobial agents.•Design strategies of effective antimicrobial surfactants with selectivity.
In the present study, phytofabricated selenium nanoparticles (PF-SeNPs) were prepared from aqueous fruit extract of
in a facile, green, economic, tactic and eco-friendly way. The aqueous fruit ...extract of
was found to be rich with various secondary metabolites including phenolics (59.18 ± 2.91 mg gallic acid equivalents/g), flavonoids (38.50 ± 2.84 mg catechin equivalents/g), and tannins (44.28 ± 3.09 mg tannic acid equivalents/g) and determined that highly appropriate for the biosynthesis of nanoparticles. The facile phytofabrication of PF-SeNPs was confirmed by UV-visible and FTIR spectroscopic analysis. The XRD pattern and Raman spectroscopy showed that synthesized PF-SeNPs were amorphous in nature. The Zeta potential analysis confirmed that PF-SeNPs were negatively charged (-24.4 mV). The DLS analysis revealed that PF-SeNPs were in nano size and less aggregated with poly-dispersity index of less than 0.2. The SEM images depicted that PF-SeNPs were spherical in shape. The EDX analysis revealed that PF-SeNPs were constituted with Se (61.60%), C (29.96%), and O (4.41%). The HR-TEM analysis determined that PF-SeNPs were in nano size with an average diameter of 15-40 nm. The PF-SeNPs have offered fascinating bio-potential applications, such as antioxidant, antimicrobial and biocompatibility. They have also exhibited dose-dependent free radical scavenging activity, and EC50 was determined as 15.67 ± 1.41 and 18.84 ± 1.02 μg/mL for DPPH and ABTS assays, respectively. The PF-SeNPs has also shown the wide range of antimicrobial activity on foodborne pathogens, and it was found to be highly efficient on fungi followed by Gram-positive and Gram-negative bacteria. The biocompatibility of PF-SeNPs was assessed in N2a cells with much higher IC50 value (dose required to inhibit 50% of cell viability) compared to sodium selenite. Also, mitochondrial membrane potential (MMP) and caspase-3 were much less altered on treatment of PF-SeNPs related to sodium selenite. The cytotoxic studies clearly determined that PF-SeNPs was much less toxic and safer related to sodium selenite. Thus, PF-SeNPs could find suitable application as antioxidant and antimicrobial agent in food, biomedical, and pharmaceutical industry.
•Hydrophobically modified PG-zein nanocomplexes showed robust storage stability for bioactive compound delivery.•Nanocomplexes exhibited effective redispersibility of freeze-dried ensuring structural ...integrity post-processing.•Encapsulated bioactive compounds demonstrated significantly increased antioxidant capacities.•Potent antimicrobial activity against Gram-positive and Gram-negative bacteria were observed.
In this study, hydrophobically modified phytoglycogen and hydrolyzed zein were utilized to develop biodegradable and redispersible nanocomplexes for encapsulation of various bioactive phytochemicals, including eugenol, thymol, carvacrol, trans-cinnamaldehyde, and their mixtures. Comprehensive physicochemical and colloidal characterizations of these nanocomplexes were performed using dynamic light scattering, and Fourier transform infrared and atomic force microscopy, which evaluated their colloidal stability and redispersibility after freeze-drying. In addition, the antioxidant capacities and antimicrobial activities of these various nanoparticles were investigated methodically. The results revealed that the phytochemical-encapsulated nanocomplexes exhibited a particle size ranging from 60 to 70 nm, displaying a uniform distribution. Additionally, these nanocomplexes demonstrated sustained morphological and colloidal stability over 30-day storage, and after freeze-drying and subsequent redispersion processing. Furthermore, significant improvements in antioxidant and antimicrobial properties in the aqueous phase were observed. These redispersible nanocomplexes from phytoglycogen and zein hold the promising potential to address the limitations and offer practical solutions for expanding their applications in the pharmaceutical and food fields.
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•Pure and Er-doped ZnO were synthesized by a wet chemical method.•XRD shows that Er-doped ZnO at high at.% kept their hexagonal structure.•The optical band gap was improved as Er at.% ...increased.•Antimicrobial activity of Er-doped ZnO was tested against Staphylococcus aureus and Escherichia coli.•ANN model was trained with lab data, such model predicts absorbance with a 1–2% error.
Antimicrobial activity of the Zn1-xErxO (0, 1, 5, 10 at.%) nanoparticles were tested against Staphylococcus aureus and Escherichia coli. The nanoparticles were successfully synthesized by wet chemical route, where polyvinyl alcohol and sucrose were used. The influence of erbium content in structural, optical, and antimicrobial activity was analyzed. The average crystallite size is under 15 nm for all the samples according to X-ray diffraction results, and no secondary phases were observed even at high erbium content. Optical results exhibit a blue shift in the ultra-violet region. The X-ray photoelectron spectroscopy analysis confirmed the variations of Zn/O ratio, together with particles size and band gap are key factor in antimicrobial properties. The microbiological essays exhibit to these nanoparticles as a high potential agent with antibacterial activity versus S. aureus, with lower impact in E. coli. The absorbance results of these assays were used in two theoretical approaches. At first, Gompertz model used in the regression analysis showed the best fit for bacterial growth. Additionally, an artificial neural network was trained to forecast the result of new experiments, showing a good performance.
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•Alginate silver@hydroxyapatite functionalized CaCO3 composite based microparticles are described.•Microparticles showed good antimicrobial activity.•Slow and prolonged silver release ...was observed.•Presence of hydroxyapatite functionalized CaCO3 reduces microparticles cytotoxicity.
This paper focuses on the preparation and characterization of antibacterial alginate microparticles containing silver@hydroxyapatite functionalized calcium carbonate composites for tissue engineering.
Microparticles were prepared by cross-linking a silver@composite sodium alginate dispersion with CaCl2. This method showed a very good silver efficiency loading and the presence of silver chloride nanoparticles was detected. Silver free microparticles, containing hydroxyapatite functionalized calcium carbonates and neat alginate microparticles were prepared as well. All microparticles were characterized for water absorption and for in vitro bioactivity by immersion in simulated body fluid (SBF). Finally, antimicrobial and antibiofilm activities as well as cytotoxicity were evaluated. Microparticles containing silver@composites exhibited good antimicrobial and antibiofilm activities against Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa and Candida albicans, but exerted a certain cytotoxicity against the tested cell models (fibroblasts and osteoblasts). Microparticles containing hydroxyapatite functionalized calcium carbonates were found to be always less cytotoxic, also in comparison to neat alginate microparticles, proving that the presence of the inorganic matrices exerts a protective effect on microparticle cytotoxicity.
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•Antimicrobial activity of different photocatalytic surfaces is tested via resazurin assay.•The inoculated hydrogel carriers are anchored onto the studied surfaces.•The four different ...situations are examined; irradiated photocatalytic surface and reference; photocatalytic surface and reference in dark.•Reduction of total analysis time; better recovery results, and the applicability to different surfaces is demonstrated comparing with standard process.
The antimicrobial activity of different types of photocatalytic surfaces (titania porous and nonporous phthalocyanine films) was tested using a resazurin assay. The gram-negative bacteria Escherichia coli was chosen as the model microorganism. A bacteria inoculum with a concentration of 1.75 × 106 CFU/ml was applied to hydrogel carriers and these were subsequently placed on the study surfaces. Half of the samples were kept in the dark and the other half were illuminated. After 4 h, the carriers were transferred to vials, resazurin added and the number of viable cells in the mixture counted. For nonporous surfaces, the effect of the addition of a biocide was investigated. The authors observed that as the amount of biocide in the layer increased, the proportion of viable cells in the samples kept in the dark decreased. These results are in good agreement with general assumptions. For the titania surfaces, the antimicrobial activity (characterized by ΔR) obtained through resazurin assay was compared to that obtained through the use of standard techniques. The final activity was very similar (the ΔR from the resazurin assay was 1.54 and the standard test gave a result of 1.56). The results confirm the reliability of the proposed method, and the use of carriers give us the possibility to test much larger installed surfaces without a need to cause damage to them.
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