Antibacterial Properties Research Articles

Green Synthesis, Characterization and Biological activity of Optimized Alfalfa‐Mediated Zirconium Nanoparticles

AbstractNanoparticle green synthesis is an emerging scientific field that focuses on the production of nanoparticles by living cells. In this work, the potential of extracts of alfalfa leaves (Medicago sativa) as affordable and fabricated zirconium nanoparticles (ZrNPs) was evaluated for the first time. alfalfa alcoholic extract and zirconium precursor were used to produce ZrNPs, the production and characteristics of nanoparticles were measured using the Tyndall effect, UV‐vis, FT‐IR, EDX, DLS, and SEM tests, antioxidant and antibacterial properties, and toxicity Measurement of nanoparticles on breast cancer (MDA‐MB‐468) and human healthy cells (HFF) was investigated. The optimization of nanoparticle production was evaluated with ANN and GN algorithms. The analysis showed that nanoparticles have spherical‐like ZrNPs shapes with an average of 50 nm size. in addition, ZrNPs have significant cytotoxic effects against human breast cancer (MDA‐MB‐468) cells, and Human foreskin fibroblast (HFF) cells exhibited the highest resistance to ZrNPs. There was a significant agreement between the results of the designed ANN‐GA model and the experimental data. In this research, ZrNP was successfully created using alfalfa extract as a renewable source of stabilizing and reducing agents with an environmentally friendly approach, and they showed significant antioxidant, antibacterial, and anticancer properties.

Bio-efficacy of Essential Oil Extracted from Locally Available Orange (Citrus sinensis) Peels from Nepal

Essential oils from various plants are valued for their therapeutic, aromatic, antimicrobial, and antioxidant properties. The majority of them are employed in cleaning procedures, aromatherapy, stress reduction, food flavouring and preservation, and beauty products. The present investigation focuses on elucidating the chemical composition along with the antimicrobial and antioxidant properties of essential oil extracted from locally available orange (Citrus sinensis) peels, mainly exploring its bio-efficacy. The antibacterial property was studied against the gram-negative bacterium Escherichia coli and the gram-positive bacterium Bacillus subtilis. The analysis results revealed significant antimicrobial activity with zones of inhibition of 4 mm and 5.5 mm, respectively. The antifungal property was studied against the opportunistic pathogenic yeast Candida albicans, which showed positive activity, producing 4.5 mm of zone of inhibition. The antioxidant activity of the oil was determined using DPPH free radical scavenging assay, which showed an IC50 value of 1.3532 µL/mL. Qualitative phytochemical screening of the essential oil as determined using some standard colour-developing methods showed the presence of alkaloids, flavonoids, terpenoids, phenols, cardiac glycosides, and saponins. The above results were validated by FT-IR and GC/MS analysis. The FT-IR analysis revealed the presence of nitrogen-containing and oxygen-containing functional groups. The GC/MS analysis showed the presence of limonene, d-limonene, 1S-α-Pinene, 1R-α-Pinene, β-myrcene, linalool, α-humulene, α-terpineol, etc. These findings demonstrated that orange peels from Nepal that are readily available locally could be a source of compounds with antibacterial, antifungal, and antioxidant properties.

Investigation of the phytochemical profiling and antioxidant, anti-diabetic, anti-inflammatory, and MDA-MB-231 cell line antiproliferative potentials of extracts from Ephedra alata Decne

Ephedra is one of the many medicinal herbs that have been used as folk/traditional medicine in Jordan and other countries to cure various illnesses. Plants of this genus are well known for their antioxidant and antibacterial properties. In this study, three different solvents were used to obtain Ephedra extracts. When evaluated, the Ephedra alata Decne ethanolic extract reportedly had the greatest levels of total phenolic compounds (TPC) and total flavonoid compounds (TFC). The aqueous extracts displayed the highest antioxidant activity in the DPPH and ABTS assays, demonstrating their considerable capacity to neutralize free radicals. However, when evaluated using the FRAP method, the acetone extracts showed the strongest antioxidant activity, indicating their high reducing power. LC–MS/MS, a potent method of analysis that combines the liquid chromatographic separation properties with mass spectrometry detection and identification capabilities, was used in this study to detect and measure phytochemical content of a total of 24 phenolic compounds and 16 terpene compounds present in the extracts of Ephedra alata Decne. Various concentrations of these chemicals were found in these extracts. The extracts’ inhibitory effects on albumin denaturation and alpha-amylase activity were also assessed; the findings demonstrated the potentials of these extracts as anti-inflammatory and anti-diabetic medicines, with the acetone extract having the lowest IC50 values in the concomitant tests (306.45 µg/ml and 851.23 µg/ml, respectively). Furthermore, the lowest IC50 value (of 364.59 ± 0.45 µg/ml) for the 80% ethanol extract demonstrated that it has the strongest antiproliferative impact regarding the MDA-MB-231 breast cancer cell line. This finding indicates that this particular extract can be potentially used to treat cancer.

Development of dual-effect AW/Ag/CHI bioactive and antibacterial coating for orthopedic implant surfaces

AbstractTitanium implants, which are widely used in orthopedic implant applications, require surface treatments due to their low osteoinduction properties and the risk of postoperative infection. In this study, apatite wollastonite (AW)-based coatings with chitosan (CHI) and silver (Ag) added were applied to the titanium surface using dip coating and drop casting techniques. The obtained coating surfaces were characterized by FESEM, EDS, XRD, FTIR, and TGA–DSC. Biomineralization behaviors were examined by immersing the resulting coatings in simulated body fluid with pH 7.2–7.4. The antibacterial activities of the coatings obtained using S. aureus and E. coli bacterial colonies were examined. Following the successful coating of AW nanoparticles on the Ag and CHI implant substrate, the Ca/P ratio of the coated surface was obtained as 1.4–1.92% after the biomineralization process performed at 37° for 7 days. Ag particles were successfully distributed homogeneously with a 40–50-nm diameter in Ag-doped coatings. It was concluded that the successfully produced composite coating with bioactive and antibacterial properties is a suitable candidate material for metallic implant surfaces. Graphical abstract

Synthesis and Antibacterial Activity of Capsaicin Derivatives Containing Phenolic Hydroxyl Groups

AbstractBacterial infections tend to cause a series of cytopathic reactions and have become a major threat to human life. Among them, phenolic compounds are widely used as a natural antibacterial derivative for antifouling and antibacterial applications. In this study, four phenolic hydroxyacrylamide monomers have been successfully prepared using capsaicinoid derivatives as inspiration (named as OHABA, PHABA, AHMA, and AMTHBA, respectively) and the chemical structures were confirmed by FT‐IR, 1H‐NMR, 13C‐NMR. The minimum inhibitory concentration (MIC) assay and plate antibacterial assay were measured to explore the antibacterial properties of the monomer. The results showed that four capsaicin derivatives exhibited antibacterial activity, and the antibacterial properties of the four monomers from strong to weak were PHABA, OHABA, AHMA and AMTHBA. The best antibacterial activity was PHABA (MIC for E. coli: 1.6 mg/mL, bacteriostasis rate: 82.46 %, MIC for S. aureus: 1.6 mg/mL, bacteriostasis rate: 69.58 %). Both the cluster effect of monomers and the spatial distribution of phenolic hydroxyl groups in the structure of derivatives affect the antibacterial properties.

Biosynthesis of Ag/Cu nanocomposite mediated by Curcuma longa: Evaluation of its antibacterial properties against oral pathogens

Abstract Curcuma longa is a popular plant around the world with various applications in food and medicinal aspects. An investigation has been conducted on the formulation of Ag/Cu nanocomposite by C. longa as a natural stabilizing agent, without the use of any toxic or harmful reagents. This bio-inspired approach is focused on applicative, facile, and green chemical research. The study also explored the potential of Ag/Cu nanocomposite to prevent dental bacteria growth and prevent adherence in vitro. The biomediated Ag/Cu@ turmeric NCs were characterized by advanced physicochemical techniques. The FE-SEM imaging has established that Ag/Cu@ turmeric has a semi-spherical shape (60.92 nm). The crystallinity of nanocomposite has been confirmed by the XRD technique. Subsequently, the biological activity of the Ag/Cu nanocomposite functionalized with biomolecules was examined. The concentration of 1,000 µg/mL showed the most effective minimum inhibitory concentrations (MICs) against Porphyromonas gingivalis and Streptococcus mutans (MIC = 16 µg/mL) during the investigation. The addition of Ag/Cu nanocomposite (MIC = 32 µg/mL) significantly hindered the S. mutans in vitro adherence. According to the findings of this research, Ag/Cu nanocomposite could potentially serve as an effective oral hygiene agent for managing periodontopathic and dental caries conditions.

Monoterpenoid synergy: a new frontier in biological applications.

Monoterpenoids, compounds found in various organisms, have diverse applications in various industries. Their effectiveness is influenced by the oil's chemical composition, which in turn is influenced by plant genotype, environmental conditions, cultivation practices, and plant development stage. They are used in various industries due to their distinctive odor and taste, serving as ingredients, additives, insecticides, and repellents. These compounds have synergistic properties, resulting in superior combined effects over discrete ones, potentially beneficial for various health purposes. Many experimental studies have investigated their interactions with other ingredients and their antibacterial, insecticidal, antifungal, anticancer, anti-inflammatory, and antioxidant properties. This review discusses potential synergistic interactions between monoterpenoids and other compounds, their sources, and biological functions. It also emphasizes the urgent need for more research on their bioavailability and toxicity, underlining the importance and relevance of this comprehensive study in the current scientific landscape.

Advancing self‐healing soy protein hydrogel with dynamic Schiff base and metal‐ligand bonds for diabetic chronic wound recovery

AbstractTo address the unique challenges of diabetic wound healing, wound dressings, particularly multifunctional hydrogels have garnered considerable interest. For the first time, a novel environmentally friendly soy protein‐based hydrogel is developed to accelerate the healing of diabetic chronic wounds. Specifically, this hydrogel framework is in direct formation through the dynamic Schiff base between oxidized guar gum and epigallocatechin‐3‐gallate (EGCG)‐modified soy protein isolate. Meantime, the addition of Ag+ enhances the cross‐linking of the hydrogel network by forming metal‐ligand bonds with the catechol groups in EGCG. Interestingly, the stretchability (up to 380%), swelling, and rheology properties of the hydrogel can be controlled by fine‐tuning the density of metal‐ligand bonds, endowing them with a high potential for precise matching. Additionally, various dynamic bonds endow hydrogel with excellent self‐healing ability, adhesiveness, and injectability. This hydrogel also exhibits good antibacterial properties, biocompatibility, and cell migration capabilities. Both in vivo and in vitro experiments demonstrated the outstanding anti‐inflammatory capacity of the hydrogel and its ability to modulate macrophage polarization. Consequently, the hydrogel has proven effective in promoting wound healing in a diabetic full‐thickness wound model through enhanced angiogenesis and collagen deposition. This eco‐friendly plant protein hydrogel offers a sustainable solution for wound care and environmental protection.

Biogenic synthesis of CeO2 nanoparticles via moringa oleifera seed extract: Photocatalytic and biological activity for textile dye degradation

This article presents a study on synthesizing cerium oxide nanoparticles utilizing cerium nitrate and Moringa oleifera seed extract as stabilizing and reducing agents. The XRD pattern of cerium oxide was a cubic structure with an average crystalline size of 11.92 nm. The surface feature of ceria nanoparticles has a foam-like nanostructure, type IV isotherms-mesoporous, with a 56.845 m2/g specific surface area. The UV–Vis absorbance and Tauc plot showed that the direct and indirect energy bandgap was 2.51 and 2.79 eV, respectively. TGA/DTA has established structural phase stability with corresponding mass changes by influencing bioactive molecules of seed extract in cerium nanoparticles. These nanoparticles exhibited effective antibacterial properties against S. aureus and E. coli pathogens, and the turbidimetry antioxidant properties were evaluated. Dye degradation through the photocatalyst was investigated, with the optimum degradation efficiency of 99.71 and 99.83 %, pseudo-first-order kinetics 4.62 × 10−2 and 5.07 × 10−2, respectively, for anionic-Congo red and cationic-Malachite green dye. The observed results concluded that green-mediated nanostructured ceria particles might effectively be used for antibacterial and photocatalytic purposes.

Facile one-pot synthesis of N-pyridinylaminonaphthol derivatives and their antibacterial evaluation against multidrug-resistant Staphylococcus aureus.

The escalating severity of the menace posed by bacterial resistance has rendered the existing antibiotics less effective, thus necessitating the discovery of new antibacterial agents. The current study reports the exploration of substituted N-pyridinylaminonaphthols produced by a straightforward, one-pot multicomponent reaction process as antibacterial agents. The synthesized derivatives were assessed in vitro for their antibacterial properties against a panel of bacterial pathogens. The analogs 4b, 4g, 4h, 4i, 4j, 4l, 4r, and 4t exhibited potent inhibitory activity with minimum inhibitory concentration (MIC) values of 1-2 µg/mL. Notably, 4b, 4l, and 4t displayed an excellent selectivity index. Additionally, they were active against the multidrug-resistant bacterial strains, with 4l exhibiting the best activity against methicillin-resistant Staphylococcus aureus and vancomycin resistant staphylococcus aureus with a MIC of 1 µg/mL. 4l showed synergism with gentamycin and showed bactericidal property in a concentration-dependent manner. Furthermore, the molecule 4l inhibited the DNA gyrase supercoiling activity. Absorption, distribution, metabolism, excretion/toxicity parameters and pharmacokinetic properties were assessed via in silico techniques, which elucidate the potential mode of action. These findings demonstrate the potential of the N-pyridinylaminonaphthol derivatives as antibacterial agents against multidrug-resistant S. aureus.

Preparation of a starch derivative bearing chloroaniline groups and the evaluation of its hemolytic, cytotoxic and antibacterial activities

AbstractA new starch derivative with antibacterial properties and non‐hemolytic effect was synthesized through the chemical grafting of 4‐chloroaniline onto the backbone of potato starch. In a first step, starch was extracted from potatoes grown in the region of Coahuila, Mexico, using the water steeping method. The hydroxyl groups (C5‐C6) of the native starch were oxidized using sodium periodate. The resulting dialdehyde was then chemically modified through a Schiff base reaction with 4‐chloroaniline. The chemical structure of this starch derivative was confirmed by Fourier transform infrared and 1H NMR spectroscopies, the thermal properties were analyzed by thermogravimetric analysis without finding significant changes and the product showed antibacterial activity against Gram‐negative E. coli and Gram‐positive S. aureus strains. Finally, the hemolytic and cytotoxic effects of native starch and its derivative were studied, showing no hemolytic effect on isolated human red blood cells and no cytotoxic effect; therefore, it can be considered biocompatible. © 2024 Society of Chemical Industry.

Tunicate cellulose nanocrystal reinforced multifunctional hydrogel with super flexible, fatigue resistant, antifouling and self-adhesive capability for effective wound healing

Hydrogels as skin wound dressings have been extensively studied owing to their good flexibility and biocompatibility. Nevertheless, the mechanical performance, adhesive capability, antifouling and antibacterial properties of conventional hydrogels are still unsatisfactory, which hinder the application of hydrogel for cutaneous healing. Here, we developed a novel biocompatible multifunctional hydrogel with super flexible, fatigue resistant, antifouling and self-adhesive capability for effective wound healing, where naturally rigid polymers including quaternized chitosan (QCS) and Tunicate cellulose nanocrystals (TCNCs) are used as bioactive cross-linkers and reinforcers to endow the hydrogel with excellent mechanical and antibacterial property, and the synergistic contributions from the poly(acrylic acid/methacrylate anhydride dopamine/sulfobetaine methacrylate) (poly(AA/DMA/SBMA)) chains and QCS endow the hydrogel with excellent adhesive property, antioxidant, antifouling and pH-responsive sustained drug release capabilities. The optimized hydrogel exhibited high tensile strength (77.69 KPa), large tensile strain (889.9 %), large toughness (307.51KJ.m−3), high adhesive strength (35.57 KPa) and ideal compressive property. The in vivo infected full-thickness skin model demonstrated that the hydrogel with vanvomycin sustained release ability efficiently improved the granulation tissue formation, facilitating collagen deposition and reducing inflammatory expression, thus effectively accelerating wound healing. This superiorly skin-adhesive antibacterial biocompatible hydrogel appears to be a promising candidate for wound therapy.

A multifunctional hydrogel with mild photothermal antibacterial and antioxidant properties based on quercetin and dopamine-coated zinc oxide nanoparticles for healing bacteria-infected wound

Bacterial infection and inflammation hinder the natural healing process of skin wounds and may also cause wound complications. In light of the aforementioned considerations, this study developed an antibacterial and antioxidant QT/PDA@ZnO /QCS/(PAM-PAMPS) hydrogel (QPQH). The hydrogel dressing employs a dual network structure and incorporates quercetin (QT), quaternary ammonium salt chitosan (QCS), and polydopamine-coated zinc oxide nanoparticles (PDA@ZnO NPs) into a Polyacrylamide–Poly(2-acrylamido-2-methyl-1-propanesulfonic acid)（PAM-co-AMPS）hydrogel. This design enables QPQH to exhibit good mechanical properties, remarkable adhesion properties, and the capacity to adhere closely to the wound. The mild photothermal properties (˃50 °C) and Zn2+ release ability of PDA@ZnO NPs can cooperate with the destruction ability of QCS to bacterial cell membranes, thereby achieving efficient sterilization. This process has been demonstrated to be effective against Staphylococcus aureus and Escherichia coli, with approximately 98.5 % and 99.8 % efficiency, respectively. The incorporation of QT into hydrogel confers excellent antioxidant properties, which serve to reduce oxidative stress in wounds and prevent inflammation. Furthermore, hydrogel displays favorable blood compatibility and cell compatibility, facilitating the repair of bacteria-Infected wounds and promoting angiogenesis and collagen deposition in skin wounds. In conclusion, the antibacterial and antioxidant QPQH dressing has considerable potential for clinical use in the treatment of bacteria-Infected wounds.

Green synthesis and antibacterial-antibiofilm properties of biogenic silver nanoparticles

The biosynthesis of metallic nanoparticles is gaining prominence as an alternative to traditional physicochemical methods, offering several advantages such as simplicity, non-toxicity, lower energy requirements and short reaction times leading to environmentally sustainable processes. The aims of this work were: to study the extracellular biosynthesis of silver nanoparticles (AgNPs) by Pseudomonas extremaustralis 2E-UNGS, to characterise the shape, monodispersity and size of AgNPs, to explore their antimicrobial and antibiofilm activities, and to evaluate the role of nitrate reductase activity in the biosynthesis process. The novelty of this work relies on the development of a green and sustainable method for the synthesis of stable AgNPs with optimal properties for potential applications in antimicrobial materials, especially when incorporated into polymeric matrices or used as agrochemical substitutes. Optimal conditions for the biosynthesis of spherical AgNPs were determined to be pH 7, 38 °C, 4 h of darkness and 120 rpm using stationary phase culture supernatants of P. extremaustralis 2E-UNGS. The involvement of extracellular nitrate reductase in AgNP biosynthesis was confirmed by enzymatic assays and supported by bioinformatics analysis, which identified the presence of the napA2 gene linked to the nirBD cluster. Antimicrobial assays demonstrated the inhibitory effect of AgNPs against both Gram-positive and Gram-negative bacteria, including Pseudomonas aeruginosa PA01 in both planktonic and biofilm states. In addition, the potential application of AgNPs in innovative antibacterial polymers was explored by incorporating them into polyurethane matrices either alone (PU-AgNP) or in combination with crystal violet as a photosensitizer (PU-AgNP-CV). Subsequent inoculation with a clinical isolate of Pseudomonas aeruginosa resulted in significant reductions in viable bacterial counts on both PU-AgNP-CV and PU-AgNP. Biogenic AgNPs showed antibacterial and antibiofilm properties for new antimicrobial material development.

Evaluation of anti-diabetic, anti-oxidant and anti-bacterial activities of essential oil collected from wildly growing Calotropis gigantea (Linn.) Aiton f. and its therapeutic applications: insights from chemical profiling, in-vitro and in-silico studies

Calotropis gigantea, often known as giant milkweed, the plant is widely known for producing herbal essential oils that are used as traditional and complementary medicine to cure various ailments. The aim of the present study was evaluation of anti-diabetic, anti-oxidant and anti-bacterial activities of essential oil collected from wildly growing Calotropis gigantea and its its therapeutic applications via chemical profiling, in-vitro and in-silico studies. After Calotropis gigantea (CEO) essential oil was extracted by hydro-distillation, its phytochemical, antioxidant, antibacterial, and anti-diabetic properties were assessed. Fingerprint analysis and GC-FID were used to create a chemical profile. Various tests for antioxidants, such as DPPH, nitric oxide radical, and iron chelating activity, were conducted. The disk diffusion approach was used for antibacterial efficacy against Gram-negative (G-) bacteria. The test of α-amylase inhibition was utilized to investigate anti-diabetic efficacy. In-silico analysis was also conducted to find out interaction of some components to α-amylase enzyme. Chemical profiling indicated the presence of phytol (24%), stearic acid (10%), and cyclohexyl ketone (6%), as predominant components. There was notable antioxidant activity ranged from 82 to 97% for various assays. IC50 values for various assays were iron chelating activity: 18.610, DPPH scavenging activity: 28.246, nitric oxide radical scavenging activity: 58.113. CEO showed a zone of inhibition value of 0.5 cm and significant antibacterial activity against Gram-negative (G-) bacteria. CEO blocked α-amylase in dose-dependent way. At a higher amount of 250 µl, CEO inhibition was 63% and mode of inhibition un-competitive. In-silico analysis validated the blocking of α-amylase and interaction of phytocomponents to α-amylase enzyme which were further validated by UV and fluorescent quenching techniques. It was determined that CEO may be extensively used in many different industries, including as food, herbal medicine, cosmetics.

Recent development of chitosan-based biomaterials for treatment of osteomyelitis

Abstract Osteomyelitis is a complex infectious disease caused by bacterial infection, which has always been a difficult problem for clinical orthopedic surgeons. Although the traditional methods are effective in treating osteomyelitis, the heavy use of antibiotics and surgical treatment cause serious side effects and lead to bone loss and healing difficulties after surgery. Chitosan (CS), a natural polymer material, is a deacetylated derivative of chitin, which has good biodegradability, antibacterial, and osteogenic properties, and has been widely used in the treatment of osteomyelitis. In this review, the recent research progress in the application of CS based composites such as micro-nano drug delivery carriers, hydrogels, coating materials, and bone tissue engineering scaffolds for the treatment of osteomyelitis is summarized, in order to provide certain experimental and theoretical support for the development of CS based composites.

Effect of antibacterial masterbatches selection on the crystal structure and properties of nanosilver composite materials

AbstractThe distribution of nanosilver in composite materials with two different matrices is related to the selection of antibacterial masterbatches, which has a profound impact on the antibacterial effectiveness of the composite materials. This study utilized ethylene‐vinyl acetate (EVA) and polypropylene (PP) as base materials to fabricate two types of nanosilver composite materials (C1‐EVA/PP and C2‐EVA/PPP) employing varying methods of antimicrobial masterbatches incorporation. Additionally, EVA‐Ag and PP‐Ag nanosilver composite materials were fabricated via melt blending, along with corresponding neat materials and blends (EVA, PP, and C0‐EVA/PP) for comparison. The study results indicate that the addition of nanosilver did not affect the functional groups of either the neat materials and the EVA/PP blends. SEM analysis revealed that nanosilver was dispersed unevenly in the C1‐EVA/PP substrate, while it was more uniformly distributed in the C2‐EVA/PP substrate. In the antibacterial test, the antibacterial rate of C2‐EVA/PP was higher than that of C1‐EVA/PP (56.0% vs. 40.0%). However, all silver‐containing composite materials did not exhibit antibacterial properties in the agar diffusion test. Additionally, nanosilver exhibited an induced crystallization effect on the PP phase of the C2‐EVA/PP composite material, increasing its Tc2 by 0.8°C. Compared with pure PP, the long period of PP‐Ag increased by 0.7 nm, and its impact resistance improved by 13.8%. By comparison, the long period of EVA‐Ag composite materials increased by only 0.2 nm compared to pure EVA. Both C1‐EVA/PP and C2‐EVA/PP composite materials showed 0.3 nm increase in long period compared to C0‐EVA/PP, with their impact resistance improving by 3.1% and 10.3%, respectively, compared to C0‐EVA/PP. The introduction of nanosilver increased the storage modulus, loss modulus, and apparent viscosity of EVA/PP blends. Optical performance analysis shows that nanosilver increases the internal haze of C1‐EVA/PPP by 60% while reducing the transmittance by 0.3%. The effect of nanosilver on the optical properties of C2‐EVA/PPP composites is relatively small. Therefore, this study provides theoretical guidance for the selection of processing methods for dual‐phase antibacterial materials.Highlights Different antibacterial masterbatch impacts silver distribution in composites. The addition of nanosilver can improve the impact performance of materials. Two process methods were used to prepare low‐silver content composite materials. The antibacterial rate of C2‐EVA/PP is higher than C1‐EVA/PP (56% vs. 40%). This study guides the processing methods for dual‐phase antibacterial materials.

Composite Liquid Media Influence on the Optical and Bactericidal Properties of Silver Nanoparticles Synthesized by Pulsed Laser Ablation in Liquids

Composite Liquid Media Influence on the Optical and Bactericidal Properties of Silver Nanoparticles Synthesized by Pulsed Laser Ablation in Liquids

Antioxidant and antibacterial properties of ethanolic pot-pollen extract of Melipona beecheii and determination of the major components by GC-MS.

Melipona beecheii pot-pollen is a natural product that has barely been studied, unlike other hive products such as honey and propolis. Its application has been reported since ancient times in traditional Mayan medicine, and it is also a functional food with high nutritional value. In the present study, samples of ethanolic pot-pollen extracts from five locations in the Yucatán Peninsula were analyzed to determine their antibacterial and antioxidant properties. All the extracts showed activity against five medically important bacteria; Pseudomonas aeruginosa and Listeria monocytogenes were the most susceptible bacteria in all samples. The evaluated antioxidant activity was higher than that reported by other studies. Palmitic, linoleic, and linolenic fatty acids and their respective ethyl ethers were detected by Gas Chromatography-Mass Spectrometry (GC-MS) in all samples in different concentrations. Based on these results, pot-pollen extract from Mama, Yucatán exhibited the best biological activities (Minimum Inhibitory Concentrations (MICs) between 6 and 40 mg/mL, EC50 DPPH 28 µg/mL, EC50 RP 30 µg/mL), which could be related to a higher content of unsaturated fatty acids and their ethyl esters. The present study demonstrates that M. beecheii pot-pollen has therapeutic potential in addition to its benefits as a nutritional supplement.

Antibacterial, Anti-Inflammatory, and Antioxidant Cotton-Based Wound Dressing Coated with Chitosan/Cyclodextrin-Quercetin Inclusion Complex Nanofibers.

Quercetin, recognized for its antioxidant, anti-inflammatory, and antibacterial properties, faces limited biomedical application due to its low solubility. Cotton, a preferred wound dressing material over synthetic ones, lacks inherent antibacterial and wound-healing attributes and can benefit from quercetin features. This study explores the potential of overcoming these challenges through the inclusion complexation of quercetin with cyclodextrins (CDs) and the development of a nanofibrous coating on a cotton nonwoven textile. Hydroxypropyl-beta-cyclodextrin (HP-β-CD) and hydroxypropyl-gamma-cyclodextrin (HP-γ-CD) formed inclusion complexes of quercetin, with chitosan added to enhance antibacterial properties. Phase solubility results showed that inclusion complexation can enhance quercetin solubility up to 20 times, with HP-γ-CD forming a more stable inclusion complexation compared with HP-β-CD. Electrospinning of the nanofibers from HP-β-CD/Quercetin and HP-γ-CD/Quercetin aqueous solutions without the use of a polymeric matrix yielded a uniform, smooth fiber morphology. The structural and thermal analyses of the HP-β-CD/Quercetin and HP-γ-CD/Quercetin nanofibers confirmed the presence of inclusion complexes between quercetin and each of the CDs (HP-β-CD and HP-γ-CD). Moreover, HP-β-CD/Quercetin and HP-γ-CD/Quercetin nanofibers showed a near-complete loading efficiency of quercetin and followed a fast-releasing profile of quercetin. Both HP-β-CD/Quercetin and HP-γ-CD/Quercetin nanofibers showed significantly higher antioxidant activity compared to pristine quercetin. The HP-β-CD/Quercetin and HP-γ-CD/Quercetin nanofibers also showed antibacterial activity, and with the addition of chitosan in the HP-γ-CD/Quercetin system, the Chitosan/HP-γ-CD/Quercetin nanofibers completely eliminated the investigated bacteria species. The nanofibers were nontoxic and well-tolerated by cells, and exploiting the quercetin and chitosan anti-inflammatory activities resulted in the downregulation of IL-6 and NO secretion in both immune as well as regenerative cells. Overall, CD inclusion complexation markedly enhances quercetin solubility, resulting in a biofunctional antioxidant, antibacterial, and anti-inflammatory wound dressing through a nanofibrous coating on cotton textiles.