Antibacterial Test Research Articles

In silico and in vitro toxicity assessment of ferulic acid and nicotinamide: analysis using admet tools and effects on bacteria, erythrocytes, and sun protection

The study addresses the properties of ferulic acid (FA) and nicotinamide (NAM), which are widely explored due to their antioxidant and anti-inflammatory effects, beneficial for cosmetic and pharmaceutical applications. The objective was to assess the toxicity of these substances, both in silico and in vitro, to predict safety and efficacy. Using software such as Molinspiration© and admetSAR©, pharmacokinetic properties, including absorption and toxicity, were calculated. The in vitro analyses involved cytotoxicity assays in human erythrocytes and antibacterial activity tests. Results indicated that both compounds comply with Lipinski's “Rule of 5,” suggesting potential for adequate absorption. Regarding toxicity, FA and NAM showed low human toxicity, though FA exhibited considerable environmental toxicity. In vitro tests revealed that FA demonstrated bacteriostatic activity against Gram-positive bacteria and a dose-dependent effect on human erythrocytes, with higher hemolysis observed at high concentrations. Additionally, FA provided effective sun protection, reaching a sun protection factor (SPF) of 25.01 at all tested concentrations. It is concluded that FA and NAM have promising safety and efficacy profiles, with FA standing out as a potential photoprotective and antimicrobial agent, while NAM exhibits neuroprotective properties due to its permeability through the blood-brain barrier.

Fabrication of Novel Polyurethane matrix-based Functional Composites with Enhanced Mechanical Performance

Thermoplastic polyurethane (TPU) has gained significant interest in several fields, including automobile steering wheels, and the electronics sector due to their easier processability, abrasive resistance, and self-lubricating performances. However, their strong inherent flammability and significant smoke and heat production during burning limit their industrial applications. Therefore, its applicability can be enhanced with the addition of high-strength reinforcement and making them antibacterial and flame-retardant. This research is designed to examine the influence of zirconium phosphate (ZrP) and zinc oxide (ZnO) nanoparticles on the novel polyurethane/glass fiber reinforced composites for flame retardant and antibacterial applications with improved mechanical performance. Three different types of novel polyurethane (PU1, PU2, PU3) matrices were prepared using different recipes, and 7% ZrP and 5% ZnO nanoparticles were added to the polyurethane matrices separately, and their corresponding composite samples were fabricated using glass reinforcement. Mechanical i.e., Charpy impact, hardness and tensile, and functional i.e., flame retardancy (FR) and antibacterial tests were performed to compare their performance. Mechanical testing results showed that PU3-based composite samples showed the highest values of impact force, hardness, and tensile strength in both ZrP and ZnO nanoparticle-based composite samples. Furthermore, 7% ZrP-PU3 composite exhibited the best performance of flame retardancy due to the presence of hexamethylene diisocyanates (HDI) content. Likewise, the 5% ZnO-PU3-based composite exhibited the highest antibacterial activity along with enhanced mechanical performance.

Enhancing cherry tomato packaging: Evaluation of physicochemical, mechanical, and antibacterial properties in tannic acid and gallic acid crosslinked cellulose/chitosan blend films

The aim of this work was to study the characteristics of composites fabricated from cellulose (CL) and chitosan (CS) blends that were reinforced with different tannic acid (TA) and gallic acid (GA) concentrations. The structure and antibacterial activity of CL/CS composite films were investigated with the addition of TA and GA. The composite films were subjected to mechanical, water contact angle (WCA), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Scanning electron microscopy (SEM), and antibacterial activity tests. The FTIR results and the uniform dense SEM images confirmed the interaction of TA and GA with the CL/CS blends. The water vapor transmission rate (WVTR) of films with 5 wt% TA and GA improved by 23.02 %. The tensile strength of the CCTA-3 film was 27.67 MPa, demonstrating higher tensile properties compared to films made from CL and CS blend film (13.20 MPa). The prepared films also showed increased resistance to moisture and water, as indicated by their higher water contact angle (WCA) values (59.43°). The antibacterial activity of the films was effective against food-borne bacteria such as S. aureus and E. coli due to the addition of TA and GA. The shelf-life of cherry tomatoes increased by approximately 15 days when covered in CCTA-3 instead of polyethylene film. Based on the results, CL/CS blend films containing TA could be beneficial for use in active food packaging.

Characterization and Sustainable Applications of Galinsoga parviflora Natural Fibers: A Pathway to Eco-Friendly Material Development

This study investigates the potential of natural fibers extracted from Galinsoga parviflora as sustainable alternatives to synthetic materials, addressing the increasing demand for eco-friendly and biodegradable options in material science. The main objectives were to evaluate the structural, mechanical, and biological properties of these fibers, focusing on their applicability in structural composites. Driven by environmental sustainability, we performed a range of analyses including X-ray Diffraction (XRD) to determine crystallinity and cellulose structure, Fourier-Transform Infrared Spectroscopy (FTIR) to identify functional groups related to biodegradability, and Scanning Electron Microscopy (SEM) to examine surface morphology and fiber dimensions. Key findings include a crystallinity index of 36.3% with cellulose I dominance, a tensile strength of 17.92 MPa, and a modulus of 11.3 GPa, indicating the fibers’ potential for structural applications. Elemental analysis using Energy-Dispersive X-ray Spectroscopy (EDX) revealed a high carbon content (53.0%) and oxygen content (41.3%), along with trace elements that may enhance interaction in polymer matrices. Antibacterial testing demonstrated effective inhibition of Staphylococcus aureus biofilms, with inhibition zones reaching up to 19 mm, comparable to streptomycin. Confocal Laser Scanning Microscopy (CLSM) further confirmed the fibers' biofilm disruption capabilities.Overall, the results highlight that G. parviflora fibers show significant promise as bio-based alternatives for sustainable material development, offering both mechanical strength and biological functionality for future eco-friendly technologies.

7-(Diethylamino) coumarin-3-carboxylic acid as a novel antibrowning agent: Activity and mechanism

Browning caused by polyphenol oxidase (PPO) and microorganisms significantly impacts the nutritional quality of fruits and vegetables. This study identified 7-(Diethylamino) coumarin-3-carboxylic acid (7-DCCA) as an effective inhibitor of both PPO and bacteria. Enzyme assays revealed that 7-DCCA competitively inhibits PPO activity with an IC50 value of 0.275 ± 0.002 mM. Fluorescence and molecular simulation methods demonstrated that 7-DCCA forms a complex with PPO through hydrogen bonding and hydrophobic interactions, altering the enzyme's structure and reducing its activity. Thermogravimetric and differential scanning calorimetry (DSC) assays showed that 7-DCCA stabilizes PPO, delaying its thermal decomposition. Antibacterial tests proved that 7-DCCA inhibits Staphylococcus aureus and Escherichia coli by disrupting cell membranes. Additionally, 7-DCCA suppressed PPO and peroxidase activities, delaying phenolic oxidation and preventing browning in fruits and vegetables. Cytotoxicity assays confirmed its safety, with over 85 % cell viability at concentrations up to 0.1 mM. Stability experiments verified that 7-DCCA had greatly light and thermal stability. This study highlighted 7-DCCA as a promising antibrowning agent with potential application in food preservation.

Emerging poly(Ani-co-Py)/Bi2O3/AgI composites for antibacterial and antioxidant applications

Poly(Ani-co-Py) was synthesized using aniline (Ani) and pyrrole (Py) and its composites poly(Ani-co-Py)/Bi2O3/AgI composites were fabricated with the extent of Bi2O3 and AgI maintaining 5 to 15 wt% ratio. FESEM analysis displayed that the freshly prepared copolymers and composites exhibited aggregated and spherical-shaped morphology with diameter 200–300 nm and 50–300 nm, respectively. The EDS data revealed the incorporation of both Bi2O3 and AgI in the composite samples. These poly(Ani-co-Py) and poly(Ani-co-Py)/Bi2O3/AgI composites were used to investigate their antibacterial properties using the resazurine-assisted microtiter plate-based antibacterial test. In the investigation, both the copolymers and composites exhibited antibacterial properties against Escherichia coli and Bacillus subtilis bacteria. Further, poly(Ani-co-Py) and Poly(Ani-co-Py)/Bi2O3/AgI composites with in vitro antioxidant activity was assessed by using free radical (α,α-diphenyl-β-picrylhydrazyl (DPPH) scavenging assay. The synthesized copolymers and composites exhibited IC50 value around 38.74 and 41.70–42.60 µg/mL, respectively indicating their better antioxidant properties. This poly(Ani-co-Py)/Bi2O3/AgI composites could be an emerging materials in the area of antimicrobial and antioxidant activity.

Antibacterial Activity of Dendrophthoe pentandra (L.) Leaves Extract Against Staphylococcus aureus and Escherichia coli

Sapuran, Wonosobo is a popular area with several local tea plantations, which are infested by mistletoe, such as Dendrophthoe pentandra (L.) Miq. Mistletoe has been widely reported to have antibacterial activity due to its secondary metabolite content. Therefore, this study aimed to identify and explore the antibacterial activity of D. pentandra leaves extract against Staphylococcus aureus and Escherichia coli. The test samples were extracted using the maceration method, followed by phytochemical screening and total assay of flavonoids, phenols, and tannins. Antibacterial activity tests were carried out using disk diffusion, Minimum Inhibitory Concentration (MIC), and Minimum Bactericidal Concentration (MBC). The yield from the maceration method using 96% ethanol solvent was 8.78%, containing secondary metabolite compounds, including alkaloids, saponins, steroids, terpenoids, and flavonoids. The total flavonoid, phenol, and tanin content obtained were 4.09 ± 0.70 mg QE/g, 1.76 ± 0.16 g GAE/g, and 1.37 ± 0.14 mg TAE/g, respectively. In addition, the extract showed medium inhibition of S. aureus at a concentration of 400 and 525 mg/m, with no inhibitory effect against E. coli. The MIC and MBC from the microdilution method for S. aureus were at 4400 and 8800 mg/mL extract, while values of 28000 and 56000 mg/mL were obtained for E. coli. Based on these results, the inhibition activity of ethanol extract of D. pentandra against S. aureus was greater compared to E. coli.

Phytochemical Constituent, Antibacterial and Antioxidant Leaves of Dracaena trifasciata (Prain) Mabb.

Sansevieria, commonly known as Dracaena trifasciata. Apart from serving as an ornamental and air-purifying plant, it also exhibits medicinal properties, making it a potential candidate for the development of novel natural drugs. The demand for natural antibacterial agents has significantly increased due to the rising incidence of resistance among pathogenic bacteria, such as Staphylococcus aureus. This research conducted to determine the antibacterial and antioxidant activities of D. trifasciata leaf extracts. The D. trifasciata leaf material was sequentially extracted using sonication, beginning with chloroform and then followed by ethanol. The Kirby-Bauer method was employed to conduct the antibacterial test, wherein the inhibition zones generated by the chloroform and ethanolic extracts were measured. The test bacteria used in this study was Staphylococcus aureus. The assessment of the antioxidant activity was conducted using the DPPH (2,2-diphenyl-1-picrylhydrazyl) method. Phytochemical compound identification in the extracts was conducted using GC-MS analysis. The ethanolic extract showed a higher yield percentage compared to the chloroform extract. Both extracts exhibited moderate antibacterial activity. The chloroform extract exhibited an inhibition zone of 73.33 mm2, while the ethanolic extract showed an inhibition zone of 110 mm2. The chloroform extract had a minimum inhibitory concentration (MIC) of 500 mg/mL and a minimum bactericidal concentration (MBC) of 1000 mg/mL. The ethanolic extract had an MIC of 31.25 mg/mL and an MBC of 62.50 mg/mL. In terms of antioxidant activity, the chloroform extract had an IC50 of 370.8±0.07 µg/mL, while the ethanolic extract had an IC50 of 647.4±0.12 µg/mL. GC-MS analysis revealed 47 compounds in the chloroform extract and 49 compounds in the ethanolic extract. Based on the results of yield, antibacterial and compound identification, the ethanolic extract of D. trifasciata leaves exhibited greater potential compared to the chloroform extract. Its antibacterial activity showed more promise than its antioxidant activity

Bioremediation of Pharmaceutical Wastewater using Oscillatoria subsalsa and Oscillatoria flos-aquae: Efficiency in Contaminant Removal, Phytochemical Analysis and Antibacterial Activity against Biofilm-Forming Bacteria

This study investigates the potential of cyanobacteria, specifically Oscillatoria subsalsa and Oscillatoria flos-aquae, for the bioremediation of pharmaceutical wastewater and their effectiveness in eliminating biofilm forming, multidrug-resistant bacteria. Cyanobacteria species were collected from the Mandapam coast in India and analyzed for their ability to treat pharmaceutical effluents. Phytochemical compounds in solvent extracts were assessed prior to remediation. The cyanobacteria were evaluated for their effectiveness in reducing pH, biochemical oxygen demand (BOD), chemical oxygen demand (COD), ammonia, nitrite, nitrate and phosphate levels in wastewater. Antibacterial activity was analyzed against biofilm-forming bacterial isolates from pharmaceutical effluents. Both O. subsalsa and O. flos-aquae demonstrated significant reductions in environmental contaminants. O. subsalsa was more effective in reducing COD, while O. flos-aquae excelled in reducing nitrate and nitrite levels. Phytochemical analysis revealed the presence of alkaloids, carbohydrates, flavonoids, phenols, saponins, tannins, terpenoids, sterols and quinones, indicating a rich profile of bioactive compounds. The antibacterial tests showed that both cyanobacterial species had significant antibacterial properties, with O. flos-aquae displaying stronger and more consistent activity, particularly against Gram-negative bacteria. The study highlights the potential of O. subsalsa and O. flos-aquae in wastewater treatment and their capability to combat multidrug-resistant pathogens. These findings suggest that cyanobacteria offer a promising, sustainable approach for effective bioremediation and management of pharmaceutical wastewater.

Formulation of Liquid Soap Preparations from Ethanol Extract of Cassava Leaves (Manihot Utilissima Polh) as Antibacterial Staphylococcus Aureus

Formulated cassava leaves in liquid soap preparations that have antibacterial activity. This study aims to determine the best liquid soap preparation formula from ethanol extract of cassava leaves (Manihot utilissima Polh) by varying stearic acid by FI 0.5%, FII 0.10%, FIII 0.15% and antibacterial tests on Staphylococcus Aureus. Cassava leaves were macerated with 70% ethanol and tested for antibacterial activity using the disc diffusion method. In the evaluation of liquid soap preparations and antibacterial tests, the evaluation results of FII were obtained as the best formula with a variation of 0.10% stearic acid with evaluation results that met the requirements. In the antibacterial test, the inhibition zone for the control (+) using ciprofloxacin was 14.635 mm (strong) and FII 15.685 mm (strong).

Biosynthesis and Characterization of Silver Nanoparticles and Simvastatin Association in Titanium Biofilms

Introduction: Simvastatin is an antilipidemic drug that has already demonstrated antibacterial activities on oral and non-oral microorganisms. Silver nanoparticles also exhibit antimicrobial properties, particularly for coating implant surfaces. In this study, we evaluated the effects of combining simvastatin with silver nanoparticles on the formation and viability of biofilms consolidated on titanium discs. Methods: Silver nanoparticles were first biosynthesized using the fungus Fusarium oxysporum and then characterized using Dynamic Light Scattering, X-ray Diffraction, Transmission Electron Microscopy, and energy dispersive spectroscopy. Species of Streptococcus oralis, Streptococcus mutans, Porphyromonas gingivalis, Methicillin-sensitive Staphylococcus aureus, and Methicillin-resistant Staphylococcus aureus were used and tested using Minimum Inhibitory Concentration assays with concentrations of silver nanoparticles and simvastatin alone and in combination. Biofilm inhibition and viability tests were performed on titanium surfaces. Toxicity tests were also performed on Galleria mellonella moth larvae. Results: The silver nanoparticles had a spherical shape without the formation of aggregates as confirmed by Transmission Electron Microscopy. Dynamic Light Scattering revealed nanoparticles with an average diameter of 53.8 nm (±1.23 nm), a polydispersity index of 0.23 and a zeta potential of −25 mV (±2.19 mV). The silver nanoparticles inhibited the growth of the strains tested in the range of 0.001592 and 63.75, while simvastatin alone inhibited the growth of the same strains in the range of 3.125–62.5 µg/mL. The antibacterial activity test of the combination of the two substances showed a reduction in the Minimum Inhibitory Concentration of about two to eight times, showing synergistic effects on Staphylococcus aureus and additive effects on Streptococcus oralis and Porphyromonas gingivalis. As for biofilm, sub-inhibitory concentrations of the combination of substances showed better antibacterial activity in inhibiting the formation of Streptococcus oralis biofilm, and this combination also proved effective in eradicating already established biofilms compared to the substances alone. The combination of silver nanoparticles and simvastatin showed low toxicity to Galleria mellonella moth larvae. Conclusions: The results presented indicate that the combination of the two substances could be an alternative for the prevention and reduction of biofilms on implants. These findings open up new possibilities in the search for alternatives for the treatment of peri-implant infections, as well as the possibility of using lower doses compared to single drugs, achieving the same results and reducing potential toxic effects.

Antibacterial and Photocatalytic Activities of Leonotis ocymifolia (L. ocymifolia)-Mediated ZnO Nanoparticles Annealed at Different Temperatures

This research achieved the successful synthesis of zinc oxide (ZnO) NPs through an eco-friendly method, utilizing the leaf extract of Leonotis ocymifolia (L.O.). This innovative approach not only highlights the potential of green synthesis but also underscores the effectiveness of natural resources in nanoparticle production. The influence of annealing temperature on the properties and performance of the synthesized ZnO NPs was evaluated by varying the annealing temperatures as follows: unannealed (000), 350 °C (350), 550 °C (550), and 750 °C (750). The XRD analysis of L.O-mediated ZnO NPs confirmed the synthesis of highly crystalline wurtzite-structured ZnO NPs, with calculated average crystallite sizes that ranged between 13.8 and 20.4 nm. The UV–Vis spectra revealed a single strong absorption peak ranging from 354 to 375 nm, and the absorption peaks red-shifted with an increase in annealing temperature. The SEM micrographs showed that annealing temperature had an effect on the morphology, particle size, and distribution, with the average particle of 53.7–66.3 nm. The BET analysis revealed that the surface area of the prepared ZnO NPs was between 31.6 and 13.2 m2/g. In addition to its significant impact on the characteristics of the L.O-mediated, annealing temperature notably boosts the L.O-mediated capacity to photodegrade Methylene blue (MB) dye. Moreover, it exhibited significant antibacterial efficacy against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The photodegradation studies under UV irradiation and in 180 min revealed 750 (71.1%) had the highest degradation efficiency compared to 000, 350, and 550. The antibacterial tests showed that 000 had greater antibacterial efficacy than 350, 550, and 750. The results from this work suggest that annealing temperature had a significant effect on the structural, morphological, and optical properties and performance of L.O-mediated ZnO NPs.

Analysis of the Chemical Composition, Antimicrobial, and Antioxidant Qualities of Microwave and Supercritical CO2-Extracted Lavender Essential Oils Cultivated in a Hyperarid Region of Türkiye

This study compares the chemical composition, antioxidant capacity, and antibacterial properties of lavender essential oils extracted using microwave-assisted extraction (MAE) and supercritical CO2 extraction (SCDE). Gas chromatography–mass spectrometry analysis revealed that the MAE oil contained higher levels of linalyl acetate (36.19%) and linalool (28.29%) compared with the SCDE oil, which had values of 28.72% and 27.48%, respectively. The MAE oil also showed superior antioxidant activity, with DPPH IC50 values of 72.99 mg/mL and FRAP values of 1.31 mM Fe2+/g, compared with 80.84 mg/mL and 1.14 mM Fe2+/g for the SCDE oil. Antibacterial tests indicated that the MAE oil exhibited lower MIC values, demonstrating twice the antibacterial activity against Bacillus cereus NRRL B3711, Bacillus subtilis PY79, and Enterococcus faecalis ATCC 29212 compared with the SCDE oil. These results highlight the superior bioactivity of MAE-extracted lavender oil, making MAE a preferred method for high-quality oil extraction from drought-affected lavender plants.

Synergistic fermentation of Cordyceps militaris and herbal substrates boosts grower pig antioxidant and immune function

BackgroundPathogenic infections can significantly impact the health of livestock. Traditionally, antibiotic growth promoters (AGPs) have been used in feed to enhance growth performance and disease control. However, concerns regarding antibiotic resistance have led to the exploration of traditional herbal medicine as a natural alternative, guided by the principle of medicine-food homology. The Taguchi method was employed to optimize the culture formula for cordycepin production, an active component of Cordyceps militaris (C. militaris). The influences of C. militaris supplementing solid-state fermentation (CMSSF) in feed on the growth performance and immune responses of grower pigs were evaluated in the present study.ResultsThe C. militaris ethanol extract (CME) displayed potent free radical scavenging activity against 2, 2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2’-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) after undergoing fermentation. Additionally, the antibacterial testing revealed that CME effectively inhibits the growth of common pig pathogens such as Glaesserella parasuis, Pasteurella multocida, Staphylococcus hyicus, and Streptococcus suis. In lipopolysaccharide (LPS)-treated intestinal porcine enterocyte cell line (IPEC-J2), CME significantly suppressed the production of pro-inflammatory cytokines, including tumor necrosis factor (TNF)-α and interleukin (IL)-6. In addition, higher antioxidative activity was detected as indicated by elevated concentration of superoxide dismutase (SOD) in pig serum. The levels of immunoglobulin M (IgM), IgA, and IgG antibodies, as well as classical swine fever virus (CSFV) antibodies (S/P ratio) in serum were all increased. Growth performance of pigs fed with dietary CMSSF supplementation was improved in comparison with the control.ConclusionsResults demonstrated that CMSSF has the potential to be used as a natural growth promoter to enhance immunity, antioxidation, as well as overall health and growth performance of grower pigs.

Potential application of andrographolide in vital pulp therapy by inducing expression of human β defensin 4

AbstractAimThis study aimed to investigate the ability of andrographolide to induce human β defensin 4 (HBD4) expression in dental pulp stem cells and its effect on inflammatory pulp tissue in rats in vivo.MethodsThe expression of HBD4 in andrographolide‐induced dental pulp stem cells was examined using quantitative polymerase chain reaction and immunofluorescence staining. High‐throughput analysis of protein acetylation was conducted to screen the mechanism of andrographolide‐induced HBD4 expression. Colony‐forming unit methods were used to study the antimicrobial ability of andrographolide‐induced HBD4 on Porphyromonas gingivalis. Finally, the ability of andrographolide to preserve vital pulp was examined using Wistar rats with irreversible pulpitis.ResultsHBD4 expression level increased after andrographolide stimulation, which was related to histone acetylation modification, as revealed by acetylome analyses. Antibacterial testing confirmed that andrographolide‐induced HBD4 was sensitive to P. gingivalis. Furthermore, andrographolide controlled pulp inflammation in a Wistar rat irreversible pulpitis model and induced the restorative dentin formation.ConclusionWe concluded that andrographolide induced the expression of HBD4 in dental pulp stem cells through histone acetylation modification and exerted inhibitory effects on pulp tissue inflammation in vivo.

Novel biocompatible magnetron-sputtered silver coating for enhanced antibacterial properties and osteogenesis in vitro

Peri-implant infection is a serious complication in orthopedic surgery. This study aimed to reduce the incidence of peri-implant infection by developing a durable and safe antibacterial silver coating. We compared the antibacterial properties and process controllability of various coating techniques to identify the most effective method for silver coating. We refined substrate treatment techniques and coating thicknesses through antibacterial and scratch tests. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) were used to analyze the coating’s morphology and composition. Micron-sized magnetron sputtering silver coating samples underwent in vitro antibacterial testing, cytotoxicity testing, silver ion release testing, and osteogenic testing using membrane contact culture, CCK-8 assay, inductively coupled plasma (ICP) detection, and alkaline phosphatase (ALP) activity/osteogenic gene PCR. Magnetron sputtering demonstrated superior antibacterial properties, uniformity, and process controllability compared to alternative techniques. The optimal adhesion strength was achieved with a 0.5 μm coating thickness and a 400 mesh sandpaper pretreatment process, without compromising antibacterial efficacy. The coating showed near-perfect antiseptic results in antibacterial and anti-biofilm tests. Fibroblasts cultured in silver ion precipitation medium exhibited growth rates of 89% on day 30 and 88% on day 90, compared to 95% in the control group. The osteogenic test indicated that the magnetron sputtering silver coating promotes osteogenesis effectively. Our study demonstrated that micron-sized magnetron sputtering silver coating has potential for clinical use to prevent peri-implant infections in the future.

Comparative Study of Antimicrobial Efficacy and Phytochemical Profiles of Ethanol and n-Hexane Extracts from the Roots of Ixora coccinea Linn

The root extracts of Ixora coccinea were evaluated for their phytochemical composition, antibacterial activity, and minimum inhibitory concentration (MIC) against Escherichia coli, Staphylococcus aureus, and Bacillus subtilis. Quantitative phytochemical analysis was conducted to determine the levels of terpenoids, flavonoids, alkaloids, tannins, and saponins. Thin Layer Chromatography (TLC) was used to confirm the presence of bioactive components in the extracts under different solvent systems, followed by antibacterial susceptibility tests using the disc diffusion method. The MIC was determined through serial dilution to identify the lowest concentration that inhibited bacterial growth. Quantitative phytochemical analysis showed that the ethanol extract contained 14.80% flavonoids, 6.00% alkaloids, 1.20% saponins, 1.80% terpenoids, and 0.03% tannins. In contrast, the n-hexane extract had higher terpenoid content (3.40%) but lower flavonoids (5.20%) and alkaloids (2.10%). Thin Layer Chromatography (TLC) analysis under varying solvent systems showed different Rf values, with the ethanol extract displaying more diverse spots, indicating a richer variety of bioactive compounds. Antibacterial susceptibility tests revealed that the ethanol extract produced larger inhibition zones (10 ± 0.4–28 ± 1.0 mm) than the n-hexane extract (6 ± 0.2–26 ± 0.8 mm). MIC results indicated that ethanol extract inhibited E. coli and S. aureus at 50 mg/L and B. subtilis at 25 mg/L, while the n-hexane extract required 100 mg/L for effective inhibition. In conclusion, the findings indicate that the plant possesses significant antibacterial potential, warranting further research to isolate and characterize the specific phytoconstituents responsible for the observed antimicrobial activities.

Multifunctional Ag-Poly(N-isopropylacrylamide/itaconic Acid) Hydrogel Nanocomposites Prepared by Gamma Irradiation for Potential Application as Topical Treatment Dressings.

Today, hydrogel dressings that can protect injury sites and effectively promote healing have become highly desirable in wound management. Therefore, multifunctional silver-poli(N-isopropylacrylamide/itaconic acid) (Ag-P(NiPAAm/IA)) hydrogel nanocomposites were developed for potential application as topical treatment dressings. The radiolytic method, used for the crosslinking of the polymer matrix as well as for the in situ incorporation of silver nanoparticles (AgNPs) into the polymer matrix, enables the preparation of hydrogel nanocomposites without introducing harmful and toxic agents. Moreover, materials produced using γ-irradiation are simultaneously sterilized, thus fulfilling one of the basic requirements regarding their potential biomedical applications. The NiPAAm/IA ratio and the presence of AgNPs influenced the microstructural parameters of the investigated systems. Increasing the IA content leads to the formation of a more porous polymer matrix with larger pores, while the incorporated AgNPs act as additional junction points, decreasing the porosity and pore size of the resulting nanocomposite hydrogels. Swelling studies showed that most investigated systems uptake the fluids from their surroundings by non-Fick diffusion. Further, the Ag+ ion release, antibacterial activity, and cytotoxicity of Ag-P(NiPAAm/IA) hydrogel nanocomposites were examined to evaluate their biomedical potential. All hydrogel nanocomposites showed an initial burst release of Ag+ ions (useful in preventing bacteria adherence and biofilm formation), followed by a slower release of the same (ensuring sterility for longer use). An antibacterial activity test against Escherichia coli and Staphylococcus aureus showed that Ag-P(NiPAAm/IA) hydrogel nanocomposites, with silver concentrations around 10 ± 1 ppm, successfully prevent bacterial growth. Finally, it was shown that the investigated hydrogel nanocomposites do not exhibit a cytotoxic effect on human keratinocyte HaCaT cells. Therefore, these multifunctional hydrogel nanocomposites may promote wound repair and show promising potential for application as functional wound dressing.

Biodegradable antibacterial food packaging based on carboxymethyl cellulose from sugarcane bagasse/cassava starch/chitosan/gingerol extract stabilized silver nanoparticles (Gin-AgNPs) and vanillin as cross-linking agent

The increasing issue of plastic waste necessitates improved solutions, and biodegradable food packaging is a promising alternative to traditional plastic. In this study, we prepared packaging films using cassava starch (CV), chitosan (CT) and carboxymethyl cellulose (CMC), with glycerol as a plasticizer. However, these films require modifications to enhance their mechanical properties. Therefore, we modified the films by adding vanillin as the crosslinking agent and gingerol extract stabilized silver nanoparticles. The films were fabricated using the film-casting method and characterized by FTIR, XRD, SEM, TGA, mechanical property test, biodegradability test, anti-bacterial test and food packaging evaluation test. Among these films, CT/CV/V/CMC/Gin-AgNPs1 exhibited superior mechanical properties and demonstrated excellent anti-bacterial property both for gram-positive (S. aureus) and gram-negative (E. coli) bacteria and biodegradability, losing over 50% of its weight after 21 days of burial in soil and effectively preserved grapes at 4 °C for 21 days.

Effect of olive leaf extract on the physicochemical properties of bio-based hair clipper lubricating oil developed from Neem seed oil

Nowadays, mineral-based oil is the most popular used lubricant in hair-clipper applications. However, producing these petroleum-based lubricants contributes to environmental pollution and climate change. This study explores the effect of olive leaf extract on the physicochemical properties of a bio-based hair clipper lubricating oil derived from neem seed oil. Neem crude oil was synthesised using a double transesterification method to develop a neem bio-based hair clipper lubricating oil. The produce neem bio-lubricant was blended with olive leaf extract at concentrations of 50 mg/ml, 100 mg/ml, and 200 mg/ml to enhance its anti-bacterial properties. The physicochemical properties of the blend, including viscosity, density, flash point, and pour point, were evaluated to determine its suitability as a sustainable alternative to conventional clipper oil. The results indicated that the flash point of the blended bio-based hair clipper lubricating oil was 180 °C, 195 °C, and 210 °C respectively, and they were found to be within the minimum requirement of the ISO standard value (EN ISO 2719) and above the conventional clipper oil (129 °C). From the pour point values obtained, the blended bio-lubricant offers a poorer value of 3 °C and 8 °C compared to that of ISO standard value (ISO standard 3016) and conventional clipper oil (-40 to -6 °C). It was also observed that the viscosities of 14.5 cSt, 15.6 cSt, and 16.7 cSt for the blended bio-lubricant conform with the minimum requirement of the ISO standard value (EN ISO 3104) and that of conventional clipper oil (7.5 to 90 cSt) at 40 °C. The density values of the blended bio-lubricant (0.897, 0.898, and 0.902) were found to be slightly above that of the ISO standard value (EN ISO 12185) and the conventional clipper oil (0.85–0.88). The antibacterial sensitivity test results of the blended bio-lubricant demonstrated a broad spectrum of activity against all tested microorganisms at both high and low concentrations, except for Escherichia coli, which showed moderate sensitivity at low concentrations (50 mg/mL). In general, the results of this work show that the bio-based hair clipper lubricating oil is a potential alternative to conventional clipper oil.