Antibacterial Test Research Articles

Green Synthesis of Silver Nanoparticles Using Gempur Batu Leaf Extract (Ruellia napifera) as Antibacterial, Antibiofilm, and Antioxidant

Silver Nanoparticles basically focus on the synthesis of nano-sized particles produced through chemical, physical, and biological processes, which contribute significantly to the control of plant and animal diseases and have shown considerable promise in improving the quality of human living conditions and health. The method of making silver nanoparticles, namely Green synthesis, involves the use of plants for the synthesis process of various types of nanoparticles. Green synthesis has the advantages of a simple method, environmentally friendly, non-polluting, antitoxic, and cost-effective. The purpose of this study was to determine the antibacterial and antioxidant activities of AgNPs. In the spectrophotometer absorption spectrum appears at a wavelength of 450 nm. FTIR measurements were used to determine the presence of bioactive molecules that may be responsible for the stabilization that acts as a capping agent. The absorption spikes at 3256, 1552, 1048, and 934 cm−1 were determined for gempur batu leaf extract, while silver nanoparticles showed absorption spikes at 3369, 1576, 1080, and 822 cm−1. The results of XRD analysis of AgNPs showed that they had been successfully synthesized, which can be seen from the formation of narrow peaks indicating the crystalline nature of the formed nanoparticles. The results of TEM analysis of AgNPs in this study are a mixture of spherical, hexagonal, and triangular shapes of silver nanoparticles. The antibacterial activity test of silver nanoparticles with gempur batu leaf extract with variations in AgNO3 solution concentration has been successful, which is indicated by the formation of inhibition zones for Eschericia coli and Staphylococcus aureus bacteria. The results of antioxidant activity in AgNPss show an increasing percentage of inhibition along with increasing concentration of AgNPss increasing from 1 to 15 ppm and ascorbic acid increasing from 1 to 5 ppm. Antibiofilm activity in AgNPs has a good ability to inhibit the formation of biofilm layers in Staphylococcus aureus and Escherichia coli bacteria by having a biofilm inhibition percentage of more than 50%.

COMPARATIVE ANALYSIS OF FLAVONOID AND TANNIN EXTRACTION FROM ULVA LACTUCA USING MACERATION AND ULTRASONIC-ASSISTED (UAE) TECHNIQUES FOR ANTIBACTERIAL ACTIVITY

Streptococcus agalactiae and Streptococcus iniae bacteria can cause mass mortality in farmed fish, resulting in negative production and economic impacts. The use of conventional antibiotics in the management of these diseases has led to resistance problems and environmental pollution. Ulva lactuca algae are known to contain bioactive compounds such as triterpenoids, flavonoids, and saponins that have antibacterial potential against Streptococcus. This study aims to evaluate the potential of Ulva lactuca algae extract as an alternative treatment for streptococcosis in Gourami (Osphronemus gouramy). The research method includes algae extraction using 90% ethanol, Streptococcus sp. bacterial culture, antibacterial activity test through disc diffusion method, and application of extracts to gouramy infected with bacteria. The results showed that Ulva lactuca extract at all concentrations did not show the ability to inhibit Streptococcus agalactiae bacteria. It is necessary to optimize the Ulva lactuca extraction process and its concentration to increase the effectiveness of Streptococcus agalactiae inhibition.

Advanced Copper Oxide Chemical and Green Synthesis: Characterization and Antibacterial Evaluation

Recent advancements in nanotechnology have improved the application of copper oxide (CuO) nanostructures, known for their diverse antibacterial, electrical, catalytic, optical, and pharmacological properties, which depend on nanoparticle morphology. This study investigated two synthesis methods for structured CuO: microwave-assisted hydrolysis and ultrasound using copper acetate and KOH, and an eco-friendly method involving cholesterol-free egg white albumin and Solanum lycopersicum extract. Characterization techniques, including XRD, FTIR, and SEM-EDS, were utilized to analyze the produced CuO. XRD confirmed high-purity monoclinic CuO structures in the sample obtained via the chemical method, while characteristic peaks of tenorite and dolerophanite were observed in the albumin-synthesized sample. ATR-FTIR analysis revealed O-H stretching bands around 3400 cm−1, indicating adsorbed H-OH or -OH and strong Cu-O bond peaks at 434 cm−1. The CuO synthesized via microwave and ultrasound methods displayed superior crystallinity compared to commercial CuO. SEM illustrated various morphologies, such as flakes, microspheres, and irregular polyhedra, influenced by the presence of proteins and organic acids. Antibacterial tests demonstrated the effective inhibition of Escherichia coli and Enterococcus faecalis, confirming the potential of CuO as a promising antibacterial agent. Overall, the findings highlight the effectiveness of green chemistry in developing crystalline CuO for various applications.

PEMBUATAN SABUN DENGAN EKSTRAK ETANOL DAUN KERSEN (MUNTINGIA CALABURA) SEBAGAI ANTISEPTIK ALAMI

Liquid soap is a liquid skin cleansing preparation made from soap base with the addition of other permitted ingredients and is used to cleanse the skin without causing irritation to the skin which can be caused by bacteria. This study aims to determine the effect of the addition of ethanol extract of kersen leaves in liquid soap preparations against Staphylococcus aureus bacteria. Liquid soap formulation of ethanol extract of kersen leaves (Muntingia calabura) was formulated in 3 (three) formulations, namely F1 soap preparation with 25% extract concentration, F2 with 30% kersen leaf ethanol extract concentration, and F3 with 35% kersen leaf ethanol extract concentration. Antibacterial testing was carried out using the disc diffusion method. The results of the antibacterial activity test of antiseptic liquid soap preparations F1 soap preparation has an inhibition of 16.82 mm, formulation 2 30% extract concentration has an inhibition of 19.52 mm, F3 extract concentration has an inhibition of 21.90 mm and positive control Dettol soap has an inhibition of 22.22 mm against Staphylococcus aureus bacteria. The conclusion of this study is that ethanol extract of kersen leaves has antibacterial activity against Staphylococcus aureus bacteria and the most optimal inhibitory concentration is kersen leaf extract soap preparation with a concentration of 35% with a very strong inhibition zone category.

Chemical Modification of Acrylonitrile-Divinylbenzene Polymer Supports with Aminophosphonate Groups and Their Antibacterial Activity Testing.

Bacterial contamination is a major public health concern on a global scale. Treatment resistance in bacterial infections is becoming a significant problem that requires solutions. We were interested in obtaining new polymeric functionalized compounds with antibacterial properties. Three components (polymeric amine, aldehyde, and phosphite) were used in the paper in a modified "one-pot" Kabachnik-Fields reaction, in tetrahydrofuran at 60 °C, to create the N-C-P skeleton in aminophosphonate groups. Two copolymers were thus prepared starting from an acrylonitriledivinylbenzene (AN-15%DVB) copolymer containing pendant primary amine groups modified by grafting aminophosphonate groups, i.e., aminobenzylphosphonate (Bz-DVB-AN) and aminoethylphosphonate (Et-DVB-AN). The two copolymers were characterized by FT-IR spectroscopy, SEM-EDX, TGA, and antibacterial properties. It was shown that the novel products have antibacterial qualities against S. aureus and E. coli bacteria. The sample with the strongest antibacterial activity was Et-DVB-AN. We assessed how well the Weibull model and the first-order kinetic model represent the inactivation of microbial cells in our samples. The main advantage of the new antibacterial agents developed in this work is their easy recovery, which helps to avoid environmental contamination.

ANTIMICROBIAL ASSAY OF ESSENTIAL OIL FROM Eucalyptus globulus LEAF

Investigating the antibacterial test of essential oil derived from Eucalyptus globulus leaves against clinically significant microbial strains is the goal of this investigation. Salmonella typhi, Pseudomonas aeruginosa, and Escherichia coli are the isolates of Gram-negative bacteria, whereas Staphylococcus aureus is an isolate of Gram-positive bacteria. In the current study, essential oil was extracted using microwave-assisted hydrodistillation, and the oil's antibacterial properties were assessed. The physical method was used to determine the oil's color, odor, and solubility. The essential oil of fresh Eucalyptus globulus leaves exhibits zone of inhibition against three of the studied species Escherichia coli, Staphylococcus aureus and Salmonella typhi at all concentrations of oil per disc but no action against Salmonella typhi at 1.43 mL/disc. At all concentrations, the essential oil did not, however, exhibit any anti-Pseudomonas aeruginosa activity. With a zone of inhibition of 17.7 mm and a concentration of 5.72 mL/disc, the oil was most effective against Staphylococcus aureus. As concentration drops, the zone of inhibition shrinks as well; at 2.86 mL/disc and 1.43 mL/disc, it is 14.7 mm and 9.7 mm, respectively. The essential oil of dried Eucalyptus globulus leaves exhibits no action against Salmonella typhi at 1.43 mL/disc, but it does exhibit a zone of inhibition against three of the examined organisms: Salmonella typhi, Staphylococcus aureus, and Escherichia coli, at all oil concentrations per disc. At all concentrations, the essential oil did not, however, exhibit any anti-Pseudomonas aeruginosa activity. With a zone of inhibition of 13.3 mm and a concentration of 5.72 mL/disc, the oil was most effective against Staphylococcus aureus. As concentration drops, the zone of inhibition shrinks as well; at 2.86 mL/disc and 1.43 mL/disc, it is 11.1 mm and 8.3 mm, respectively. It is advised that the essential oil's effectiveness be evaluated against fungus in order to investigate the best combinations and uses to maximize its medicinal potential. For direct use, in vivo assay is advised.

Fraction and Antibacterial Activity of Bitter Melons (Momordica charantia) in Koi Fish (Cypinus carpio) Infected with Aeromonas salmonicida Bacteria and its Effect on Gills Histopathology

Koi fish (Cyprinus carpio) is a type of freshwater ornamental fish with significant economic value, attracting widespread public interest due to its vibrant colors and agile movements. Therefore, this study introduces a novel approach by evaluating the antibacterial activity of bitter melon extract fraction (Momordica charantia) against A. salmonicida infection in koi fish and its impact on gill histopathology. The novelty of this study lies in the exploration of bitter melon extract fraction as a natural, eco-friendly antibacterial alternative to synthetic antibiotics in aquaculture. This research is crucial as it addresses the growing global concern over antibiotic resistance and the urgent need for sustainable, natural solutions in fish health management. Antibacterial tests were conducted to assess the ability of the bitter melon extract to inhibit bacterial growth, while histopathological analysis aimed to observe the specific changes in gill tissues of infected koi fish. The results revealed that the bitter melon extract fraction significantly reduced bacterial count and improved gill tissue integrity. Histopathological improvements were observed, including reduced hyperplasia, lamellar fusion, edema, and necrosis, indicating tissue recovery. This finding highlights the potential of bitter melon extract fraction as a natural antibacterial agent for controlling bacterial infections in fish, offering an alternative to chemical antibiotics. Further research is needed to determine the optimal dosage and to explore its antibacterial mechanism, ensuring its safe and effective application in aquaculture.

Synergistic Effects and Mechanisms of Action of Rutin with Conventional Antibiotics Against Escherichia coli.

Rutin is a widely known plant secondary metabolite that exhibits multiple physiological functions. The present study focused on screening for synergistic antibacterial combinations containing rutin, and further explored the mechanisms behind this synergy. In vitro antibacterial test results of rutin showed that the ranges of minimum inhibitory concentration (MIC) and Minimum bactericidal concentration (MBC) are 0.125-1 and 0.125-2 mg/mL, respectively. However, rutin and amikacin have a significant synergistic effect, with a fractional inhibitory concentration index (FICI) range of 0.1875-0.5. The time bactericidal curve proved that the combination of rutin and amikacin inhibited bacterial growth within 8 h. Scanning electron microscopy (SEM) revealed that a low-dose combination treatment could disrupt the cell membrane of Escherichia coli (E. coli). A comprehensive analysis using alkaline phosphatase (AKP), K+, and a protein leakage assay revealed that co-treatment destroyed the cell membrane of E. coli, resulting in the significant leakage of AKP, intracellular K+, and proteins. Moreover, confocal laser scanning microscopy (CLSM) and red-green cell ratio analysis indicated severe damage to the E. coli cell membrane following the co-treatment of rutin and amikacin. This study indicates the remarkable potential of strategically selecting antibacterial agents with maximum synergistic effect, which could significantly control antibiotic resistance.

PENGARUH EKSTRAK ETANOL DAUN MANGKOKAN (Nothopanax scutellarium) YANG DIMANFAATKAN SEBAGAI ANTIBAKTERI DARI BAKTERI Vibrio sp

One of the pathogenic bacteria found in aquatic environments is Vibrio sp., which causes vibriosis. The use of mangkokan leaf extract as an antibacterial agent against Vibrio has not been studied before. The aim of this research was to evaluate the antibacterial activity of mangkokan leaf extract in inhibiting the growth of Vibrio sp. The antibacterial test in this study used the disc diffusion method. In addition, the study also conducted tests for yield and phytochemical analysis. The results showed that mangkokan leaf extract at concentrations of 100% and 75% exhibited moderate antibacterial activity, with average inhibition zone diameters of 8.5 mm and 6.35 mm, respectively. The yield of the ethanol extract from mangkokan leaves was 10.2%. The mangkokan leaf extract contains secondary metabolites such as flavonoids, steroids, alkaloids, tannins, and saponins.

PENGARUH PENAMBAHAN MADU GALO-GALO TERHADAP AKTIVITAS ANTIBAKTERI KOMBUCHA KULIT NANAS DAN AIR KELAPA

Kombucha is a fermented beverage known for its various health benefits, one of which is its antibacterial properties, making it a potential base for soap production. This study aims to evaluate the effect of adding Galo-Galo honey on the antibacterial activity of kombucha made from pineapple peel and coconut water waste. Fermentation was carried out for 15 days, and observations were made on pH value, total titratable acidity (TTA), and antibacterial activity against Escherichia coli using the disk diffusion method. The study was designed using a completely randomized design with three repetitions. The results showed that the higher the concentration of Galo-Galo honey added, the more significantly the kombucha pH decreased (p < 0.05), with the lowest pH found in the 25% honey treatment (3.09 ± 0.02). The highest total titratable acidity was also found in the 25% honey treatment (1.33 ± 0.11), along with the decrease in pH, indicating an increase in organic acid content. The antibacterial activity test showed that kombucha with a higher honey concentration had a larger inhibition zone against E. coli, with the largest inhibition zone found in the 25% honey treatment (11 ± 1.26 mm). The addition of Galo-Galo honey was proven to enhance the chemical properties of kombucha and strengthen its antibacterial activity.

Characterization, antimicrobial and antioxidant activity of bee bread encapsulated with chitosan nanoparticle

The potential of bee bread as an apitherapeutic agent was investigated in this study, focusing on its immune-stimulating abilities. The novel aspect of the study is how bee bread is combined with chitosan, a biopolymer with antibacterial and antioxidant properties, to increase its therapeutic efficacy. Free freeze-drying technology accomplished encapsulation at a critical temperature of −80 °C. The encapsulated constructs were characterized using analytical techniques like FTIR (Fourier Transform Infrared Spectroscopy), X-ray diffraction (XRD), Zeta potential analysis, and Scanning Electron Microscopy (SEM). Furthermore, the ethanolic extract of bee bread was analyzed using Gas Chromatography-Mass Spectrometry (GCMS) to identify phytochemicals. UV spectrophotometry was used to quantify antioxidant activity. Antibacterial tests using the disc diffusion method revealed a significant inhibitory effect on Bacillus subtilis, a Gram-positive bacterium, whereas Gram-negative bacteria showed reduced sensitivity to the encapsulated agents.

Broadly Accessible 3D In Vitro Skin Model as a Comprehensive Platform for Antibacterial Therapy Screening.

Skin infections are currently a worldwide emergency as antibiotic-resistant bacteria are spreading, leading to the ineffectiveness of most antibiotics and antibacterial strategies. Consequently, there is an urgency of developing and testing innovative antibacterial therapies. As traditional 2D cell culture and planktonic bacteria culture can be obsolete due to their incapability of resembling the complex infection environment, 3D in vitro skin models can be a powerful tool to test and validate therapies. In this article, a 3D in vitro epidermis-dermis skin model has been developed and biofabricated to be broadly available, reaching a balance between the simplicity and reproducibility of the model and its complexity in terms of wound, infection, and treatment response. The results are really promising, as the skin model developed a comprehensive physical barrier. To further investigate the skin model, controlled wounding, infection, and antibiotic treatments were performed. The results were remarkable: Not only was the unwounded epidermal barrier able to partially stop the bacterial proliferation, but the entire system reacted to both wound and infection in a complex and complete way. Extracellular matrix deposition and remodeling, inflammatory response, antimicrobial peptide production, and change in cellular behaviors, from epithelial to mesenchymal and from fibroblasts to myofibroblasts, were witnessed, with different extents depending on the bacterial strain. In addition, the inflammatory response to the antibiotic administration was opposite for the two bacterial infections, probably revealing the release of inflammatory endotoxins during Escherichia coli death. In conclusion, the presented 3D in vitro skin model has all the characteristics to be a future landmark as a platform for antibacterial strategy therapy testing.

Characterization The Flavonoids Extract of Tridax Procumbens l. Leaves and Betel Lime as Materials for Open Wound Analgesic Ointment

Tridax procumbens L. has quite high flavonoid content (6.51%). Flavonoids have antimicrobial effects that can fight bacteria. Besides that, the flavonoid content of T. procumbens leaves as an analgesic inhibits has the potential to be used as an analgesic ointment material for open wounds. Betel lime (CaCO3) also helps speed up the healing of open wounds. This research aims to optimize a mixture of T. procumbens leaves and betel lime to make a material-based herbal ointment that effective in healing open wounds. This research uses quantitative and qualitative approaches. The dependent variables used are the results of FTIR characterization, SEM-EDX, and antibacterial tests. Research results show that the 1:1 ointment sample has the highest homogeneity with an average particle size distribution of 11.95 nm. The weight and total atomic weight of carbon and calcium elements fluctuated with increasing leaf extract concentration, but the 2:1 ointment sample showed a higher calcium element content than the other samples because the amount of whiting was greater than the leaf extract. Flavonoid functional groups were successfully detected, O-H, C-H, and C-O-C. In S. aureus, it was shown that the 1:1 ointment sample was able to inhibit bacterial growth with an inhibition zone diameter of 0.062 to 1.510 cm. In addition, the contents of stigmasterol, β-sitosterol, and n-hexadecanoid acid are the main components that play a role in the inhibitory activity of bacteria. Keywords: Analgesic ointment, flavonoids, open wounds

Study of the antibacterial activity of hybrid nanocomposites “metal oxide/alginate” synthesized for therapeutic purposes

IntroductionBacterial infections pose a significant health challenge, leading to chronic ailments and high mortality rates. Antibiotic resistance due to improper usage necessitates novel antimicrobial solutions. Metal oxide nanoparticles, particularly in nanocomposites with sodium alginate, offer promising antibacterial properties. This study aims to synthesize and evaluate metal oxide/alginate nanocomposites for enhanced antibacterial activity.Material and methodMetal oxide nanoparticles (ZnO, Ag2O, CuO, NiO, CoO, FeO, Fe2O3, Cr2O3) were synthesized using a precipitation method. Nanocomposites (MO-Alg) were formed by incorporating these nanoparticles into a sodium alginate matrix. The physicochemical properties, stability, and antibacterial activity of the nanocomposites were assessed through ATR-IR analysis, SEM imaging, granulometry analysis, and XRD patterns. Antibacterial tests were conducted against Gram-negative (Pseudomonas aeruginosa, Escherichia coli) and Gram-positive bacteria (Staphylococcus aureus, Enterococcus faecalis).Result and discussionCharacterization revealed well-defined metal oxide structures (ATR-IR) within the alginate matrix. SEM images showcased uniform dispersion and distinctive rod-like configurations of metal oxide nanoparticles. XRD patterns confirmed crystalline phases. Antibacterial tests demonstrated varying efficacy, the lowest inhibition concentration for (G +) samples was 65 µg/ml for ZnO-Alg and Ag2O-Alg NCs. For (G-) samples, inhibition of P. aeruginosa was observed at 65 µg/ml with Ag2O-Alg, FeO-Alg, and Fe2O3-Alg, and for E. coli, inhibition was observed with all NCs except ZnO-Alg, with 65 µg/ml for Ag2O-Alg, NiO-Alg, FeO-Alg, and Fe2O3-Alg.ConclusionThe study successfully synthesized and characterized metal oxide/alginate nanocomposites with promising antibacterial properties. The nanocomposites exhibited stability and bactericidal effects, highlighting their potential for diverse biomedical applications, including wound dressings, medical implants, and packaging materials. The findings contribute to advancing nanomaterials in biomedical fields, encouraging further exploration and development.

Preparation and performance analysis of zinc-iron-based nanomaterials for targeted transport

Background Nanomaterials have applications in traditional Chinese medicine in the fields of medical equipment manufacturing, targeted transportation, and drug synergistic therapy. Objective The research aims to discuss the performance and performance of zinc-iron-based nanomaterials in medical drug delivery and synergistic drug therapy. Methods Using Prussian materials as precursors, magnetic zinc-iron nanomaterials were prepared by ZnCl2 and K3[Fe (CN)6]. Moreover, the morphology and composition of the material were analyzed. Results X-ray analysis was conducted on the prepared Zn3[Fe (CN)6]2·xH2O nanomaterials, and their purity met the design requirements. At the same time, drug loading analysis was conducted on Zn3[Fe(CN)6]2·xH2O, and the release of capsaicin reached 86.3% under a certain phosphate buffer solution. Meanwhile, Zn3[Fe (CN)6]2·xH2O loaded tetracycline could release up to 90% in phosphate buffer solution. Antibacterial tests were conducted on self-made Zn3[Fe(CN)6]2·xH2O samples and ZnFe2O4/ZnO. The Zn3[Fe(CN)6]2·xH2O samples showed a more significant inhibitory effect on cancer cells after loading with capsaicin. Conclusion The zinc-iron-based nanomaterials prepared by the research have excellent performance in drug loading and safety, indicating their significant potential for development in the medical field.

Treating Burn Infections With Topical Delivery of Positively Charged Norfloxacin-Loaded Lipid-Polymer Hybrid Nanoparticles.

Norfloxacin (NFX) is a wide-spectrum antibacterial agent that suffers from low water solubility and first-pass metabolism. This diminishes its oral bioavailability by 60-70%. This work aims to formulate a topical gel of NFX-loaded lipid polymer hybrid nanoparticles (NFX-LPHNPs) that combine the merits of liposomes and polymeric nanoparticles to overcome these problems. NFX-LPHNPs formulations were developed using Precirol ATO (lipid) and Eudragit RL100 (polymer). They were characterized for particle size, uniformity of distribution, entrapment efficiency, zeta potential, and in-vitro release. Box-Behnken design was applied to study sequentially different variables' impact on material attributes. Then the optimized formula was re-evaluated, and incorporated in an HPMC-gel formulation. The gel formulation was evaluated for its physical properties, in vitro-release, and antibacterial activity. NFX-LPHNPs exhibited particle sizes ranging from 28.92 to 730.30 nm. Particles were uniformly distributed with a positively charged surface (indicated by zeta potential with values from +3.91 to +60.2 mV). Formulations showed a % cumulative drug release of 87.9-100% in 8 h. The optimized formula showed a satisfied fit of measured-to-predicted responses with 159 nm particle size, 92.61% release and 79.2% entrapment efficiency. Gel formulation showed a sustained release over 24h. Antibacterial testing against Staphylococcus aureus, Acinetobacter baumannii and Pseudomonas aeruginosa revealed enhanced activity of NFX-LPHNPs against these pathogens compared to bare NFX loaded gel. These results illustrated the high potential of lipid-polymer hybrid nanoparticles to improve NFX activity against resistant pathogens common in burn infections. Moreover, the topical application helps overcome Norfloxacin oral-associated problems.

Antibacterial Activity Of Sago Caterpillar Oil (Rhynchoporus bilineatus L.) From Minahasa Against Salmonella typhi and Staphylococcus aureus

Sago caterpillars are ethnomedically used as food and medicine by the people of several tribes in Indonesia. Sago caterpillar oil contains active compounds, especially fatty acids that have antibacterial potential. Research has been carried out which aims to obtain the bioactive content of sago worm oil and the antibacterial activity of Salmonella typhi and Staphylococcus aureus bacteria. Sago caterpillars are obtained from the Minahasa region. Four to six instar sago caterpillars are used for oil isolation. Analysis of the content of sago worm oil using the Gas Chromatography Mass Spectrophotometry method. Meanwhile, the antibacterial test used the agar diffusion method using pure cultures of Salmonella thypii and Staphylococcus aureus. The results showed that the average sago caterpillar oil was 0.26 to 0.28 ml per head. The results of the antibacterial test showed the highest inhibition of S. aureus at a concentration of 1000 mg/L, namely 8.04 mm, while the inhibition of growth of S. thypii was highest at a concentration of 1000 mg/L, namely 7.69 mm. Sago caterpillar oil has antibacterial potential.

Biocompatible Carbon Dots/Polyurethane Composites as Potential Agents for Combating Bacterial Biofilms: N-Doped Carbon Quantum Dots/Polyurethane and Gamma Ray-Modified Graphene Quantum Dots/Polyurethane Composites.

Background: Pathogen bacteria appear and survive on various surfaces made of steel or glass. The existence of these bacteria in different forms causes significant problems in healthcare facilities and society. Therefore, the surface engineering of highly potent antimicrobial coatings is highly important in the 21st century, a period that began with a series of epidemics. Methods: In this study, we prepared two types of photodynamic polyurethane-based composite films encapsulated by N-doped carbon quantum dots and graphene quantum dots irradiated by gamma rays at a dose of 50 kGy, respectively. Further, we investigated their structural, optical, antibacterial, antibiofouling and biocompatibility properties. Results: Nanoelectrical and nanomechanical microscopy measurements revealed deviations in the structure of these quantum dots and polyurethane films. The Young's modulus of elasticity of the carbon and graphene quantum dots was several times lower than that for single-walled carbon nanotubes (SWCNTs) with chirality (6,5). The electrical properties of the carbon and graphene quantum dots were quite similar to those of the SWCNTs (6,5). The polyurethane films with carbon quantum dots were much more elastic and smoother than the films with graphene quantum dots. Antibacterial tests indicated excellent antibacterial activities of these films against a wide range of tested bacteria, whereas the antibiofouling activities of both composite films showed the best results against the Staphylococcus aureus and Escherichia coli biofilms. Biocompatibility studies showed that neither composite film exhibited any cytotoxicity or hemolysis. Conclusions: Obtained results indicate that these composite films could be used as antibacterial surfaces in the healthcare facilities.

Adsorption Behaviors of ctDNA and Biological Activities Based on Polyvinyl Alcohol/Polyethylene Glycol/Quaternized Chitosan Composite Hydrogel.

In this study, a polyvinyl alcohol/polyethylene glycol/hydroxypropyltrimethyl ammonium chloride chitosan (PVA/PEG/HACC) ternary composite hydrogel was synthesized using electron-beam radiation. The materials were thoroughly characterized via Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, Brunauer-Emmett-Teller analysis, gelation fraction tests, and swelling rate tests. Systematic adsorption experiments revealed that the rate of adsorption of calf thymus DNA (ctDNA) by the PVA/PEG/HACC hydrogel reached 89%. The adsorption process followed the Langmuir isotherm and pseudo-second-order kinetic model. This process was mainly characterized by monolayer chemical adsorption, with intraparticle diffusion playing a crucial role. In addition, the process was spontaneous, with higher temperatures enhancing adsorption. The possible adsorption mechanisms included electrostatic interactions, hydrogen bonding, and van der Waals forces. The maximum ctDNA desorption rate was 81.67%. The adsorption rate remained at 71.39% after five adsorption-desorption cycles. The bioactivity of the PVA/PEG/HACC hydrogel was validated by antibacterial, cytotoxicity, and apoptosis tests. The results of this study demonstrated the crucial application potential of adsorbent materials in DNA adsorption and biomedical applications.

Evaluation of the Antibacterial and Cell Culture Properties of Anodic Porous Alumina Prepared in Concentrated H2SO4.

The antibacterial activity of anodic porous alumina (APA) prepared using phosphoric, oxalic, and sulfuric acids was tested, and it was found that APA prepared using sulfuric acid had the highest antibacterial activity against Staphylococcus aureus and Escherichia coli. In addition, the results of the antibacterial test using APA prepared with different concentrations of sulfuric acid showed that APA prepared in concentrated sulfuric acid exhibited significantly higher antibacterial activity. APA formed in concentrated sulfuric acid also showed excellent antibacterial activity even at a high culture medium concentration, at which bacterial cells tend to multiply easily. Trace amounts of Al and S that leached out to the culture medium from APA prepared in concentrated sulfuric acid did not affect the antibacterial activity of APA, indicating that the APA surface exhibits excellent antibacterial activity. It was shown that the surface of APA prepared in concentrated sulfuric acid had excellent culture properties for fibroblasts while exhibiting antibacterial activity. APA prepared in concentrated sulfuric acid can be used in various applications that require excellent antibacterial activity as well as on surfaces that suppress bacterial growth and selectively cultivate target cells.