Robust Antibacterial Activity Research Articles

Synthesis, Characterization, Density Functional Theory Study, Antibacterial Activity and Molecular Docking of Zeolitic Imidazolate Framework‐8

ABSTRACTIn this study, Zeolitic Imidazolate Framework‐8 (ZIF‐8) nanomaterials were synthesized using a co‐precipitation one‐pot method that uses ethanol, methanol, and water as solvents for the precursors (2‐methylimidazole and Zinc nitrate hexahydrate), resulting in yields of 66.77%, 73.14%, and 68.12%, respectively. The as‐synthesized ZIF‐8 nanomaterials were thoroughly characterized by X‐ray diffraction analysis, transmission electron microscopy, ultraviolet–visible spectroscopy, and Fourier‐transform infrared spectroscopy. The X‐ray diffraction analysis showed that the crystallite size of ethanol‐based ZIF‐8 (24.76 ± 1.67 nm) was smaller than those synthesized in water (26.92 ± 1.89 nm) and methanol (31.39 ± 1.03 nm). However, methanol‐based ZIF‐8 exhibited lower crystallinity (85.93%) than water‐based ZIF‐8 (91.48%) and ethanol‐based ZIF‐8 (92.71%). Zeta potential studies revealed that ethanol‐based ZIF‐8 had a larger surface charge (+37 mV) than water‐based ZIF‐8 (+35 mV) or methanol‐based ZIF‐8 (+24 mV). Transmission electron microscopy analysis confirmed particle sizes of 54.35 ± 2.11 nm for ethanol‐based ZIF‐8, 57.91 ± 2.26 nm for water‐based ZIF‐8, and 63.25 ± 4.12 nm for methanol‐based ZIF‐8. Thermogravimetric analysis indicated thermal stability up to 800 °C, with mass losses of 55.98% for ethanol‐ZIF‐8, 50.12% for water‐based ZIF‐8, and 65.36% for methanol‐based ZIF‐8 by 600 °C. In antibacterial studies, water‐based ZIF‐8 exhibited the largest zone of growth inhibition (17.30 ± 0.26 mm) against Escherichia coli compared to ethanol‐based ZIF‐8 (15.57 ± 0.32 mm) and methanol‐based ZIF‐8 (14.70 ± 0.20 mm). Pearson's correlation study revealed that zeta potential, crystallinity, and antibacterial activity are positively related. Furthermore, water‐based ZIF‐8, with a minimum inhibitory concentration of 50 μg/100 μL, confirmed evident cell membrane disruption. Molecular docking experiments revealed ZIF‐8's significant binding affinity for the E. coli protein 5AZC, supporting its robust antibacterial activity.

Tea polyphenol nano-crosslinked dynamical hyaluronic acid-based hydrogel for diabetic wound healing

Diabetic wound healing remains a significant clinical challenge for the complex wound microenvironment characterized by oxidative stress, inflammation, and bacterial infection. To address these challenges, we present a novel hydrogel incorporates tea polyphenol-stabilized silver nanoparticles (TP@Ag NPs) into a dynamic hyaluronic acid-phenylboronic acid network crosslinked via borate ester bonds. This design leverages the inherent biocompatibility and biodegradability of hyaluronic acid alongside the antioxidant, anti-inflammatory, and antibacterial properties of tea polyphenols and silver nanoparticles. The HP-TP@Ag hydrogel exhibited glucose-responsive degradation and TP@Ag NPs release, enabling targeted delivery within the diabetic wound microenvironment. In vitro assays demonstrated the hydrogel's potent antioxidant activity, effectively scavenging ROS and protecting both HaCaT and RAW264.7 cells from oxidative stress. Furthermore, the HP-TP@Ag hydrogel significantly suppressed the production of pro-inflammatory cytokines and exhibited robust antibacterial activity against both E. coli and S. aureus. In vivo studies using a diabetic mouse model revealed accelerated wound closure, reduced inflammation, enhanced collagen deposition, and promoted angiogenesis and tissue remodeling in HP-TP@Ag hydrogel-treated wounds. These findings highlight the promise of HP-TP@Ag hydrogel as an advanced wound dressing for effective diabetic wound management, offering a synergistic approach to overcome the multifaceted challenges associated with this complex condition.

A novel antimicrobial peptide MP-4: Insights into its antimicrobial properties and intestinal regulation on E. coli-infected mice

The quest for novel, potent antimicrobial agents with low resistance potential poses a significant challenge for the advancement of the food and medical sectors. This study aimed to elucidate the antibacterial potency of antimicrobial peptides derived from koumiss in a murine model. Leveraging an antimicrobial peptide database, six peptides (MP-1 to MP-6) were meticulously predicted and screened for their antibacterial properties. These peptides were subsequently synthesized using chemical solid-phase methods and their antibacterial activities were rigorously validated. Remarkably, among the six peptides, MP-4 demonstrated a profound antibacterial effect against E. coli, achieving rapid bacterial eradication within 240 min. Flow cytometry analysis further corroborated its significant bactericidal activity. In vivo experiments conducted on mice infected with E. coli revealed that oral administration of MP-4 significantly ameliorated symptoms such as lethargy, anorexia, and weight loss. Additionally, it effectively reduced the colonic E. coli burden, attenuated inflammatory responses, and favorably modulated the intestinal microbiota composition. This study not only validates the robust antibacterial activity of the koumiss-derived antimicrobial peptide MP-4, but also underscores its potential therapeutic application in mitigating E. coli infections and promoting intestinal health.

Deciphering the Intracellular Action of the Antimicrobial Peptide A11 via an In-Depth Analysis of Its Effect on the Global Proteome of Acinetobacter baumannii.

The potential antimicrobial activity and low propensity to induce the development of bacterial resistance have rendered antimicrobial peptides (AMPs) as novel and ideal candidate therapeutic agents for the treatment of infections caused by drug-resistant pathogenic bacteria. The targeting of bacterial membranes by AMPs has been typically considered their sole mode of action; however, increasing evidence supports the existence of multiple and complementary functions of AMPs that result in bacterial death. An in-depth characterization of their mechanism of action could facilitate further research and development of AMPs with higher potency. The current study employs biophysics and proteomics approaches to unveil the mechanisms underlying the antibacterial activity of A11, a potential candidate AMP, against Acinetobacter baumannii, a leading cause of hospital-acquired infections (HAIs) and consequently, a serious global threat. A11 peptide was found to induce membrane depolarization to a high extent, as revealed by flow cytometry and electron microscopy analyses. The prompt intracellular penetration of A11 peptide, observed using confocal microscopy, was found to occur concomitantly with a very low degree of membrane lysis, suggesting that its mode of action predominantly involves a nonlytic killing mechanism. Quantitative proteomics analysis employed for obtaining insights into the mechanisms underlying the antimicrobial activity of A11 peptide revealed that it disrupted energy metabolism, interfered with protein homeostasis, and inhibited fatty acid synthesis that is essential for cell membrane integrity; all these impacted the cellular functions of A. baumannii. A11 treatment also impacted signal transduction associated with the regulation of biofilm formation, hindered the stress response, and influenced DNA repair processes; these are all crucial survival mechanisms of A. baumannii. Additionally, robust antibacterial activity was exhibited by A11 peptide against multidrug-resistant (MDR) and extensively drug-resistant (XDR) clinical isolates of A. baumannii; moreover, A11 peptide exhibited synergy with levofloxacin and minocycline as well as low propensity for inducing resistance. Taken together, the findings emphasize the therapeutic potential of A11 peptide as an antibacterial agent against drug-resistant A. baumannii and underscore the need for further investigation.

Fast fabrication of “all-in-one” injectable hydrogels as antibiotic alternatives for enhanced bacterial inhibition and accelerating wound healing

Skin wound infection has become a notable medical threat. Herein, the polysaccharide-based injectable hydrogels with multifunctionality were developed by a simple and fast gelation process not only to inactivate bacteria but also to accelerate bacteria-infected wound healing. Sodium nitroprusside (SNP) loaded PCN-224 nanoparticles were introduced into the polymer matrix formed by the dynamic and reversible coordinate bonds between Ag+ with carboxyl and amino or hydroxyl groups on carboxymethyl chitosan (CMCS), hydrogen bonds and electrostatic interactions in the polymer to fabricate SNP@PCN@Gel hydrogels. SNP@PCN@Gel displayed interconnected porous structure, excellent self-healing capacity, low cytotoxicity, good blood compatibility, and robust antibacterial activity. SNP@PCN@Gel could produce reactive oxygen species (ROS) and NO along with Fe2+, and showed long-term sustained release of Ag+, thereby effectively killing bacteria by synergistic photothermal (hyperthermia), photodynamic (ROS), chemodynamic (Fenton reaction), gas (NO) and ion (Ag+ and -NH3+ in CMCS) therapy. Remarkably, the hydrogels significantly promoted granulation tissue formation, reepithelization, collagen deposition and angiogenesis as well as wound contraction in bacteria-infected wound healing. Taken together, the strategy represented a general method to engineer the unprecedented photoactivatable “all-in-one” hydrogels with enhanced antibacterial activity and paved a new way for development of antibiotic alternatives and wound dressing.Graphical abstract

Rational design of robust Cu@Ag core-shell nanowires for wearable electronics applications

Copper nanowires (CuNWs) have shown great potential as transparent electrodes for cost-effective wearable electronics. However, its unsatisfactory electrical conductivity and intrinsic susceptibility to oxidation hinder practical applications. To address these issues, herein, ultra-stable Cu@Ag core–shell NWs have been designed via a facile galvanic replacement method for wearable applications. The thermal stability of the NWs is significantly enhanced after introducing Ag, and superior stability is achieved with a more uniform Ag coating. The structural integrity of the percolation networks is basically maintained after 5 days’ annealing treatment at a high temperature (≥150 °C). The devices based on core–shell NWs show reliable heating performance, and can further be used for defrosting and heating water/ice applications. Owing to optimized contact between Ag-coated NWs, the devices exhibit excellent mechanical performance under repetitive bending. Based on above structural design, the resultant strain sensors show high sensitivity, good repeatability and a wide sensing range, which are capable to detect various hand gestures and communicate with Morse code. Furthermore, the fabricated core–shell NWs show robust antibacterial activity, which is essential for wearable healthcare applications, outperforming that of pristine CuNWs. This work provides a promising way for the design of high-performance metal NWs for advanced wearable electronics.

Phytochemical profiling and investigation of antioxidant, anti-proliferative, and antibacterial properties in spontaneously grown Sicilian sumac (Rhus coriaria L.) fruits

This study aimed to assess the phytochemical profile and associated functional properties of sumac (Rhus coriaria L.) fruits harvested from wild plants in Sicily.Chemical characterization unveiled exceptionally high levels of polyphenols (10.99 g GAE/100 g DW), including substantial quantities of proanthocyanidins (61.577 mg PACE/100 g DW), and identified 82 phytochemicals belonging to various flavonoid classes. The hydroalcoholic extract from Sicilian sumac exhibited remarkable redox-active properties, providing antioxidant protection in a cell-based model of lipid peroxidation (CAA50: 1.116 μg/mL). Additionally, it displayed significant antiproliferative activity against four human tumor epithelial cell lines with GI50 values ranging from 31.08 to 149.74 μg/mL and robust antibacterial activity against major foodborne pathogens (MIC: 12.5–25.0 mg/mL).Our findings highlight Sicilian sumac fruit as a rich source of phytochemicals that positively contribute to the cellular redox state even when consumed in small quantities. Additionally, its diverse bioactivities indicate potential applications across food and non-food sectors.

Encapsulated pomegranate peel extract as a potential antimicrobial ingredient from food waste.

Pomegranate peel waste is a valuable reservoir of heat-sensitive total hydrolysable tannins (THT), with potential applications in food and pharmaceuticals. Preserving THT is challenging due to degradation post-extraction. We explore ionic gelation as an encapsulation method to optimize THT utilization. Through external gelation, we optimized the process variables using Box-Behnken design. At 40 g kg-1 sodium alginate, 25 g kg-1 calcium chloride, and 300 g kg-1 pomegranate peel extract (PPE), we achieved an 83.65% encapsulation efficiency. Compared to spray drying, external gelation demonstrated superior performance, with enhanced release percentages and stability. Physical, phytochemical, and release profiles of encapsulates were extensively analysed. External gelation achieved an 87.5% release in 30 min, outperforming spray-dried counterparts (69.7% in 25 min). Encapsulated PPE exhibited robust antibacterial activity against Staphylococcus aureus (ATCC 25923) in powdered infant formula, with a 32 ± 0.01 mm zone of inhibition and 300 μg mL-1 minimum inhibitory concentration. Insights into S. aureus growth curves underlined the mechanism of action via membrane potential alterations. The results of carried investigations also showed that the antibacterial activity of the encapsulated PPE extracts against the targeted organism was identical to the antibacterial activity exhibited by synthetic antibiotics used generally to kill microorganisms in food. Therefore, from the findings, it can be concluded that the PPE encapsulate produced using the external gelation technique at the optimized condition displayed superior storage stability possessing strong antimicrobial activity when compared to encapsulate produced using the spray drying technique. External gelation emerges as a potent technique for developing effective encapsulates enriched with natural antimicrobials or antibiotics. This approach holds promise for applications in food, pharmaceuticals, and nutraceuticals, enhancing stability and efficacy while reducing reliance on synthetic antibiotics. © 2024 Society of Chemical Industry.

Enhancing Selective Antimicrobial and Antibiofilm Activities of Melittin through 6-Aminohexanoic Acid Substitution.

Leucine residues are commonly found in the hydrophobic face of antimicrobial peptides (AMPs) and are crucial for membrane permeabilization, leading to the cell death of invading pathogens. Melittin, which contains four leucine residues, demonstrates broad-spectrum antimicrobial properties but also significant cytotoxicity against mammalian cells. To enhance the cell selectivity of melittin, this study synthesized five analogs by replacing leucine with its structural isomer, 6-aminohexanoic acid. Among these analogs, Mel-LX3 exhibited potent antibacterial activity against both Gram-positive and Gram-negative bacteria. Importantly, Mel-LX3 displayed significantly reduced hemolytic and cytotoxic effects compared to melittin. Mechanistic studies, including membrane depolarization, SYTOX green uptake, FACScan analysis, and inner/outer membrane permeation assays, demonstrated that Mel-LX3 effectively permeabilized bacterial membranes similar to melittin. Notably, Mel-LX3 showed robust antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) and multidrug-resistant Pseudomonas aeruginosa (MDRPA). Furthermore, Mel-LX3 effectively inhibited biofilm formation and eradicated existing biofilms of MDRPA. With its improved selective antimicrobial and antibiofilm activities, Mel-LX3 emerges as a promising candidate for the development of novel antimicrobial agents. We propose that the substitution of leucine with 6-aminohexanoic acid in AMPs represents a significant strategy for combating resistant bacteria.

NIR light-activated nanocomposites combat biofilm formation and enhance antibacterial efficacy for improved wound healing

Nanoparticle-based therapies are emerging as a pivotal frontier in biomedical research, showing their potential in combating infections and facilitating wound recovery. Herein, selenium-tellurium dopped copper oxide nanoparticles (SeTe-CuO NPs) with dual photodynamic and photothermal properties were synthesized, presenting an efficient strategy for combating bacterial infections. In vitro evaluations revealed robust antibacterial activity of SeTe-CuO NPs, achieving up to 99% eradication of bacteria and significant biofilm inhibition upon near-infrared (NIR) irradiation. Moreover, in vivo studies demonstrated accelerated wound closure upon treatment with NIR-activated SeTe-CuO NPs, demonstrating their efficacy in promoting wound healing. Furthermore, SeTe-CuO NPs exhibited rapid bacterial clearance within wounds, offering a promising solution for wound care. Overall, this versatile platform holds great promise for combating multidrug-resistant bacteria and advancing therapeutic interventions in wound management.

Robust antibacterial activity of rare-earth ions on planktonic and biofilm bacteria.

Bacterial infections pose a serious threat to human health, with emerging antibiotic resistance, necessitating the development of new antibacterial agents. Cu2+and Ag+are widely recognized antibacterial agents with a low propensity for inducing bacterial resistance; however, their considerable cytotoxicity constrains their clinical applications. Rare-earth ions, owing to their unique electronic layer structure, hold promise as promising alternatives. However, their antibacterial efficacy and biocompatibility relative to conventional antibacterial agents remain underexplored, and the variations in activity across different rare-earth ions remain unclear. Here, we systematically evaluate the antibacterial activity of five rare-earth ions (Yb3+, Gd3+, Sm3+, Tb3+, and La3+) againstStaphylococcus aureusandPseudomonas aeruginosa, benchmarked against well-established antibacterial agents (Cu2+, Ag+) and the antibiotic norfloxacin. Cytotoxicity is also assessed via live/dead staining of fibroblasts after 24 h rare-earth ion exposure. Our findings reveal that rare-earth ions require higher concentrations to match the antibacterial effects of traditional agents but offer the advantage of significantly lower cytotoxicity. In particular, Gd3+demonstrates potent bactericidal efficacy against both planktonic and biofilm bacteria, while maintaining the lowest cytotoxicity toward mammalian cells. Moreover, the tested rare-earth ions also exhibited excellent antifungal activity againstCandida albicans. This study provides a critical empirical framework to guide the selection of rare-earth ions for biomedical applications, offering a strategic direction for the development of novel antimicrobial agents.

Exploring the anti-acne potential of Muntingia calabura L leaves against Staphylococcus epidermidis: In vitro and in silico perspective

Introduction: Muntingia calabura is a medicinal plant possessing antimicrobial properties against various bacteria. The purpose of this study was to examine in vitro and in silico activity of the ethyl acetate fraction of M. calabura leaves against the acne-causing commensal bacterium, Staphylococcus epidermidis. Methods: In this study, M. calabura leaves were extracted using ethanol and then further fractionated with ethyl acetate. The phytochemicals in the fraction were identified with thin layer chromatography (TLC). The activity of the fraction was then tested in S. epidermidis culture using the agar diffusion method. Additionally, the molecular docking of M. calabura phytochemicals constituents was simulated to teicoplanin-associated locus regulator (TcaR) of S. epidermidis. Results: The ethyl acetate fraction of M. calabura exhibited robust antibacterial activity against S. epidermidis culture, resulting in inhibition zones ranging from 5 to 10 mm. The fraction was found to contain flavonoids, saponins, and tannins as identified constituents. Further, during the molecular docking analysis, stigmasterol and 7-methoxyflavone demonstrated binding to TcaR with a lower and comparable binding energy of -7.40 and -6.19 kcal/mol, respectively, compared to the control drug, Penicillin-G (-6.40 kcal/mol). Conclusion: M. calabura has the potential to serve as a valuable source of active phytochemical compounds for addressing acne. Further studies are needed to isolate and evaluate each compound found in M. calabura individually against S. epidermidis.

Exploring the Antimicrobial Efficacy of <i>Panchavalkala Kwatha</i> and <i>Arka</i>: A Comprehensive Study

Panchavalkala, a combination of five tree barks, is significant in Ayurvedic formulations as an individual ingredient and in composite preparations. These five barks are Vata (Ficus bengalensis L.), Udumbara (Ficus glomerata Roxb.), Ashwatha (Ficus religiosa L.), Parisha (Thespesia populanea Soland. ex-Correa.), and Plaksha (Ficus lacor Buch-Ham.). As per Ayurveda, Panchavalkala Kwatha has vrana ropana (wound healing) properties and is also known for its diverse properties encompassing antiseptic, anti-inflammatory, antioxidant, antibacterial, and antimicrobial attributes, rendering it valuable for wound purification and healing. This study aims to investigate the antimicrobial potential of Panchavalkala Kwatha (PVK) while validating its ancient Ayurvedic significance in wound healing. The study involves meticulously preparing Panchavalkala Kwatha and Panchavalkala Arka. Panchavalkala Kwatha is meticulously prepared by the guidelines stipulated in Sharangadhara Samhita, while Panchavalkala Arka (PVA) follows the principles outlined in Arka Prakasha. The antimicrobial activity of Panchavalkala Kwatha and Panchavalkala Arka was assessed using Escherichia coli and Staphylococcus aureus through the well-diffusion assay. Panchavalkala Kwatha exhibits a substantial zone of inhibition measuring 25 mm against E. coli and 28 mm against S. aureus. This antimicrobial efficacy is comparable to Ciprofloxacin’s, signifying potent antimicrobial activity. In contrast, Panchavalkala Arka shows no inhibitory effect on microbial growth. These results underscore the robust antibacterial activity of Panchavalkala Kwatha against both E. coli and S. aureus, while Panchavalkala Arka remains inert. This research furnishes primary evidence supporting the antibacterial properties of Panchavalkala Kwatha against E. coli and S. aureus. These findings suggest the potential utility of this Ayurvedic formulation in expediting wound healing processes.

Additive Manufacturing of Nanocellulose Aerogels with Structure-Oriented Thermal, Mechanical, and Biological Properties.

Additive manufacturing (AM) is widely recognized as a versatile tool for achieving complex geometries and customized functionalities in designed materials. However, the challenge lies in selecting an appropriate AM method that simultaneously realizes desired microstructures and macroscopic geometrical designs in a single sample. This study presents a direct ink writing method for 3D printing intricate, high-fidelity macroscopic cellulose aerogel forms. The resulting aerogels exhibit tunable anisotropic mechanical and thermal characteristics by incorporating fibers of different length scales into the hydrogel inks. The alignment of nanofibers significantly enhances mechanical strength and thermal resistance, leading to higher thermal conductivities in the longitudinal direction (65mWm-1K-1) compared to the transverse direction (24mWm-1K-1). Moreover, the rehydration of printed cellulose aerogels for biomedical applications preserves their high surface area (≈300m2g-1) while significantly improving mechanical properties in the transverse direction. These printed cellulose aerogels demonstrate excellent cellular viability (>90% for NIH/3T3 fibroblasts) and exhibit robust antibacterial activity through in situ-grown silver nanoparticles.

Evaluation of antibacterial activity and influencing factors of normal and nanostructured copper-based materials

BackgroundCopper-based materials have garnered extensive recognition for their effective nature against microorganisms and their minimal toxicity. However, the evaluation for their antibacterial activity is still in its nascent stages, and the evaluation results based on existing criteria are not representative of real-world application. AimTo evaluate the antibacterial activity and primary determinants of influence of copper-based materials in order to investigate their practical antibacterial activity and potential mechanisms of such materials. MethodsStaphylococcus aureus and Escherichia coli bacterial suspensions were applied via inoculation onto the surfaces of normal and nanostructured copper foil. Following incubation of the inoculated surfaces under diverse experimental conditions—including varying compositions of the bacterial suspension, the use of chemical neutralizers, the existence of organic interferents, and low temperature and humidity—surviving bacteria were enumerated. Using the scanning electron microscopy and X-ray photoelectron spectroscopy, the surface changes of copper-based materials were examined. FindingsFollowing 1 h of exposure to 37 °C and 90% relative humidity, Staphylococcus aureus was reduced by 4.45 log10 on normal copper foil, while all of the bacteria were eradicated on nanostructured copper foil. In addition, it was discovered that preparing a bacterial suspension with PBS results in a significant number of Escherichia coli fatalities during the test, whereas using TPS promotes the bacteria's normal growth. Furthermore, the outcomes of the antibacterial activity test were diminished when chemical neutralization was employed, and the presence of organic interferents had distinct impacts on normal copper foil and nanostructured copper foil. Additionally, low temperatures and humidity diminished the antibacterial activity of copper foil, whereas normal copper foil produced significantly better results. ConclusionWhile copper-based materials exhibit robust antibacterial activity as determined by standard assays, their efficacy in real-world applications is subject to various influencing mechanisms. In order to objectively evaluate the antibacterial activity of copper-based materials and provide precise guidance for their development and practical application, it is essential to regulate test conditions with targeted.

Hyaluronidase-Responsive Bactericidal Cryogel for Promoting Healing of Infected Wounds: Inflammatory Attenuation, ROS Scavenging, and Immune Regulation.

Wounds infected with multidrug-resistant (MDR) bacteria are increasingly threatening public health and challenging clinical treatments because of intensive bacterial colonization, excessive inflammatory responses, and superabundant oxidative stress. To overcome this malignant burden and promote wound healing, a multifunctional cryogel (HA/TA2/KR2) composed of hyaluronic acid (HA), tannic acid (TA), and KR-12 peptides is designed. The cryogel exhibited excellent shape-memory properties, strong absorption performance, and hemostatic capacity. In vitro experiments demonstrated that KR-12 in the cryogel can be responsively released by stimulation with hyaluronidase produced by bacteria, reaching robust antibacterial activity against Escherichia coli (E. coli), MDR Pseudomonas aeruginosa (MDR-PA), and methicillin-resistant Staphylococcus aureus (MRSA)by disrupting bacterial cell membranes. Furthermore, the synergetic effect of KR-12 and TA can efficiently scavenge ROS and decrease expression of pro-inflammatory cytokines (tumor necrosis factor (TNF)-α & interleukin (IL)-6), as well as modulate the macrophage phenotype toward the M2 type. In vivo animal tests indicated that the cryogel can effectively destroy bacteria in the wound and promote healing process via accelerating angiogenesis and re-epithelialization. Proteomic analysis revealed the underlying mechanism by which the cryogel mainly reshaped the infected wound microenvironment by inhibiting the Nuclear factor kappa B (NF-κB) signaling pathway and activating the Janus kinase-Signal transducer and activator of transcription (JAK-STAT6) signaling pathway. Therefore, the HA/TA2/KR2 cryogel is a promising dressing candidate for MDR bacteria-infected wound healing.

Putative Role of Anti-microbial Peptide Recovered from Lactiplantibacillus spp. in Biocontrol Activity.

Antimicrobial peptides (AMPs) stand as a promising alternative to conventional pesticides, leveraging a multifaceted approach to combat plant pathogens. This study focuses on identifying and characterizing the AMP produced by Lactiplantibacillus argentoratensis strain IT, demonstrating potent antibacterial activity against various harmful microorganisms. Evaluation of AMPs' antibacterial activity was conducted through an agar well diffusion assay, a reliable method for assessing secondary metabolite antimicrobial efficacy. The study unveils the antimicrobial potential of the purified extract obtained from Lactiplantibacillus argentoratensis IT, isolated from goat milk. Notably, the AMP exhibited robust antibacterial activity against phytopathogens affecting solanaceous crops, including the Gram-negative Ralstonia solanacearum. Expression conditions and purification methods were optimized to identify the peptide's mass and sequence, utilizing LC-MS and SDS-PAGE. This paper underscores the application potential of Lactiplantibacillus spp. IT as a biocontrol agent for managing bacterial infectious diseases in plants. Results indicate optimal AMP production at 37°C, with a culture broth pH of 5 during fermentation. The obtained peptide sequence corresponded to peaks at 842.5 and 2866.4m/z ratio, with a molecular weight of approximately 5kDa according to tricine SDS-PAGE analysis. In conclusion, this study lays the foundation for utilizing Lactiplantibacillus spp. IT derived AMPs in plant biocontrol strategies, showcasing their efficacy against bacterial phytopathogens. These findings contribute valuable insights for advancing sustainable agricultural practices.

Novel terpyridines as Staphylococcusaureus gyrase inhibitors: efficientsynthesis and antibacterialassessment viasolvent-drop grinding.

Aim: This study was designed to synthesize a novel series of terpyridines with potential antibacterial properties, targeting multidrug resistance. Materials & methods: Terpyridines (4a-h and 6a-c) were synthesized via a one-pot multicomponent reaction using 2,6-diacetylpyridines, benzaldehyde derivativesand malononitrile or ethyl 2-cyanoacetate. The reactions, conducted under grinding conditions with glacial acetic acid, produced high-yield compounds, confirmed by spectroscopic data. Results: The synthesized terpyridines exhibited potent antibacterial activity. Notably, compounds 4d and 4h demonstrated significant inhibition zones against Staphylococcusaureus and Bacillussubtilis, outperformingciprofloxacin. Conclusion: Molecular docking studies highlighted compounds 4d, 4hand 6c as having strong binding affinity to DNA gyrase B, correlating with their robust antibacterial activity, suggesting their potential as effective agents against multidrug-resistant bacterial strains.

Highly stable color-tunable organic long-persistent luminescence from a single-component exciplex copolymer for in vitro antibacterial.

Developing exciplex-based organic long-persistent luminescence (OLPL) materials with high stability is very important but remains a formidable challenge in a single-component system. Here, we report a facile strategy to achieve highly stable OLPL in an amorphous exciplex copolymer system via through-space charge transfer (TSCT). The copolymer composed of electron donor and acceptor units can not only exhibit effective TSCT for intra/intermolecular exciplex emission but also construct a rigid environment to isolate oxygen and suppress non-radiative decay, thereby enabling stable exciplex-based OLPL emission with color-tunable feature for more than 100 h under ambient conditions. These single-component OLPL copolymers demonstrate robust antibacterial activity against Escherichia coli under visible light irradiation. These results provide a solid example to exploit highly stable exciplex-based OLPL in polymers, shedding light on how the TSCT mechanism may potentially contribute to OLPL in a single-component molecular system and broadening the scope of OLPL applications.

S-Nitrosylated CuS Hybrid Hydrogel Patches with Robust Antibacterial and Repair-Promoting Activity for Infected Wound Healing.

Development of wound dressing with robust antibacterial and repair-promoting activity has always been an urgent biomedical task during the past years. The therapeutic effect of current hydrogel dressings containing single bioactive agent like nanoparticle or gas is still unsatisfactory for the treatment of infected wound. Herein, a CuS/NO co-loaded hydrogel (CuS/NO Gel) is proposed, which is constructed by sequential polymerization, reduction, and S-nitrosylation of CuS hybrid hydrogel with disulfide bonds. These CuS/NO Gel patches show good mechanical stability, high photothermal activity and excellent biocompatibility. When being applied to treat infected wound, CuS/NO Gel can not only eliminate infection effectively by the synergistic effect of mild photothermal heating and boosted NO release in infection phase, but also promote vascularization and collagen deposition due to the synchronous supply of Cu ion nutrients and low concentration NO signaling molecules in wound repair phase. Compared to hydrogel dressings with individual active agent (CuS Gel or NO Gel), CuS/NO Gel exhibits better antibacterial and repair-promoting activity both in vitro and in vivo. Therefore, this CuS/NO Gel holds great promise in the future clinical treatment against infected wound.