Antimicrobial Functions Research Articles

Construction of Vine-Inspired Antimicrobial Filter with Multiscale 3D Nanonetwork for High-Efficiency Air Filtration.

Enhancing the antimicrobial activity of high-efficiency particulate air (HEPA) filters while maintaining filtration efficiency and pressure drop is currently an urgent issue for preventing the spread of pathogenic microorganisms. Herein, inspired by vines which can enwind fences to fix as well as decorate them, a flexible antimicrobial chitin nanofiber (ChNF@CuOx) was fabricated and loaded onto the rigid glass fiber (GF) skeleton of a HEPA filter. Through the physical interaction, ChNF@CuOx was spontaneously enwound on GF, and ChNF@CuOx itself interweaved to form a new nanonetwork between the GF skeleton. The obtained antimicrobial air filter (ChNF@CuOx/GF) with a unique nanonetwork increased the filtration efficiency of the HEPA filter. Meanwhile, it possessed excellent inactivation ability against Staphylococcus aureus, Escherichia coli, and Candida albicans due to the urchin-like in situ grown CuOx on the ChNF. In particular, the oxygen vacancies generated unexpectedly in CuOx enabled it to produce reactive oxygen species. After eight cycles of antimicrobial assays, the antimicrobial rates of bacteria were higher than 99.5%, and those of fungi were greater than 98.3%. The successful synthesis of antimicrobial fibers and the construction of multidimensional nanoscale structures through a simple postprocessing method provide a new design mentality for antimicrobial functionalization for HEPA filters.

Optimization of starch foam extrusion through PVA polymerization, moisture content control, and CMCS incorporation for enhanced antibacterial cushioning packaging

Melt strength and moisture content are critical parameters in starch foam extrusion, as they dictate bubble expansion dynamics, which subsequently determine the foam's properties. Despite continuous advancements in the development and application of starch foams, challenges such as water resistance, mechanical strength, and antibacterial activity remain unresolved. This research investigates the influence of polyvinyl alcohol (PVA) polymerization and moisture content on the properties of extruded foam while also exploring the potential for enhancing antimicrobial functionality by incorporating carboxymethyl chitosan (CMCS) into conventional starch foams. The findings underscore the significance of melt strength and intermolecular entanglements in shaping foam characteristics, confirming that bioactive components effectively improve hydrophobicity, foaming characteristics, and antibacterial capabilities. Moreover, by precisely regulating PVA polymerization and moisture content, it became feasible to optimize foam properties and achieve the desired performance. Specifically, foam with a moisture content of 12 % and a PVA polymerization degree of 1700 exhibited exceptional performance, including the highest foaming ratio of 45.62, the minimal water absorption rate of 6.31 %, and the greatest recovery rate of 88.95 %. Furthermore, increasing CMCS concentrations substantially enhances the antibacterial properties of the foam, demonstrating its potential for application in antibacterial cushioning packaging and emphasizing its versatility and practicality.

Antimicrobial Functionalization of Surfaces by a Chimeric Adhesive Protein.

The main aim of this work is to account for the prevention and control of microbial growth on surfaces of interest in medical technology. Surface modification is often achieved by physiotherapy or chemical treatments that can involve time-consuming steps, hazardous reagents, and harsh conditions. One of the ways to overcome these drawbacks is the use of surface-active proteins such as hydrophobins. They can form stable protein layers on different surfaces, serving as anchoring points for other molecules of interest. The fungal hydrophobin Vmh2, already exploited for its adhesive ability, has been fused with the antimicrobial peptide GKY20, forming the chimeric protein used herein for functionalizing polystyrene (PS) and bacterial cellulose (BC). As a natural biomass, BC has multiple advantages, including biodegradability, low cost, renewability, high purity, and excellent mechanical properties. The chimeric protein has been proven to successfully adhere to both surfaces. A strong decrease in biofilm formation on PS and a good bactericidal effect of BC have been demonstrated. These findings provide evidence of an alternative strategy to obtain functional composites using a green, easy process.

Three in One with Dual-Functional Hydrogel of Lactoferrin/NZ2114/LMSH Promoting Staphylococcus aureus-Infected Wound Healing.

Wound infections caused by Staphylococcus aureus often result in localized suppurative lesions that severely impede the healing process, so it is urgent to develop a dress with efficient antimicrobial and pro-healing functions. In this study, the bifunctional injectable hydrogel lactoferrin (Lf)/NZ2114/lithium magnesium silicate hydrogel (LMSH) was first successfully prepared through the electrostatic interaction method. The physical, biological, and efficacy properties are systematically analyzed with good shear-thinning capacity and biocompatibility. More importantly, it inhibits infection and promotes wound healing in a mouse wound infection model after 14 d treatment, and the bactericidal rate and healing rate were over 99.92% and nearly 100%, respectively. Meanwhile, the massive reduction of inflammatory cells, restoration of tissue structure, and angiogenesis in mice showed the anti-inflammatory and pro-healing properties of the hydrogel. The healed wounds showed thickening with more hair follicles and glands, suggesting that the hydrogel Lf/NZ2114/LMSH (Three in One) could be a better dressing candidate for the treatment of S. aureus-induced wound infections.

The Role of Plant Extracts in Enhancing Nutrition and Health for Dogs and Cats: Safety, Benefits, and Applications.

Plant extracts, derived from various natural sources, encompass primary and secondary metabolites, which include plant polysaccharides, polyphenols, alkaloids, flavonoids, glycosides, terpenes, and volatile oils. These compounds exhibit a range of biological activities such as antioxidant, anti-inflammatory, and antimicrobial functions. Currently, polyphenols and other bioactive compounds are being incorporated into the diets of farm animals, fish, and pets to promote health benefits. Despite this, the application and potential of plant extracts in canine and feline nutrition have not been comprehensively explored. Many aspects of the mechanisms underlying the action of these plant metabolites remain to be analyzed and elucidated. Furthermore, leveraging natural plant extracts for the treatment of clinical conditions in dogs and cats is a crucial component of clinical nutrition. Consequently, this review aims to highlight the impact of plant extracts on overall health, gastrointestinal health, immune health, cardiovascular health, redox balance, and pathology in dogs and cats.

Electrospun nanofiber composites as a novel preservation coating with antimicrobial and antifungal functions for the archaeological linen textiles

In an attempt to prevent the biodeterioration of ancient textiles, we utilized electrospun composite nanofibers (NFs) for the first time as a coating layer to enhance their antimicrobial and antifungal properties. In this study, we applied a few layers of electrospun NFs derived from various polymers loaded with silver nanoparticles (n-Ag) and 4-chloro-m-cresol onto the surface of aged linen fabric mockups, simulating ancient textiles. The results showed that the coating layer had no discernible effect on the tested samples’ morphology, colour, and optical appearance. Additionally, the investigated samples exhibited significant antibacterial efficacy against Escherichia coli and Staphylococcus aureus. Furthermore, the examined samples displayed significant inhibition of growth in cultures of Aspergillus species isolated from ancient linen fragments preserved in the Cairo Egyptian Museum. These results suggest that electrospun NFs offer a promising strategy for conserving archaeological textiles against biodeterioration and may open a new avenue for using electrospun NFs in the conservation of other archaeological materials.

Phenolic components from carrot (Daucus carota L.) pomace: Optimizing the extraction and assessing its potential antioxidant and antimicrobial activities

Carrot pomace is a significant agricultural byproduct. Obtained during carrot juice processing. This residue is an appropriate reservoir of constituents with bioactive properties that could be investigated in the development of food constituents and nutritional supplements and in improving the quality and safety of foods. For this purpose, the objective of the present investigation was to extract the polyphenols from carrot pomace utilizing maceration and ultrasound-based extraction (UAE) procedures and to evaluate the antioxidant properties of phenolic constituents. To maximize the extraction of carrot pomace, a response surface approach was used. The optimal mixture of extraction time (A, min), ultrasonication power (B, w), and solvent type (C, v/v) for the highest yield of carrot pomace was found using a three-variable composite rotatable design (CRD). In order to assess different functional groups, Fourier transform infrared spectroscopy was utilized to investigate the extract collected under optimal circumstances. The highest polyphenols (26.53 %) were extracted by ethanol 70 % at 10 min with a sonication power of 250 w. The optimized extract also exhibited significant antioxidant and antimicrobial functions. The total phenolic compounds and scavenging of the DPPH radical were 85 mg GAE/gr and EC50: 55 ± 1 μg/mL, respectively. Together with Staphylococcus aureus, the highest zone of inhibition (12 mm) was identified. Our finding revealed that carrot pomace is an appropriate source of bioactive phenolic constituents, exhibiting antioxidant and antibacterial attributes, and could be applied as a natural preserver for promoting safety and quality properties in food products on an industrial scale.

Effects of a pH-Regulating Emollient Cream in Mild Atopic Dermatitis Patients with Moderate Localized Lesions

Introduction: Increased skin pH values in patients with atopic dermatitis (AD) contribute to poor antimicrobial and permeability barrier functions of the skin. In practice, the majority of topical preparations available for dry skin conditions do not provide sufficient pH and buffering capacity for maintaining optimum skin surface conditions. To address this issue, we tested a novel zinc lactobionate preparation to determine whether the regular application would lower skin surface pH, and in doing so improve the condition of lesional skin. Methods: The assessment for local severity of AD was done with the Scoring Atopic Dermatitis Index (SCORAD) and skin dryness was assessed by capacitance measurement. Results: The results showed that the test product lowered skin pH and improved AD skin lesions from moderate to mild during 2 weeks of application. In the treated area a lowered pH of about 0.85 units was found. Together with the lowering of pH, the local SCORAD significantly improved from 8.3 on average down to 4.0, while in the untreated area, only a slight improvement (from 8.2 to 6.4) was found. Conclusion: Synergistic effects of the test product’s pH lowering and emollient properties might explain the observed improvements in clinical signs of AD and further research against a comparator would allow the specific contribution of pH modulation to these improvements to be unambiguously isolated.

Eco-friendly film with highly efficient sterilization for food preservation by incorporating natural products into starch/polyvinyl alcohol matrix

An advanced biodegradable packaging film with antimicrobial and fresh-maintaining functions was constructed by incorporating berberine and L-arginine into the starch/polyvinyl alcohol (PVA) film matrix. The film was endowed with a dual antibacterial capacity thanks to the intrinsic antibacterial capability of berberine and cascaded photodynamic sterilization. The aggregated berberine presents an excellent photodynamic activity to generate reactive oxygen species (ROS), which further triggers the NO release from L-arginine. Under the synergetic action of ROS and NO, the as-prepared film not only has an antibacterial efficiency of over 99 % against both S. aureus and E. coli but also delays fruit ripening through antagonistic effects on ethylene to extend the shelf life of food. Meanwhile, the as-prepared film presents UV-shielding properties, thermal stability, and considerable mechanical properties. Specifically, the packaging film exhibits good biocompatibility and is biodegradable, with a degradation rate of 56 % within 16 days, which has great potential for improving food safety and environmental events.

The potential therapeutic role of itaconate and mesaconate on the detrimental effects of LPS-induced neuroinflammation in the brain

Despite advances in antimicrobial and anti-inflammatory treatment, inflammation and its consequences remain a major challenge in the field of medicine. Inflammatory reactions can lead to life-threatening conditions such as septic shock, while chronic inflammation has the potential to worsen the condition of body tissues and ultimately lead to significant impairment of their functionality. Although the central nervous system has long been considered immune privileged to peripheral immune responses, recent research has shown that strong immune responses in the periphery also affect the brain, leading to reactive microglia, which belong to the innate immune system and reside in the brain, and neuroinflammation. The inflammatory response is primarily a protective mechanism to defend against pathogens and tissue damage. However, excessive and chronic inflammation can have negative effects on neuronal structure and function. Neuroinflammation underlies the pathogenesis of many neurological and neurodegenerative diseases and can accelerate their progression. Consequently, targeting inflammatory signaling pathways offers potential therapeutic strategies for various neuropathological conditions, particularly Parkinson’s and Alzheimer’s disease, by curbing inflammation. Here the blood–brain barrier is a major hurdle for potential therapeutic strategies, therefore it would be highly advantageous to foster and utilize brain innate anti-inflammatory mechanisms. The tricarboxylic acid cycle-derived metabolite itaconate is highly upregulated in activated macrophages and has been shown to act as an immunomodulator with anti-inflammatory and antimicrobial functions. Mesaconate, an isomer of itaconate, similarly reduces the inflammatory response in macrophages. Nevertheless, most studies have focused on its esterified forms and its peripheral effects, while its influence on the CNS remained largely unexplored. Therefore, this study investigated the immunomodulatory and therapeutic potential of endogenously synthesized itaconate and its isomer mesaconate in lipopolysaccharide (LPS)-induced neuroinflammatory processes. Our results show that both itaconate and mesaconate reduce LPS-induced neuroinflammation, as evidenced by lower levels of inflammatory mediators, reduced microglial reactivity and a rescue of synaptic plasticity, the cellular correlate of learning and memory processes in the brain. Overall, this study emphasizes that both itaconate and mesaconate have therapeutic potential for neuroinflammatory processes in the brain and are of remarkable importance due to their endogenous origin and production, which usually leads to high tolerance.

Structural Classification Insights Into the Plant Defensive Peptides.

This study presents a structural phylogenetic analysis of plant defensive peptides, revealing their evolutionary relationships, structural diversification, and functional adaptations. Utilizing a robust dataset comprising both experimental and predicted structures sourced from the RCSB Protein Data Bank and AlphaFold DB, we constructed a detailed phylogenetic tree to elucidate the distinct evolutionary paths of plant defensive peptide families. Our findings showcase the evolutionary intricacies of defensive peptides, highlighting their diversity and the conservation of key structural motifs critical to their antimicrobial or defensive functions. The results also underscore the adaptive significance of defensive peptides in plant evolution, highlighting their roles in responding to ecological pressures and pathogen interactions.

Dysregulated Airway Host Defense in Hyper IgE Syndrome due to STAT3 Mutations.

Hyper IgE syndrome (STAT3-HIES), also known as Job's syndrome, is a rare immunodeficiency disease typically caused by dominant-negative STAT3 mutations. STAT3-HIES syndrome is characterized by chronic pulmonary infection and inflammation, suggesting impairment of pulmonary innate host defense. To identify airway epithelial host defense defects consequent to STAT3 mutations that, in addition to reported mutant STAT3 immunologic abnormalities, produce pulmonary infection. STAT3-HIES sputum was evaluated for biochemical/biophysical properties. STAT3-HIES excised lungs were harvested for histology; bronchial brush samples were collected for RNA sequencing and in vitro culture. A STAT3-HIES-specific mutation (R382W), expressed by lentiviruses, and a STAT3 knockout, generated by CRISPR/Cas9, were maintained in normal human bronchial epithelia under basal or inflammatory (IL1β) conditions. Effects of STAT3 deficiency on transcriptomics, and epithelial ion channel, secretory, antimicrobial, and ciliary functions were assessed. Mucus concentrations and viscoelasticity were increased in STAT3-HIES sputum. STAT3-HIES excised lungs exhibited mucus obstruction and elevated IL1β expression. STAT3 deficiency impaired CFTR-dependent fluid and mucin secretion, inhibited expression of antimicrobial peptides, cytokines, and chemokines, and acidified airway surface liquid at baseline and post-IL1β exposure in vitro. Notably, mutant STAT3 suppressed IL1R1 expression. STAT3 mutations also inhibited ciliogenesis in vivo and impaired mucociliary transport in vitro, a process mediated via HES6 suppression. Administration of a γ-secretase inhibitor increased HES6 expression and improved ciliogenesis in STAT3 R382W mutant cells. STAT3 dysfunction leads to multi-component defects in airway epithelial innate defense, which, in conjunction with STAT3-HIES immune deficiency, contributes to chronic pulmonary infection.

Discovery and engineering of a novel peptide, Temporin-WY2, with enhanced in vitro and in vivo efficacy against multi-drug resistant bacteria

Infections by drug-resistant microorganisms are a threat to global health and antimicrobial peptides are considered to be a new hope for their treatment. Temporin-WY2 was identified from the cutaneous secretion of the Ranidae frog, Amolops wuyiensis. It presented with a potent anti-Gram-positive bacterial efficacy, but its activity against Gram-negative bacteria and cancer cell lines was unremarkable. Also, it produced a relatively high lytic effect on horse erythrocytes. For further improvement of its functions, a perfect amphipathic analogue, QUB-1426, and two lysine-clustered analogues, 6K-WY2 and 6K-1426, were synthesised and investigated. The modified peptides were found to be between 8- and 64-fold more potent against Gram-negative bacteria than the original peptide. Additionally, the 6K analogues showed a rapid killing rate. Also, their antiproliferation activities were more than 100-fold more potent than the parent peptide. All of the peptides that were examined demonstrated considerable biofilm inhibition activity. Moreover, QUB-1426, 6K-WY2 and 6K-1426, demonstrated in vivo antimicrobial activity against MRSA and E. coli in an insect larvae model. Despite observing a slight increase in the hemolytic activity and cytotoxicity of the modified peptides, they still demonstrated a improved therapeutic index. Overall, QUB-1426, 6K-WY2 and 6K-1426, with dual antimicrobial and anticancer functions, are proposed as putative drug candidates for the future.

Antimicrobial and antioxidant functionalization of cellulosic fabric via mushroom and neem oil treatment: A step toward sustainable textiles

AbstractNowadays, the demand for protective clothing for specific activities has been fueled by consumer's attitudes toward hygiene and their active lifestyles. The aim of the present work is focused on creating protective textiles that are safe for the environment. This study uses mushroom–neem oil and neem oil to test their antioxidant properties to make cotton fabric that resists bacterial growth. Pad dry cure is used to create antimicrobial fabric with mushroom–neem oil and neem oil with citric acid (1%) as a cross‐linking agent. The antibacterial activity against Escherichia coli and antioxidant activity by DPPH assay were assessed by applying mushroom–neem oil and neem oil separately to cotton knitted fabric at 120, 130, 140, and 150°C. FTIR and EDS were used to study the incorporation of mushroom–neem oil and neem oil on cotton fabric surfaces. Both the treated and untreated fabric surface morphology were examined using scanning electron microscopy. An increase in curing temperature was found to change the comfort characteristics of the treated fabric. The analysis also found that antimicrobials reduced thermal conductivity. Most importantly, increasing the curing temperature improved all comfort properties. Notably, fabric treated with mushroom neem oil is more comfortable than fabric treated with neem oil.Highlights Cotton fabrics with mushroom–neem and neem oil showed antibacterial activity. Neem oil‐treated fabrics had better antioxidant properties than mushroom–neem oil. Higher curing temperatures reduced thermal conductivity and improved comfort. Mushroom–neem oil samples have superior physical properties. Bioactive material treatments can reduce chemical and environmental impact.

Albumin reprograms the B cell transcriptional landscape and improves neutrophil antimicrobial function in patients with decompensated cirrhosis

Background&AimPatients with acutely decompensated (AD) cirrhosis are immunocompromised and particularly susceptible to infections. This study investigated the immunomodulatory actions of albumin by which this protein may lower the incidence of infections. MethodsBlood immunophenotyping was performed in 11 AD patients and 10 healthy volunteers (HV). Bulk and single-cell (sc) RNA sequencing (RNA-seq) and flow cytometry were performed in peripheral blood mononuclear cells (PBMCs) from 20 AD patients and 34 HV exposed to albumin. Albumin’s effects on degranulation, phagocytosis, chemotaxis, and swarming of neutrophils from 6 AD patients and 9 HV were assessed by myeloperoxidase enzymatic activity, engulfment of fluorescent-labeled Escherichia coli and zymosan and interactions at single-cell resolution of neutrophils with Candida albicans in microfluidic chambers, respectively. Whole blood RNA-seq analyses were performed in 45 patients admitted for severe AD of whom 30 received albumin during hospitalization. ResultsCompared to HV, AD patients showed severe lymphopenia and defective neutrophil anti-microbial function. Bulk and scRNA-seq analyses revealed significantly (false discovery rate (FDR)<0.05) increased signatures related to B cells, myeloid cells and CD4+ T cells in PBMCs incubated with albumin. Changes in the B cell population were confirmed by flow cytometry. Neutrophils exposed to albumin also exhibited augmented chemotactic and degranulation responses, enhanced phagocytosis, and increased pathogen-restrictive swarming. Analysis of RNA-seq data in patients who had received albumin revealed specific upregulation of signatures related to B cells and neutrophils together with transcriptional changes in CD4+ T cells (FDR<0.05). ConclusionsThe finding that albumin promotes the transcriptional reprogramming and expansion of the B cell compartment and improves neutrophil antimicrobial functions indicates mechanisms that may lower the incidence of infections in patients with severe AD receiving albumin therapy.

2D TiO2 Nanosheets Decorated Via Sphere-Like BiVO4: A Promising Non-Toxic Material for Liquid Phase Photocatalysis and Bacterial Eradication.

An in-depth investigation was conducted on a promising composite material (BiVO4/TiO2), focusing on its potential toxicity, photoinduced catalytic properties, as well as its antibiofilm and antimicrobial functionalities. The preparation process involved the synthesis of 2D TiO2 using the lyophilization method, which was subsequently functionalized with sphere-like BiVO4 through wet impregnation. Finally, we developed BiVO4/TiO2 S-scheme heterojunctions which can greatly promote the separation of electron-hole pairs to achieve high photocatalytic performance. The evaluation of concentration- and time-dependent viability inhibition was performed on human lung carcinoma epithelial A549 cells. This assessment included the estimation of glutathione levels and mitochondrial dehydrogenase activity. Significantly, the BiVO4/TiO2 composite demonstrated minimal toxicity towards A549 cells. Impressively, the BiVO4/TiO2 composite exhibited notable photocatalytic performance in the degradation of rhodamine B (k=0.135 min-1) and phenol (k=0.016 min-1). In terms of photoinduced antimicrobial performance, the composite effectively inactivated both gram-negative E. coli and gram-positive E. faecalis bacteria upon 60 minutes of UV-A light exposure, resulting in a significant log 6 (log 10 CFU/mL) reduction in bacterial count. In addition, a 49 % reduction of E. faecalis biofilm was observed. These promising results can be attributed to the unique 2D morphology of TiO2 modified by sphere-like BiVO4, leading to an increased generation of (intracellular) hydroxyl radicals, which plays a crucial role in the treatments of both organic pollutants and bacteria. This research has significant potential for various applications, particularly in addressing environmental contamination and microbial infections.

Removal of circulating mitochondrial N-formyl peptides via immobilized antibody therapy restores sepsis-induced neutrophil dysfunction.

During recovery from septic shock, circulating mitochondrial N-formyl peptides (mtFPs) predispose to secondary infection by occupying formyl peptide receptor 1 (FPR1) on the neutrophil (polymorphonuclear leukocyte, PMN) membrane, suppressing cytosolic calcium ([Ca2+]i)-dependent responses to secondarily encountered bacteria. However, no study has yet investigated therapeutic clearance of circulating mtFPs in clinical settings. Thus, we studied how to remove mtFPs from septic-shock plasma and whether such removal could preserve cell-surface FPR1 and restore sepsis-induced PMN dysfunction by normalizing [Ca2+]i flux. In in vitro model systems, mtFP removal rescued PMN FPR1-mediated [Ca2+]i flux and chemotaxis that had been suppressed by prior mtFP exposure. However, PMN functional recovery occurred in a stepwise fashion over 30 - 90 minutes. Intracellular Ca2+-calmodulin appears to contribute to this delay. In ex vivo model systems using blood samples obtained from patients with septic shock, anti-mtFP antibodies alone failed to eliminate mtFPs from septic-shock plasma or inhibit mtFP activity. We therefore created a beads-based anti-mtFP antibody cocktail (bb-AMfpA) by combining protein A/sepharose with antibodies specific for the most potent human mtFP chemoattractants. The bb-AMfpA treatment successfully removed those active mtFPs from septic-shock plasma. Furthermore, the bb-AMfpA treatment significantly restored chemotactic and bactericidal dysfunction of PMNs obtained from patients with septic shock who developed secondary infections. By clearing circulating mtFPs, the immobilized anti-mtFP antibody therapy prevented mtFP interactions with surface FPR1, thereby restoring [Ca2+]i-dependent PMN antimicrobial function in clinical septic-shock environments. This approach may help prevent the development of secondary, nosocomial infections in patients recovering from septic shock.

Systemic Factors Effecting Human Beta-Defensins in Oral Cavity.

Human beta-defensins are host defense peptides with broad antimicrobial and inflammatory functions. In the oral cavity, these peptides are produced mainly by the keratinocytes of the epithelium; however, fibroblasts, monocytes, and macrophages also contribute to oral human beta-defensin expressions. The resident and immune cells of the oral cavity come into contact with various microbe-associated molecular patterns continuously and simultaneously. The overall antimicrobial cellular response is highly influenced by local and environmental factors. Recent studies have produced evidence showing that not only systemic chronic diseases but also systemic factors like hyperglycemia, pregnancy, the long-term use of certain vitamins, and aging can modulate oral cellular antimicrobial responses against microbial challenges. Therefore, the aim of this narrative review is to discuss the role of systemic factors on oral human beta-defensin expressions.

Microstructure versus topography: the impact of crystallographic substrate modification during ultrashort pulsed direct laser interference patterning on the antibacterial properties of Cu

Introduction: Topographic surface patterning in the micro- and nanometer scale has evolved into a well applied approach in surface functionalization following biomimetic blueprints from nature. Depending on the production process an additional impact of process-related substrate modification has to be considered in functional surface optimization. This is especially true in case of antimicrobial applications of Cu surfaces where a modification of the substrate properties might impact bactericidal efficiency.Methods: In this regard, the effect of ultrashort pulsed direct laser interference patterning on the microstructure of pure Cu and resulting antimicrobial properties was investigated alongside line-like patterning in the scale of single bacterial cells.Results and Discussion: The process-induced microstructure modification was shown to play an important role in corrosion processes on Cu surfaces in saline environment, whereas the superficial microstructure impacts both corrosive interaction and ion emission. Surprisingly, antimicrobial efficiency is not predominantly following deviating trends in Cu ion release rates but rather depends on surface topography and wettability, which was shown to be impacted by the substrate microstructure state, as well. This highlights the need of an in-depth understanding on how different surface properties are simultaneously modulated during laser processing and how their interaction has to be designed to acquire an effective surface optimization e.g., to agitate active antimicrobial surface functionalization.

Vimentin regulates mitochondrial ROS production and inflammatory responses of neutrophils.

The intermediate filament vimentin is present in immune cells and is implicated in proinflammatory immune responses. Whether and how it supports antimicrobial activities of neutrophils are not well established. Here, we developed an immortalized neutrophil model to examine the requirement of vimentin. We demonstrate that vimentin restricts the production of proinflammatory cytokines and reactive oxygen species (ROS), but enhances phagocytosis and swarming. We observe that vimentin is dispensable for neutrophil extracellular trap (NET) formation, degranulation, and inflammasome activation. Moreover, gene expression analysis demonstrated that the presence of vimentin was associated with changes in expression of multiple genes required for mitochondrial function and ROS overproduction. Treatment of wild-type cells with rotenone, an inhibitor for complex I of the electron transport chain, increases the ROS levels. Likewise, treatment with mitoTEMPO, a SOD mimetic, rescues the ROS production in cells lacking vimentin. Together, these data show vimentin regulates neutrophil antimicrobial functions and alters ROS levels through regulation of mitochondrial activity.