Bactericidal Capabilities Research Articles

Hyaluronic Acid/Gelatin-Based Multifunctional Bioadhesive Hydrogel Loaded with a Broad-Spectrum Bacteriocin for Enhancing Diabetic Wound Healing.

The development of multifunctional wound adhesives is critical in clinical settings due to the scarcity of dressings with effective adhesive properties while protecting against infection by drug-resistant bacteria. Polysaccharide and gelatin-based hydrogels, known for their biocompatibility and bioactivity, assist in wound healing. This study introduces a multifunctional bioadhesive hydrogel developed through dynamic covalent bonding and light-triggered covalent bonding, comprising oxidized hyaluronic acid, methacrylated gelatin, and the bacteriocin recently discovered by our lab, named jileicin (JC). The adhesion strength of the hydrogel, measured at 180 kPa, was 4.35 times higher than that of the fibrin glue. Furthermore, the hydrogel demonstrated robust platelet adhesion, procoagulant activity, and outstanding hemostatic properties in a mouse liver injury model. Incorporating JC significantly enhanced the phagocytosis and bactericidal capabilities of the macrophages. This immunomodulatory function on host cells, coupled with its potent bacterial membrane-disrupting ability, makes JC an effective killer against methicillin-resistant Staphylococcus aureus. In wound repair experiments on diabetic mice with infected full-thickness skin defects, the hydrogel treatment group showed a notable reduction in bacterial load, accelerated M2-type macrophage polarization, diminished inflammation, and hastened wound healing. Owing to its outstanding biocompatibility, antibacterial activity, and controlled adhesion, this hydrogel presents a promising therapeutic option for treating infected skin wounds.

A low-molecular-weight α-glucan from edible fungus Agaricus blazei Murrill activates macrophage TFEB-mediated antibacterial defense to combat implant-associated infection

Implant-associated infection (IAI) is a prevalent and potentially fatal complication of orthopaedic surgery. Boosting antibacterial immunity, particularly the macrophage-mediated response, presents a promising therapeutic approach for managing persistent infections. In this study, we successfully isolated and purified a homogeneous and neutral water-soluble polysaccharide, designated as AM-1, from the edible fungus Agaricus blazei Murrill. Structure analysis revealed that AM-1 (Mw = 3.87 kDa) was a low-molecular-weight glucan characterized by a primary chain of →4)-α-D-Glcp-(1 → and side chains that were linked at the O-6 and O-3 positions. In vivo assays showed that AM-1 effectively attenuated the progression of infection and mitigated infectious bone destruction in IAI mouse models. Mechanistically, AM-1 promotes intracellular autophagy-lysosomal biogenesis by inducing the nuclear translocation of transcription factor EB, finally enhancing the bactericidal capabilities and immune-modulatory functions of macrophages. These findings demonstrate that AM-1 significantly alleviates the progression of challenging IAIs as a presurgical immunoenhancer. Our research introduces a novel therapeutic strategy that employs natural polysaccharides to combat refractory infections.

Ribosomal protein L17 functions as an antimicrobial protein in amphioxus

Antimicrobial peptides (AMPs), characterized by their cationic nature and amphiphilic properties, play a pivotal role in inhibiting the biological activity of microbes. Currently, only a fraction of the antimicrobial potential within the ribosomal protein family has been explored, despite its extensive membership and resemblance to AMPs. Herein we demonstrated that amphioxus RPL17 (BjRPL17) exhibited not only upregulated expression upon bacterial stimulation but also possessed bactericidal capabilities against both Gram-negative and -positive bacteria through combined action mechanisms including interaction with cell surface molecules LPS, LTA, and PGN, disruption of cell membrane integrity, promotion of membrane depolarization, and induction of intracellular ROS production. Furthermore, a peptide derived from residues 127–141 of BjRPL17 (termed BjRPL17-1) showed antibacterial activity against Staphylococcus aureus and its methicillin-resistant strain via the same mechanism observed for the full-length protein. Additionally, the rpl17 gene was highly conserved in Metazoa, hinting it may play a universal role in the antibacterial defense system in different animals. Importantly, neither BjRPL17 nor peptide BjRPL17-1 exhibited toxicity towards mammalian cells thereby offering prospects for designing novel AMP agents based on these findings. Collectively, our results establish RPL17 as a novel member of AMPs with remarkable evolutionary conservation.

Anti-Staphy Peptides Rationally Designed from Cry10Aa Bacterial Protein.

Bacterial infections pose a significant threat to human health, constituting a major challenge for healthcare systems. Antibiotic resistance is particularly concerning in the context of treating staphylococcal infections. In addressing this challenge, antimicrobial peptides (AMPs), characterized by their hydrophobic and cationic properties, unique mechanism of action, and remarkable bactericidal and immunomodulatory capabilities, emerge as promising alternatives to conventional antibiotics for tackling bacterial multidrug resistance. This study focuses on the Cry10Aa protein as a template for generating AMPs due to its membrane-penetrating ability. Leveraging the Joker algorithm, six peptide variants were derived from α-helix 3 of Cry10Aa, known for its interaction with lipid bilayers. In vitro, antimicrobial assays determined the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) required for inhibiting the growth of Staphylococcus aureus, Escherichia coli, Acinetobacter baummanii, Enterobacter cloacae, Enterococcus facallis, Klebsiella pneumonia, and Pseudomonas aeruginosa. Time-kill kinetics were performed using the parental peptide AMPCry10Aa, as well as AMPCry10Aa_1 and AMPCry10Aa_5, against E. coli ATCC, S. aureus 111 and S. aureus ATCC strains showing that AMPCry10Aa_1 and AMPCry10Aa_5 peptides can completely reduce the initial bacterial load with less than 2 h of incubation. AMPCry10Aa_1 and AMPCry 10Aa_5 present stability in human serum and activity maintenance up to 37 °C. Cytotoxicity assays, conducted using the MTT method, revealed that all of the tested peptides exhibited cell viability >50% (IC50). The study also encompassed evaluations of the structure and physical-chemical properties. The three-dimensional structures of AMPCry10Aa and AMPCry10Aa_5 were determined through nuclear magnetic resonance (NMR) spectroscopy, indicating the adoption of α-helical segments. Electron paramagnetic resonance (EPR) spectroscopy elucidated the mechanism of action, demonstrating that AMPCry10Aa_5 enters the outer membranes of E. coli and S. aureus, causing substantial increases in lipid fluidity, while AMPCry10Aa slightly increases lipid fluidity in E. coli. In conclusion, the results obtained underscore the potential of Cry10Aa as a source for developing antimicrobial peptides as alternatives to conventional antibiotics, offering a promising avenue in the battle against antibiotic resistance.

Universal antibacterial and anti-inflammatory treatment using chitosan-prussian blue nanozyme

Bacterial infections are a growing global public health problem, exacerbated by the widespread and often inappropriate use of antibiotics, leading to the emergence of non-antibiotic pathogens. Herein, we synthesized a chitosan-Prussian blue nanozyme (CS@PB), a non-antibiotic agent, for universal antibacterial and anti-inflammatory treatment of bacterial infections. Confocal microscopy images showed that CS@PB significantly enhanced the physical interaction between chitosan and bacteria, thereby increasing the antibacterial ability. Moreover, these nanozymes exhibited potent antioxidant and anti-inflammatory properties, promoting macrophage polarization toward the M2-like phenotype, reducing oxidative stress, and alleviating inflammation. This dual-action approach effectively accelerates the healing of bacteria-infected inflammatory wounds. The synergistic bactericidal and anti-inflammatory properties of CS@PBs inhibited wound infection and promoted the healing of skin infections in a mouse model. In addition, CS@PB displayed remarkable lung retention and potent bactericidal effects, resulting in significantly improved survival rates in mouse models of acute pulmonary bacterial infections. In conclusion, CS@PBs exhibited exceptional bactericidal capabilities, anti-inflammatory properties, and minimal toxicity, suggesting that they are promising candidates for a new generation of non-antibiotic antimicrobial agents for the treatment of bacterial infections.

Management of Isoniazid Monoresistant Tuberculosis

lsoniazid (INH) is one of the main first-line drugs used for the treatment of active tuberculosis (TB) and latent TB infection because it has bactericidal capabilities and a good level of safety. The presence of TB germs that are resistant to INH will reduce the effectiveness of TB treatment. The treatment mix for INH monoresistant TB patients is a combination of rifampicin (R), isoniazid (H), pyrazinamide (Z), ethambutol (E), and levofloxacin (Lfx) or R-H-Z-E-Lfx given for 6 months. If a health facility provides loose TB medication, the patient can be given a combination of treatment without INH (R-Z-E-Lfx). In conditions where the Lfx drug cannot be used because there is severe intolerance (serious adverse events) or there are contra indications, the treatment given is the R-H-Z-E combination for 6 months. Clinical monitoring for patients with INH monoresistant TB follows the same principles as treatment of drug-sensitive TB. In conclusion, the treatment guide for INH monoresistant TB patients is a combination of rifampicin (R), isoniazid (H), pyrazinamide (Z), ethambutol (E), and levofloxacin (Lfx) or R-H-Z-E-Lfx for 6 months.

Synergistic antibacterial and antifouling wound dressings: Integration of photothermal-activated no release and zwitterionic surface modification

Addressing the pervasive issue of bacteria and biofilm infections is crucial in the development of advanced antifouling wound dressings. In this study, a novel wound healing treatment using sulfobetaine (SBMA) decorated electrospun fibrous membrane based on polycaprolactone (PCL)/nitric oxide (NO) donors was developed. The fabrication involved a dual strategy, first integrating NO donors into mesoporous polydopamine (MPDA) and complexed with PCL/PEI to electrospin nanofibers. The fibrous membrane exhibited a potent antibacterial response upon irradiation at 808 nm, owing to a combination of NO and photothermal effect that effectively targets bacteria and disrupts biofilms. Surface functionalization of the membrane with PEI allowed for the attachment of SBMA via Michael addition, fabricating a zwitterionic surface, which significantly hinders protein adsorption and reduces biofilm formation on the wound dressing. In vitro and in vivo assessments confirmed the rapid bactericidal capabilities and its efficacy in biofilm eradication. Combining photothermal activity, targeted NO release and antifouling surface, this multifaceted wound dressing addresses key challenges in bacterial infection management and biofilm eradication, promoting efficient wound healing.

Calcium hydroxide nanoparticles synthesized with medicinal plants extract as surface coating for titanium alloy bone implants using a simple method: Characterization and biomechanical evaluation

Advanced techniques have been developed to enhance the bioactivity and efficacy of biomedical titanium implants by modifying their surfaces. One such approach involves coating the titanium surface with biomaterials at the nanoscale level. In recent times, medicinal plant extracts have generated attention for nanoparticle synthesis due to their advantageous biomedical properties. Greenly synthesized carob-mediated calcium hydroxide nanoparticles exhibited promising results concerning both anti-inflammatory and osteogenic potentials during in vitro investigations. This study aimed to deposit these nanoparticles onto titanium-alloy bone implants through modifications to the established eco-friendly drop-casting method, characterize the surface, and biomechanically test it on rabbit tibias using torque removal analysis. Surface characterization utilizing scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction analysis successfully coated titanium implants with this material. A biomechanical study conducted on New Zealand rabbits revealed significantly higher peak torque removal values of the coated implants compared to uncoated implants (p < 0.01), suggesting enhanced osseointegration. The drop-casting method employed in this study is a straightforward, cost-efficient, and simple technique for coating various biomaterials onto titanium surfaces. This research lays the groundwork for further exploration of the potential benefits of using calcium hydroxide nanoparticles as titanium bone implant coatings, including their impact on bone healing, bactericidal capabilities, hemostatic potentials, and cellular activities.

S-scheme CoFe2O4/g-C3N4 nanocomposite with high photocatalytic activity and antibacterial capability under visible light irradiation

Photocatalysts with bactericidal capabilities are taken much more into consideration due to the water disinfection aside from water purification Therefore, a magnetically separable CoFe2O4/g-C3N4 nanocomposite has been synthesized via a simple in-situ chemical method, and its performance in degrading methylene blue (MB), methyl orange (MO), and phenol has been investigated. Multiple characterization techniques were conducted to confirm the successful synthesis of cobalt ferrite (CF), graphitic carbon nitride (CN), and cobalt ferrite/graphitic carbon nitride (CF/CN) nanocomposites. The microscopy images indicated a great reduction in the size of CF nanoparticles in nanocomposites. The magnetic characteristics were studied by a vibrating sample magnetometer (VSM). CF showed a high magnetization value (41.4 emu/g) and by compositing CF with CN, the nanocomposite also showed considerable magnetic properties. Optical properties of the photocatalysts were analyzed and the results denoted that heterostructure formation between CF and CN led to better light absorption, reduction in the band gap energy, and enhancement of charge carriers separation. Among the different synthesized nanocomposites, 400 mg/L of the CF/25 wt% CN nanocomposite showed the best photocatalytic activity in 180 min by degrading 100% of MB. The Mott-Schottky analysis and the results of scavenging experiments divulged the superoxide radicals as the main active species along with proposing a S-scheme mechanism on the degradation pathway for CF/CN nanocomposite. The optimized nanocomposite demonstrated high stability after three cycles by over 98% degradation of MB. Eventually, the antibacterial feature of CF/25CN nanocomposite was assessed against Escherichia coli and Staphylococcus aureus bacteria and resulted in a magnificent performance by reducing 99.9% of both bacteria in 30 min.

Advancing Photodynamic Antimicrobial Strategy: Sustainable Fabrication of Novel Lauryl Gallate-Chitosan Hydrophobic Films with Rapid Bacterial Capture and Biofilms Elimination Capabilities for Promoting Wound Healing.

Bioinspired photoactive composites, in terms of photodynamic inactivation, cost-effectiveness, and biosafety, are promising alternatives to antibiotics for combating bacterial infections while avoiding antibacterial resistance. However, the weak bacterial membrane affinity of the photoactive substrate and the lack of synergistic antibacterial effect remain crucial shortcomings for their antibacterial applications. Herein, we developed a hydrophobic film from food antioxidant lauryl gallate covalently functionalized chitosan (LG-g-CS conjugates) through a green radical-induced grafting reaction that utilizes synergistic bacteria capture, contact-killing, and photodynamic inactivation activities to achieve enhanced bactericidal and biofilm elimination capabilities. Besides, the grafting reaction mechanism between LG and CS in the ascorbic acid (AA)/H2O2 redox system was further proposed. The LG-g-CS films feature hydrophobic side chains and photoactive phenolic hydroxyl groups, facilitating dual bactericidal activities through bacteria capture and contact-killing via strong hydrophobic and electrostatic interactions with bacterial membranes as well as blue light (BL)-driven photodynamic bacterial eradication through the enhanced generation of reactive oxygen species. As a result, the LG-g-CS films efficiently capture and immobilize bacteria and exhibit excellent photodynamic antibacterial activity against model bacteria (Escherichia coli and Staphylococcus aureus) and their biofilms under BL irradiation. Moreover, LG-g-CS films could significantly promote the healing process of S. aureus-infected wounds. This research demonstrates a new strategy for designing and fabricating sustainable bactericidal and biofilm-removing materials with a high bacterial membrane affinity and photodynamic activity.

HucMSC-Exo Induced N2 Polarization of Neutrophils: Implications for Angiogenesis and Tissue Restoration in Wound Healing.

Neutrophils rapidly accumulate in large numbers at sites of tissue damage, exhibiting not only their well-known bactericidal capabilities but also playing crucial roles in angiogenesis and tissue repair. While exosomes derived from human umbilical cord mesenchymal stem cells (HucMSC-Exo) have emerged as a promising therapeutic tool, their exact mechanisms of action remain partly elusive. We hypothesize that HucMSC-Exo treatment may modulate neutrophil phenotypes, thereby significantly influencing wound healing outcomes. HucMSC-Exo were isolated via ultracentrifugation and subsequently administered through subcutaneous injection into full-thickness cutaneous wounds in mice. To determine the impact of host neutrophils on the healing effects of HucMSC-Exo in skin injuries, strategies including neutrophil depletion and adoptive transfer were employed. Flow cytometry was used to evaluate the proportion of N2 subtype neutrophils in both normal and diabetic wounds, and the effect of HucMSC-Exo on this proportion was assessed. Furthermore, the mitochondrial metabolic reprogramming driven by HucMSC-Exo during N2 polarization was investigated through JC1 staining, ATP quantification, fatty acid uptake assays, and assessment of FAO-related genes (Cpt1b, Acadm, and Acadl). Depleting host neutrophils strikingly dampened prohealing effect of HucMSC-Exo on skin injury, while adoptive transfer of bone marrow neutrophils rescued this process. During normal healing process, some neutrophils expressed N2 markers, in contrast, diabetic wounds exhibited a reduced expression of N2 markers. After treatment with HucMSC-Exo, most neutrophils increased the phosphorylation of STAT6, leading to mitochondrial metabolic reprogramming and thus acquired an N2 phenotype. These N2 neutrophils, polarized by HucMSC-Exo, boosted the release of proangiogenic factors, particularly BV8, a myeloid cell-derived proangiogenic factor, and induced angiogenesis thereby favoring tissue restoration. This research uniquely demonstrates the identification of N2 neutrophils in skin injury and shows that HucMSC-Exo could skew neutrophils toward N2 phenotype, enhancing our insight into how cells react to HucMSC-Exo.

Discovery of Unique Bis-Substituted Aromatic Amide Derivatives as Novel Highly Potent Antibiotics for Combating Methicillin-Resistant Staphylococcus aureus (MRSA).

Due to the increasing antibiotic resistance, developing novel antimicrobials to fight infections caused by resistant bacteria is imperative. Herein, a series of novel bis-substituted aromatic amides were designed and synthesized through modifying the hit compound 1, and their antimicrobial activities were evaluated. Among them, compound 4t, as the most potent lead, exhibited excellent antimicrobial activities against Gram-positive bacteria, including clinical methicillin-resistant Staphylococcus aureus (MRSA) isolates, while keeping weak hemolytic and mammalian cytotoxic activities. Furthermore, compound 4t displayed rapid bactericidal capabilities, low tendency to produce resistance, and favorable capacities to destroy bacterial biofilms. Further explorations indicated that compound 4t induces bacterial death by binding to cardiolipin (CL) on the bacterial membrane, disrupting the cell membrane, and facilitating the accumulation of reactive oxygen species (ROS). Additionally, compound 4t showed remarkable anti-MRSA activity in vivo, demonstrating compound 4t could be developed as a potential candidate to combat MRSA infections.

Investigation of Allogeneic Neutrophil Transfusion in Improving Survival Rates of Severe Infection Mice.

The management of granulocytopenia-associated infections is challenging, and a high mortality rate is associated with traditional supportive therapies. Neutrophils-the primary defenders of the human immune system-have potent bactericidal capabilities. Here, we investigated the dynamic in vivo distribution of neutrophil transfusion and their impact on the treatment outcome of severe granulocytopenic infections. We transfused 89Zr-labeled neutrophils in the C57BL/6 mice and observed the dynamic neutrophil distribution in mice for 24 h using the micro-positron emission tomography (Micro-PET) technique. The labeled neutrophils were predominantly retained in the lungs and spleen up to 4 h after injection and then redistributed to other organs, such as the spleen, liver, and bone marrow. Neutrophil transfusion did not elicit marked inflammatory responses or organ damage in healthy host mice. Notably, allogeneic neutrophils showed rapid chemotaxis to the infected area of the host within 1 h. Tail vein infusion of approximately 107 neutrophils substantially bolstered host immunity, ameliorated the inflammatory state, and increased survival rates in neutrophil-depleted and infected mice. Overall, massive allogeneic neutrophil transfusion had a therapeutic effect in severe infections and can have extensive applications in the future.

Enhanced osteogenesis and bactericidal performance with additively manufactured MgO and Cu-added CpTi for load-bearing implants.

Titanium, being the ultimate choice of metallic material for implant applications, its bio-inertness causes delayed bone-tissue integration at the implant site and prevents expedited healing for the patient. This can cause a severe issue for patients with immunocompromised bone health. Infections at the implant site are another concern; titanium does not offer inherent antimicrobial properties. Current strategies addressing the issues above include using cemented implants as a coating on Ti6Al4V bulk material for orthopedic applications. Roadblock arises with coating failure due to weak interfacial bond at the Ti-cement interface, resulting in revision surgeries. We have added osteogenic MgO and antibacterial Cu to CpTi and processed them using metal additive manufacturing (AM) to address these issues. Mg, an essential trace element in the body, has been proven to enhance osseointegration in vivo. Cu has been popular for its bactericidal capabilities. With 1 wt.% of MgO addition in the CpTi matrix, we have observed a four-fold increase in the mineralized bone formation at the bone-implant interface in vivo. The presence of 3 wt.% of Cu showed no cytotoxicity markers, and adding Cu to CpTi-MgO chemical makeup showed similar in vivo performance to CpTi-MgO. In vitro bacterial studies with gram-positive Staphylococcus aureus bacteria showed 81% bacterial efficiency displayed by CpTi-MgO-Cu at the end of 72 h of culture. Our findings highlight the synergistic benefits of CpTi-MgO-Cu, which exhibit superior early-stage osseointegration and antimicrobial capabilities.

Comparative Evaluation of Mechanical Properties and Bond Strength of Glass Ionomer Cement reinforced with three different concentrations of Silver Nanoparticles as against Conventional Glass Ionomer Cement in Primary Teeth.

Introduction: Restorative dental materials are defined as substances that are used to repair, replace, or enhance a patient's teeth. Various materials used in paediatric dentistry are zinc oxide eugenol, glass ionomer cement, resin composite, calcium hydroxide, silver amalgam, giomers etc. GIC is a biocompatible material having a low thermal expansion coefficient and fluoride release property. There are still a few drawbacks of GIC due of their poor mechanical properties therefore addition of Silver Nanoparticles demonstrated improved mechanical and bactericidal capabilities. There hasn't been much study on the quality of the bond contact between silver nanoparticles and dentin, as well as the color's durability. Aim: To evaluate and compare the mechanical properties and bond strength of Glass ionomer cement reinforced with three different concentrations of silver nanoparticle as against conventional glass ionomer cement in primary Teeth. Materials and Method: Silver nanoparticles will be prepared using three chemicals namely, silver nitrate, sodium citrate and tannic acid. Traditional GIC (GC Fuji II, GC Corporation, Tokyo, Japan) will be purchased. Three different concentrations of silver nanoparticles will be prepared i.e., 0.2, 0.4, and 0.6%. The GIC specimens will then be divided into 4 groups: GIC without silver nanoparticles (AgNPs),0.2%,0.4% and 0.6% AgNPs. Mechanical properties will be checked such as compressive, tensile, and bond strength using Universal Testing Machine. Expected Results: GIC reinforced with silver nano particles is expected to have better mechanical strength, less microleakage and wear resistance, greater fracture resistance and adhesive bond strength. Conclusion: GIC reinforced with silver nano particles will be expected to have better mechanical and physical properties than conventional Type II GICs and is expected to be a promising material for restoration in primary teeth.

Functional flexibility and plasticity in immune control of systemic Salmonella infection.

Immunity to systemic Salmonella infection depends on multiple effector mechanisms. Lymphocyte-derived interferon gamma (IFN-γ) enhances cell-intrinsic bactericidal capabilities to antagonize the hijacking of phagocytes as replicative niches for Salmonella. Programmed cell death (PCD) provides another means through which phagocytes fight against intracellular Salmonella. We describe remarkable levels of flexibility with which the host coordinates and adapts these responses. This involves interchangeable cellular sources of IFN-γ regulated by innate and adaptive cues, and the rewiring of PCD pathways in previously unknown ways. We discuss that such plasticity is likely the consequence of host-pathogen coevolution and raise the possibility of further functional overlap between these seemingly distinct processes.

Optimization of the Extraction of Chitosan and Fish Gelatin from Fishery Waste and Their Antimicrobial Potential as Active Biopolymers.

Fishery residues are abundant raw materials that also provide numerous metabolites with high added value. Their classic valorization includes energy recovery, composting, animal feed, and direct deposits in landfills or oceans along with the environmental impacts that this entails. However, through extraction processes, they can be transformed into new compounds with high added value, offering a more sustainable solution. The aim of this study was to optimize the extraction process of chitosan and fish gelatin from fishery waste and their revalorization as active biopolymers. We successfully optimized the chitosan extraction process, achieving a yield of 20.45% and a deacetylation degree of 69.25%. For the fish gelatin extraction process, yields of 11.82% for the skin and 2.31% for the bone residues were achieved. In addition, it was demonstrated that simple purification steps using activated carbon improve the gelatin's quality significantly. Finally, biopolymers based on fish gelatin and chitosan showed excellent bactericidal capabilities against Escherichia coli and Listeria innocua. For this reason, these active biopolymers can stop or decrease bacterial growth in their potential food packaging applications. In view of the low technological transfer and the lack of information about the revalorization of fishery waste, this work offers extraction conditions with good yields that can be easily implemented in the existing industrial fabric, reducing costs and supporting the economic development of the fish processing sector and the creation of value from its waste.

Gallium-niobium nanofiber surface of niobium/PEKK composite with anti-inflammatory, osteogenesis and anti-bacterial effects for facilitating osteoblastic differentiation and ameliorating osteointegration

Biomaterial-induced infection and inadequate osteointegration are regarded as two major reasons for the failure of implants. Herein, niobium (Nb)/polyetherketoneketone (PEKK) composite (NPC) was prepared, and a gallium (Ga)-Nb nanofiber surface on NPC (NPCG) was fabricated through sequential treatment with sodium hydroxide and gallium nitrate solution. Compared with PEKK and NPC, NPCG with nanofiber surface exhibited significant enhancements in surface properties with higher hydrophilicity and roughness, etc. NPCG remarkably facilitated multiplication and osteoblastic differentiation of bone mesenchymal stem cells in vitro. Moreover, NPCG obviously promoted the RAW264.7 cells polarization to M2 macrophages, which secreted anti-inflammatory cytokines in vitro, demonstrating an anti-inflammatory effect. Furthermore, NPCG significantly boosted osteogenesis and ameliorated osseointegration in vivo. The enhancements of osteoblastic response and M2 macrophage polarization in vitro and osseointegration in vivo for NPCG were attributed to the Ga–Nb nanofiber surface. Further, NPCG displayed outstanding bactericidal capability, which not only inhibited the bacteria growth in vitro but also resisted infection in vivo owing to the sustained release of Ga ions from the nanofiber surface. In short, NPCG with good biocompatibility exhibited anti-inflammatory, bactericidal and osteogenic capabilities, which facilitated osteoblastic differentiation and M2 macrophage polarization, and ameliorated osseointegration, thereby revealing great potential for bone substitute in orthopedics.

Development of copper impregnated bio-inspired hydrophobic antibacterial nanocoatings for textiles

Due to their bactericidal and fluid repellent capabilities, antimicrobial textiles with hydrophobic properties have aroused a lot of interest in healthcare, hygiene, air purifiers, water purification systems, food packaging, and other domains. Silver and silver-derived compounds have long been employed in antimicrobial coatings; nevertheless, they are costly, limiting their widespread use. In this work, we combined mussel-inspired polydopamine (pDA) coating chemistry with graphene oxide (GO) and antimicrobial copper compounds (Cu(NO3)2, CuCl2, Cu nanoparticles (CuNPs), and Cu-Carbon nanofibers (Cu-CNF)) to create hydrophobic antimicrobial nanocoatings on cotton fabric. The structural, morphological, wettability, and antibacterial characteristics of the produced coatings were evaluated. The fabric coated with Cu(NO3)2 and CuNPs had good hydrophobicity, which was stabilized for 30 min following GO integration. The coated fabric with GO and CuNPs showed 100% bacterial inhibition for S. aureus and a 99.995% reduction for P. aeruginosa bacteria. Overall, this bioinspired approach to developing antimicrobial coatings on fabric utilizing Cu(NO3)2 and CuNPs with GO shows a lot of promise in preventing the transmission of bacterial and viral infections through contaminated garments and has potential in designing clothing for healthcare settings such as PPEs, gowns, aprons, face mask filters, curtains, and so on.

Therapeutic stem cell-derived alveolar-like macrophages display bactericidal effects and resolve Pseudomonas aeruginosa-induced lung injury.

Bacterial lung infections lead to greater than 4 million deaths per year with antibiotic treatments driving an increase in antibiotic resistance and a need to establish new therapeutic approaches. Recently, we have generated mouse and rat stem cell‐derived alveolar‐like macrophages (ALMs), which like primary alveolar macrophages (1'AMs), phagocytose bacteria and promote airway repair. Our aim was to further characterize ALMs and determine their bactericidal capabilities. The characterization of ALMs showed that they share known 1'AM cell surface markers, but unlike 1'AMs are highly proliferative in vitro. ALMs effectively phagocytose and kill laboratory strains of P. aeruginosa (P.A.), E. coli (E.C.) and S. aureus, and clinical strains of P.A. In vivo, ALMs remain viable, adapt additional features of native 1'AMs, but proliferation is reduced. Mouse ALMs phagocytose P.A. and E.C. and rat ALMs phagocytose and kill P.A. within the lung 24 h post‐instillation. In a pre‐clinical model of P.A.‐induced lung injury, rat ALM administration mitigated weight loss and resolved lung injury observed seven days post‐instillation. Collectively, ALMs attenuate pulmonary bacterial infections and promote airway repair. ALMs could be utilized as an alternative or adjuvant therapy where current treatments are ineffective against antibiotic‐resistant bacteria or to enhance routine antibiotic delivery.