Excellent Antibacterial Activity Research Articles

Ultrasound-driven radical chain reaction and immunoregulation of piezoelectric-based hybrid coating for treating implant infection

The poor efficiency of US-responsive coatings on implants restricts their practical application. Immunotherapy that stimulates immune cells to enhance their antibacterial activity is expected to synergize with sonodynamic therapy for treating implant infection effectively and safely. Herein, US-responsive hybrid coatings composed of the oxygen-deficient BaTiO3 nanorod arrays and l-arginine (BaTiO3-x/LA) are designed and prepared on titanium implants for sonocatalytic therapy-cooperated immunotherapy to treat Methicillin-resistant Staphylococcus aureus (MRSA) infection. BaTiO3-x/LA can generate more oxidizing reactive oxygen species (ROS, hydroxyl radical (·OH)) and reactive nitrogen species (RNS, peroxynitrite anion (ONOO−)). The construction of nanorod arrays and oxygen defects balances the piezoelectric properties and sonocatalytic capability during US treatment. The generated piezoelectric electric field provides a sufficient driving force to separate electrons and holes, and the oxygen defects attenuate the electron-hole recombination efficiency, consequently increasing the yield of ROS during the US treatment. Moreover, nitric oxide (NO) released by l-arginine reacts with the superoxide radical (·O2−) to produce ONOO−. Since, this radical chain reaction improves the oxidizing ability between bacteria and radicals, the cell membrane (argB, secA2) and DNA (dnaBGXN) are destroyed. The bacterial self-repair mechanism indirectly accelerates bacterial death based on the transcriptome analysis. In addition to participating in the radical chain reaction, NO positively affects macrophage M1 polarization to yield potent phagocytosis to MRSA. As a result, without introducing an extra sonosensitizer, BaTiO3-x/LA exhibits excellent antibacterial activity against MRSA after the US treatment for 15 min. Furthermore, BaTiO3-x/LA facilitates macrophage M2 polarization after implantation and improves osteogenic differentiation. The combined effects of sonodynamic therapy and immunoregulation lead to an effective and safe treatment method for implant-associated infections.

Amide Modification of Glycolipid Biosurfactants as Promising Biocompatible Antibacterial Agents.

Discovering new antibacterial agents is crucial to addressing the increasing risk of bacterial infections induced by antimicrobial resistance in food and agricultural industries. Here, biocompatible acidic-type sophorolipids (ASLs) and glucolipids (GLs) prepared via chemical modification of natural sophorolipids from fermentation were functionalized via amide modification for use as potential antibacterial agents. It was found that the arginine methyl ester derivative of GLs (GLs-d-Arg-OMe) showed excellent antibacterial activity, killing more than 99.99% of Escherichia coli at 200 mg/L. The sterilization dosage of the GLs against Bacillus subtilis, Bacillus cereus, and Staphylococcus aureus was 16-64 mg/L, in contrast to 32-64 mg/L for the fungus Candida albicans. In particular, GLs-d-Arg-OMe showed the best biocompatibility with a therapeutic index of up to 18. It was shown that amide modification of glycolipids can effectively improve antibacterial activity while maintaining biocompatibility, which can be exploited for the development of novel antibiotics in food and agricultural fields.

The mitigation potential of synergistic quorum quenching and antibacterial properties for biofilm proliferation and membrane biofouling

Biofouling has been a persistent problem hindering the application of membranes in water treatment, and quorum quenching has been identified as an effective method for mitigating biofouling, but surface accumulation of live bacteria still induces biofilm secretion, which poses a significant challenge for sustained prevention of membrane biofouling. In this study, we utilized quercetin, a typical flavonoid with the dual functions of quorum quenching and bacterial inactivation, to evaluate its role in preventing biofilm proliferation and against biofouling. Quercetin exhibited excellent antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), and the decreased bioactivity was positively correlated with the quercetin concentration, with inhibition rates of 53.1 % and 57.4 %, respectively, at the experimental concentrations. The RT-qPCR results demonstrated that quercetin inhibited AI-2 of E. coli and AGR of S. aureus mediated quorum sensing system, and reduced the expression of genes such as adhesion, virulence, biofilm secretion, and key regulatory proteases. As a result, the bacterial growth cycle was retarded and the biomass and biofilm maturation cycles were alleviated with the synergistic effect of quorum quenching and antibacterial activity. In addition, membrane biofouling was significantly declined in the dynamic operation experiments, dead cells in the biofilm overwhelmingly dominated, and the final normalized water fluxes were increased by more than 49.9 % and 34.5 % for E. coli and S. aureus, respectively. This work demonstrates the potential for mitigating biofouling using protocols that quorum quenching and inactivate bacteria, also provides a unique and long-lasting strategy to alleviate membrane fouling.

Synthesis and docking of new 4-(2-((1-phenyl-1H-1,2,3-triazol-4-yl)methoxy)phenyl)thiazol-2-amine derivatives as an antimicrobial agent

The novel series of 4-(2-((1-phenyl-1H-1,2,3-triazol-4-yl)methoxy)phenyl)thiazol-2-amine 5a-h have been synthesized by oxidation reaction of acetophenone tethered 1,4-disubstituted triazole derivatives with thiourea in the presence of iodine. All newly synthesized compounds were characterized by IR, 1H NMR, 13C NMR, HRMS, and elemental analysis techniques. The antibacterial activity of novel compounds were evaluated against S. aureus, P. aeruginosa, E. coli and S. pyogenes bacterial strains whereas antifungal activity were screened against A. niger, C. albicans and A. clavatus pathogen of fungi. The compounds 5a, 5b, 5f and 5h showed excellent antibacterial activity, whereas 5f and 5g showed excellent antifungal activity. This may be attributed due to the presence of 4-CH3, 3-F, 4-F and 4-CF3 functional groups in benzene ring. The all results were compared with standard Ampicillin and Griseofulvin antibacterial and antifungal drugs, respectively. The molecular docking studies of compounds were carried out to measure effective bindings and molecular interactions. The experimentally observed values of antifungal activity and binding affinities values of molecular docking showed good correlation.

A dual network cross-linked hydrogel with multifunctional Bletilla striata polysaccharide/gelatin/tea polyphenol for wound healing promotion

Wound healing is a dynamic and complex biological process, and traditional biological excipients cannot meet the needs of the wound healing process, and there is an urgent need for a biological dressing with multifunctionality and the ability to participate in all stages of wound healing. This study developed tea polyphenol (TP) incorporated multifunctional hydrogel based on oxidized Bletilla striata polysaccharide (OBSP) and adipic acid dihydrazide modified gelatin (Gel-ADH) with antimicrobial, antioxidant hemostatic, and anti-inflammatory properties to promote wound healing. The composite OBSP, Gel-ADH, TP (OBGTP) hydrogels prepared by double crosslinking between OBSP, TP and Gel-ADH via Schiff base bonding and hydrogen bonding had good rheological and swelling properties. The introduction of TP provided the composite hydrogel with excellent antioxidant antibacterial activities against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coil). In the rat liver hemorrhage model and skin injury model, the OBGTP composite hydrogel had significant (p < 0.001) hemostatic ability, and had the ability to accelerate collagen deposition, reduce the expression of inflammatory factors, and promote rapid wound healing. In addition, OBGTP hydrogels had adhesive properties and good biocompatibility. In conclusion, OBGTP multifunctional composite hydrogels have great potential for wound healing applications.

Multi-functional nanofibrous membrane with antibacterial property for highly effective capture of PM0.3 and hydrogen sulfide

In order to reduce the possible harm caused by air pollution, including particulate matters (PM), harmful gases and airborne pathogens, high-efficiency air filtration materials are attracting more and more attention. Therefore, multifunctional materials that can filter these pollutants and kill pathogenic bacteria simultaneously are urgently desired. Herein, a copper-coordinated nanofibrous membrane, named PAN-P-Cu, was successfully prepared based on polyacrylonitrile (PAN) nanofibers grafted polyethyleneimine (PEI) by electrospinning and coordination assembly method. The PAN-P-Cu showed high filtration efficiency (99.9%) towards PM0.3 under an airflow velocity of 5.3 cm s−1 and high filtration efficiency (99.94%) towards PM10, respectively. Importantly, used membrane could be regenerated by a simple washing process. Moreover, PAN-P-Cu possessed removal property of 60 mg g−1 for hydrogen sulfide through the occurrence of chemical reactions. Furthermore, the PAN-P-Cu also exhibited excellent antibacterial activities against Escherichia coli and Staphylococcus aureus (>99.99%). This work may provide new insights on designing high-performance and multi-functional air filtration materials for public health protection in complicated environments.

Green and facile fabrication of multifunctional cellulose nanocrystal and carvacrol together reinforced chitosan bio-nanocomposite coatings for fruit preservation

The continuous development of sustainable food-active packaging materials and practices with high performance is a response to the increasing challenges posed by microbial food safety and environmental contamination. In this study, a multifunctional bio-nanocomposite composed primarily of chitosan, cellulose nanomaterials and carvacrol was proposed as a conformal coating for fruit preservation. The coating exhibits excellent antioxidant and antibacterial activities owing to the incorporation of the carvacrol. The inhibition rate of the coating on E. coli and S. aureus is enhanced by 57.13 % and 62.18 %, respectively. And its antioxidant activities is also improved by 77.45 %. In addition, the oxygen permeability (OP) and water vapor permeability (WVP) of this CS/CNC coating are significantly lowered by 67 % and 46 %, respectively, comparing with the CS coating. The coating exhibited excellent biosafety and cytocompatibility because of over 90 % of the HepG2 cells remained alive in each concentration of the coating after 24 h incubation. Additionally, the efficacy of the coating in prolonging the freshness and visual appeal of perishable fruits is substantiated by the experiment involving two fruit specimens. Furthermore, the coating's ease of production, ingestibility, washability, and utilization of cost-effective and easily accessible biomaterials, including renewable waste materials, indicate its potential as a viable economic substitute for commercially accessible fruit coatings.

Recent Advances in Antibacterial Coatings to Combat Orthopedic Implant-Associated Infections.

Implant-associated infections (IAIs) represent a major health burden due to the complex structural features of biofilms and their inherent tolerance to antimicrobial agents and the immune system. Thus, the viable options to eradicate biofilms embedded on medical implants are surgical operations and long-term and repeated antibiotic courses. Recent years have witnessed a growing interest in the development of robust and reliable strategies for prevention and treatment of IAIs. In particular, it seems promising to develop materials with anti-biofouling and antibacterial properties for combating IAIs on implants. In this contribution, we exclusively focus on recent advances in the development of modified and functionalized implant surfaces for inhibiting bacterial attachment and eventually biofilm formation on orthopedic implants. Further, we highlight recent progress in the development of antibacterial coatings (including self-assembled nanocoatings) for preventing biofilm formation on orthopedic implants. Among the recently introduced approaches for development of efficient and durable antibacterial coatings, we focus on the use of safe and biocompatible materials with excellent antibacterial activities for local delivery of combinatorial antimicrobial agents for preventing and treating IAIs and overcoming antimicrobial resistance.

Developing Composite Coating of PEEK and AgNP on 316L Stainless Steel Substrate for Biomedical Implant

Biomedical implants play a crucial role in modern healthcare, but their long-term success hinges on the materials used. This study focuses on developing a composite coating of polyetheretherketone (PEEK) and silver nanoparticles (AgNP) on 316L stainless steel substrates, aiming to enhance their biocompatibility and antibacterial properties. PEEK is known for its biocompatibility and mechanical properties, while AgNP exhibit excellent antibacterial activity. By combining these materials, we aim to create a coating that not only supports the integration of implants with surrounding tissue but also reduces the risk of infections, a common complication in implant surgery. The fabrication process involves depositing a PEEK layer on the stainless steel substrate, followed by the incorporation of AgNP using a suitable method such as electro spinning or dip coating. The coated substrates will undergo comprehensive characterization, including mechanical testing, surface analysis, and antibacterial efficacy assessment. The mechanical properties of the coating will be critical to ensure its durability and resistance to wear in the demanding environment of the human body. Furthermore, the chemical and biological properties of the coating will be evaluated to ensure its biocompatibility and safety for implantation. This study aims to contribute to the development of advanced coatings for biomedical implants, ultimately improving their performance and longevity. The findings of this research could lead to the development of safer and more effective biomedical implants, benefiting patients and healthcare systems worldwide.

Grafting of Poly(ionic liquid) Brushes through Fe0-Mediated Surface-Initiated Atom Transfer Radical Polymerization for Marine Antifouling.

Surface-tethered poly(ionic liquid) brushes have attracted considerable attention in widespread fields, from bioengineering to marine antifouling. However, their applications have been constrained due to the poor polymerization efficiency and sophisticated operation process. In this work, we efficiently synthesized the poly(ionic liquid) brushes with unparalleled speed (up to 98 nm h-1) through Fe0-mediated surface-initiated atom transfer radical polymerization (Fe0 SI-ATRP) while consuming only microliter of monomer solution under ambient conditions. We also demonstrated that poly(ionic liquid) brushes with gradient thickness and wettability were easily accessible by regulating the distance between the opposite plates of Fe0 SI-ATRP. Moreover, the resultant poly(ionic liquid) brushes presented excellent antibacterial activities against Escherichia coli (99.2%) and Bacillus subtilis (88.1%) after 24 h and low attachment for proteins and marine algae (≤5%) for over 2 weeks. This research provided pathways to the facile and controllable fabrication of poly(ionic liquid) materials for marine antifouling applications.

Fabrication of silicon-based nickel nanoflower-encapsulated gelatin microspheres as an active antimicrobial carrier

Local antibiotic application might mitigate the burgeoning problem of rapid emergence of antibiotic resistance in pathogenic microbes. To accomplish this, delivery systems must be engineered. Hydrogels have a wide range of physicochemical properties and can mimic the extracellular matrix, rendering them promising materials for local antibacterial agent application. Here, we synthesized antibacterial silicon (Si)-based nickel (Ni) nanoflowers (Si@Ni) and encapsulated them in gelatin methacryloyl (GelMA) using microfluidic and photo-crosslink technology, constructing uniform micro-sized hydrogel spheres (Si@Ni-GelMA). Si@Ni and Si@Ni-GelMA were characterized using X-ray diffraction, transmission electron microscopy, and scanning electron microscopy. Injectable Si@Ni-GelMA exhibited excellent antibacterial activities owing to the antibiotic effect of Ni against Pseudomonas aeruginosa, Klebsiella pneumoniae, and methicillin-resistant Staphylococcus aureus, while showing negligible cytotoxicity. Therefore, the Si@Ni-GelMA system can be used as drug carriers owing to their injectability, visible light-mediated crosslinking, degradation, biosafety, and superior antibacterial properties.

High-efficient and intelligent antibacterial face mask integrated with airflow-temperature dual-function sensors for respiratory monitoring and disease prevention

Intelligent face masks play crucial roles in health monitoring and disease prevention, having attracted huge attention in recent years. However, most of the current intelligent face masks focus on monitoring single physical signal, which were unable to provide comprehensive information. Herein, an intelligent face mask with airflow and temperature sensing abilities, high-efficiency filtration and excellent antibacterial activity was proposed. The real-time airflow monitoring was realized by a triboelectric nanogenerator (TENG), which was composed of electrospun nanofibrous membrane and polydimethylsiloxane (PDMS) composite film. The fabricated electrospun nanofibrous membrane simultaneously played roles as tribo-positive material, filter and antibacterial membrane. The PDMS composite film prepared by co-blending and surface modification was applied as tribo-negative material. It was found that the combination of co-blending and surface modification enhanced the tribo-negative property of the PDMS film, resulting in an increment of output performance of TENG. The TENG integrated into a face mask could monitor respiratory rate and respiration intensity in real time. Additionally, the temperature sensing was achieved by a serpentine PDMS/laser-induced graphene temperature sensor. The temperature sensor exhibited a temperature coefficient of resistance of 0.316% °C−1, which could detect subtle temperature variations. Furthermore, the electrospun nanofibrous membrane exhibited excellent filtration performance and antibacterial activity. Therefore, the prepared intelligent face mask showed promising potential for healthcare applications.

Increased antibacterial activity of silver nanoparticles synthesized from leaf extract of Isodon coetsa

Application of nanotechnology for the synthesis of silver nanoparticles using plant extract can be a promising alternative to traditional chemical methods. Products of biological origin have less side effects, thus are safe for human health besides being cost-effective and pollution-free. Keeping in view this, the current work was designed for the environment- friendly production of silver nanoparticles (AgNPs) utilising Isodon coetsa acetone leaf extract. The effect of some important variables including incubation time, pH, AgNO3 concentration, temperature and volume of plant extract were examined for the optimum production of AgNPs. Synthesized nanoparticles were further characterized using atomic force microscopy (AFM), X-ray diffraction spectroscopy (XRD), and UV-visible absorption spectroscopy. In addition, the antibacterial potential of nanoparticles was also determined by agar-well diffusion method. The optimal conditions for synthesis of AgNPs achieved after 24 h of incubation at pH 9.0, 2mM AgNO3, 60°C temperature, and using 10% I. coetsa leaf extract. X-ray diffraction spectroscopy revealed that the size of the strongest peak for AgNPs was 9.5 nm, while atomic force microscopy confirmed their spherical shape with smooth surface without any pinholes or cracks. AgNPs showed excellent antibacterial action against Gram-positive and Gram-negative bacteria. The current study has contributed to the development of a simple and fast bioprocess for the synthesis of AgNPs of the appropriate size and form which also have increased antibacterial activity in comparison to crude extract. Therefore, the process of biogenically synthesised AgNPs from plants is a straightforward, commercially feasible, and environmentally benign approach that can be used in disease control while utilizing their important role as therapeutic agent for treating various ailments caused by pathogenic bacteria.

Electrospun L-Lysine/Amorphous Calcium Phosphate Loaded Core-Sheath Nanofibers for Managing Oral Biofilm Infections and Promoting Periodontal Tissue Repairment.

Periodontitis, a chronic inflammatory disease prevalent worldwide, is primarily treated through GTR for tissue regeneration. The efficacy of GTR, however, remains uncertain due to potential infections and the intricate microenvironment of periodontal tissue. Herein, We developed a novel core-shell structure multifunctional membrane using a dual-drug-loaded coaxial electrospinning technique (Lys/ACP-CNF), contains L-lysine in the outer layer to aid in controlling biofilms after GTR regenerative surgery, and ACP in the inner layer to enhance osteogenic performance for accelerating alveolar bone repair. The biocompatibility and cell adhesion were evaluated through CCK-8 and fluorescence imaging, respectively. The antibacterial activity was assessed using a plate counting assay. ALP, ARS, and RT-qPCR were used to examine osteogenic differentiation. Additionally, an in vivo experiment was conducted on a rat model with acute periodontal defect and infection. Micro-CT and histological analysis were utilized to analyze the in vivo alveolar bone regeneration. Structural and physicochemical characterization confirmed the successful construction of the core-shell fibrous structure. Additionally, the Lys/ACP-CNF showed strong antibacterial coaggregation effects and induced osteogenic differentiation of PDLSCs in vitro. The in vivo experiment confirmed that Lys/ACP-CNF promotes new bone formation. Lys/ACP-CNF rapidly exhibited excellent antibacterial activity, protected PDLSCs from infection, and was conducive to osteogenesis, demonstrating its potential application for clinical periodontal GTR surgery.

Grewia tenax bark extract mediated silver nanoparticles as an antibacterial, antibiofilm and antifungal agent

Grewia tenax plant possesses many medicinal qualities that can be harnessed for bio-applications via nanotechnology in a cost-effective and environment-friendly manner. The synthesised silver nanoparticles (GTB-AgNPs) from Grewia tenax bark extract were first detected by observing the change in colour from yellowish brown to dark brown and confirmed by UV–vis spectroscopy. UV–vis spectral analysis recorded the surface plasmon resonance at 420 nm. In the current research, several process parameters (time, temperature, concentration of AgNO3 and the ratio of extract to AgNO3) were adjusted by using one variable at a time (OVAT) approach. Spectroscopy accompanied by dynamic light scattering (DLS), x-ray diffraction (XRD) and scanning electron microscopy (SEM) with energy dispersive x-ray (EDX) determines the size, nature, morphological variations and chemical constituents of GTB-AgNPs. The size range was found within 35−45 nm and the image clearly showed that the GTB-AgNPs were spherical in shape and well dispersed in nature. Zeta potential and Fourier-transform infrared spectroscopy (FTIR) were done to analyse GTB-AgNPs stability, dispersion and the biomolecules in aqueous bark extract liable for the bioreduction of silver particles. These GTB-AgNPs showed excellent antibacterial action against Gram-positive (S. aureus and B. subtilis) and Gram-negative bacteria (P. aeruginosa and E. coli) which was observed by disc diffusion assay. Congo red agar plate (CRA) assay effectively unveiled the antibiofilm proficiency of the particles. These studies displayed a reduction in bacterial sustainability and the formation of exopolysaccharides. Disc diffusion assay confirmed the antifungal competency against A. niger and C. albicans. SEM was performed to elucidate the intracellular breakage and morphological transformations in cells of Gram-positive bacteria and fungi after treatment with GTB-AgNPs. The current study, therefore, enlightened applications of GTB-AgNPs as an efficient antimicrobial agent and applicable substitute in the pharmaceutical area.

MgO@polydopamine Nanoparticle-Loaded Photothermal Microneedle Patches Combined with Chitosan Gel Dressings for the Treatment of Infectious Wounds.

As for wound drug delivery, microneedles (MNs) have attracted wide attention. However, while effective at increasing the depth of drug delivery, traditional MNs often have limited drug loads and have difficulty penetrating scabs on wounds. Herein, we develop a drug delivery system combining MgO@polydopamine (MgO@PDA) nanoparticle-loaded photothermal MN patches and chitosan (CS) gel to inhibit the formation of scabs and deliver sufficient drugs into deep tissue. When inserted into the wound, the MN system can keep the wound bed moist and weakly acidic to inhibit the formation of scabs and accelerate wound closure. The released MgO@PDA nanoparticles from both the tips and the backing layer, which immensely increase the drug load, continuously release Mg2+ in the moist, weakly acidic wound bed, promoting tissue migration and the formation of microvessels. MgO@PDA nanoparticles show excellent antibacterial activity under near-infrared irradiation synergized with the CS gel, and the PDA coating can also overcome the adverse effects of oxidative stress. Through in vitro and in vivo experiments, the MN system showed remarkable antibacterial, antioxidant, anti-inflammatory, and pro-angiogenic effects, indicating its potential in the treatment of infectious wounds.

Synthesis of iodine-povidone-co-thiazole nanoporous membrane with antibacterial activity and application in water treatment

In order to prevent the spread of the epidemics caused by pathogenic microorganisms, it is very important to explore antimicrobial materials. In this paper, a novel antimicrobial polymer materials with dual active centers, iodine-povidone-co-thiazole nanoporous membrane (IPoTaNm), was successfully synthesized by one-pot emulsion polymerization followed by iodine complexation. The micromorphology and composition were characterized by scanning electron microscope (SEM), Fourier transform infrared spectra (FT-IR), dynamic light scattering (DLS), X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD) and contact angle test. Then, its antimicrobial performance was measured by using Escherichia coli and Staphylococcus aureus as test strains. It indicated that IPoTaNm exhibits excellent antibacterial activity, which the inhibition rate got to 99.9 % after 48 h. It also presented sustaining bactericidal activity, which the antimicrobial activity maintained 99.9 % even after >7 days. The synergistic antimicrobial mechanism of thiazole units (AcT) and iodine in IPoTaNm was discussed, and some facters for their inhibitory effects in the water column were investigated. In summary, the obtained IPoTaNm with dual active centers was an excellent candidate for minimizing bacteria-infection in different functional materials, which has potential applications in wastewater treatment to reduce bacterial infections.

Nickel-doped microtubular CeVO4 inspired by wood powder structure for visible light photocatalytic degradation of methylene blue and bacterial inactivation

In this study, inspired by natural wood powder structure, nickel-doped microtubular cerium vanadate (Ni/T-CeVO4) was obtained using wood powder as a biological template. Photocatalytic experiments under visible light revealed that Ni/T-CeVO4-3wt possessed the highest photocatalytic activity, with a degradation efficiency of up to 99 % for methylene blue. The enhanced photocatalytic performance was not only attributed to the microtubule wood powder structure assigned the composite a larger specific surface area but also the nickel doping narrowed the band gap of the composites while introducing more oxygen vacancies. The rapidly generated current in transient photocurrent responses and small arc radius in electrochemical impedance spectra further indicated the higher photogenerated carrier separation and smaller photogenerated electron transfer resistance within the composite. ESR spin-trapping tests proved that O2− and OH dominated the photocatalytic process. Furthermore, owing to its unique structural characteristics, the composite showed excellent photocatalytic antibacterial activity against Staphylococcus aureus and Escherichia coli. The present study provides a theoretical basis for developing efficient dual-effect photocatalysts using visible light to remove organic dyes and pathogenic bacteria from the water environment.

Gluing blood into adhesive gel by oppositely charged polysaccharide dry powder inspired by fibrin fibers coagulation mediator

Hemostatic powders that adapt to irregularly shaped wounds, allowing for easy application and stable storage, have gained popularity for first-aid hemorrhage control. However, traditional powders often provide weak thrombus support and exhibit limited tissue adhesion, making them susceptible to dislodgment by the bloodstream. Inspired by fibrin fibers coagulation mediator, we have developed a bi-component hemostatic powder composed of positively charged quaternized chitosan (QCS) and negatively charged catechol-modified alginate (Cat-SA). Upon application to the wound, the bi-component powders (QCS/Cat-SA) rapidly absorb plasma and dissolve into chains. These chains interact with each other to form a network, which can effectively bind and entraps clustered red blood cells and platelets, ultimately leading to the creation of a durable and robust thrombus. Significantly, these interconnected polymers adhere to the injury site, offering protection against thrombus disruption caused by the bloodstream. Benefiting from these synthetic properties, QCS/Cat-SA demonstrates superior hemostatic performance compared to commercial hemostatic powders like Celox™ in both arterial injuries and non-compressible liver puncture wounds. Importantly, QCS/Cat-SA exhibits excellent antibacterial activity, cytocompatibility, and hemocompatibility. These advantages of QCS/Cat-SA, including strong blood clotting, wet tissue adherence, antibacterial activity, biosafety, ease of use, and stable storage, make it a promising hemostatic agent for emergency situations.

Cohering Plasma into Adhesive Gel by Natural Biopolymer-Nanoparticle Hybrid Powder for Efficient Hemostasis and Wound Healing.

Hemostatic powder is commonly used in emergency bleeding control due to its suitability for irregularly shaped wounds, ease of use, and stable storage. However, traditional powder often has limited tissue adhesion and weak thrombus support, which makes it vulnerable to displacement by blood flow. Herein, we have developed a tricomponent hemostatic powder (MQS) composed of mesoporous bioactive glass nanoparticle (MBG), positively charged quaternized chitosan (QCS), and negatively charged catechol-modified alginate (SADA). Upon application to the wound, MBG with its high specific surface area quickly absorbs plasma, concentrating the blood coagulation factor. Simultaneously, the water-soluble QCS and SADA interact with each other and form a net, which can be further cross-linked by MBG. This network efficiently binds and entraps clustered blood coagulation factors, ultimately resulting in the formation of a durable and robust thrombus. Furthermore, the formed net adheres to the injury site, offering protection against thrombus disruption caused by the bloodstream. Benefiting from the synergistic effect of these three components, MQS demonstrates superior hemostatic performance compared to commercial hemostatic powders like Celox in both arterial injuries and noncompressible liver puncture wounds. Furthermore, MQS can effectively accelerate wound healing. In addition, MQS exhibits excellent antibacterial activity, cytocompatibility, and hemocompatibility. These advantages of MQS, including strong blood clotting, wet tissue adherence, antibacterial activity, wound healing ability, biosafety, ease of use, and stable storage, make it a promising hemostatic agent for emergency situations.