Excellent Antibacterial Effect Research Articles

Preparation, sustained-release and antibacterial activity of SBA-15/CG antibacterial agent

This paper aims to construct a novel antibacterial mesoporous silica (SBA-15) material containing chlorhexidine gluconate (CG), and to investigate its characterization, release, antibacterial activity, and toxicity. According to the results, SBA-15/CG antibacterial agents, which were successfully prepared with different drug concentrations, exhibited promising sustained-release properties, as well as excellent antibacterial effects against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Moreover, different doses of SBA-15/CG did not cause pathological changes in the organs of rats. Therefore, SBA-15/CG is non-toxic and has promising and broad clinical applications for bacterial infections.

A novel bacteriocin RSQ01 with antibacterial activity and its application and metabolomic mechanism in milk preservation

Milk poses a high-risk for microbial contamination (e.g., Salmonella Enteritidis) and spoilage. In recent years, lactic acid bacteria (LAB) bacteriocins have been widely acknowledged as the potential natural antibacterial substance in food biopreservation due to their excellent antibacterial effects. However, studies on the benefits of LAB bacteriocins for maintenance of milk quality were lacking. In the present study, a novel bacteriocin RSQ01 of Lactococcus lactis was purified and characterized extensively. The RSQ01 possessed a molecular weight of 1.90 kDa and an amino acid sequence of GTPSGGADGIGFAFHPEEVG, which exhibited an extensive antimicrobial spectrum against both gram-positive and gram-negative bacteria. Moreover, RSQ01 exhibited excellent tolerance to heat and acid-base treatments, and sensitivity to the proteolytic enzymes, such as trypsin, proteinase K, and pepsin, with a MIC value of 11.63 μg/mL against S. Enteritidis_35. Furthermore, RSQ01 maintained the nutritional composition, antioxidant parameters, and sensory properties of milk. Additionally, 238 differentially abundant metabolites (DAMs) were identified between the RSQ01-treated and -free milk by global metabolomics, which were assigned to eight categories/superclasses (e.g., organic acids and derivatives, lipids and lipid-like molecules, and organoheterocyclic compound). Finally, fourteen metabolic pathways enriched by DAMs were primarily involved in amino acid, lipids, and organic acid metabolism (e.g., phenylalanine/pyrimidine/tryptophan metabolism, glycerophospholipid metabolism, and C5-branched dibasic acid metabolism). The results provide evidence suggesting that abundance changes in metabolomes caused by RSQ01 contributed to the milk quality. Overall, this study indicated potential of RSQ01 in milk preservation.

Coordination-Driven One-Step Rapid Self-Assembly Synthesis of Dual-Functional Ag@Pt Nanozyme.

Realizing high-precise and adjustable regulation of engineering nanozyme is important in nanotechnology. Here, Ag@Pt nanozymes with excellent peroxidase-like and antibacterial effects are designed and synthesized by nucleic acid and metal ions coordination-driven one-step rapid self-assembly. The adjustable NA-Ag@Pt nanozyme is synthesized within 4min using single-stranded nucleic acid as templates, and peroxidase-like enhancing FNA-Ag@Pt nanozyme is received by regulating functional nucleic acids (FNA) based on NA-Ag@Pt nanozyme. Both Ag@Pt nanozymes that are developed not only has simple and general synthesis approaches, but also can produce artificial precise adjustment and possess dual-functional. Moreover, when lead ion-specific aptamers as FNA are introduced to NA-Ag@Pt nanozyme, the Pb2+ aptasensor is successfully constructed by increasing electron conversion efficiency and improving the specificity of nanozyme. In addition, both nanozyme has good antibacterial properties, with ~100% and ~85% antibacterial efficiency against Escherichia coli and Staphylococcus aureus, respectively. This work provides a synthesis method of novelty dual-functional Ag@Pt nanozymes and successful application in metal ions detection and antibacterial agents.

Multilayer electrospun nanofibrous membranes for drug - controlled release

Absorbing exudate and realizing drug - controlled release are considered to be the ideal objectives and effects of wound dressing. Therefore, multi - layer wound dressing is regarded as to be a common means for treating burns and other wounds with more exudate in skin tissue engineering. We report a unique platform based on multilayer nanofiber membrane, which can simultaneously inhibit bacterial breeding and prevent wound infection. An electrospun fiber pad containing tetracycline hydrochloride (TCH) was prepared as the core layer, and a layer of polyethylene oxide (PEO)/sodium alginate (SA) nanofiber membrane was covered on the upper and lower layers. The average diameter of multilayer nanofiber membrane is 440 nm, which has good biocompatibility and excellent antibacterial effect. Due to the regular arrangement of nanofibers and more small voids, it is conducive to cell adhesion and proliferation, and the drug in the core layer of fiber membrane has a relatively long release time. Through the bacteriostatic circle experiment, it has a good effect on inhibiting the growth and invasion of bacteria.

A HAase/NIR responsive surface on titanium implants for treating bacterial infection and improving osseointegration

• A mild antibacterial system for S. aureus and MRSA was constructed based on the synergistic effect of photothermal and antibiotic. • Antibiotic in MPDA can be sealed with HAc, which can avoid the damage to normal tissue caused by the burst release CIP and inhibit the early adhesion of bacteria. • Bacteria can secrete bacterial hyaluronidase to accelerate the degradation of HAc, realizing the smart enzyme-triggered release of antimicrobials at the site of infection on demand. • NIR light irradiation can not only accelerate the CIP release but also activate the photothermotherapy of MPDA nanoparticles. Bacterial infection and insufficient osseointegration are critical factors affecting the long-term success of titanium-based implants. Unfortunately, the direct application of antibiotic on Ti implants easily leads to poor cytocompatibility, as well as the production of drug-resistant bacteria. So, in this work, we designed a prospective antibacterial strategy by combining photothermal and ciprofloxacin (CIP). The synergistic effect of photothermal and antibiotic may provide an effective bacteriostatic efficacy without sacrificing osteogenesis at a mild condition of moderate temperature and less antibiotic. Herein, CIP was loaded into mesoporous polydopamine (MPDA) nanoparticles (MPDA@CIP), which were anchored on the surface of titanium and finally covered with sodium hyaluronate-catechol (HAc) coating. The hydrophilic HAc layer could inhibit the early adhesion of bacteria, and some bacteria could secrete bacterial hyaluronidase to accelerate the degradation of HAc. This enabled smart enzyme-triggered release of antimicrobials at the site of infection on-demand and avoided unwanted side effects on normal tissues. In addition, NIR light irradiation had a positive influence on both CIP release and MPDA nanoparticle's photothermal effect. Moreover, before anchoring MPDA@CIP, by the construction of hydroxyapatite microstructure on Ti surface with micro-arc oxidation and alkali heat treatment, the ability of bone formation of Ti could be promoted also. Both in vitro as well as in vivo assays demonstrated that functional Ti has an excellent antibacterial effect and osteogenic ability.

Durable Rapid Self-Disinfection, Reusable Protective Clothing Based on the Ag-Pd@MoS2 Nanozyme with Enhanced Triple-Mode Synergistic Antibacterial Effect.

Personal protective clothing plays an important role in isolating microorganisms and harmful ultrafine dust, but it cannot quickly inactivate bacteria intercepted on the surface, making it a potential source of infection. However, spontaneous and durable rapid sterilization is a major challenge for commercial protective clothing. Herein, we exquisitely engineered a visible light-enhanced Ag-Pd@MoS2 nanozyme-based fabric, named PVDF/Ag-Pd@MoS2/PAN fabric (PAPMP fabric), with prominent triple-mode synergistic antibacterial effect through the replacement reaction, electrospinning technique, and vacuum filtration method. The modification of Ag-Pd greatly strengthened the absorption of MoS2 nanosheets to the visible light spectrum (390-780 nm) and its corresponding catalytic performance. Meanwhile, the combination of MoS2 nanosheets significantly enhanced the oxidase-like characteristics of Ag-Pd under sunlight irradiation, increasing the yield of surface-bound 1O2 ∼4.54 times in 5 min. In addition, the obtained Ag-Pd@MoS2 nanozyme showed an excellent photo-to-thermal conversion property (36.12%), which enabled the sharp increase in the surface temperature of the PAPMP fabric to 62.8 °C in 1 min under a solar simulator (1 W/cm2). Correspondingly, the obtained PAPMP fabric exhibited excellent intrinsic antibacterial effect and greatly shortened the sterilization time from 4 h to only 5 min under sunlight stimulation. The rapid antibacterial effect of the fabric was attributable to the enhanced production rate of surface-bound reactive oxygen species and the increased temperature by solar irradiation. Notably, the fabric still maintained the efficient germicidal effect even after 30 washing cycles. In addition to high reusability, the fabric also had outstanding biological compatibility and water resistance. Our work provides a novel strategy to improve the inherent timely sterilization and heat preservation efficiency of protective clothing.

Facile preparation of fatty acids/nano [Al(OH)3/Al2O3]/wool fabric introducing thermal energy management with multifunctional properties

Development of facile fabrication of thermal energy storage for diverse purposes has become essential to improve energy efficiency. In this regard, for the first time, fatty acids/nano Al-based/wool composite was prepared by a simple one-step procedure through in situ formation. The treated fabric was characterized by FT-IR, Raman, XRD and SEM. DSC, TGA and thermal conductivity were conducted to investigate thermal behavior of the treated wool. The experimental results show the appropriate melting and solidifying temperature, 36.59 and 29.58 °C with responding enthalpies 59.22 and 52.08 J/g, respectively, for the desired application. TGA revealed the relatively improvement in thermal durability of the treated wool fabric. Embedding Al(OH)3/Al2O3 nanoparticles in eutectic phase change materials results in a 104.16 % increase in thermal conductivity. Despite the negative effect of fatty acids on flame retardant feature of the composite, aluminum hydroxide nanoparticles incorporated into the prepared composites imparted a good smoke suppression to the prepared composite. Moreover, the optimal sample illustrated excellent antibacterial and anti-fungal effects. The finished fabric also showed good activity for degradation of methylene blue under daylight irradiation. The treatment also greatly increased the water absorption of the composite and shrinkage resistance and also decreased alkali solubility. As a result, this thermos-regulative simple approach has a potentiality to be applied in various textile materials for diverse industries.

A Study on the Antimicrobial and Antioxidant Activity of Phytoncide Extract

Purpose: This study aims to confirm the physiological activity of cytotoxicity, antioxidant effects, and antibacterial effects of 9 kinds phytoncide extracts were investigated and the possibility of their application as cosmetic materials was studied.Methods: The 9 kinds natural products related to phytoncide extract were selected, extracted, and used as samples. Safety was confirmed through MTT assay, and antioxidant effect through DPPH radical scavenging activity evaluation and antibacterial effect through disc diffusion assay, minimum inhibitory concentration (MIC), and minimum bacteriological concentration (MBC) were evaluated.Results: All 9 kinds phytoncide extracts were confirmed to be safe against Fibroblast cytotoxicity at a concentration of 3.00% or less. The DPPH radical scavenging ability was similar in all phytoncide extracts, and it was confirmed that there was an antioxidant effect. The antibacterial effect did not show strong antibacterial activity against gram-negative bacteria, yeast and fungi as a whole, but it showed excellent antibacterial activity against gram-positive bacteria. Dendranthema zawadskii (Herb.) Tzvelev, Cupressus sempervirens showed antibacterial activity only on gram-positive bacteria. Juniperus chinensis showed excellent antibacterial activity against gram-positive bacteria, yeast. Angelica tenuissima Nakai showed high antibacterial activity against fungi rather than bacteria.Conclusion: These results show that excellent antibacterial and antioxidant effects were confirmed in Dendranthema zawadskii (Herb.) Tzvelev, Cupressus sempervirens, Juniperus chinensis and Angelica tenuissima Nakai at a concentration of 3.00% or less. It is judged that highly likely to be use as a cosmetic material with natural ingredients that replace synthetic preservatives or antioxidants.

Development of ZnO/selenium nanoparticles embedded chitosan-based anti-bacterial wound dressing for potential healing ability and nursing care after paediatric fracture surgery.

The current study was aimed at the assessment of the effect of chitosan-ZnO/Selenium nanoparticles scaffold on infected wound healing and care of paediatric surgery treatment. The nanoparticle scaffolds were developed from sources such as chitosan (CS), different concentrations of zinc oxide (ZnO), and Selenium (SeNPs) nanoparticles by freeze-drying method. The structural and chemical properties of nanoparticles were investigated by UV-Vis, fourier transform infrared spectroscopy (FTIR), and phase identification by x-ray diffraction analysis. The surface morphology of CS, chitosan-ZnO (CS-ZnO) and chitosan-ZnO/SeNPs was analysed using a scanning electron microscope. The incorporation of ZnO and SeNPs along with CS polymer induces antioxidant and antimicrobial functions. The bacterial susceptibility to nanoparticle scaffolds against Escherichia coli and Staphylococcus aureus showed the excellent antibacterial effects of ZnO and SeNPs. In-vitro studies of fibroblast of NIH 3T3 and HaCaT cell lines revealed the biocompatibility, cell adhesion, cell viability, and proliferation of scaffold in the wound site. Also, results of in-vivo studies strongly enhanced collagen synthesis, re-epithelialization, and rapid wound closure. Thus, the synthesised chitosan-ZnO/SeNPs nanoparticle scaffold resulted in significant improvement in histopathological indices in the full thickness of wound healing after nursing care of paediatric fracture surgery.

The potential mechanism of the Ruhao Dashi formula in treating acute pneumonia via network pharmacology and molecular docking.

Acute pneumonia (AP) has a high seasonal prevalence every year, which seriously threatens the lives and health of patients. Six traditional Chinese medicines in Ruhao Dashi formula (RDF) have excellent antiinflammatory, antibacterial, and antiviral effects. RDF is commonly used in the clinical treatment of AP. However, the mechanism and target of RDF are unclear. Therefore, this study aimed to use network pharmacology and molecular docking to evaluate the target and mechanism of RDF in the treatment of AP. The Herbs and Disease Gene databases were searched to identify common targets of AP and RDF. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, and Protein-Protein Interaction (PPI) network analyses were performed to identify the potential molecular mechanisms behind RDF. Molecular docking was performed to compare the binding activities of the active molecules with that of the target protein. The "drug-component-common target" network contained 64 active compounds and 134 targets. GO and KEGG analyses indicated that RDF could act by regulating cell death, cell proliferation, apoptosis, and hypoxic response. The PPI network and "pathway-target" network identified 31 core targets. Molecular docking revealed that the 14 active ingredients of RDF bind vigorously to the core targets. Through network pharmacology and molecular docking, we found that RDF contains 14 active components and 31 core AP targets. These targets were linked to the development of an antiinflammatory response and could be used to develop new drugs to treat AP.

Multifunctional Hydrogel Dressing That Carries Three Antibiotics Simultaneously and Enables Real-Time Ultrasound Bacterial Colony Detection.

We have developed a multifunctional hydrogel that can carry three synergistic antibiotics commonly used in clinical practice. This hydrogel was discovered to have drug encapsulation efficiencies of 94% for neomycin, 97% for bacitracin, and 88% for polymyxin B. Drug release data indicated that the release profiles of these three antibiotics were different. A swelling test demonstrated that the hydrogel absorbed liquid after the release of its antibiotics until it became saturated, which occurred within 48 h. Moreover, this hydrogel exhibited excellent antibacterial effects against Escherichia coli and Pseudomonas aeruginosa and biocompatibility; it can thus protect a wound from microbial invasion. When the alginate hydrogel is used to cover a wound, the wound can be checked for colonization at any time using ultrasound imaging; this can thus enable the prevention of wound biofilm formation in the early stages of infection. We evaluated the hydrogel against commercially available wound dressings and discovered that these wound dressings did not have the aforementioned desirable features. In conclusion, our multifunctional hydrogel can carry three types of antibiotics simultaneously and is a suitable medium through which an ultrasound can be performed to detect the growth of colonies in wounds. The hydrogel is expected to make a valuable contribution to the prevention of wound infections in the future.

Study on emergency treatment of minor oil leakage of closed circulation cooling water system

With the increasing shortage of water resources and the requirements of environmental protection, the closed circulation cooling water system will inevitably usher in a larger application space. However, when the leakage of the system, especially minor oil leakage, occurs, which is common and inevitable, the water quality of closed circulation cooling water will be deteriorated, and the cooling efficiency of the system will be affected due to the limited drainage and water refill. In view of such situations, this paper focuses on the slight oil leakage in the closed circulation cooling water system of Shaanxi Natural Gas General Plant, through the analysis of the water quality of the closed circulation cooling water system and the system basket filter intercepts in the case of slight oil leakage, with the experimental device of rotary hanging piece method and the inoculation of fresh intercepts to simulate the field conditions of slight oil leakage, the treatment effects of different treating agents are studied. The results show that: In the case of slight oil leakage in the closed circulation cooling water system, the corrosion of carbon steel and stainless steel increases and the corrosion of carbon steel is more serious than that of stainless steel. The metal material attached to the system is mainly corrosion products, and the bactericidal stripping agent SW-01 has almost no effect on the stripping effect of corrosion products, with excellent bactericidal effect. After 6 days of , 3.0g/L of the corrosion inhibition stripping agent HS-01 was added, the peeling effect of corrosion products was obvious, and the peeling effect of 0.3g/L biological dispersant was improved to a certain extent, but not particularly obvious. The peeling effect of the fixtures could be completed on the 9th day. This treatment method can make the corrosion rate of carbon steel and stainless steel fully meet the requirements of circulating cooling water under the condition of little drainage and large water refill, and the peeling effect of the fixtures is obvious. The effect can meet emergency handling requirements.

Polyethersulfone membrane modified by zwitterionic groups for improving anti-fouling and antibacterial properties

Ultrafiltration (UF) membranes are commonly confronted with threats from pollutants during long-term operation. The zwitterions with high hydrophilicity are expected to be the critical material to improve the anti-fouling and antibacterial abilities of membranes. Herein, a new zwitterionic polyethersulfone (PES) (zwitterionic PES - ZPES) was synthesized. The as-prepared ZPES was used to fabricate a zwitterionic UF membrane via the non-solvent induced phase inversion (NIPS) method. Zwitterionic polymer skeleton enhanced the hydrophilicity, permeability and anti-fouling properties of the material. As a result, the ZPES membrane exhibited doubled water flux growth (269.6 L·m−2·h−1) compared with that of the PES (125.3 L·m−2·h−1) and high protein rejection (98.6%). Besides, the ZPES membrane could maintain an excellent flux recovery rate (94.1%) and antibacterial effect (more than 95%). Therefore, the excellent anti-fouling and antibacterial abilities of the ZPES membrane broaden its application scope further.

An Antibacterial Polypeptide Coating Prepared by In Situ Enzymatic Polymerization for Preventing Delayed Infection of Implants.

Delayed implant-associated infection is an important challenge, as the treatment involves a high risk of implant replacement. Mussel-inspired antimicrobial coatings can be applied to coat a variety of implants in a facile way, but the adhesive 3,4-dihydroxyphenylalanine (DOPA) group is prone to oxidation. Therefore, an antibacterial polypeptide copolymer poly(Phe7-stat-Lys10)-b-polyTyr3 was designed to prepare the implant coating upon tyrosinase-induced enzymatic polymerization for preventing implant-associated infections. Both poly(Phe7-stat-Lys10) and polyTyr3 blocks have specific functions: the former provides intrinsic antibacterial activity with a low risk to induce antimicrobial resistance, and the latter is attachable to the surface of implants to rapidly generate an antibacterial coating by in situ injection of polypeptide copolymer since tyrosine could be oxidized to DOPA under catalyzation of skin tyrosinase. This polypeptide coating with excellent antibacterial effect and desirable biofilm inhibition activity is promising for broad applications in a multitude of biomedical materials to combat delayed infections.

The eradication of biofilm for therapy of bacterial infected chronic wound based on pH-responsive micelle of antimicrobial peptide derived biodegradable microneedle patch

Chronic wound caused by bacterial biofilm infection is difficult to heal and has been regard as a medical challenge. Herein, a biodegradable drug-loaded microneedle (MN) patch is designed for biofilm eradication and chronic wound repair. The microneedle system is loaded with micelle (DPP@AC) formed by the self-assembly of pH-responsive tri-block polymer (DMA-PEI-PLGA, DPP) and Ce6-coupled antimicrobial peptide (AMP-Ce6, AC), the micelle is about 68 nm in size and can release the DMA group and present positive charge in an acidic environment, thereby significantly improving the specific targeting ability of the antimicrobial peptide to bacteria. In vitro experiment shows that the MIC90 value of DPP@AC against S. aureus under laser irradiation is less than 5 μM and can inhibit 90% of biofilm formation. In vivo experiment shows that the MNs are basically degraded after 10 min of skin insertion, and the MN patch loaded with DPP@AC is applied to the wound of S. aureus biofilm-infected diabetic mice and irradiated with laser, showing excellent antibacterial peptide and photodynamic synergistic antimicrobial effect, which completely heals the wound within 15 d and achieved synergistic biofilm eradication and subsequent cascade activation of wound healing. Both in vitro and in vivo experiments confirm the biosafety of the microneedle system. This microneedle-assisted antimicrobial therapy provides a highly effective strategy for the treatment of chronic wound with biofilm-associated infection.

The Antibacterial Effect, Biocompatibility, and Osteogenesis of Vancomycin-Nanodiamond Composite Scaffold for Infected Bone Defects.

The repair and treatment of infected bone defects (IBD) is a common challenge faced by orthopedic clinics, medical materials science, and tissue engineering. Based on the treatment requirements of IBD, we utilized multidisciplinary knowledge from clinical medicine, medical materials science, and tissue engineering to construct a high-efficiency vancomycin sustained-release system with nanodiamond (ND) and prepare a composite scaffold. Its effect on IBD treatment was assessed from materials, cytology, bacteriology, and zoology perspectives. The results demonstrated that the Van-ND-45S5 scaffold exhibited an excellent antibacterial effect, biocompatibility, and osteogenesis in vitro. Moreover, an efficient animal model of IBD was established, and a Van-ND-45S5 scaffold was implanted into the IBD. Radiographic and histological analyses and bone repair-related protein expression, confirmed that the Van-ND-45S5 scaffold had good biocompatibility and osteogenic and anti-infective activities in vivo. Collectively, our findings support that the Van-ND-45S5 scaffold is a promising new material and approach for treating IBD with good antibacterial effects, biocompatibility, and osteogenesis.

Janus amphiphilic nanofiber membranes synergistically drive antibacterial and anti-inflammatory strategies for skin wound healing

Prevention of bacterial infection and control of inflammatory responses play critical roles in wound healing. Wound dressing loaded with antibacterial or anti-inflammatory drugs/molecules is one of the feasible routes in clinical applications. Nonetheless, effective and controllable drug release remains challenging. Herein, by electrospinning polyvinyl alcohol (PVA), polylactic acid-glycolic acid (PLGA) with copper sulfide nanoparticles (CuS NPs) and two model drugs, namely antibacterial drugs (mupirocin, M) and anti-inflammatory drugs (valsartan, V), an operable wound-healing patch consist of amphiphilic Janus nanofiber membrane (PLGAV-CuS/PVAM) was prepared which was used to controllable gradient drug release in wound healing. Janus nanofiber membrane shows typical amphiphilic characteristics, with low biological toxicity and good biocompatibility. In vitro experiments showed that the nanofiber membrane could slowly and continuously release mupirocin in a hydrophilic environment for antibacterial purposes. In addition, the excellent photothermal effect of PLGAV CuS/PVAM can regulate the release rate of the anti-inflammatory drug valsartan, effectively reduce the inflammatory reaction in the wound healing process, and also show enhanced bacteriostasis efficiency (96.3% of Escherichia coli and 97.8% of Staphylococcus aureus). The prepared patches exhibited excellent antibacterial, anti-inflammatory, and sustained-release effects, which is of great significance for board the avenue of nanofiber in the biomedical field.

Enhanced Bacterial-Infected Wound Healing by Nitric Oxide-Releasing Topological Supramolecular Nanocarriers with Self-Optimized Cooperative Multi-Point Anchoring.

Polymeric systems that provide cationic charges or biocide-release therapeutics are used to treat the bacteria-infected wound. However, most antibacterial polymers based on topologies with restricted molecular dynamics still do not satisfy the clinical requirements due to their limited antibacterial efficacy at safe concentrations in vivo. Here a NO-releasing topological supramolecular nanocarrier with rotatable and slidable molecular entities is reported to provide conformational freedom to promote the interactions between the carrier and the pathogenic microbes, hence greatly improving the antibacterial performance. With improved contacting-killing and efficient delivery of NO biocide from the molecularly dynamic cationic ligand design, the NO-loaded topological nanocarrier achieves excellent antibacterial and anti-biofilm effects via destroying the bacterial membrane and DNA. MRSA-infected rat model is also brought out to demonstrate its wound-healing effect with neglectable toxicity in vivo. Introducing flexible molecular motions into therapeutic polymeric systems is a general design to enhance the healing of a range of diseases.

Penicillin G amidase-activatable near-infrared imaging guiding PDT of bacterial infections

The antibiotic therapy usually leads to the bacterial resistance, and the traditional photosensitizer was in “always on” state with damage to normal tissue. Fortunately, the activatable near-infrared photosensitizer has a high depth of tissue penetration, and can be specifically released with low side effect. Therefore, we designed and synthesized a penicillin G acylase (PGA) activable photosensitizer (NFh-PGA), which could be activated to produce NFh-OH. NFh-OH can product singlet oxygen (1O2) under near-infrared light 730 nm excitation, and have an excellent antibacterial effect in vitro and in vivo. The probe accelerates the healing of bacterial infection wounds by near-infrared imaging guiding PDT. This work provides a strategy for the integrated design of diagnosis and treatment of bacterial infection.

A robust anticorrosive coating derived from superhydrophobic, superoleophobic, and antibacterial SiO2@POS/N+ composite materials

Traditional coatings are easily susceptible by the contamination of organic pollutants and parasitism of bacterium, resulting in severe corrosion damage to the protected substrates. The coating with superhydrophobic, superoleophobic and antibacterial properties would not only spontaneously form an air layer when it is immersed into corrosive medium and effectively obstruct corrosive medium to devastate metal matrix, but also be beneficial to improve the coating's anti-fouling performance along with its antibacterial functionality. However, traditional anticorrosive methods are problematic with low anticorrosion efficiency and single function. Herein, a robust anticorrosive coating stemmed from superhydrophobic, superoleophobic, and antibacterial SiO2 @POS/N+5 composite was prepared by sol-gel and spray method, with water contact angle and water sliding angle up to 160.8 ± 3.1° and 3.0° and oil contact angle and oil sliding angle up to 152.5 ± 3.0° and 3.0° were achieved, respectively. The SiO2@POS/N+5 coating has excellent protection performance (99.98 %), mechanical properties and corrosion durability (21 d). Notably, the SiO2@POS/N+5 composite material has excellent antibacterial effect against Staphylococcus aureus (S. aureus) (100 %) as well. The superamphiphobic coating proposed in this study affords a feasible strategy for bacterial contamination of metal surfaces in marine industries.