Nucleic acid strand displacement for indirect determination of foodborne bacteria by capillary electrophoresis and its application in antagonism and bacteriostasis studies.

Foodborne bacteria threaten human's health. Capillary electrophoresis (CE) is a powerful separation means for the determination of bacteria. Direct separation of bacteria suffers from the shortages of low resolution, channel adsorption, and bacterial aggregation. In this work, a method of nucleic acid strand displacement was developed to indirect separate the bacteria by CE. DNA complexes, consisting of probes and aptamers, were mixed with the three bacteria Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. The aptamers could specifically bond with bacteria and release the probes. Through the separation of the probes, the bacteria could be indirectly determined by CE. This method avoided the shortages of direct separation of bacteria. Under the optimized conditions, the three probes for the bacteria could be separated and detected within 2.5 min by high-speed CE with laser-induced fluorescence detection. The limits of detection for the bacteria were in the range 4.20 × 106 to 1.75 × 107  CFU/mL. Finally, the developed method was applied on the study of antagonism of the coexistent bacteria to reveal the relationship between them. Furthermore, the efficiency of bacteriostasis of three traditional Chinese medicines, Coptis chinensis, Schisandra chinensis, and honeysuckle, was also studied by this method.

Identification and Characterization of a Novel Prophage Lysin against Streptococcus dysgalactiae.

Streptococcus dysgalactiae infection can cause bovine mastitis and lead to huge economic losses for the dairy industry. The abuse of antibiotics has resulted in growing drug resistance of S. dysgalactiae, which causes hard-to-treat infections. Bacteriophage lysin, as a novel antibacterial agent, has great potential for application against drug-resistant gram-positive bacteria. However, few studies have been conducted on the prophage lysin of S. dysgalactiae. In this study, we mined a novel prophage lysin, named Lys1644, from a clinical S. dysgalactiae isolate by genome sequencing and bioinformatic analysis. Lys1644 was expressed and purified, and the lytic activity, antibacterial spectrum, optimal pH and temperature, lytic activity in milk in vitro, and synergistic bacteriostasis with antibiotics were assessed. The Lys1644 prophage lysin showed high bacteriolysis activity specifically on S. dysgalactiae, which resulted in CFU 100-fold reduction in milk. Moreover, Lys1644 maintained high activity over a wide pH range (pH 5-10) and a wide temperature range (4-42 °C). Synergistic bacteriostatic experiments showed that the combination of low-dose Lys1644 (50 µg/mL) with a subinhibitory concentration of aminoglycoside antibiotics (kanamycin or spectinomycin) can completely inhibit bacterial growth, suggesting that the combination of Lys1644 and antibiotics could be an effective therapeutic strategy against S. dysgalactiae infection.

A novel l-rhamnose-binding lectin participates in defending against bacterial infection in zebrafish.

l-rhamnose-binding lectin (RBL), which is a class of animal lectins independent of Ca2+, can specifically bind l-rhamnose or d-galactose. Although several lectins in zebrafish have been reported, their functional mechanisms have not been fully uncovered. In this study, we discovered a novel l-rhamnose binding lectin (DrRBL) and studied its innate immune function. The DrRBL protein contains only one carbohydrate-recognition domain (CRD), which includes two strictly conserved motifs, "YGR" and "DPC". DrRBL was detected in all tested tissues and was present at high levels in the spleen, hepatopancreas and skin. After Aeromonas hydrophila challenge, the DrRBL mRNA level was significantly upregulated. Additionally, DrRBL was secreted into the extracellular matrix. Recombinant DrRBL (rDrRBL) could significantly inhibit the growth of gram-positive/negative bacteria, bind to several bacteria and cause obvious agglutination. The rDrRBL protein could combine with polysaccharides, such as PGN and LPS, rather than LTA. A more detailed study showed that rDrRBL could combine with monosaccharides, such as mannose, rhamnose and glucose, which are important components of PGN and LPS. However, rDrRBL could not bind to ribitol, which is an important component of LTA. The DrRBL deletion mutants, DrRBLΔ144-150 and DrRBLΔ198-200, were also constructed. DrRBLΔ144-150 ("ANYGRTD" deficient) showed weak bacterial inhibiting ability. However, DrRBLΔ198-200 ("DPC" deficient) showed weak agglutination ability. These results suggest that the "DPC" domain is important for agglutination. The conserved domain "ANYGRTD" is essential for inhibiting bacterial growth.

Analysis of the Antibacterial Properties of Compound Essential Oil and the Main Antibacterial Components of Unilateral Essential Oils.

Plant essential oils are widely used in food, medicine, cosmetics, and other fields because of their bacteriostatic properties and natural sources. However, the bacteriostatic range of unilateral essential oils is limited, and compound essential oil has become an effective way to improve the antibacterial properties of unilateral essential oils. In this study, based on the analysis of the antibacterial properties of Chinese cinnamon bark oil and oregano oil, the proportion and concentration of the compound essential oil were optimized and designed, and the antibacterial activity of the compound essential oil was studied. The results showed that the antibacterial activity of Chinese cinnamon bark oil was higher than that of oregano oil. The compound essential oil prepared by a 1:1 ratio of Chinese cinnamon bark oil and oregano oil with a concentration of 156.25 ppm showed an excellent antibacterial activity against Escherichia coli and Staphylococcus aureus. The GC-MS results showed that cinnamaldehyde was the main antibacterial component of Chinese cinnamon bark essential oil, and carvacrol and thymol in oregano oil were the main antibacterial components.

Characterization and genomic analysis of a Demerecviridae phage SP76 with lytic multiple-serotypes of Salmonella.

With the increase in antimicrobial resistance of Salmonella, phages have been paid more attention to as an alternative to antibiotics. In this study, a phage designated as SP76 was isolated from sewage. It can lyse several serotypes of Salmonella, including S. typhimurium (21/33), S. enteritidis (7/7), S. dublin (4/4), S. pullorum (2/2) and S. choleraesuis (1/2). SP76 showed a latent time of about 10 min, and maintained good lytic activity at a pH range of 3-10 and temperatures between 4 and 37 °C. Moreover, its optimal multiplicity of infection (MOI) was 0.0001. Based on the results of genomic sequence and analysis, SP76 was found to have a genome of 111,639 bp that encoded 166 predicted ORFs and belong to the Demerecviridae family, order Caudovirales. No virulence or lysogen formation gene clusters were identified in the SP76 genome. A pan-genome analysis based on 100 phages within the subfamily Markadamsvirinae indicated that SP76 had 23 core genes and 1199 accessory genes. We grouped the subfamily Markadamsvirinae and found that the main difference was in group III. In vitro bacteriostasis, experiments showed that the phage SP76 reduced planktonic bacteria by 1.52 log10 CFU/mL, and biofilms (24 h old) by 0.372 log10 CFU/mL, respectively. Thus, we isolated a safe and efficient phage that might be a good antibacterial agent.

Involvement of galectin-9 from koi carp (Cyprinus carpio) in the immune response against Aeromonas veronii infection.

Galectins are ß-galactoside sugar binding proteins which function as important pattern recognition receptors (PRRs) in innate immunity. Here, we identified a galectin-9 gene from koi carp (Cyprinus carpio), named kGal-9. The ORF of kGal-9 is 963 bp in length, which encodes a polypeptide of 320 amino acids without either signal peptide. The predicted molecular weight is 36.25 kDa, and the isoelectric point is 8.3. Multiple sequence alignment showed that the putative kGal-9 contains two carbohydrate recognition domains (CRD), which are conserved in Galectin-9s. The phylogenetic tree showed that kGal-9 clustered to Galectin-9s from other teleosts, and shared the highest identity of 87.5% with Qihe crucian (Carassius auratus). kGal-9 mRNA was abundant in head kidney, gills, and gut, but low in liver and muscle. Further, the expression level of kGal-9 in the head kidney and liver increased significantly after Aeromonas veronii (abbreviated A.v) infection. Unexpectedly, kGal-9 showed a remarkable downregulation in the spleen at various time points post A.v infection. Intramuscular injection of pckGal-9 not merely reduced the bacterial load of spleen tissue, but also improved the survival rate of koi carp post A.v challenge. Besides, administration of pckGal-9 stimulated the expression of several immuno-related genes including proinflammatory cytokines (IL-1ß, IL-6), anti-inflammatory cytokine (IL-10), complement components (C4, C9), with fluctuation in spleen and head kidney. Taken together, the obtained results suggest that kGal-9 occupies an important role in innate immunity and defense against bacterial infection in koi carp.

Optimization of extraction and bioactivity detection of celery leaf flavonoids using BP neural network combined with genetic algorithm and response.

In the present study, ultrasound-assisted extraction was employed to extract the general flavone from celery leaves using response surface methodology and BP neural network model with a genetic algorithm (GA). The effects of temperature, time, solid-liquid ratio, and ethanol concentration on the extraction results were assessed by Box-Behnken design. Further optimization of the process was performed by GA-BP. Our results showed that the optimal conditions were an ethanol concentration of 70.31%, a temperature of 67.2 °C and an extraction time of 26.6 min. In addition, significant antioxidant activity and in vitro bacteriostasis were observed. We found that the total flavonoids of the celery leaves exerted a strong inhibitory effect on Escherichia coli, Staphylococcus aureus, and Bacillus subtilis. Additionally, considerable DPPH· and ·OH scavenging effects were exerted by flavonoids. Therefore, flavonoids from celery leaves can be considered natural antioxidants and bacterial inhibitors.

[In vivo study of liposome-modified polyetheretherketone implant on bacteriostasis and osseointegration].

OBJECTIVE: To develop dexamethasone plus minocycline-loaded liposomes (Dex/Mino liposomes) and apply them to improve bioinert polyetheretherketone (PEEK) surface, which could prevent post-operative bacterial contamination, enhance ossification for physiologic osseointegration, and finally reduce implant failure rates. METHODS: Dex/Mino liposomes were covalently grafted onto the PEEK surface using polydopamine (pDA) coating as a medium. Confocal laser scanning microscopy was used to confirm the binding of fluorescently labeled liposomes onto the PEEK substrate, and a microplate reader was used to semiquantitatively measure the average fluorescence intensity of fluorescently labeled liposome-decorated PEEK surfaces. Moreover, the mouse subcutaneous infection model and the beagle femur implantation model were respectively conducted to verify the bioactivity of Dex/Mino liposome-modified PEEK in vivo, by means of micro computed tomography (micro-CT) and hematoxylin and eosin (HE) staining analysis. RESULTS: The qualitative and quantitative results of fluorescently labeled liposomes showed that, the red fluorescence intensity of the PEEK-pDA-lipo group was stronger than that of the PEEK-NF-lipo group (P < 0.05); the liposomes were successfully and uniformly decorated on the PEEK surfaces due to the pDA coating. After mouse subcutaneous implantation of PEEKs for 24 hours, HE staining results showed that the number of inflammatory cells in the PEEK-Dex/Mino lipo group were lower than that in the inert PEEK group (P < 0.05), indicating a lower degree of infection in the test group. These results suggested that the Mino released from the liposome-functionalized surface provided an effective bacteriostasis in vivo. After beagle femoral implantation of PEEK for 8 weeks, micro-CT results showed that the PEEK-Dex/Mino lipo group newly formed more continuous bone when compared with the inert PEEK group; HE staining results showed that more new bones were formed in the PEEK-Dex/Mino lipo group than in the inert PEEK group, which were firmly bonded to the functionalized PEEK surface and extended along the PEEK interface. These results suggested that the Dex released from the liposome-functionalized surface induced effective bone regeneration in vivo. CONCLUSION: Dex/Mino liposome modification enhanced the bioactivity of inert PEEK, the functionalized PEEK with enhanced antibacterial and osseointegrative capacity has great potential as an orthopedic/dental implant material for clinical application.

[GC-MS analysis of volatile oil components of Mastiche and Olibanum and study on antibacterial activity of Helicobacter pylori].

The volatile oil from Mastiche and Olibanum medicinal materials was extracted by steam distillation, and the chemical components of the volatile oil were analyzed by GC-MS technology. The differences of the volatile oil components were compared and study on the Helicobacter pylori in vitro antimicrobial activitiy was conducted. The results showed that the yields of the volatile oil from Mastiche and Olibanum were 11.93% and 2.40%, respectively. A total of 46 compounds(91.31%) were identified from the volatile oil from Mastiche annd 35 compounds(92.49%) from Olibanum. The classification and comparison study of the components showed that the content of monoterpenes in the volatile oil from Mastiche was the highest(40.69%), followed by alcohols(28.48%); while the content of alcohols in the volatile oil from Olibanum was the highest(35.81%), followed by esters(24.92%). There were significant differences in the components of volatile oil from Mastiche and Olibanum, which might be one of the reasons for the difference in efficacy and application. In vitro bacteriostatic experiments showed that the minimum inhibitory concentration(MIC) of the volatile oil from Mastiche against H. pylori was 1 mg·mL~(-1), and the MIC of the volatile oil from Olibanum against H. pylori was more than 1 mg·mL~(-1). In combination with the results of the oil yield experiment, Mastiche had the advantage of inhibiting H. pylori activity. The research results provide scientific basis for the rational application of Mastiche and Olibanum.

Research Progress of the Biosynthesis of Natural Bio-Antibacterial Agent Pulcherriminic Acid in Bacillus.

Pulcherriminic acid is a cyclic dipeptide found mainly in Bacillus and yeast. Due to the ability of pulcherriminic acid to chelate Fe3+ to produce reddish brown pulcherrimin, microorganisms capable of synthesizing pulcherriminic acid compete with other microorganisms for environmental iron ions to achieve bacteriostatic effects. Therefore, studying the biosynthetic pathway and their enzymatic catalysis, gene regulation in the process of synthesis of pulcherriminic acid in Bacillus can facilitate the industrial production, and promote the wide application in food, agriculture and medicine industries. After initially discussing, this review summarizes current research on the synthesis of pulcherriminic acid by Bacillus, which includes the crystallization of key enzymes, molecular catalytic mechanisms, regulation of synthetic pathways, and methods to improve efficiency in synthesizing pulcherriminic acid and its precursors. Finally, possible applications of pulcherriminic acid in the fermented food, such as Chinese Baijiu, applying combinatorial biosynthesis will be summarized.

A Hydrolytically Stable Vanadium(IV) Metal-Organic Framework with Photocatalytic Bacteriostatic Activity for Autonomous Indoor Humidity Control.

Metal-organic frameworks (MOFs) with long-term stability and reversible high water uptake properties can be ideal candidates for water harvesting and indoor humidity control. Now, a mesoporous and highly stable MOF, BIT-66 is presented that has indoor humidity control capability and a photocatalytic bacteriostatic effect. BIT-66 (V3 (O)3 (H2 O)(BTB)2 ), possesses prominent moisture tunability in the range of 45-60 % RH and a water uptake and working capacity of 71 and 55 wt %, respectively, showing good recyclability and excellent performance in water adsorption-desorption cycles. Importantly, this MOF demonstrates a unique photocatalytic bacteriostatic behavior under visible light, which can effectively ameliorate the bacteria and/or mold breeding problem in water adsorbing materials.

The role of copper and zinc accumulation in defense against bacterial pathogen in the fujian oyster (Crassostrea angulata).

Cu and Zn are hyper-accumulated in oysters, and the accumulation of these metals increases host resistance to pathogens. However, the role of Cu/Zn in oyster immune defense remains unclear. In this study, Crassostrea angulata with different levels of Cu and Zn were obtained through metal exposure or selective breeding. Both in vivo and in vitro experiments showed that oysters accumulating more Cu/Zn exhibited stronger antibacterial abilities. Vibrio harveyi infection significantly promoted the metal redistribution in oysters: Cu and Zn concentrations decreased in the mantle, but increased in the plasma and hemocytes. This redistribution was accompanied by changes in the expression levels of Cu and Zn transporter genes (CTR1, ATP7A, ZIP1, and ZNT2), suggesting that the Cu/Zn burst observed in the hemocytes was likely due to the transfer of heavy metals from plasma (mediated by the metal importer proteins) or released from intracellular stores. The degree to which Cu/Zn concentration increased in the plasma and hemocytes was more dramatic in oysters with high levels of Cu/Zn accumulation. In vitro, Cu and Zn both inhibited the growth of V. harveyi, while Cu plus H2O2 was lethal to the bacteria. The strength of the growth-inhibition and lethal effects depended on the metal dose. In addition to these effects, increases in Cu concentration increased the activity levels of PO in the oyster plasma and hemocytes in vivo and in vitro. However, SOD activity was not affected by Cu or Zn accumulation. Thus, our results suggested that the Cu/Zn burst in the hemolymph was an important factor in the oyster immune reaction, creating a toxic internal environment for the pathogen, as well as catalyzing inorganic or enzymatic reactions to strengthen bacteriostasis. By determining the extent of Cu/Zn burst in the immune response, Cu/Zn accumulated levels could affect the resistance of oysters to pathogens.

Bursicon homodimers induce innate immune by activating the expression of anti-microbial peptide genes in the shrimp Neocaridina heteropoda.

Bursicon is a neurohormone belonging to the cystine knot protein family. It consists of two subunits (burs α and burs ß) and plays a pivotal role in cuticle tanning and wing expansion in insects. Recent studies show that homologous crustacean bursicon stimulates cuticle thickening and granulation of hemocytes in the crab Callinectes sapidus. Here we investigate whether bursicon homodimers function in immunoprotective defense systems of shrimp. We found that abdominal ganglion was the main neurohemal release site of bursicon in Neocaridina heteropoda. Bacterial infections induced overexpression of burs α (bursicon α) and burs ß (bursicon ß). RNAi of burs α, burs ß or both inhibited the expression of anti-microbial peptide (AMP) genes. Treating shrimp adults with r-bursicon (recombinant bursicon) homodimers led to up-regulation of three AMP genes. Besides, through the induced AMPs, r-bursicon homodimers enhanced the bacteriostasis of shrimp in vivo and in vitro. These findings demonstrate a novel function of bursicon in crustacean that it induces innate immune via up-regulating the expression of genes encoding AMPs.

Preparation, Evaluation and Characterization of Rutin-Chitooligosaccharide Complex.

Rutin possesses a wide range of application prospects with various bioactivities. However, its bitter and water-insoluble properties restrict its application in the field of functional foods. A new complex of rutin and chitooligosaccharide (Rutin-COS) was prepared via spray-drying method (100 °C, 1 L/h) and freeze-drying method (-80 °C, 24 h), respectively. The water solubility, bitterness, antioxidant and antibacterial activities of Rutin-COS were evaluated, and the complexation of Rutin-COS was characterized by SEM, 1H-NMR and ROESY. Compared to freeze-drying method, spray-drying method was more effective for preparing stable Rutin-COS complex. The spray-dried Rutin-COS showed increased water solubility, weakened bitterness, enhanced antioxidant and antibacterial activity compared to rutin. The Rutin-COS complex was demonstrated to be formed through hydrogen bonds between the A, B rings of rutin and COS.

MazF-induced growth inhibition and persister generation in Escherichia coli.

Toxin-antitoxin systems are ubiquitous in nature and present on the chromosomes of both bacteria and archaea. MazEF is a type II toxin-antitoxin system present on the chromosome of Escherichia coli and other bacteria. Whether MazEF is involved in programmed cell death or reversible growth inhibition and bacterial persistence is a matter of debate. In the present work the role of MazF in bacterial physiology was studied by using an inactive, active-site mutant of MazF, E24A, to activate WT MazF expression from its own promoter. The ectopic expression of E24A MazF in a strain containing WT mazEF resulted in reversible growth arrest. Normal growth resumed on inhibiting the expression of E24A MazF. MazF-mediated growth arrest resulted in an increase in survival of bacterial cells during antibiotic stress. This was studied by activation of mazEF either by overexpression of an inactive, active-site mutant or pre-exposure to a sublethal dose of antibiotic. The MazF-mediated persistence phenotype was found to be independent of RecA and dependent on the presence of the ClpP and Lon proteases. This study confirms the role of MazEF in reversible growth inhibition and persistence.

Zeolitic imidazolate framework-8@polydopamine decorated carboxylated chitosan hydrogel with photocatalytic and photothermal antibacterial activity for infected wound healing.

Open wounds are susceptible to bacterial infections, and antibiotics are commonly used to treat these infections. However, widespread use of antibiotics will easily induce bacterial resistance. Green antibacterial agents serve as excellent alternative for antibiotics in infection therapy. In this work, polydopamine (PDA) was used to modify the surface of ZIF-8, which not only enhances the water stability of Zeolitic imidazolate framework-8(ZIF-8) but also improves its photocatalytic and photothermal capabilities. ZIF-8@PDA was incorporated into carboxylated chitosan (CCS) films as an antibacterial agent, the resulting ZIF-8@PDA-CCS films exhibit excellent ionic/photocatalytic/photothermal antibacterial performance. The film exhibited an impressive 99% in vitro bacterial inhibition rate. After treatment with ZIF-8@PDA-CCS, the bacteria in infected wounds can be completely suppressed. These findings suggest that ZIF-8@PDA-CCS could serve as a potentional antibacterial dressing.

Acetolactate Decarboxylase as an Important Regulator of Intracellular Acidification, Morphological Features, and Antagonism Properties in the Probiotic Lactobacillus reuteri.

SCORE: This study identifies the coding gene (aldB) of acetolactate decarboxylase (ALDC) as an important regulatory gene of the intracellular pH in Lactobacillus reuteri (L. reuteri), uncovering the important role of ALDC in regulating intracellular pH, morphological features, and antagonism properties in the probiotic organism L. reuteri. METHODS AND RESULTS: The aldB mutant (ΔaldB) of L. reuteri is established using the homologous recombination method. Compare to the wild-type (WT) strain, the ΔaldB strain shows a smaller body size, grows more slowly, and contains more acid in the cell cytoplasm. The survival rate of the ΔaldB strain is much lower in low pH and simulated gastric fluid (SGF) than that of the WT strain, but higher in simulated intestinal fluid (SIF). The antagonism test demonstrates the ΔaldB strain can inhibit Listeria monocytogenes (L. monocytogenes) and Salmonella more effectively than the WT strain. Additionally, there is a dramatic decrease in the adhesion rate of Salmonella to Caco-2 and HT-29 cells in the presence of the ΔaldB strain compared to the WT strain. Simultaneously analyze, the auto-aggregation, co-aggregation, cell surface hydrophobicity (CSH), hemolytic, temperature, NaCl, oxidative stress, and antibiotic susceptibility of the ΔaldB strain are consistent with the features of probiotics. CONCLUSION: This study highlights that the aldB gene plays a significant role in the growth and antibacterial properties of L. reuteri.

Using polycaprolactone and sodium alginate to prepare self-pumping/super-absorbent/transportable drug dressings for stage 3-4 pressure ulcer treatment.

Pressure ulcer dressings with different functions can enhance wound healing ability to varying degrees; however, pressure ulcer dressings that integrate various functions and break the resistance of bacteria to traditional antibiotics have not been widely studied. We proposed a self-pumping/super-absorbent/transportable drug dressing (PLD-SLD), polycaprolactone (PCL)/sodium alginate (SA) was used to load platelet-derived growth factor (PDGF) and lidocaine hydrochloride (LID) by Janus electrospinning and self-assembly technology, and Ɛ-polylysine was used as a biological bacteriostatic agent to prepare a multi-layer dressing. SEM showed that the dressing had a fluffy structure. The dressing can pump the exudate to the SA layer away from the skin. The swelling ratio reached 1378.667 ±â€¯44.752 %. Coagulate blood in 5 min. On the 8th day, the unclosed area rate of the PLD-SLD dressing group was 16.112 ±â€¯0.088 % lower than that of the model group. Importantly, the dressing can induce the expression of CD31, VEGF, α-SMA, and reduce the expression of CD68, thereby giving priority to wound healing. There was no scar formation after healing. In this study, a new dressing preparation method was proposed for the problems of exudate management, infection control, pain relief and healing promotion of stage 3-4 pressure ulcer healing.

Coaxial electrospun Ag-NPs-loaded endograft membrane with long-term antibacterial function treating mycotic aortic aneurysm.

The use of endovascular stent-graft has become an important option in the treatment of aortic pathologies. However, the currently used endograft membranes have limited ability to prevent bacterial colonization. This makes them unsuitable for the treatment of mycotic aneurysms, as the infection is prone to progress after endograft implantation. Moreover, even in non-mycotic aortic pathologies, endograft infections can occur in the short or long term, especially for patients with diabetes mellitus or in immune insufficiency conditions. So, this study aimed to develop a kind of Ag-NPs-loaded endograft membrane by coaxial electrospinning technique, and a series of physical and chemical properties and biological properties of the Ag-NPs-loaded membrane were characterized. Animal experiments conducted in pigs confirmed that the Ag-NPs-loaded membrane was basically non-toxic, exhibited good biocompatibility, and effectively prevented bacterial growth in a mycotic aortic aneurysm model. In conclusion, the Ag-NPs-loaded membrane exhibited good biocompatibility, good anti-infection function and slow-release of Ag-NPs for long-term bacteriostasis. Thus, the Ag-NPs-loaded membrane might hold potential for preventing infection progression and treating mycotic aortic aneurysms in an endovascular way.

Research status and prospects of organic photocatalysts in algal inhibition and sterilization: a review.

An increasing amount of sewage has been discharged into water bodies in the progression of industrialization and urbanization, causing serious water pollution. Meanwhile, the increase of nutrients in the water induces water eutrophication and rapid growth of algae. Photocatalysis is a common technique for algal inhibition and sterilization. To improve the utilization of visible light and the conversion efficiency of solar energy, more organic photocatalytic materials have been gradually developed. In addition to ultraviolet light, partial infrared light and visible light could also be used by organic photocatalysts compared with inorganic photocatalysts. Simultaneously, organic photocatalysts also exhibit favorable stability. Most organic photocatalysts can maintain a high degradation rate for algae and bacteria after several cycles. There are various organic semiconductors, mainly including small organic molecules, such as perylene diimide (PDI), porphyrin (TCPP), and new carbon materials (fullerene (C60), graphene (GO), and carbon nanotubes (CNT)), and large organic polymers, such as graphite phase carbon nitride (g-C3N4), polypyrrole (PPy), polythiophene (PTH), polyaniline (PANI), and polyimide (PI). In this review, the classification and synthesis methods of organic photocatalytic materials were elucidated. It was demonstrated that the full visible spectral response (400-750 nm) could be stimulated by modifying organic photocatalysts. Moreover, some problems were summarized based on the research status related to algae and bacteria, and corresponding suggestions were also provided for the development of organic photocatalytic materials.