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Rapid fabrication of silver nanoparticle/polydopamine functionalized polyester fibers
摘要： In this paper, silver nanoparticles functionalized poly(ethylene terephthalate) (PET) fibers with antimicrobial activity, electrical conductivity and good coating stability are reported. Firstly, silver plated PET fibers were fabricated by rapid polydopamine (PDA) modification followed by electroless plating. Secondly, the surface morphologies and compositions of PDA modified and silver coated PET fibers were characterized by employing scanning electron microscopy, atomic force microscopy, X-ray diffraction and energy dispersive spectrometry. Finally, the antimicrobial properties and electrical conductivity of the silver plated PET fibers were investigated. The results showed that the silver coated PET fibers exhibited excellent antimicrobial activity to both Escherichia coli and Staphylococcus aureus (with an antimicrobial efficiency of 100 and 99.99%, respectively), and that the antimicrobial activity was well maintained after washing. The silver coated PET fibers showed electrical resistance of 0.76 Ω per 1 cm, indicating good conductivity. It was also demonstrated that the silver layer that formed had good mechanical durability, as indicated by conductivity measurements during tensile loading and observation of the surface morphology of the fibers under various modes of deformation.
关键词： silver nanoparticles,electrical conductivity,antimicrobial,PET fibers,polydopamine
更新于2025-09-19 17:15:36
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Photoinactivation of planktonic and biofilm forms of Escherichia coli through the action of cationic zinc(II)phthalocyanines
摘要： Novel water soluble Zn(II)phthalocyanines (ZnPc) peripherally substituted with 4-dimethylaminopyridine (DMAP) units (ZnPc 1-2) and the corresponding quaternized derivatives (ZnPc 1a-2a) were synthesized and their photodynamic inactivation (PDI) efficiency against a Gram-negative bacterium, a recombinant bioluminescent Escherichia coli strain either in planktonic and biofilm form was investigated. The analysis of the photophysical properties revealed that the increase in the number of DMAP units on ZnPc shifted the absorption and emission band in aqueous media to red. The presence of multi-positive charges on ZnPc derivatives prevented aggregation and enhances the solubility in aqueous medium. The quaternized derivatives ZnPc 1a and 2a displayed good stability and promising efficacy to generate singlet oxygen (1O2). The affinity of the amphiphilic ZnPc 1-2 and quaternized ZnPc 1a-2a to planktonic bacterial cells corresponded to an average uptake of ~106 PS molecules.CFU-1. The PDI assays conducted with planktonic cells and biofilms of E. coli show that irradiation with red or white light (150 mW.cm-2) in the presence of 20 μM of ZnPc derivatives caused an effective inactivation. ZnPc 1a and ZnPc 2a exhibited the highest inactivation efficiency, particularly of the planktonic form, causing 5 log (99.99%) reductions in bioluminescence. The inactivation factor for biofilms was 99% (2 log). ZnPc 1a and ZnPc 2a can be regarded as promising photosensitizers for the photodynamic inactivation of Gram-negative bacteria.
关键词： Reactive Oxygen Species,Cationic Phthalocyanines,E. coli,Bacterial Resistance,Biofilm,Antimicrobial Photoinactivation
更新于2025-09-19 17:15:36
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Photoexcitation triggering via semiconductor Graphene Quantum Dots by photochemical doping with Curcumin versus perio-pathogens mixed biofilms
摘要： Background: Recently, antimicrobial photodynamic therapy (aPDT) as an alternative treatment modality has been used adjunctively in the treatment of periodontitis and peri-implantitis. Photosensitizing agents in the form of nanoparticles have been designed for improving the e?ciency of aPTD. Graphene quantum dots are a special type of nanocrystals that can promote aPDT when coupled with curcumin (Cur). The main objective of the present study was to investigate the e?ects of photoexcited GQD-Cur on the metabolic activity of perio-pathogen mixed bio?lms. Materials and methods: GQD-Cur was synthesized and characterized by scanning electron microscopy (SEM), dynamic light scattering (DLS), fourier transform infrared (FTIR) spectroscopy, ultraviolet-visible spectrometry (UV–Vis), and X-ray di?raction (XRD). The cell cytotoxicity e?ect of GQD-Cur was evaluated on primary human gingival ?broblast (HuGu) cells. Perio-pathogen mixed bio?lms including Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Prevotella intermedia photosensitized with GQD doped with Cur were irradiated with a blue LED at a wavelength of 435 ± 20 nm for 1 min, and then bacterial viability measurements were performed. The antimicrobial susceptibility pro?le, bio?lm formation ability, amount of reactive oxygen species (ROS) released, and variations of gene expressions involved in bio?lm formation were assessed. Results: The SEM, DLS, FTIR, UV–Vis spectrometry, and XRD pattern con?rmed that GQD-Cur was synthesized successfully. According to the results, GQD-Cur exhibited no cytotoxicity against HuGu cells. Photoexcited GQD-Cur resulted in a signi?cant reduction in cell viability (93%) and bio?lm formation capacity (76%) of peri-pathogens compared to the control group (P < 0.05). According to the results, a signi?cant concentration-dependent increase in the ROS generation was observed in perio-pathogens mixed cells treated with di?erent doses of GQD-Cur-aPDT. Moreover, rcpA, ?mA, and inpA gene expression pro?les were downregulated by 8.1-, 9.6-, and 11.8-folds, respectively. Conclusions: Based on the results, photoexcited GQD-Cur have a high potency of perio-pathogens suppression in planktonic and bio?lm forms and downregulation of the bio?lm genes expression pattern was exploited as a nanoscale-based platform for periodontitis.
关键词： Curcumin,Antimicrobial photodynamic therapy,Graphene Quantum Dot,Peri-implantitis,Periodontitis
更新于2025-09-19 17:13:59
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Blue laser light inhibits biofilm formation in vitro and in vivo by inducing oxidative stress
摘要： Resolution of bacterial infections is often hampered by both resistance to conventional antibiotic therapy and hiding of bacterial cells inside biofilms, warranting the development of innovative therapeutic strategies. Here, we report the efficacy of blue laser light in eradicating Pseudomonas aeruginosa cells, grown in planktonic state, agar plates and mature biofilms, both in vitro and in vivo, with minimal toxicity to mammalian cells and tissues. Results obtained using knock-out mutants point to oxidative stress as a relevant mechanism by which blue laser light exerts its anti-microbial effect. Finally, the therapeutic potential is confirmed in a mouse model of skin wound infection. Collectively, these data set blue laser phototherapy as an innovative approach to inhibit bacterial growth and biofilm formation, and thus as a realistic treatment option for superinfected wounds.
关键词： oxidative stress,Pseudomonas aeruginosa,blue laser light,antimicrobial effect,biofilm formation
更新于2025-09-19 17:13:59
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Safety of a novel Thulium fiber laser for lithotripsy: an in vitro study on the thermal effect and its impact factor
摘要： Akirin, which are members of the NF-κB signaling pathway, play critical roles in regulating the expression of antimicrobial peptides. In the present study, the Akirin gene from Penaeus monodon was identified from a transcriptome database and designated as PmAkirin. The complete sequence of the PmAkirin cDNA was 1508 bp, encoding a protein of 213 amino acids, and it showed 99% amino acid identity to the Litopenaeus vannamei Akirin. Two predicted nuclear localization signals (NLSs) were found, and the amino acid sequence alignments showed that PmAkirin was highly conserved at the N-terminus and C-terminus. PmAkirin expression was found to be the highest in the hemolymph, followed by the heart, gill, stomach, hepatopancreas, intestine, and muscle. When challenged with Vibrio parahaemolyticus infection, the PmAkirin mRNA and three antimicrobial peptides (AMPs: PmALF2, PmALF3, and PmCrus4) were upregulated. However, another five AMPs (PmALF6, PmCrus1, PmPEN3a, PmPEN3b, and PmPEN5) were downregulated by V. parahaemolyticus infection. Silencing PmAkirin by dsRNA significantly decreased the expression of the eight AMPs, which lead to an increase in the blood concentration of V. parahaemolyticus and higher mortality in the shrimp. In contrast, the overexpression of PmAkirin significantly increased the expression of the eight AMPs, which led to a reduction in the blood concentration of V. parahaemolyticus and promoted the survival of the shrimp. Taken together, we concluded that PmAkirin plays an important role in regulating the expression of AMPs in black tiger shrimp to defend against V. parahaemolyticus infection.
关键词： Antimicrobial peptides,Akirin,Vibrio parahaemolyticus,RNAi,Penaeus monodon
更新于2025-09-19 17:13:59
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The in vitro Photoinactivation of Helicobacter pylori by a Novel LED-Based Device
摘要： The rise of antibiotic resistance is the main cause for the failure of conventional antibiotic therapy of Helicobacter pylori infection, which is often associated with severe gastric diseases, including gastric cancer. In the last years, alternative non-pharmacological approaches have been considered in the treatment of H. pylori infection. Among these, antimicrobial PhotoDynamic Therapy (aPDT), a light-based treatment able to photoinactivate a wide range of bacteria, viruses, fungal and protozoan parasites, could represent a promising therapeutic strategy. In the case of H. pylori, aPDT can exploit photoactive endogenous porphyrins, such as protoporphyrin IX and coproporphyrin I and III, to induce photokilling, without any other exogenous photosensitizers. With the aim of developing an ingestible LED-based robotic pill for minimally invasive intragastric treatment of H. pylori infection, it is crucial to determine the best illumination parameters to activate the endogenous photosensitizers. In this study the photokilling effect on H. pylori has been evaluated by using a novel LED-based device, designed for testing the appropriate LEDs for the pill and suitable to perform in vitro irradiation experiments. Exposure to visible light induced bacterial photokilling most effectively at 405 nm and 460 nm. Sub-lethal light dose at 405 nm caused morphological changes on bacterial surface indicating the cell wall as one of the main targets of photodamage. For the first time endogenous photosensitizing molecules other than porphyrins, such as flavins, have been suggested to be involved in the 460 nm H. pylori photoinactivation.
关键词： flavins,porphyrins,LEDs,antimicrobial PDT,Helicobacter pylori
更新于2025-09-19 17:13:59
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CdS quantum dots embedded in PVP: Inorganic phosphate ion sensing in real sample and its antimicrobial activity
摘要： Polyvinyl-pyrrolidone capped spherical cadmium sulphide quantum dots (CdS-PVP QDs), 2–6 nm in size, were developed as a selective turn-on fluorescence nanosensor for monohydrogen phosphate ion (HPO4 2?) in aqueous medium. Fluorescence intensity of CdS-PVP QDs significantly increased with addition of HPO4 2? ions, whereas the other common inorganic ions had very little effect on the fluorescence intensity. The proposed sensor may be efficiently used for the detection of HPO4 2? ions at a low level of concentration up to 213 nM in real urine sample. Cell imaging study indicates that the CdS-PVP QDs are cell permeable and can detect the intracellular distribution of HPO4 2? ions under fluorescence microscope. The CdS-PVP QDs showed considerable activity against Staphylococcus aureus also.
关键词： Chemosensor,CdS,Antimicrobial activity,Cell image,Quantum dots,Phosphate ion sensing
更新于2025-09-19 17:13:59
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High incidence of urinary tract infections after photoselective laser vaporisation of the prostate: a risk factor analysis of 665 patients
摘要： Purpose Although photoselective laser vaporisation of the prostate (PVP) is a recognised alternative to transurethral resection in treating benign prostatic obstruction, there is limited data on the incidence and determinants of postoperative urinary tract infections (UTI). We assessed patients subjected to PVP, evaluating incidence and potential determinants of postoperative UTIs. Materials and methods Consecutive patients undergoing PVP between April 2010 and August 2018 were candidates for this retrospective cohort study. The primary outcome measure was microbiologically confirmed postoperative UTI. We fitted uni- and multi-variable Cox models to identify potential risk factors. Results Among the 665 included patients, 20% developed postoperative UTIs. The overall incidence rate per 100 patient-days was 0.65 (95% confidence interval [CI] 0.55–0.77). Risk factors for postoperative UTIs were end-stage renal failure (adjusted hazard ratio [aHR] = 14.10, 95% CI 2.08-64.58; p = 0.001) and presence of at least one of the following factors in the 3?months preceding PVP: (i) placement of urinary catheter, (ii) bacteriuria, (iii) UTI, or (iv) antimicrobial treatment (composite aHR = 1.99, 95% CI 1.22?3.24; p < 0.001). There was no apparent association between choice or duration of antimicrobial prophylaxis and incident UTIs. Conclusions Our analysis revealed a high incidence of UTIs after PVP and served to identify certain preoperative risk factors. Neither the choice of antimicrobial regimen nor its duration affected the incidence of UTIs. Prolonged antimicrobials proved to be disproportionately high, warranting further scrutiny in randomised controlled trials.
关键词： Catheter,Greenlight laser vaporisation,Urinary tract infection,Antimicrobial prophylaxis
更新于2025-09-16 10:30:52
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Oral mucosal irritation potential of antimicrobial chemotherapy involving hydrogen peroxide photolysis with high-power laser irradiation for the treatment of periodontitis
摘要： In the present study, we assessed the oral mucosal irritation potential of antimicrobial chemotherapy involving hydrogen peroxide (H2O2) photolysis with a 405-nm laser device at an output power of ≥100 mW in hamsters. Twenty-four cheek pouches from 12 male Syrian hamsters received 7-min treatment with pure water (PW), 3% H2O2, laser irradiation of PW at 100 mW, laser irradiation of 3% H2O2 at 100 mW, laser irradiation of PW at 200 mW, or laser irradiation of 3% H2O2 at 200 mW (n = 4 each). The diameter of the irradiation area was set at 3 mm; accordingly, the calculated irradiances (optical power densities) of the 100- and 200-mW laser lights were approximately 1400 and 2800 mW/cm2, respectively. In addition, 12 cheek pouches from six animals received laser irradiation of 3% H2O2 at 100 mW for 1, 3, or 5 min (n = 4 each). Each treatment was repeated three times at 1-h intervals. Macroscopic and histological changes were evaluated 24 h after the last treatment. In addition, in vitro bactericidal activity of the treatment against periodontal pathogens was evaluated. We found that 405-nm laser irradiation of 3% H2O2 caused moderate to severe oral mucosal irritation when performed at powers of 100 and 200 mW for ≥3 min, while the same treatment performed at 100 mW for 1 min resulted in mild irritation. Moreover, 1-min H2O2 photolysis at 100 mW caused a >4-log decrease in viable bacterial counts. These findings suggest that 1-min H2O2 photolysis, which can effectively kill periodontal pathogens, may be acceptable when a 405-nm laser device is used at 100 mW. However, use of the laser at a lower power would be preferable for the prevention of unnecessary oral mucosal irritation.
关键词： hydroxyl radicals,photolysis,periodontitis,oral mucosal irritation,laser irradiation,antimicrobial chemotherapy,hydrogen peroxide
更新于2025-09-16 10:30:52
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Laser Patterned ZNO Substituted Calcium Phosphate Scaffolds via Viscous Polymer Processing for Bone Graft
摘要： Polymer dough processing is a method which can easily overcome this problem. In current study ZnO doped calcium phosphate (Zn-CaP) micropatterned scaffold was explored through viscous polymer processing route. Zn-CaP nanopowder was synthesized using the wet chemical route. It was characterized using SEM, TEM, XRD and EDX. Highly ductile micro-patterned bone grafts were constructed using ZnO doped calcium phosphate scaffolds using roll milling followed by Laser machining. It was kept for cell culture and cytocompatibility using MTT, DNA quantification, and ALP assay. Hemolysis and blood cell aggregation assay was conducted for in vivo applicability. The cellular growth was also observed using fluorescence microscopy, live-dead assay, and SEM. Further gene expression was analyzed using PCR studies which showed osteogenic differentiation of bone marrow-derived stem cells without any supplemented media. The material showed a significant zone of inhibition against both gram positive and negative bacteria. Selective cellular growth was observed at micropatterned zone.
关键词： Doping,Antimicrobial activity,Bioactivity,Micropatterning,Viscous polymer processing
更新于2025-09-16 10:30:52