This article reviews the present state of the art in the field of flexible antibacterial coatings which efficiently kill bacteria on their surfaces. Coatings are formed using a reactive magnetron sputtering. The effect of the elemental composition and structure of the coating on its antibacterial and mechanical properties is explained. The properties of Cr-Cu-O, Al-Cu-N, and Zr-Cu-N antibacterial coatings are used as examples and described in detail. The efficiency of killing of bacteria was tested for the Escherichia coli bacterium. The principle of the formation of thick, flexible antibacterial coatings which are resistant to cracking under bending is explained. It is shown that magnetron sputtering enables production of robust, several-micrometer thick, flexible antibacterial coatings for long-term use. The antibacterial coatings produced by magnetron sputtering present huge potential for many applications.
- Keywords
- antibacterial coatings, efficiency of bacteria killing, magnetron sputtering, mechanical properties, physical properties, resistance to cracking,
- MeSH
- Anti-Bacterial Agents chemistry pharmacology MeSH
- Coated Materials, Biocompatible chemistry pharmacology MeSH
- Escherichia coli drug effects MeSH
- Copper chemistry MeSH
- Titanium chemistry MeSH
- Publication type
- Journal Article MeSH
- Review MeSH
- Names of Substances
- Anti-Bacterial Agents MeSH
- Coated Materials, Biocompatible MeSH
- Copper MeSH
- Titanium MeSH
The evolution of multiple-drug resistant bacteria is contributing to the global antimicrobial crisis, hence driving us to search for novel antimicrobial(s). Among animals, invertebrates represent up to 80% of all known species suggesting their wide distribution. Despite their ubiquitous and plentiful nature, they have been largely unexplored as potential source of antibacterials. In this study, we selected a broad range of invertebrates from terrestrial and marine environments and tested their lysates for antibacterial activity against methicillin-resistant Staphylococcus aereus (MRSA) and neuropathogenic Escherichia coli K1. Cockroaches, centipedes, tarantulas, prawns, lobster, and mud crabs showed antibacterial activity with selected lysates exhibiting more than 90% bactericidal effects. The red-headed centipede's hemolymph showed 90% and 50% bacteriostatic activity against MRSA and E. coli K1, respectively. Tarantula's body extracts exhibited antibacterial activity against MRSA and E. coli K1. Gut extracts of tiger prawn exhibited more than 90% bacteriostatic activity against both bacteria. The selected lobster and mud crab extract exhibited up to 90% growth inhibitory activity against MRSA. Overall, these results showed that selected invertebrates are an untapped source of broad-spectrum antibacterial activity and suggest the presence of biologically active molecules.
- Keywords
- Antibacterial, Drug resistant bacteria, Insects, Invertebrates,
- MeSH
- Anti-Bacterial Agents pharmacology MeSH
- Invertebrates MeSH
- Escherichia coli MeSH
- Methicillin-Resistant Staphylococcus aureus * MeSH
- Microbial Sensitivity Tests MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- Anti-Bacterial Agents MeSH
The main aims of the research were to produce efficient nanofibrous filters with long-term antibacterial properties and to confirm the functionality of samples under real filtration conditions. A polyurethane solution was modified by micro- or nanoparticles of copper oxide in order to juxtapose the aggregation tendency of particles depending on their size. Modified solutions were electrospun by the Nanospider technique. The roller spinning electrode with a needle surface and static wire electrode were used for the production of functionalized nanofibers. The antibacterial properties of the modified nanofibrous layers were studied under simulated conditions of water and air filtration. Particular attention was paid to the fixation mechanism of modifiers in the structure of filters. It was determined that the rotating electrode with the needle surface is more efficient for the spinning of composite solutions due to the continuous mixing and the avoidance of particle precipitation at the bottom of the bath with modified polyurethane. Moreover, it was possible to state that microparticles of copper oxide are more appropriate antimicrobial additives due to their weaker aggregation tendency but stronger fixation in the fibrous structure than nanoparticles. From the results, it is possible to conclude that nanofibers with well-studied durable antibacterial properties may be recommended as excellent materials for water and air filtration applications.
- Keywords
- antibacterial properties, copper oxide, electrospinning, filtration, microparticles, nanofibers, nanoparticles, polyurethane,
- MeSH
- Anti-Bacterial Agents chemistry pharmacology MeSH
- Bacterial Infections drug therapy microbiology pathology MeSH
- Humans MeSH
- Copper chemistry MeSH
- Membranes, Artificial MeSH
- Nanoparticles chemistry MeSH
- Nanofibers chemistry MeSH
- Polyurethanes chemistry MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- Anti-Bacterial Agents MeSH
- cuprous oxide MeSH Browser
- Copper MeSH
- Membranes, Artificial MeSH
- Polyurethanes MeSH
The creation of an antibacterial material with triggerable properties enables us to avoid the overuse or misuse of antibacterial substances and, thus, prevent the emergence of resistant bacterial strains. As a potential light-activated antibacterial material, polymethylmethacrylate (PMMA) nanofibers doped with silver nanoparticles (AgNPs) and meso-tetraphenylporphyrin (TPP) were prepared by electrospinning. TPP was chosen as an effectively reactive oxygen species (ROS) producer. Antibacterial tests on Staphylococcus epidermidis (S. epidermidis) and Enterococcus faecalis (E. faecalis) showed the excellent light-triggerable antibacterial activity of the doped materials. Upon light irradiation at the wavelength corresponding to the TPP absorption peak (405nm), antibacterial activity dramatically increased, mostly due to the release of AgNPs from the polymer matrix. Furthermore, under prolonged light irradiation, the AgNPs/TPP/PMMA nanofibers, displayed enhanced longevity and photothermal stability. Thus, our results suggest that the proposed material is a promising option for the photodynamic inactivation of bacteria.
- Keywords
- Antibacterial, Light-activated, Polymethylmethacrylate, Silver nanoparticle, Triggerable release,
- MeSH
- Anti-Bacterial Agents chemistry MeSH
- Enterococcus faecalis growth & development MeSH
- Metal Nanoparticles chemistry ultrastructure MeSH
- Nanofibers chemistry ultrastructure MeSH
- Polymethyl Methacrylate chemistry MeSH
- Staphylococcus epidermidis growth & development MeSH
- Silver chemistry MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- Anti-Bacterial Agents MeSH
- Polymethyl Methacrylate MeSH
- Silver MeSH
Low-density polyethylene (LDPE) samples were treated in air plasma discharge, coated by polyallyamine brush thought copolymeric grafting surface-from reaction and deposited four common antibacterial agents (benzalkonium chloride, bronopol, chlorhexidine and triclosan) to gain material with active antibacterial properties. Surface characteristics were evaluated by static contact angle measurement with surface energy evaluation ATR-FTIR, X-ray Photoelectron Spectroscopy (XPS) and SEM analysis. Inhibition zone on agar was used as in vitro test of antibacterial properties on two representative gram positive Staphylococcus aureus (S. aureus) and gram negative Escherichia coli (E. coli) strains. It was confirmed, that after grafting of polyallyamine, more antibacterial agent is immobilized on the surface. The highest increase of antibacterial activity was observed by the sample containing triclosan. Samples covered by bronopol did not show significant antibacterial activity.
- MeSH
- Allylamine chemistry MeSH
- Anti-Bacterial Agents chemistry pharmacology MeSH
- Benzalkonium Compounds chemistry MeSH
- Chlorhexidine chemistry MeSH
- Photoelectron Spectroscopy MeSH
- Microbial Sensitivity Tests MeSH
- Molecular Structure MeSH
- Polyamines chemistry MeSH
- Polyethylene chemistry MeSH
- Propylene Glycols chemistry MeSH
- Spectroscopy, Fourier Transform Infrared MeSH
- Triclosan chemistry MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- Allylamine MeSH
- Anti-Bacterial Agents MeSH
- Benzalkonium Compounds MeSH
- bronopol MeSH Browser
- Chlorhexidine MeSH
- polyallylamine MeSH Browser
- Polyamines MeSH
- Polyethylene MeSH
- Propylene Glycols MeSH
- Triclosan MeSH
The preparation of light-activated hybrid antibacterial agent combining the porphyrin molecules, bound to the silver nanoparticles (AgNPs) surface is reported. AgNPs were synthesized by N-methyl-2-pyrrolidone-initiated reduction without additional reducing agents. The chemical structure of protoporphyrin IX was modified with the aim to introduce thiol groups. The size distribution and shape features of AgNPs were checked using TEM and HRTEM microscopies. The introduction of thiol groups into the porphyrin was proved by IR spectroscopy. The AgNPs-porphyrin binding was performed in solution and confirmed by fluorescence quenching, Raman spectroscopy and energy-filtered transmission electron microscopy (EFTEM). The antibacterial tests were performed against S. epidermidis and E. coli upon to LED illumination and in the dark. The synergetic effect of AgNPs and porphyrin as well as light activation of the created antibacterial conjugates were observed.
- Keywords
- Antibacterial, Light-triggered, Porphyrin, Silver nanoparticles,
- MeSH
- Anti-Bacterial Agents chemical synthesis pharmacology MeSH
- Escherichia coli drug effects MeSH
- Metal Nanoparticles chemistry ultrastructure MeSH
- Luminescence MeSH
- Microbial Sensitivity Tests MeSH
- Porphyrins chemical synthesis chemistry pharmacology MeSH
- Staphylococcus epidermidis drug effects MeSH
- Silver chemistry pharmacology MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- Anti-Bacterial Agents MeSH
- Porphyrins MeSH
- Silver MeSH
The in-vitro biological activity of N-benzylsalicylthioamides against 8 bacterial strains was determined by broth microdilution method; results were compared with those obtained with neomycin, penicillin G, ciprofloxacin and penicillin V. The compounds showed moderate to high activity against G(+) bacteria; especially compounds 4, 6, 13, 16-21 and 24 exhibited comparable or higher activity than reference drugs. The antibacterial activity was analyzed by quantitative structure-activity relationship (QSAR). The antibacterial activity increased with lipophilicity, with the presence of halogens and with increasing value of Hammet substituent constant σ.
- MeSH
- Anti-Bacterial Agents chemistry pharmacology MeSH
- Gram-Negative Bacteria drug effects MeSH
- Gram-Positive Cocci drug effects MeSH
- Humans MeSH
- Microbial Sensitivity Tests MeSH
- Thioamides chemistry pharmacology MeSH
- Structure-Activity Relationship MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- Anti-Bacterial Agents MeSH
- Thioamides MeSH
The antibacterial properties of poly(hydroxybutyrate) (PHB) non-woven fabric were explored in this study. The PHB was activated by plasma modification and subsequently processed with either immersion into a solution of nanoparticles or direct metallization. The wettability and surface chemistry of the PHB surface was determined. The thickness of the sputtered nanolayer on PHB fabric was characterized. It was found that plasma modification led to a formation of strongly hydrophilic surface, while the subsequent metallization by silver or gold resulted in a significantly increased water contact angle. Further, it was found that antibacterial activity may be controlled by the type of a metal and deposition method used. The immersion of plasma modified fabric into Ag nanoparticle solution led to enhanced antibacterial efficiency of PHB against Escherichia coli (E. coli). Direct silver sputtering on PHB fabric was proved to be a simple method for construction of a surface with strong antibacterial potency against both Escherichia coli (E. coli) and Staphylococcus epidermidis (S. epidermidis). We demonstrated the antibacterial activity of PHB fabric modified by plasma activation and consecutive selection of a treatment method for an effective antibacterial surface construction.
- Keywords
- Antibacterial properties, Biopolymers, Characterization, Metal nanostructure, Plasma modification,
- MeSH
- Anti-Bacterial Agents chemistry pharmacology MeSH
- Escherichia coli drug effects MeSH
- Microbial Sensitivity Tests MeSH
- Nanoparticles chemistry MeSH
- Polyesters chemistry pharmacology MeSH
- Surface Properties MeSH
- Wettability MeSH
- Staphylococcus epidermidis drug effects MeSH
- Silver chemistry MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- Anti-Bacterial Agents MeSH
- Polyesters MeSH
- Silver MeSH
Bacterial infection associated with medical implants is a major threat to healthcare. This work reports the fabrication of Copper(II)-Chitosan (Cu(II)-CS) complex coatings deposited by electrophoretic deposition (EPD) as potential antibacterial candidate to combat microorganisms to reduce implant related infections. The successful deposition of Cu(II)-CS complex coatings on stainless steel was confirmed by physicochemical characterizations. Morphological and elemental analyses by scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) spectroscopy verified the uniform distribution of copper in the Chitosan (CS) matrix. Moreover, homogeneous coatings without precipitation of metallic copper were confirmed by X-ray diffraction (XRD) spectroscopy and SEM micrographs. Controlled swelling behavior depicted the chelation of copper with polysaccharide chains that is key to the stability of Cu(II)-CS coatings. All investigated systems exhibited stable degradation rate in phosphate buffered saline (PBS)-lysozyme solution within seven days of incubation. The coatings presented higher mechanical properties with the increase in Cu(II) concentration. The crack-free coatings showed mildly hydrophobic behavior. Antibacterial assays were performed using both Gram-positive and Gram-negative bacteria. Outstanding antibacterial properties of the coatings were confirmed. After 24 h of incubation, cell studies of coatings confirms that up to a certain threshold concentration of Cu(II) were not cytotoxic to human osteoblast-like cells. Overall, our results show that uniform and homogeneous Cu(II)-CS coatings with good antibacterial and enhanced mechanical stability could be successfully deposited by EPD. Such antibiotic-free antibacterial coatings are potential candidates for biomedical implants.
- Keywords
- antibacterial, chitosan, coatings, complexes, copper, electrophoretic deposition,
- MeSH
- Anti-Bacterial Agents chemistry pharmacology MeSH
- Coated Materials, Biocompatible * MeSH
- Chemical Phenomena * MeSH
- Chitosan chemistry MeSH
- X-Ray Diffraction MeSH
- Electrophoresis * MeSH
- Humans MeSH
- Copper chemistry MeSH
- Microbial Sensitivity Tests MeSH
- Nanostructures chemistry ultrastructure MeSH
- Spectroscopy, Fourier Transform Infrared MeSH
- Cell Survival MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- Anti-Bacterial Agents MeSH
- Coated Materials, Biocompatible * MeSH
- Chitosan MeSH
- Copper MeSH
The paper addresses laboratory preparation and antibacterial activity testing of kaolinite/nanoTiO2 composite in respect of the daylight irradiation time. Kaolinite/nanoTiO2 composites with 20 and 40 wt% of TiO2 were laboratory prepared, dried at 105 °C and calcined at 600 °C. The calcination caused transformation of kaolinite to metakaolinite and origination of the metakaolinite/nanoTiO2 composite. X-ray powder diffraction, Raman and FTIR spectroscopic methods revealed titanium dioxide only in the form of anatase in all evaluated samples (non-calcined and calcined) and also transformation of kaolinite to metakaolinite after the calcination treatment. Scanning electron microscopy was used as a method for characterization of morphology and elemental composition of the studied samples. A standard microdilution test was used to determine the antibacterial activity using four human pathogenic bacterial strains (Staphylococcus aureus, Escherichia coli, Enterococcus faecalis, Pseudomonas aeruginosa). A lamp with a wide spectrum bulb simulating daylight was used for induction of photocatalysis. The antibacterial assays found all the KATI samples to have antibacterial potency with different onset of the activity when calcined samples exhibited antibacterial activity earlier than the non-calcined. Significant difference in antibacterial activity of KATI samples for different bacterial strains was not observed.
- Keywords
- Antibacterial activity, FTIR, Kaolinite/TiO(2) composites, Raman spectroscopy, Staphylococcus aureus, XRD,
- MeSH
- Anti-Bacterial Agents chemistry pharmacology radiation effects MeSH
- Bacteria drug effects MeSH
- Time Factors MeSH
- Kaolin chemistry radiation effects MeSH
- Catalysis radiation effects MeSH
- Nanoparticles chemistry radiation effects MeSH
- Nanocomposites chemistry radiation effects MeSH
- Surface Properties MeSH
- Light * MeSH
- Titanium chemistry radiation effects MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- Anti-Bacterial Agents MeSH
- Kaolin MeSH
- Titanium MeSH
- titanium dioxide MeSH Browser
