The field of nanotechnology has the mysterious capacity to reform every subject it touches. Nanotechnology advancements have already altered a variety of scientific and industrial fields. Nanoparticles (NPs) with sizes ranging from 1 to 100 nm (nm) are of great scientific and commercial interest. Their functions and characteristics differ significantly from those of bulk metal. Commercial quantities of NPs are synthesized using chemical or physical methods. The use of the physical and chemical approaches remained popular for many years; however, the recognition of their hazardous effects on human well-being and conditions influenced serious world perspectives for the researchers. There is a growing need in this field for simple, non-toxic, clean, and environmentally safe nanoparticle production methods to reduce environmental impact and waste and increase energy productivity. Microbial nanotechnology is relatively a new field. Using various microorganisms, a wide range of nanoparticles with well-defined chemical composition, morphology, and size have been synthesized, and their applications in a wide range of cutting-edge technological areas have been investigated. Green synthesis of the nanoparticles is cost-efficient and requires low maintenance. The present review highlights the synthesis of the nanoparticles by different microbes, their characterization, and their biotechnological potential. It further deals with the applications in biomedical, food, and textile industries as well as its role in biosensing, waste recycling, and biofuel production.

• Klíčová slova
• Biofuels, Food industry, Microbial nanotechnology, Omics, Waste management,
• MeSH
• Bacteria metabolismus   MeSH
• biotechnologie trendy   MeSH
• nanočástice * chemie   MeSH
• nanotechnologie * trendy   MeSH
• zemědělství * metody   MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

The number of antibiotic-resistant bacterial strains is increasing due to the excessive and inappropriate use of antibiotics, which are therefore becoming ineffective. Here, we report an effective way of enhancing and restoring the antibacterial activity of inactive antibiotics by applying them together with a cyanographene/Ag nanohybrid, a nanomaterial that is applied for the first time for restoring the antibacterial activity of antibiotics. The cyanographene/Ag nanohybrid was synthesized by chemical reduction of a precursor material in which silver cations are coordinated on a cyanographene sheet. The antibacterial efficiency of the combined treatment was evaluated by determining fractional inhibitory concentrations (FIC) for antibiotics with different modes of action (gentamicin, ceftazidime, ciprofloxacin, and colistin) against the strains Escherichia coli, Pseudomonas aeruginosa, and Enterobacter kobei with different resistance mechanisms. Synergistic and partial synergistic effects against multiresistant strains were demonstrated for all of these antibiotics except ciprofloxacin, which exhibited an additive effect. The lowest average FICs equal to 0.29 and 0.39 were obtained for colistin against E. kobei and for gentamicin against E. coli, respectively. More importantly, we have experimentally confirmed for the first time, that interaction between the antibiotic's mode of action and the mechanism of bacterial resistance strongly influenced the combined treatment's efficacy.

• MeSH
• antibakteriální látky * chemie   farmakologie   MeSH
• ciprofloxacin farmakologie   MeSH
• Escherichia coli MeSH
• gentamiciny farmakologie   MeSH
• kolistin * farmakologie   MeSH
• mikrobiální testy citlivosti MeSH
• Pseudomonas aeruginosa MeSH
• synergismus léků MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antibakteriální látky * MeSH
• ciprofloxacin MeSH
• gentamiciny MeSH
• kolistin * MeSH

The food packaging industry explores economically viable, environmentally benign, and non-toxic packaging materials. Biopolymers, including chitosan (CH) and gelatin (GE), are considered a leading replacement for plastic packaging materials, with preferred packaging functionality and biodegradability. CH, GE, and different proportions of silver nanoparticles (AgNPs) are used to prepare novel packaging materials using a simple solution casting method. The functional and morphological characterization of the prepared films was carried out by using Fourier transform infrared spectroscopy (FTIR), UV-Visible spectroscopy, and scanning electron microscopy (SEM). The mechanical strength, solubility, water vapor transmission rate, swelling behavior, moisture retention capability, and biodegradability of composite films were evaluated. The addition of AgNPs to the polymer blend matrix improves the physicochemical and biological functioning of the matrix. Due to the cross-linking motion of AgNPs, it is found that the swelling degree, moisture retention capability, and water vapor transmission rate slightly decrease. The tensile strength of pure CH-GE films was 24.4 ± 0.03, and it increased to 25.8 ± 0.05 MPa upon the addition of 0.0075% of AgNPs. The real-time application of the films was tested by evaluating the shelf-life existence of carrot pieces covered with the composite films. The composite film containing AgNPs becomes effective in lowering bacterial contamination while comparing the plastic polyethylene films. In principle, the synthesized composite films possessed all the ideal characteristics of packaging material and were considered biodegradable and biocompatible food packaging material and an alternate option for petroleum-based plastics.

• Klíčová slova
• antimicrobial, bio-nanocomposites, chitosan, food packaging, gelatin, silver nanoparticles,
• Publikační typ
• časopisecké články MeSH

The ability to manipulate the structure and function of promising systems via external stimuli is emerging with the development of reconfigurable and programmable multifunctional materials. Increasing antifungal and antitumor activity requires novel, effective treatments to be diligently sought. In this work, the synthesis, characterization, and in vitro biological screening of pure α-Ag2WO4, irradiated with electrons and with non-focused and focused femtosecond laser beams are reported. We demonstrate, for the first time, that Ag nanoparticles/α-Ag2WO4 composite displays potent antifungal and antitumor activity. This composite had an extreme low inhibition concentration against Candida albicans, cause the modulation of α-Ag2WO4 perform the fungicidal activity more efficient. For tumor activity, it was found that the composite showed a high selectivity against the cancer cells (MB49), thus depleting the populations of cancer cells by necrosis and apoptosis, without the healthy cells (BALB/3T3) being affected.

• MeSH
• antifungální látky farmakologie   MeSH
• apoptóza MeSH
• buňky BALB 3T3 MeSH
• Candida albicans účinky léků   MeSH
• elektrony * MeSH
• kovové nanočástice aplikace a dávkování   chemie   účinky záření   MeSH
• lidé MeSH
• myši MeSH
• nádorové buňky kultivované MeSH
• nádory močového měchýře farmakoterapie   patologie   MeSH
• oxidy chemie   účinky záření   MeSH
• proliferace buněk MeSH
• protinádorové látky farmakologie   MeSH
• stříbro chemie   účinky záření   MeSH
• wolfram chemie   účinky záření   MeSH
• xenogenní modely - testy protinádorové aktivity MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antifungální látky MeSH
• oxidy MeSH
• protinádorové látky MeSH
• stříbro MeSH
• tungsten oxide MeSH Prohlížeč
• wolfram MeSH

Silver nanoparticles (SNPs) were synthesized on the basis of exopolysaccharides (low and high molar mass) of diazotrophic Bradyrhizobium japonicum 36 strain. The synthesis of SNPs was carried out by direct reduction of silver nitrate with ethanol-insoluble (high molar mass, HMW) and ethanol-soluble (low molar mass, LMW) fractions of exopolysaccharides (EPS), produced by diazotrophic strain B. japonicum 36. SNPs were characterized using UV-vis spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). SNPs synthesized on the basis of LMW EPS absorbed radiation in the visible regions of 420 nm, whereas SNPs based on the HMW EPS have a wavelength maximum at 450 nm because of the strong SPR transition. Moreover, the antibacterial and antifungal activities of the SNPs were examined in vitro against Escherichia coli, Staphylococcus aureus, and Candida albicans. SNPs synthesized on the basis of LMW EPS were active than those synthesized on the basis of HMW EPS. Besides, UV-visible spectroscopic evaluation confirmed that SNPs synthesized on the basis of LMW EPS were far more stable than those obtained on the basis of HMW EPS.

• MeSH
• antiinfekční látky metabolismus   farmakologie   MeSH
• bakteriální polysacharidy metabolismus   MeSH
• Bradyrhizobium metabolismus   MeSH
• Candida albicans účinky léků   MeSH
• difrakce rentgenového záření MeSH
• Escherichia coli účinky léků   MeSH
• mikrobiální testy citlivosti MeSH
• nanočástice chemie   metabolismus   ultrastruktura   MeSH
• oxidace-redukce MeSH
• spektrofotometrie MeSH
• spektroskopie infračervená s Fourierovou transformací MeSH
• Staphylococcus aureus MeSH
• stříbro metabolismus   farmakologie   MeSH
• transmisní elektronová mikroskopie MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antiinfekční látky MeSH
• bakteriální polysacharidy MeSH
• stříbro MeSH

The resistance of bacteria towards traditional antibiotics currently constitutes one of the most important health care issues with serious negative impacts in practice. Overcoming this issue can be achieved by using antibacterial agents with multimode antibacterial action. Silver nano-particles (AgNPs) are one of the well-known antibacterial substances showing such multimode antibacterial action. Therefore, AgNPs are suitable candidates for use in combinations with traditional antibiotics in order to improve their antibacterial action. In this work, a systematic study quantifying the synergistic effects of antibiotics with different modes of action and different chemical structures in combination with AgNPs against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus was performed. Employing the microdilution method as more suitable and reliable than the disc diffusion method, strong synergistic effects were shown for all tested antibiotics combined with AgNPs at very low concentrations of both antibiotics and AgNPs. No trends were observed for synergistic effects of antibiotics with different modes of action and different chemical structures in combination with AgNPs, indicating non-specific synergistic effects. Moreover, a very low amount of silver is needed for effective antibacterial action of the antibiotics, which represents an important finding for potential medical applications due to the negligible cytotoxic effect of AgNPs towards human cells at these concentration levels.

• Klíčová slova
• antibacterial, antibiotics, cytotoxicity, resistant bacteria, silver nanoparticle, synergism,
• MeSH
• antibakteriální látky chemie   farmakologie   MeSH
• bakteriální léková rezistence účinky léků   MeSH
• buňky NIH 3T3 MeSH
• Escherichia coli účinky léků   MeSH
• kovové nanočástice chemie   MeSH
• mikrobiální testy citlivosti MeSH
• molekulární struktura MeSH
• myši MeSH
• Pseudomonas aeruginosa účinky léků   MeSH
• Staphylococcus aureus účinky léků   MeSH
• stříbro chemie   MeSH
• synergismus léků MeSH
• viabilita buněk účinky léků   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antibakteriální látky MeSH
• stříbro MeSH

The diverse mechanism of antimicrobial activity of Ag and AgBr nanoparticles against gram-positive and gram-negative bacteria and also against several strains of candida was explored in this study. The AgBr nanoparticles (NPs) were prepared by simple precipitation of silver nitrate by potassium bromide in the presence of stabilizing polymers. The used polymers (PEG, PVP, PVA, and HEC) influence significantly the size of the prepared AgBr NPs dependently on the mode of interaction of polymer with Ag+ ions. Small NPs (diameter of about 60-70 nm) were formed in the presence of the polymer with low interaction as are PEG and HEC, the polymers which interact with Ag+ strongly produce nearly two times bigger NPs (120-130 nm). The prepared AgBr NPs were transformed to Ag NPs by the reduction using NaBH4. The sizes of the produced Ag NPs followed the same trends--the smallest NPs were produced in the presence of PEG and HEC polymers. Prepared AgBr and Ag NPs dispersions were tested for their biological activity. The obtained results of antimicrobial activity of AgBr and Ag NPs are discussed in terms of possible mechanism of the action of these NPs against tested microbial strains. The AgBr NPs are more effective against gram-negative bacteria and tested yeast strains while Ag NPs show the best antibacterial action against gram-positive bacteria strains.

• MeSH
• antiinfekční látky chemická syntéza   chemie   farmakologie   MeSH
• Bacteria účinky léků   MeSH
• bromidy chemie   farmakologie   MeSH
• Candida účinky léků   MeSH
• kovové nanočástice chemie   MeSH
• polymery chemie   MeSH
• sloučeniny stříbra chemie   farmakologie   MeSH
• stříbro chemie   farmakologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH
• Názvy látek
• antiinfekční látky MeSH
• bromidy MeSH
• polymery MeSH
• silver bromide MeSH Prohlížeč
• sloučeniny stříbra MeSH
• stříbro MeSH

It is expected that the projected increased usage of implantable devices in medicine will result in a natural rise in the number of infections related to these cases. Some patients are unable to autonomously prevent formation of biofilm on implant surfaces. Suppression of the local peri-implant immune response is an important contributory factor. Substantial avascular scar tissue encountered during revision joint replacement surgery places these cases at an especially high risk of periprosthetic joint infection. A critical pathogenic event in the process of biofilm formation is bacterial adhesion. Prevention of biomaterial-associated infections should be concurrently focused on at least two targets: inhibition of biofilm formation and minimizing local immune response suppression. Current knowledge of antimicrobial surface treatments suitable for prevention of prosthetic joint infection is reviewed. Several surface treatment modalities have been proposed. Minimizing bacterial adhesion, biofilm formation inhibition, and bactericidal approaches are discussed. The ultimate anti-infective surface should be "smart" and responsive to even the lowest bacterial load. While research in this field is promising, there appears to be a great discrepancy between proposed and clinically implemented strategies, and there is urgent need for translational science focusing on this topic.

• MeSH
• antibakteriální látky farmakologie   terapeutické užití   MeSH
• Bacteria účinky léků   MeSH
• biokompatibilní potahované materiály farmakologie   terapeutické užití   MeSH
• infekce spojené s protézou prevence a kontrola   MeSH
• lidé MeSH
• ortopedie MeSH
• povrchové vlastnosti MeSH
• protézy a implantáty MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• antibakteriální látky MeSH
• biokompatibilní potahované materiály MeSH