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Bacterial infectious diseases are serious health problem which extends to economic and social complications. Moreover, bacterial antibiotic resistance, lack of suitable vaccine or emergence of new mutations is forcing the development of novel antimicrobial agents. The objective of this study is to synthesize and characterize star-like zinc oxide nanoparticles for the application of antibacterial activities in cellulose based hygiene products. ZnO NPs were in situ synthesized via precipitation method on the surface of cellulose fibers. Since bactericidal activity of nanoparticles in part depends on the concentration in the growth medium, various amount of ZnO was incorporated into cellulose matrix ranging from 1 to 3 wt%. Microscopic (TEM, SEM) and spectroscopic (FT-IR, XRD) methods were utilized to investigate the final products. The infrared absorption spectra analysis supported by theoretical finding that during the reaction, ZnO nanoparticles could be bonded with cellulose fibers via hydrogen bonding. The yield of functionalization was determined through thermogravimetric analysis. Collected data proved the successful functionalization of the cellulose fibers with nanoparticles. Static contact angle measurements were carried out showing absorptive character of as prepared fabrics. All the samples were tested for the antibacterial properties and the results were compared to the samples prepared from the pristine cellulose fibers. Moreover, mechanical tests were performed revealing that the addition of only 2 wt% of the nanofiller boosted tensile, tearing and bursting strength by a factor of 1.6, 1.4 and 2.2 in comparison to unfunctionalized paper sample, respectively. Fabricated fabric presenting high hydrophilicity and antibacterial properties have gained increased applications in fabric industry, including hygiene product industry and hence the result of this study would be a welcomed option., (© 2022. The Author(s).)

Medical device-associated infections are a serious medical threat, particularly for patients with impaired mobility and/or advanced age. Despite a variety of antimicrobial coatings for medical devices being explored to date, only a limited number have been introduced for clinical use. Research into new bactericidal agents with the ability to eradicate pathogens, limit biofilm formation, and exhibit satisfactory biocompatibility, is therefore necessary and urgent. In this study, a series of varied-morphology gold nanoparticles in shapes of rods, peanuts, stars and spherical-like, porous ones with potent antibacterial activity were synthesized and thoroughly tested against spectrum of Candida albicans, Pseudomonas aeruginosa, Staphylococcus aureus clinical strains, as well as spectrum of uropathogenic Escherichia coli isolates. The optimization of gold nanoparticles synthesis allowed to develop nanomaterials, which are proved to be significantly more potent against tested microbes compared with the gold nanoformulations reported to date. Notably, their antimicrobial spectrum includes strains with different drug resistance mechanisms. Facile and cost-efficient synthesis of gold nanoparticles, remarkable bactericidal efficiency at nanogram doses, and low toxicity, underline their potential for development as a new coatings, as indicated by the example of urological catheters. The presented research fills a gap in microbial studies of non-spherical gold nanoparticles for the development of antimicrobial coatings targeting multidrug-resistant pathogens responsible for device-associated nosocomial infections.

Finding a safe and broad-spectrum medication is a goal of scientists, pharmacists, and physicians, but developing and fabricating the right medicine can be challenging. The current study describes the formation of silver nanoparticles (AgNPs) by Fusarium mangiferae . It involves the antibiofilm activity of the nanoparticles against Staphylococcus aureus . It also involves cytotoxic effect against mammalian cell lines. Well-dispersed nanoparticles are formed by F. mangiferae . The sizes of the nanoparticles were found to range from 25 to 52 nm, and UV-Vis scan showed absorption around 416-420 nm. SEM, TEM, and AFM results displayed spherical and oval shapes. Furthermore, the FTIR histogram detected amide I and amide II compounds responsible for the stability of AgNPs in an aqueous solution. AgNPs were observed to decrease the formation of biofilm at 75% (v/v). DNA reducing, smearing, and perhaps fragmentation were noticed after treating the bacterial cells with 50% (v/v). Additionally, cell lysis was detected releasing proteins in the supernatant. It was also observed that the AgNPs have the ability to cause 59% cervical cancer cell line (HeLa) deaths at 25% (v/v), however, they showed about 31% toxicity against rat embryo fibroblast transformed cell lines (REF). The results of this study prove the efficiency of AgNPs as an antibiofilm against S. aureus , suggesting that AgNPs could be an alternative to antibiotics. It must also be emphasized that AgNPs displayed cytotoxic behavior against mammalian cell lines. Further studies are needed for assessing risk in relation to the possible benefit of prescribing AgNPs.

Loomstate-, scoured- and bleached cotton fabrics were first activated by treatment with ethanolamine and; thus obtained three fabrics were submitted independently to in-situ formation of silver nanoparticles (AgNPs) using different concentrations of silver nitrate (AgNO3) in absence of other external precursor. The magnitude of AgNPs on the fabric increases by increasing AgNO 3 concentrations during synthesis of AgNPs loaded fabrics irrespective of the fabric used. Loomstate- and scoured cotton fabrics with the highest amount of AgNPs exhibit spherical shape with less aggregates; opposite to their bleached mate where AgNPs are irregularly shaped with bigger size due to aggregation. The formation of AgNPs is confirmed through monitoring UV-vis absorption peak. Results signify also the formation of high density coating of silver on the surface of cotton fabric. Fabrics loaded with AgNPs exhibit superior antibacterial activity. Treatment with distilled water of AgNPs loaded scoured cotton fabric filtered by centrifugation verify the very slow launching of AgNPs indicating excellent durability; a point which advocates the use of such fabrics in infection prevention applications. Indeed, the basic and practice entailed in current studies can be nominated strongly for cleaner bactericidal finishing of cotton., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Emergence of multiple drug resistant strains of pathogenic bacteria calls for new initiatives to combat infectious diseases. Gold nanoparticles (AuNPs), because of their non-toxic nature and size/shape dependent optical properties, offer interesting possibility. Here we report the antibacterial efficacy of AuNPs of different size and shape (AuNS10, AuNS100 and AuNR10; the number indicating the diameter in nm; S stands for sphere and R for rod) against the classical (O395) and El Tor (N16961) biotypes of Vibrio cholerae, the etiological agent responsible for cholera. Growth kinetics was monitored by measuring optical density at different time intervals and fitted by non-linear regression of modified Buchanan model. Sigmoidal growth curve for VcO395 indicated the existence of single phenotype population and was affected by AuNR10 only, implying the importance of morphology of AuNP. Growth of VcN16961 was affected by all three AuNPs indicating the vulnerability of El Tor biotype. Interestingly, VcN16961 exhibited the occurrence of two phenotypic subpopulations - one with shorter (vulnerable Type 1) and the other with extended (tolerant Type 2) lag phase. Various assays were conducted to probe the impact of AuNPs on bacterial cells. Apart from AuNR10, antimicrobial efficacy of AuNS10 was better compared to AuNS100.

The effectiveness of nanoparticle-based functional devices depends strongly on the surface morphology and area of the support. An emerging powerful approach of increasing the available surface area without decreasing strength or increasing bulk is to attach arrays of suitable nanotubes on the surface, and to attach the necessary nanoparticles to them. Earlier publications by this team have shown that carpet-like arrays of carbon nanotubes (CNTs) can be successfully grown on a variety of larger carbon substrates such as graphite, foams and fabric, which offer hierarchical multiscale supporting architecture suitable for the attachment of silver nanoparticles (AgNPs). A limiting factor of pure CNT arrays in fluid-based applications is their hydrophobicity, which can reduce the percolation of an aqueous medium through individual nanotubes. Previous studies have demonstrated that the treatment of CNT carpets with dry (oxygen) plasma can induce reversible wettability, and treatment with wet (sol-gel) coating can impart permanent wettability. In this paper, we report the influence of such treatments on the attachment of AgNPs, and their effectiveness in water disinfection treatments. Both types of hydrophilic surface treatment show an increase in silver loading on the CNT carpets. Oxygen-plasma treated surfaces (O-CNT) show fine and densely packed AgNPs, whereas silica-coated nanotubes (silica-CNT) show uneven clusters of AgNPs. However, O-CNT surfaces lose their hydrophilicity during AgNP deposition, whereas silica-CNT surfaces remain hydrophilic. This difference significantly impacts the antibacterial effectiveness of these materials, as tested in simulated water containing Gram negative Escherichia coli (E. coli, JM109). AgNPs on silica-coated CNT substrates showed significantly higher reduction rates of E. coli compared to AgNPs on plasma-treated CNT substrates, despite the finer and better dispersed AgNP distribution in the latter. These results provide important insights into different aspects of surface modification approaches that can control the wettability of CNT carpets, and their applicability in water treatment applications.

Background: Despite improvement in operative techniques and antibiotic therapy, septic complications still occur in open fractures. We developed silver ion containing ceramic nano powder for implant coating to provide not only biocompatibility but also antibacterial activity to the orthopaedic implants., Questions/purposes: We hypothesised silver ion doped calcium phosphate based ceramic nano-powder coated titanium nails may prevents bacterial colonisation and infection in open fractures as compared with uncoated nails., Methods: 33 rabbits divided into three groups. In the first group uncoated, in the second group hydroxyapatite coated, and in the third group silver doped hydroxyapatite coated titanium nails were inserted left femurs of animals from knee regions with retrograde fashion. Before implantation of nails 50 μl solution containing 10(6)CFU/ml methicillin resistance Staphylococcus aureus (MRSA) injected intramedullary canal. Rabbits were monitored for 10 weeks. Blood was taken from rabbits before surgery and on 2nd, 6th and 10th weeks. Blood was analysed for biochemical parameters, blood count, C-reactive protein and silver levels. At the end of the 10 weeks animals were sacrificed and rods were extracted in a sterile fashion. Swab cultures were taken from intramedullary canal. Bacteria on titanium rods were counted. Liver, heart, spleen, kidney and central nervous tissues samples were taken for determining silver levels. Histopathological evaluation of bone surrounding implants was also performed., Results: No significant difference was detected between the groups from hematologic, biochemical, and toxicological aspect. Microbiological results showed that less bacterial growth was detected with the use of silver doped ceramic coated implants compared to the other two groups (p=0.003). Accumulation of silver was not detected. No cellular inflammation was observed around the silver coated prostheses. No toxic effect of silver on bone cells was seen., Conclusion: Silver ion doped calcium phosphate based ceramic nano powder coating to orthopaedic implants may prevents bacterial colonisation and infection in open fractures compared with those for implants without any coating., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Technological advances allowing routine nanoparticle (NP) manufacture have enabled their use in electronic equipment, foods, clothing and medical devices. Although some NPs have antibacterial activity, little is known about their environmental impact and there is no information on the influence of NPs on soil in the possibly vulnerable ecosystems of polar regions. The potential toxicity of 0.066% silver, copper or silica NPs on a high latitude (>78°N) soil was determined using community level physiological profiles (CLPP), fatty acid methyl ester (FAME) assays and DNA analysis, including sequencing and denaturing gradient gel electrophoresis (DGGE). The results of these different investigations were amalgamated in order to develop a community toxicity indicator, which revealed that of the three NPs examined, silver NPs could be classified as highly toxic to these arctic consortia. Subsequent culture-based studies confirmed that one of the community-identified plant-associating bacteria, Bradyrhizobium canariense, appeared to have a marked sensitivity to silver NPs. Thus, NP contamination of arctic soils particularly by silver NPs is a concern and procedures for mitigation and remediation of such pollution should be a priority for investigation., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Background: In recent years nano-metaloxides which easily penetrate into the cells with special interest due to their higher chemical reactivity as compared to that of similar materials in the bulk form. Of particular interest are nano-TiO(2) and ZnO, which have been widely used for their bactericidal and anticancerous properties., Purpose: The aim of the present study was to examine the bactericidal properties of nano-TiO(2) and ZnO combined with visible light on S. aureus and S. epidermitis, known for their high prevalence in infected wounds., Study: Using the technique of electron-spin resonance (ESR) coupled with spin trapping, we examined the ability of TiO(2) and ZnO nanoparticle suspensions in water to produce reactive oxygen species (ROS) with and without visible light irradiation. The possibility of exciting these nanoparticles with visible light in order to enhance their antimicrobial activity was also tested., Results: Electron-spin resonance measurements revealed that ZnO and TiO(2) nanoparticles are able to produce ROS in water suspension. A remarkable enhancement of ROS production was found following illumination with blue light. In addition, illumination significantly enhanced the antibacterial activity of the nanoparticles., Conclusion: The results suggest that nanoparticles combined with visible light can be used for sterilization purposes and may be effective for treating infected wounds., (Copyright © 2011 Wiley-Liss, Inc.)

By comparing the photocatalytic bactericidal effect on different crystal faces of bulk ZnO crystal, we found that an electron degradation mechanism dominates the photocatalytic processes of ZnO material.