Preventing biofilms by chitosan-based nanoantimicrobials (NAMs)

2020 ◽  
Author(s):  
Ekaterina A. Kukushkina ◽  
Maria Chiara Sportelli ◽  
Nicoletta Ditaranto ◽  
Rosaria Anna Picca ◽  
Nicola Cioffi

<p>Chitosan (CS), a natural non-toxic polysaccharide, shows intrinsic antimicrobial activity against a wide range of pathogens. CS and CS-based biomaterials can be effective additives in food and medicine-related industries to inhibit growth of pathogens. The application of inorganic nanophases, such as metal and metal oxide nanoparticles, has received attention due to their broad and pronounced antimicrobial activity. Upon combination with CS, which can act as stabilizer, with active inorganic nanophases, robust synergistic nanoantimicrobial (NAM) systems can be produced. These hybrid NAMs offer an alternative strategy to fight antimicrobial resistance and overcome limitations of conventional antibiotics. Bioactive ZnO, Cu and Ag nanophases produced by green electrochemical approach [Nanomaterials, 10(3) (2020), 473] and laser ablation in solution [(Coll. Surf. A, 559 (2018), 148-158), (Food packaging shelf, 22 (2019), 1000422)] can be combined with antimicrobial CS to develop synergistic antimicrobial nanohybrids with amplified biological action. CS-based NAMs were preliminary characterized by electron microscopies and spectroscopic techniques. Hybrid NAMs may find application in the control and inhibition of biofilm growth.</p> <p>Acknowledgements<br />Financial support is acknowledged from European Union’s 2020 research and innovation program under the Marie Sklodowska-Curie Grant Agreement No. 813439</p>

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Shipra Tripathi ◽  
G. K. Mehrotra ◽  
P. K. Dutta

AbstractAntimicrobial packaging is one of the most promising active packaging systems. Antimicrobial packaging is the packaging system that is able to kill or inhibit spoilage and pathogenic microorganisms that are contaminating foods. A tremendous effort has been made over the last decade to develop and test films with antimicrobial properties to improve food safety and shelf life. For food preservation, chitosan films are very effective. Chitosan has widely been used in antimicrobial films, to provide edible protective coating, dipping and spraying for the food products due to its antimicrobial properties. Chitosan can be formed into fibers, films, gels, sponges, beads or nanoparticles. Chitosan films have been used as a packaging material for the quality preservation of a variety of food. Chitosan has great potential for a wide range of applications due to its biodegradability, biocompatibility, antimicrobial activity, non-toxicity and versatile chemical and physical properties. The present review outlines the preparation and antimicrobial activity of chitosan based films.


2020 ◽  
Vol 11 ◽  
pp. 1450-1469
Author(s):  
Matías Guerrero Correa ◽  
Fernanda B Martínez ◽  
Cristian Patiño Vidal ◽  
Camilo Streitt ◽  
Juan Escrig ◽  
...  

The investigation of novel nanoparticles with antimicrobial activity has grown in recent years due to the increased incidence of nosocomial infections occurring during hospitalization and food poisoning derived from foodborne pathogens. Antimicrobial agents are necessary in various fields in which biological contamination occurs. For example, in food packaging they are used to control food contamination by microbes, in the medical field the microbial agents are important for reducing the risk of contamination in invasive and routine interventions, and in the textile industry, they can limit the growth of microorganisms due to sweat. The combination of nanotechnology with materials that have an intrinsic antimicrobial activity can result in the development of novel antimicrobial substances. Specifically, metal-based nanoparticles have attracted much interest due to their broad effectiveness against pathogenic microorganisms due to their high surface area and high reactivity. The aim of this review was to explore the state-of-the-art in metal-based nanoparticles, focusing on their synthesis methods, types, and their antimicrobial action. Different techniques used to synthesize metal-based nanoparticles were discussed, including chemical and physical methods and “green synthesis” methods that are free of chemical agents. Although the most studied nanoparticles with antimicrobial properties are metallic or metal-oxide nanoparticles, other types of nanoparticles, such as superparamagnetic iron-oxide nanoparticles and silica-releasing systems also exhibit antimicrobial properties. Finally, since the quantification and understanding of the antimicrobial action of metal-based nanoparticles are key topics, several methods for evaluating in vitro antimicrobial activity and the most common antimicrobial mechanisms (e.g., cell damage and changes in the expression of metabolic genes) were discussed in this review.


Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1790 ◽  
Author(s):  
Ana Maria Diez-Pascual

Thermosetting polymers derived from vegetable oils (VOs) exhibit a wide range of outstanding properties that make them suitable for coatings, paints, adhesives, food packaging, and other industrial appliances. In addition, some of them show remarkable antimicrobial activity. Nonetheless, the antibacterial properties of these materials can be significantly improved via incorporation of very small amounts of metal oxide nanoparticles (MO-NPs) such as TiO2, ZnO, CuO, or Fe3O4. The antimicrobial efficiency of these NPs correlates with their structural properties like size, shape, and mainly on their concentration and degree of functionalization. Owing to their nanoscale dimensions, high specific surface area and tailorable surface chemistry, MO-NPs can discriminate bacterial cells from mammalian ones, offering long-term antibacterial action. MO-NPs provoke bacterial toxicity through generation of reactive oxygen species (ROS) that can target physical structures, metabolic paths, as well as DNA synthesis, thereby leading to cell decease. Furthermore, other modes of action—including lipid peroxidation, cell membrane lysis, redox reactions at the NP–cell interface, bacterial phagocytosis, etc.—have been reported. In this work, a brief description of current literature on the antimicrobial effect of VO-based thermosetting polymers incorporating MO-NPs is provided. Specifically, the preparation of the nanocomposites, their morphology, and antibacterial properties are comparatively discussed. A critical analysis of the current state-of-art on these nanomaterials improves our understanding to overcome antibiotic resistance and offers alternatives to struggle bacterial infections in public places.


2008 ◽  
Vol 15 (05) ◽  
pp. 537-543 ◽  
Author(s):  
YUQING MIAO ◽  
JIANRONG CHEN ◽  
XIAOHUA WU

Matrine is an important natural occurring component in sophora roots. It has a wide range of pharmacological actions. In this work, electrochemical investigation of matrine and its interaction with L-cysteine (L-Cys) is reported. Via the electrochemical approach, we have proved that the distribution coefficients of protonated and deprotonated matrine affect its electrochemical response on Au or L-Cys modified Au electrodes. The study by ultraviolet spectroscopy also finds that the molecular interaction between matrine and L-Cys changes with the distribution coefficients of protonated and deprotonated matrine at different pH value. Compared with the response of matrine on the bare gold electrode, the L-Cys/Au self-assembled monolayers modified electrodes exhibit obviously higher current response toward matrine oxidation. The oxidation current of matrine at L-Cys assembled electrode has a good linear relation in the range of 0.2–5 mM, with the correlation coefficient of 0.989 by cyclic voltammagrams. Electrochemical combined with spectroscopic techniques would provide relatively easy way to better understand the underlying mechanism of matrine/L-Cys interaction and will be helpful for the development of electroanalytical techniques for the determination of matrine.


2020 ◽  
Vol 36 (6) ◽  
pp. 1043-1048
Author(s):  
Goutam Kumar ◽  
P.P. Badoni ◽  
Arun K. Khajuria ◽  
Mahender Singh ◽  
Sapna Tyagi ◽  
...  

In recent years, there is significant increase in the attention towards the green synthesis of metal oxide nanoparticles, particularly by the interaction of plant extracts and metal salts; still there is no such published evidence is available on the synthesis of ZnO nanoparticles from aqueous leaf extract of Cotoneaster acuminatus. The synthesis of ZnO nanoparticles was confirmed by using several spectroscopic techniques i.e., UV-Vis, FT-IR, powder-XRD and TEM. It was confirmed from the spectroscopic data that the synthesized nanoparticles were hexagonally orientated, size in the 16-38 nm range and encapsulated by biochemicals present in the leaf extract. These nanoparticles were further evaluated for antimicrobial activity Bacillus subtilisNCFT.583.08, Staphylococcus aureusNCFT.576.08, Pseudomonas aeruginosaNCFT.645.11, Candida albicansNCFT.1006.11 and Saccharomyces cerevisiae NCFT.1008.11strains. This research work might be considered as a successful attempt to create and evaluate medicinal properties of ZnO nanoparticles in combination with Cotoneaster acuminatus leaf extract.


2020 ◽  
Vol 16 ◽  
Author(s):  
Mahboob Ali ◽  
Momin Khan ◽  
Khair Zaman ◽  
Abdul Wadood ◽  
Maryam Iqbal ◽  
...  

: Background: The inhibition of α-amylase enzyme is one of the best therapeutic approach for the management of type II diabetes mellitus. Chalcone possesses a wide range of biological activities. Objective: In the current study chalcone derivatives (1-17) were synthesized and evaluated their inhibitory potential against α-amylase enzyme. Method: For that purpose, a library of substituted (E)-1-(naphthalene-2-yl)-3-phenylprop-2-en-1-ones was synthesized by ClaisenSchmidt condensation reaction of 2-acetonaphthanone and substituted aryl benzaldehyde in the presence of base and characterized via different spectroscopic techniques such as EI-MS, HREI-MS, 1H-, and 13C-NMR. Results: Sixteen synthetic chalcones were evaluated for in vitro porcine pancreatic α-amylase inhibition. All the chalcones demonstrated good inhibitory activities in the range of IC50 = 1.25 ± 1.05 to 2.40 ± 0.09 μM as compared to the standard commercial drug acarbose (IC50 = 1.34 ± 0.3 μM). Conclusion: Chalcone derivatives (1-17) were synthesized, characterized, and evaluated for their α-amylase inhibition. SAR revealed that electron donating groups in the phenyl ring have more influence on enzyme inhibition. However, to insight the participation of different substituents in the chalcones on the binding interactions with the α-amylase enzyme, in silico (computer simulation) molecular modeling analyses were carried out.


Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 200
Author(s):  
Celeste Cottet ◽  
Andrés G. Salvay ◽  
Mercedes A. Peltzer ◽  
Marta Fernández-García

Poly(itaconic acid) (PIA) was synthesized via conventional radical polymerization. Then, functionalization of PIA was carried out by an esterification reaction with the heterocyclic groups of 1,3-thiazole and posterior quaternization by N-alkylation reaction with iodomethane. The modifications were confirmed by Fourier transform infrared (FTIR) and proton nuclear magnetic resonance (1H-NMR), as well as ζ-potential measurements. Their antimicrobial activity was tested against different Gram-negative and Gram-positive bacteria. After characterization, the resulting polymers were incorporated into gelatin with oxidized starch and glycerol as film adjuvants, and dopamine as crosslinking agent, to develop antimicrobial-active films. The addition of quaternized polymers not only improved the mechanical properties of gelatin formulations, but also decreased the solution absorption capacity during the swelling process. However, the incorporation of synthesized polymers increased the deformation at break values and the water vapor permeability of films. The antioxidant capacity of films was confirmed by radical scavenging ability and, additionally, those films exhibited antimicrobial activity. Therefore, these films can be considered as good candidates for active packaging, ensuring a constant concentration of the active compound on the surface of the food, increasing products’ shelf-life and reducing the environmental impact generated by plastics of petrochemical origin.


Author(s):  
Kolathuru Puttamadaiah Ramesha ◽  
Nagabhushana Chandra Mohana ◽  
Bettadapura Rameshgowda Nuthan ◽  
Devaraju Rakshith ◽  
Sreedharamurthy Satish

Abstract Background Endophyte bestows beneficial aspects to its inhabiting host, along with a contribution to diverse structural attributes with biological potential. In this regard, antimicrobial profiling of fungal endophytes from medicinal plant Adiantum philippense revealed bioactive Nigrospora sphaerica from the leaf segment. Chemical and biological profiling through TLC–bioautography and hyphenated spectroscopic techniques confirmed the presence of phomalactone as an antimicrobial metabolite. Results The chemical investigation of the broth extract by bioassay-guided fractionation confirmed phomalactone as a bioactive antimicrobial secondary metabolite. The antimicrobial activity of phomalactone was found to be highest against Escherichia coli by disc diffusion assay. The MIC was found to be significant against both Escherichia coli and Xanthomonas campestris in the case of bacteria and dermatophyte Candida albicans at 150 μg/ml, respectively. Conclusions Overall, the results highlighted the antimicrobial potential of phomalactone from the endophyte Nigrospora sphaerica exhibiting a broad spectrum of antimicrobial activity against human and phytopathogenic bacteria and fungi. This work is the first report regarding the antibacterial activity of phomalactone.


Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1406
Author(s):  
Rita Cava-Roda ◽  
Amaury Taboada-Rodríguez ◽  
Antonio López-Gómez ◽  
Ginés Benito Martínez-Hernández ◽  
Fulgencio Marín-Iniesta

Plant bioactive compounds have antimicrobial and antioxidant activities that allow them to be used as a substitute for synthetic chemical additives in both food and food packaging. To improve its sensory and bactericidal effects, its use in the form of effective combinations has emerged as an interesting possibility in the food industry. In this study, the antimicrobial activities of essential oils (EOs) of cinnamon bark, cinnamon leaves, and clove and the pure compounds vanillin, eugenol, and cinnamaldehyde were investigated individually and in combination against Listeria monocytogenes and Escherichia coli O157:H7. The possible interactions of combinations of pure compounds and EOs were performed by the two-dimensional checkerboard assay and isobologram methods. Vanillin exhibited the lowest antimicrobial activity (MIC of 3002 ppm against L. monocytogenes and 2795 ppm against E. coli O157:H7), while clove and cinnamon bark EOs exhibited the highest antimicrobial activity (402–404 against L. monocytogenes and 778–721 against E. coli O157:H7). For L. monocytogenes, pure compound eugenol, the main component of cinnamon leaves and clove, showed lower antimicrobial activity than EOs, which was attributed to the influence of the minor components of the EOs. The same was observed with cinnamaldehyde, the main component of cinnamon bark EO. The combinations of vanillin/clove EO and vanillin/cinnamon bark EO showed the most synergistic antimicrobial effect. The combination of the EOs of cinnamon bark/clove and cinnamon bark/cinnamon leaves showed additive effect against L. monocytogenes but indifferent effect against E. coli O157:H7. For L. monocytogenes, the best inhibitory effects were achieved by cinnamon bark EO (85 ppm)/vanillin (910 ppm) and clove EO (121 ppm)/vanillin (691 ppm) combinations. For E. coli, the inhibitory effects of clove EO (104 ppm)/vanillin (1006 ppm) and cinnamon leaves EO (118 ppm)/vanillin (979 ppm) combinations were noteworthy. Some of the tested combinations increased the antimicrobial effect and would allow the effective doses to be reduced, thereby offering possible new applications for food and active food packaging.


Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 659
Author(s):  
Iva Rezić ◽  
Mislav Majdak ◽  
Vanja Ljoljić Bilić ◽  
Ivan Pokrovac ◽  
Lela Martinaga ◽  
...  

In this work the in vitro antimicrobial activity of colloidal solutions of nine different commercially available nanoparticles were investigated against Staphylococcus aureus strains, both methicillin-sensitive (MSSA) and methicillin-resistant (MRSA). Research covered antimicrobial investigation of different metal and metal-oxide nanoparticles, including Ag 10 nm, Ag 40 nm, Al2O3 100 nm, Au 20 nm, Pt 4 nm, TiO2 100 nm, Y2O3 100 nm, ZnO 100 nm and ZrO2 100 nm nanoparticles. Such materials were foreseen to be applied as coatings on 3D-printed biodegradable polymers: i.e., catheters, disposable materials, hospital bedding items, disposable antimicrobial linings and bandages for chronic wounds. Therefore, the antimicrobial activity of the nanoparticles was determined by agar well diffusion assays and serial microdilution broth assays. In addition, the chromatographic characterization of elements present in trace amounts was performed as a method for tracing the nanoparticles. Moreover, the potential of preparing the rough surface of biodegradable polymers for coating with antimicrobial nanoparticles was tested by 3D-printing fused deposition methodology. The in vitro results have shown that particular nanoparticles provided powerful antimicrobial effects against MSSA and MRSA strains, and can be easily applied on different biopolymers.


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