scholarly journals Bacterial Nanocellulose-Enhanced Alginate Double-Network Hydrogels Cross-Linked with Six Metal Cations for Antibacterial Wound Dressing

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2683
Author(s):  
Mina Shahriari-Khalaji ◽  
Siyi Hong ◽  
Gaoquan Hu ◽  
Ying Ji ◽  
Feng F. Hong
Keyword(s):  
Mechanical Properties ◽  
Antibacterial Activity ◽  
Wound Dressing ◽  
Biomedical Applications ◽  
Antibacterial Activities ◽  
Ph Responsive ◽  
Time Saving ◽  
Bacterial Nanocellulose ◽  
Vacuum Suction ◽  
Copper Zinc

Alginate (Alg) and bacterial nanocellulose (BNC) have exhibited great potential in biomedical applications, especially wound dressing. Non-toxicity and a moisture-maintaining nature are common features making them favorable for functional dressing fabrication. BNC is a natural biopolymer that promotes major advances to the current and future biomedical materials, especially in a flat or tubular membrane form with excellent mechanical strength at hydrated state. The main drawback limiting wide applications of both BNC and Alg is the lack of antibacterial activity, furthermore, the inherent poor mechanical property of Alg leads to the requirement of a secondary dressing in clinical treatment. To fabricate composite dressings with antibacterial activity and better mechanical properties, sodium alginate was efficiently incorporated into the BNC matrix using a time-saving vacuum suction method followed by cross-linking through immersion in separate solutions of six cations (manganese, cobalt, copper, zinc, silver, and cerium). The results showed the fabricated composites had not only pH-responsive antibacterial activities but also improved mechanical properties, which are capable of acting as smart dressings. All composites showed non-toxicity toward fibroblast cells. Rat model evaluation showed the skin wounds covered by the dressings healed faster than by BNC.

Studies of mechanical properties of electrospun zein/poly(ɛ-caprolactone) composites and antibacterial properties against Listeria monocytogenes strains of zein/poly(ɛ-caprolactone)/ poly(ɛ-lysine) films

2017 ◽  
Vol 88 (24) ◽  
pp. 2800-2809 ◽  
Author(s):  
Xiyu Hu ◽  
Liang liang Yang ◽  
Kaijun Wang ◽  
Yanli Zixuan Wei ◽  
Hongwu Deng ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Listeria Monocytogenes ◽  
Wound Dressing ◽  
Antibacterial Properties ◽  
Antibacterial Activities ◽  
Mechanical Analysis ◽  
Hydrophilic Surface ◽  
Packing Materials ◽  
Antimicrobial Films ◽  
Scanning Electron

Ultra-fine fibers of zein/poly(ɛ-caprolactone) (PCL) composites were prepared by oriented electrospun technology to enhance the toughness and ductility of zein. The mechanical, morphological and thermal properties of fibrous films of zein/PCL were studied by texture analysis and nanoindentation tests, scanning electron microscopy and dynamic mechanical analysis. Wettability of fibrous films was also measured and discussed. The mechanical properties of these fibrous films were significantly improved with the addition of PCL. Research on the antibacterial activities of poly(ɛ-lysine) (EPL) loaded films of zein/PCL/poly(ɛ-lysine) shows that the films could inhibit the growth of Listeria monocytogenes. Films of zein/PCL blend systems with a hydrophilic surface do not dissolve in water and have excellent toughness and ductility. This is very favorable for applications in biodegradable materials, food packing materials, facial masks and as antimicrobial films for wound dressing.

scholarly journals Synergistic Effects of Anionic/Cationic Dendrimers and Levofloxacin on Antibacterial Activities

Molecules ◽  
2019 ◽  
Vol 24 (16) ◽  
pp. 2894 ◽  
Author(s):  
Natalia Wrońska ◽  
Jean Pierre Majoral ◽  
Dietmar Appelhans ◽  
Maria Bryszewska ◽  
Katarzyna Lisowska
Keyword(s):  
Antibacterial Activity ◽  
Biomedical Applications ◽  
Synergistic Effects ◽  
Antibacterial Activities ◽  
Drug Dosage ◽  
General Interest ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Fluoroquinolone Antibiotics ◽  
Proteus Hauseri

Despite the numerous studies on dendrimers for biomedical applications, the antibacterial activity of anionic phosphorus dendrimers has not been explored. In our research, we evaluated the antibacterial activity of modified polycationic and polyanionic dendrimers in combination with levofloxacin (LVFX) against Gram-negative (Escherichia coli ATCC 25922, Proteus hauseri ATCC 15442) and Gram-positive (Staphylococcus aureus ATCC 6538) bacteria. In the case of Gram-negative bacteria, we concluded that a combination of dendrimers and antibiotic gave satisfactory results due to a synergistic effect. The use of fluoroquinolone antibiotics, such as LVFX, not only caused resistance in disease-causing microorganisms but also increased environmental pollution. Therefore, reduction of drug dosage is of general interest.

scholarly journals Formulation and Antibacterial Activity Evaluation of Quaternized Aminochitosan Membrane for Wound Dressing Applications

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2428
Author(s):  
Ahmed M. Omer ◽  
Tamer M. Tamer ◽  
Randa E. Khalifa ◽  
Abdelazeem S. Eltaweil ◽  
Mona M. Agwa ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Surface Roughness ◽  
Antibacterial Activity ◽  
Wound Dressing ◽  
Antibacterial Activities ◽  
Sample Concentration ◽  
Inhibition Concentration ◽  
Maximum Inhibition ◽  
Chitosan Biopolymer

Much attention has been paid to chitosan biopolymer for advanced wound dressing owing to its exceptional biological characteristics comprising biodegradability, biocompatibility and respectable antibacterial activity. This study intended to develop a new antibacterial membrane based on quaternized aminochitosan (QAMCS) derivative. Herein, aminochitosan (AMCS) derivative was quaternized by N-(2-Chloroethyl) dimethylamine hydrochloride with different ratios. The pre-fabricated membranes were characterized by several analysis tools. The results indicate that maximum surface potential of +42.2 mV was attained by QAMCS3 membrane compared with +33.6 mV for native AMCS membrane. Moreover, membranes displayed higher surface roughness (1.27 ± 0.24 μm) and higher water uptake value (237 ± 8%) for QAMCS3 compared with 0.81 ± 0.08 μm and 165 ± 6% for neat AMCS membranes. Furthermore, the antibacterial activities were evaluated against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus cereus. Superior antibacterial activities with maximum inhibition values of 80–98% were accomplished by QAMCS3 membranes compared with 57–72% for AMCS membrane. Minimum inhibition concentration (MIC) results denote that the antibacterial activities were significantly boosted with increasing of polymeric sample concentration from 25 to 250 µg/mL. Additionally, all membranes unveiled better biocompatibility and respectable biodegradability, suggesting their possible application for advanced wound dressing.

Advances in Biomedical Application of Nanocellulose-Based Materials: A Review

2020 ◽  
Vol 28 ◽  
Author(s):  
Qi Yuan ◽  
Jing Bian ◽  
Ming-Guo Ma
Keyword(s):  
Mechanical Properties ◽  
Drug Delivery ◽  
Wound Dressing ◽  
Biomedical Applications ◽  
Biomedical Application ◽  
Cellulose Nanofibers ◽  
Three Dimensional ◽  
Two Dimensional ◽  
One Dimensional ◽  
Sustainable Resources

Background: Recently, there has been increasing interest in nanomaterials processed using renewable and sustainable resources. Nanocellulose-based materials are of paramount value in the applications of biomedicine owing to their tailorable surface modification, favorable optical transparency, good hydrophilicity, excellent biocompatibility, and outstanding mechanical properties. Methods: In the review, the recent advancements of nanocellulose, including cellulose nanofibers (CNFs), cellulose nanocrystals (CNCs), and bacterial cellulose (BC), are summarized, which are promising for biomedical applications. Results: By discussing different forms (one-dimensional (1D), two-dimensional (2D), and three-dimensional (3D)), the superiority of the nanocellulose-based materials with different constructed structures will be clarified for various biomedical applications, such as biosensing, drug delivery, wound dressing, and tissue engineering. Conclusion: Furthermore, the challenges and prospects for future development of nanocellulose-based materials in biomedical applications are also discussed at the end in the review.

Mechanical Analysis of Bacterial Nanocellulose for Biomedical Applications

2012 ◽  
Author(s):  
Joseph M. Schwertz ◽  
Paul Gatenholm ◽  
Alan W. Eberhardt
Keyword(s):  
Mechanical Properties ◽  
Biomedical Applications ◽  
Chemical Structure ◽  
Mechanical Analysis ◽  
Gluconacetobacter Xylinus ◽  
Bacterial Nanocellulose

Bacterial nanocellulose (BNC) is a biopolymer that has been used in a variety of applications ranging from speaker diaphragms to biomedical products. With the exact chemical structure as that produced by plants, BNC is created by microbes like Gluconacetobacter xylinus. One of the unique aspects of BNC is its ability to have a wide variety of mechanical properties while in hydrogel form.

COPPER ALLOY No. 675

Alloy Digest ◽  
1971 ◽  
Vol 20 (11) ◽  
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Shear Strength ◽  
Physical Properties ◽  
Tensile Properties ◽  
Copper Alloy ◽  
Heat Treating ◽  
Zinc Alloy ◽  
Good Corrosion Resistance ◽  
Copper Zinc

Abstract COPPER ALLOY No. 675 is a copper-zinc alloy having excellent mechanical properties and good corrosion resistance. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear strength. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Cu-244. Producer or source: Brass mills.

Antioxidant and Antibacterial Activities of Artemisia herba-alba Asso Essential Oil from Middle Atlas, Morocco

2018 ◽  
Vol 16 (S1) ◽  
pp. S48-S54
Author(s):  
Y. Ez zoubi ◽  
S. Lairini ◽  
A. Farah ◽  
K. Taghzouti ◽  
A. El Ouali Lalami
Keyword(s):  
Antibacterial Activity ◽  
Essential Oil ◽  
Foodborne Pathogens ◽  
Food Systems ◽  
Antibacterial Activities ◽  
Culture Collection ◽  
Bornyl Acetate ◽  
Bacterial Strains ◽  
Disk Diffusion Assay ◽  
Different Strains

The purpose of this study was to determine the chemical composition and to evaluate the antioxidant and antibacterial effects of the Moroccan Artemisia herba-alba Asso essential oil against foodborne pathogens. The essential oil of Artemisia herba-alba was analyzed by gas chromatography coupled with mass spectroscopy. The antibacterial activity was assessed against three bacterial strains isolated from foodstuff and three bacterial strains referenced by the ATCC (American Type Culture Collection) using the disk diffusion assay and the macrodilution method. The antioxidant activity was evaluated using the DPPH (2, 2-diphenyl-1- picrylhydrazyl) method. The fourteen compounds of the Artemisia herba-alba essential oil were identified; the main components were identified as β-thujone, chrysanthenone, α-terpineol, α-thujone, α-pinene, and bornyl acetate. The results of the antibacterial activity obtained showed a sensitivity of the different strains to Artemisia herba-alba essential oil with an inhibition diameter of 8.50 to 17.00 mm. Concerning the MICs (minimum inhibitory concentrations), the essential oil exhibited much higher antibacterial activity with MIC values of 2.5 μl/ml against Bacillus subtilis ATCC and Lactobacillus sp. The essential oil was found to be active by inhibiting free radicals with an IC50 (concentration of an inhibitor where the response is reduced by half) value of 2.9 μg/ml. These results indicate the possible use of the essential oil on food systems as an effective inhibitor of foodborne pathogens, as a natural antioxidant, and for potential pharmaceutical applications. However, further research is needed in order to determine the toxicity, antibacterial, and antioxidant effects in edible products.

Cellulose Nanofibrils-based Hydrogels for Biomedical Applications: Progresses and Challenges

2020 ◽  
Vol 27 (28) ◽  
pp. 4622-4646 ◽  
Author(s):  
Huayu Liu ◽  
Kun Liu ◽  
Xiao Han ◽  
Hongxiang Xie ◽  
Chuanling Si ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Metal Ion ◽  
Biomedical Applications ◽  
Biomedical Application ◽  
Cellulose Nanofibrils ◽  
Wound Dressings ◽  
Preparation Methods ◽  
Tissue Scaffold ◽  
Surface Areas ◽  
Mechanical Methods

Background: Cellulose Nanofibrils (CNFs) are natural nanomaterials with nanometer dimensions. Compared with ordinary cellulose, CNFs own good mechanical properties, large specific surface areas, high Young's modulus, strong hydrophilicity and other distinguishing characteristics, which make them widely used in many fields. This review aims to introduce the preparation of CNFs-based hydrogels and their recent biomedical application advances. Methods: By searching the recent literatures, we have summarized the preparation methods of CNFs, including mechanical methods and chemical mechanical methods, and also introduced the fabrication methods of CNFs-based hydrogels, including CNFs cross-linked with metal ion and with polymers. In addition, we have summarized the biomedical applications of CNFs-based hydrogels, including scaffold materials and wound dressings. Results: CNFs-based hydrogels are new types of materials that are non-toxic and display a certain mechanical strength. In the tissue scaffold application, they can provide a micro-environment for the damaged tissue to repair and regenerate it. In wound dressing applications, it can fit the wound surface and protect the wound from the external environment, thereby effectively promoting the healing of skin tissue. Conclusion: By summarizing the preparation and application of CNFs-based hydrogels, we have analyzed and forecasted their development trends. At present, the research of CNFs-based hydrogels is still in the laboratory stage. It needs further exploration to be applied in practice. The development of medical hydrogels with high mechanical properties and biocompatibility still poses significant challenges.

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