Cellulose Acetate Based Material with Antibacterial Properties Created by Supercritical Solvent Impregnation

Supercritical CO2 was used as a green solvent and impregnation medium for loading cellulose acetate beads with carvacrol in order to obtain a biomaterial with antibacterial properties. Supercritical solvent impregnation was performed in a high-pressure view cell at temperature of 50°C and pressures of 10, 21, and 30 MPa with the processing time ranging from 2 to 18 h. The rate of impregnation increased with the pressure increase. However, maximum impregnation yield (round 60%) was not affected by the pressure applied. Selected samples of the impregnated cellulose acetate containing 6–60% of carvacrol were proven to have considerable antibacterial effect against Gram-positive and Gram-negative bacterial strains including methicillin-resistant Staphylococcus aureus which causes severe infections in humans and animals. In addition, cellulose acetate beads containing 6.0–33.6% of carvacrol were shown to have a porous structure with submicron pores which is of interest for the controlled delivery applications.

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Functional Modification of Cellulose Acetate Microfiltration Membranes by Supercritical Solvent Impregnation

Molecules ◽

10.3390/molecules26020411 ◽

2021 ◽

Vol 26 (2) ◽

pp. 411

Author(s):

Irena Zizovic ◽

Marcin Tyrka ◽

Konrad Matyja ◽

Ivana Moric ◽

Lidija Senerovic ◽

...

Keyword(s):

Cellulose Acetate ◽

Ion Beam ◽

Antibacterial Properties ◽

Cross Flow ◽

Batch Mode ◽

Impregnation Process ◽

Supercritical Solvent ◽

Cross Flow Filtration ◽

Microfiltration Membranes ◽

The Impact

This study investigates the modification of commercial cellulose acetate microfiltration membranes by supercritical solvent impregnation with thymol to provide them with antibacterial properties. The impregnation process was conducted in a batch mode, and the effect of pressure and processing time on thymol loading was followed. The impact of the modification on the membrane’s microstructure was analyzed using scanning electron and ion-beam microscopy, and membranes’ functionality was tested in a cross-flow filtration system. The antibiofilm properties of the obtained materials were studied against Staphyloccocus aureus and Pseudomonas aeruginosa, while membranes’ blocking in contact with bacteria was examined for S. aureus and Escherichia coli. The results revealed a fast impregnation process with high thymol loadings achievable after just 0.5 h at 15 MPa and 20 MPa. The presence of 20% of thymol provided strong antibiofilm properties against the tested strains without affecting the membrane’s functionality. The study showed that these strong antibacterial properties could be implemented to the commercial membranes’ defined polymeric structure in a short and environmentally friendly process.

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Printable Resin Modified by Grafted Silver Nanoparticles for Preparation of Antifouling Microstructures with Antibacterial Effect

Polymers ◽

10.3390/polym13213838 ◽

2021 ◽

Vol 13 (21) ◽

pp. 3838

Author(s):

Hazem Idriss ◽

Roman Elashnikov ◽

Silvie Rimpelová ◽

Barbora Vokatá ◽

Petr Haušild ◽

...

Keyword(s):

Silver Nanoparticles ◽

Antibacterial Effect ◽

Low Cost ◽

Antibacterial Properties ◽

Silver Ions ◽

Polymerization Process ◽

Resin Matrix ◽

Bacterial Strains ◽

Ion Release ◽

3D Printed

The usage of three-dimensional (3D) printed materials in many bioapplications has been one of the fastest-growing sectors in the nanobiomaterial industry in the last couple of years. In this work, we present a chemical approach for grafting silver nanoparticles (AgNPs) into a resin matrix, which is convenient for 3D printing. In this way, the samples can be prepared and are able to release silver ions (Ag+) with excellent antibacterial effect against bacterial strains of E. coli and S. epidermidis. By the proposed process, the AgNPs are perfectly mixed and involved in the polymerization process and their distribution in the matrix is homogenous. It was also demonstrated that this approach does not affect the printing resolution and the resin is therefore suitable for the construction of microstructures enabling controlled silver ion release and antifouling properties. At the same time the physical properties of the material, such as viscosity and elasticity modulus are preserved. The described approach can be used for the fabrication of facile, low-cost 3D printed resin with antifouling-antibacterial properties with the possibility to control the release of Ag+ through microstructuring.

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Antibacterial Effect of Colloidal Suspensions Varying in Silver Nanoparticles and Ions Concentrations

Nanomaterials ◽

10.3390/nano12010031 ◽

2021 ◽

Vol 12 (1) ◽

pp. 31

Author(s):

Varvara Platania ◽

Alexandra Kaldeli-Kerou ◽

Theodora Karamanidou ◽

Maria Kouki ◽

Alexander Tsouknidas ◽

...

Keyword(s):

Silver Nanoparticles ◽

Antibacterial Effect ◽

Antibacterial Properties ◽

Antimicrobial Properties ◽

Colloidal Suspensions ◽

Silver Ions ◽

Cellular Level ◽

Bacterial Strains ◽

Three Samples ◽

Flow Filtration

A lot of effort has been dedicated recently to provide a better insight into the mechanism of the antibacterial activity of silver nanoparticles (AgNPs) colloidal suspensions and their released silver ionic counterparts. However, there is no consistency regarding whether the antibacterial effect displayed at cellular level originates from the AgNPs or their ionic constitutes. To address this issue, three colloidal suspensions exhibiting different ratios of AgNPs/silver ions were synthesized by a wet chemistry method in conjunction with tangential flow filtration, and were characterized and evaluated for their antimicrobial properties against two gram-negative, Escherichia coli (E. coli) and Pseudomonas aeruginosa (P. aeruginosa), and two gram-positive, Staphylococcus aureus (S. aureus) and Staphylococcus epidermidis (S. epidermidis), bacterial strains. The produced samples contained 25% AgNPs and 75% Ag ions (AgNP_25), 50% AgNPs and 50% Ag ions (AgNP_50), and 100% AgNPs (AgNP_100). The sample AgNP_100 demonstrated the lowest minimum inhibitory concentration values ranging from 4.6 to 15.6 ppm for all four bacterial strains, while all three samples indicated minimum bactericidal concentration (MBC) values ranging from 16.6 ppm to 62.5 ppm against all strains. An increase in silver ions content results in higher bactericidal activity. All three samples were found to lead to a significant morphological damage by disruption of the bacterial cell membranes as analyzed by means of scanning electron microscopy (SEM). The growth kinetics demonstrated that all three samples were able to reduce the bacterial population at a concentration of 3.1 ppm. SEM and growth kinetic data underline that S. epidermidis is the most sensitive among all strains against the investigated samples. Our results showed that all three AgNPs colloidal suspensions exhibited strong antibacterial properties and, thus, they can be applied in medical devices and antimicrobial control systems.

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The antibacterial effect of sonication and its potential medical application

SICOT-J ◽

10.1051/sicotj/2019017 ◽

2019 ◽

Vol 5 ◽

pp. 19

Author(s):

Srinath Kamineni ◽

Chifu Huang

Keyword(s):

Antibacterial Effect ◽

Tennis Elbow ◽

Wide Spectrum ◽

Bacterial Species ◽

Antibacterial Properties ◽

Bacterial Strains ◽

Ultrasonic Probe ◽

Kill Rate ◽

Aerobic And Anaerobic ◽

Bacterial Effect

Introduction: Recent applications of ultrasonic probes include cataract removal and tennis elbow treatment. Early data support the use of ultrasonic probe debridement in the treatment of recalcitrant diabetic foot ulcers. No data are available concerning the potential antibacterial properties of the clinical grade, lower energy ultrasound probes. We investigated the effect of a clinically available ultrasonic debridement probe with respect to bacterial viability. Methods: A commercially available Tenex sonication machine with a Tx1 probe was used for this study. Three bacterial strains, aerobic and anaerobic, were investigated, G-negative (Porphyromonas gingivalis) and G-positive bacteria (Staphylococcus aureus and Streptococcus gordonii). These bacteria were cultured and tested with sonication for varying lengths of time (10, 30, 60, and 120 s). The tested bacterial samples were plated, the number of colonies on each plate counted, and the anti-bacterial effect was calculated. Statistical analysis was conducted using a one-way analysis of variance. Results: Sonication exhibited a significant time-dependent antibacterial effect. Statistically significant anti-bacterial effect was observed in all three species tested. When comparing the kill rate between the control and 120 s of sonication; S. gordonii had a 34% kill rate, S. aureus had a 60% kill rate, and P. gingivalis had a 64% kill rate. When comparing control to all of the time intervals tested, S. aureus kill rate was statistically significant at all times, S. gordonii was statistically significant at all times above 10 s, and P. gingivalis was only statistically significant at 120 s. Conclusion: This study demonstrates that a clinically available ultrasonic probe has an antibacterial effect against a wide spectrum of gram-positive, gram-negative, aerobic and anaerobic bacterial species. This may partially explain the dramatic healing of long-standing recalcitrant diabetic ulcers debrided with this device and may have a place in treating pathologies with bacterial mechanisms.

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The Assessment of Chitosan Solutions Effects on Bacterial Strains

Revista de Chimie ◽

10.37358/rc.18.6.6351 ◽

2018 ◽

Vol 69 (6) ◽

pp. 1485-1488

Author(s):

Marioara Nicoleta Filimon ◽

Roxana Popescu ◽

Adrian Sinitean ◽

Paula Maniu ◽

Gabi Dumitrescu ◽

...

Keyword(s):

Escherichia Coli ◽

Streptococcus Pyogenes ◽

Legionella Pneumophila ◽

Antibacterial Effect ◽

Antibacterial Properties ◽

Bacterial Strains ◽

Antibacterial Effects ◽

E Coli ◽

Bacterial Cell Viability ◽

And Staphylococcus Aureus

The interest in the antimicrobial actions of chitosan is due to its multiple properties and effects. The aim of the study was to assess the potential antibacterial effects of chitosan applied on 7 bacterial strains: Escherichia coli, Streptococcus pyogenes, Pseudomonas aeruginosa, Enterococcus faecalis, Clostridium perfringens, Legionella pneumophila and Staphylococcus aureus. Six different concentrations of chitosan were dissolved in 1% acetic acid, following two working protocols (Kirby-Bauer method and testing for bacterial cell viability). The sensitivity of tested bacterial strains following the effect of exposure to chitosan decreased as follows: E. coli] L. pneumophila] S. aureus] S. pyogenes] C. perfringens] P. aeruginosa] E. faecalis. The inhibition rates for the bacterial strains E. faecalis, S. pyogenes and S. aureus highlighted again the strong antibacterial properties of this product. Conclude that the chitosan presents a different antibacterial effect against several bacterial strains of interest directly with the employed concentrations.

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Antibacterial Properties of Canine Platelet-Rich Plasma and Other Non-Transfusional Hemo-Components: An in vitro Study

Frontiers in Veterinary Science ◽

10.3389/fvets.2021.746809 ◽

2021 ◽

Vol 8 ◽

Author(s):

Anna-Rita Attili ◽

Cristina Iacoucci ◽

Evelina Serri ◽

Vincenzo Cuteri ◽

Andrea Cantalamessa ◽

...

Keyword(s):

Bacterial Infections ◽

Antibacterial Effect ◽

Platelet Rich Plasma ◽

Antibacterial Properties ◽

In Vitro Study ◽

Diffusion Method ◽

Resistant Bacteria ◽

Veterinary Antibiotics ◽

Bacterial Strains

This in vitro study was carried out to evaluate the potential antibacterial properties of canine non-transfusional hemo-components. Therapeutic formulations commonly used for regenerative medicine purposes (platelet-rich plasma, platelet gel, platelet lysate, fibrin glue), considering both leukocyte-rich and leukocyte-poor formulations, but also platelet-poor plasma and activating substances (thrombin, calcium gluconate), were tested to detect elements with potential antimicrobial properties. The antibacterial effect was tested on different bacterial strains (Staphylococcus aureus subspecies aureus, Staphylococcus cohnii subspecies cohnii, Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae subspecies pneumoniae) isolated from canine wounds and classified as susceptible, multidrug-, extensively, and pandrug-resistant bacteria toward a known panel of human and veterinary antibiotics. The evaluation was carried out by agar gel diffusion method (Kirby–Bauer) and micro-inhibition in broth using microplates and spectrophotometer reading. The study findings confirmed the hypothesized antibacterial properties of canine non-transfusional hemo-components. A more effective bacteriostatic effect was found against Gram-negative bacteria, drug-resistant too. The presence of leukocytes or platelets does not appear to be essential for the antibacterial effect. Further studies should be conducted to evaluate the exact mechanism of action of the antimicrobial activity. However, non-transfusional hemo-components could be a useful natural aid in controlling bacterial infections in dogs.

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Green Synthesis and Incorporation of Sericin Silver Nanoclusters into Electrospun Ultrafine Cellulose Acetate Fibers for Anti-Bacterial Applications

Polymers ◽

10.3390/polym13091411 ◽

2021 ◽

Vol 13 (9) ◽

pp. 1411

Author(s):

Mujahid Mehdi ◽

Huihui Qiu ◽

Bing Dai ◽

Raja Fahad Qureshi ◽

Sadam Hussain ◽

...

Keyword(s):

Electron Microscopy ◽

Green Synthesis ◽

Cellulose Acetate ◽

Antibacterial Properties ◽

Vital Role ◽

Silver Nanoclusters ◽

Composite Fibers ◽

E Coli ◽

Antibacterial Performance ◽

Field Emission Electron Microscopy

Fiber based antibacterial materials have gained an enormous attraction for the researchers in these days. In this study, a novel Sericin Encapsulated Silver Nanoclusters (sericin-AgNCs) were synthesized through single pot and green synthesis route. Subsequently these sericin-AgNCs were incorporated into ultrafine electrospun cellulose acetate (CA) fibers for assessing the antibacterial performance. The physicochemical properties of sericin-AgNCs/CA composite fibers were investigated by transmission electron microscopy (TEM), field emission electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FTIR) and wide X-ray diffraction (XRD). The antibacterial properties of sericin-AgNCs/CA composite fibers against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were systematically evaluated. The results showed that sericin-AgNCs incorporated in ultrafine CA fibers have played a vital role for antibacterial activity. An amount of 0.17 mg/mL sericin-AgNCs to CA fibers showed more than 90% results and elevated upto >99.9% with 1.7 mg/mL of sericin-AgNCs against E. coli. The study indicated that sericin-AgNCs/CA composite confirms an enhanced antibacterial efficiency, which could be used as a promising antibacterial product.

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Effect of Gold Nanoparticles and Silicon on the Bioactivity and Antibacterial Properties of Hydroxyapatite/Chitosan/Tricalcium Phosphate-Based Biomicroconcretes

Materials ◽

10.3390/ma14143854 ◽

2021 ◽

Vol 14 (14) ◽

pp. 3854

Author(s):

Joanna Czechowska ◽

Ewelina Cichoń ◽

Anna Belcarz ◽

Anna Ślósarczyk ◽

Aneta Zima

Keyword(s):

Gold Nanoparticles ◽

Antibacterial Activity ◽

Tricalcium Phosphate ◽

Setting Time ◽

Antibacterial Properties ◽

Bone Substitutes ◽

Bacterial Strains ◽

Setting Times ◽

Biological Studies

Bioactive, chemically bonded bone substitutes with antibacterial properties are highly recommended for medical applications. In this study, biomicroconcretes, composed of silicon modified (Si-αTCP) or non-modified α-tricalcium phosphate (αTCP), as well as hybrid hydroxyapatite/chitosan granules non-modified and modified with gold nanoparticles (AuNPs), were designed. The developed biomicroconcretes were supposed to combine the dual functions of antibacterial activity and bone defect repair. The chemical and phase composition, microstructure, setting times, mechanical strength, and in vitro bioactive potential of the composites were examined. Furthermore, on the basis of the American Association of Textile Chemists and Colorists test (AATCC 100), adapted for chemically bonded materials, the antibacterial activity of the biomicroconcretes against S. epidermidis, E. coli, and S. aureus was evaluated. All biomicroconcretes were surgically handy and revealed good adhesion between the hybrid granules and calcium phosphate-based matrix. Furthermore, they possessed acceptable setting times and mechanical properties. It has been stated that materials containing AuNPs set faster and possess a slightly higher compressive strength (3.4 ± 0.7 MPa). The modification of αTCP with silicon led to a favorable decrease of the final setting time to 10 min. Furthermore, it has been shown that materials modified with AuNPs and silicon possessed an enhanced bioactivity. The antibacterial properties of all of the developed biomicroconcretes against the tested bacterial strains due to the presence of both chitosan and Au were confirmed. The material modified simultaneously with AuNPs and silicon seems to be the most promising candidate for further biological studies.

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Prenylated Flavonoids and C-15 Isoprenoid Analogues with Antibacterial Properties from the Whole Plant of Imperata cylindrica (L.) Raeusch (Gramineae)

Molecules ◽

10.3390/molecules26164717 ◽

2021 ◽

Vol 26 (16) ◽

pp. 4717

Author(s):

Romeo Nago ◽

Paul Nayim ◽

Armelle Mbaveng ◽

James Mpetga ◽

Gabin Bitchagno ◽

...

Keyword(s):

Silica Gel ◽

Methanol Extract ◽

Antibacterial Properties ◽

Imperata Cylindrica ◽

Drug Resistant ◽

Bacterial Strains ◽

Prenylated Flavonoids ◽

Whole Plant ◽

Crude Methanol Extract ◽

Potential Origin

The local botanical Imperata cylindrica in Cameroon was investigated for its antibacterial potency. The methanol extract afforded a total of seven compounds, including five hitherto unreported compounds comprising three flavonoids (1–3) and two C-15 isoprenoid analogues (4 and 5) together with known derivatives (6 and 7). The novelty of the flavonoids was related to the presence of both methyl and prenyl groups. The potential origin of the methyl in the flavonoids is discussed, as well as the chemophenetic significance of our findings. Isolation was performed over repeated silica gel and Sephadex LH-20 column chromatography and the structures were elucidated by (NMR and MS). The crude methanol extract and isolated compounds showed considerable antibacterial potency against a panel of multi-drug resistant (MDR) bacterial strains. The best MIC values were obtained with compound (2) against S. aureus ATCC 25923 (32 µg/mL) and MRSA1 (16 µg/mL).

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Synthesis, Characterization, Antibacterial Properties, and In Vitro Studies of Selenium and Strontium Co-Substituted Hydroxyapatite

International Journal of Molecular Sciences ◽

10.3390/ijms22084246 ◽

2021 ◽

Vol 22 (8) ◽

pp. 4246

Author(s):

Muhammad Maqbool ◽

Qaisar Nawaz ◽

Muhammad Atiq Ur Atiq Ur Rehman ◽

Mark Cresswell ◽

Phil Jackson ◽

...

Keyword(s):

Negative Impact ◽

Antibacterial Properties ◽

Biological Properties ◽

Ion Concentration ◽

Charge Composition ◽

Bacterial Strains ◽

X Ray Diffraction ◽

Molar Ratios ◽

Human Osteosarcoma Cells

In this study, as a measure to enhance the antimicrobial activity of biomaterials, the selenium ions have been substituted into hydroxyapatite (HA) at different concentration levels. To balance the potential cytotoxic effects of selenite ions (SeO32−) in HA, strontium (Sr2+) was co-substituted at the same concentration. Selenium and strontium-substituted hydroxyapatites (Se-Sr-HA) at equal molar ratios of x Se/(Se + P) and x Sr/(Sr + Ca) at (x = 0, 0.01, 0.03, 0.05, 0.1, and 0.2) were synthesized via the wet precipitation route and sintered at 900 °C. The effect of the two-ion concentration on morphology, surface charge, composition, antibacterial ability, and cell viability were studied. X-ray diffraction verified the phase purity and confirmed the substitution of selenium and strontium ions. Acellular in vitro bioactivity tests revealed that Se-Sr-HA was highly bioactive compared to pure HA. Se-Sr-HA samples showed excellent antibacterial activity against both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus carnosus) bacterial strains. In vitro cell–material interaction, using human osteosarcoma cells MG-63 studied by WST-8 assay, showed that Se-HA has a cytotoxic effect; however, the co-substitution of strontium in Se-HA offsets the negative impact of selenium and enhanced the biological properties of HA. Hence, the prepared samples are a suitable choice for antibacterial coatings and bone filler applications.

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