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12 pages, 17489 KiB

Open AccessArticle

Porous Coatings to Control Release Rates of Essential Oils to Generate an Atmosphere with Botanical Actives

by Kai Hettmann, Fabien W. Monnard, Gabriela Melo Rodriguez, Florentine M. Hilty, Selçuk Yildirim and Joachim Schoelkopf

Materials 2022, 15(6), 2155; https://doi.org/10.3390/ma15062155 - 15 Mar 2022

Cited by 4 | Viewed by 1992

Abstract

Essential oils have been used in diverse areas such as packaging, agriculture and cosmetics, for their antimicrobial and pesticide activity. The organic volatile compounds of the essential oils are involved in its activity. Controlling their release helps to prolong their functionality. In this [...] Read more.

Essential oils have been used in diverse areas such as packaging, agriculture and cosmetics, for their antimicrobial and pesticide activity. The organic volatile compounds of the essential oils are involved in its activity. Controlling their release helps to prolong their functionality. In this study, a functionalized calcium carbonate porous coating was employed to control the release of thyme and rosemary oil in a confined space. The release rate was evaluated at 7 °C and 23 °C, gravimetrically. It was shown that the capillary effect of the porous coating slowed down the release of the volatiles into the headspace compared to the bulk essential oil. A linear drive force model was used to fit the obtained data from both essential oils. The model showed that rosemary reached the asymptotic mass loss equilibrium faster than thyme. This result can be explained by the diverse composition and concentration of monoterpenoids between the two essential oils. Temperature and degree of loading also played important roles in the desorption of the essential oils. It was observed that at high degrees of loading and temperatures the desorption of essential oils was higher. The above-described technology could be used for applications related to food preservation, pest control among others. Full article

(This article belongs to the Special Issue Novel Materials for Antimicrobial Application)

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11 pages, 1477 KiB

Open AccessCommunication

Antimicrobial, Antibiofilm, and Antioxidant Activity of Functional Poly(Butylene Succinate) Films Modified with Curcumin and Carvacrol

by Łukasz Łopusiewicz, Szymon Macieja, Artur Bartkowiak and Mirosława El Fray

Materials 2021, 14(24), 7882; https://doi.org/10.3390/ma14247882 - 20 Dec 2021

Cited by 5 | Viewed by 1769

Abstract

The use of food industry waste as bioactive compounds in the modification of biodegradable films as food packaging remains a major challenge. This study describes the preparation and bioactivity characterization of poly(butylene succinate) (PBS)-based films with the addition of the bioactive compounds curcumin [...] Read more.

The use of food industry waste as bioactive compounds in the modification of biodegradable films as food packaging remains a major challenge. This study describes the preparation and bioactivity characterization of poly(butylene succinate) (PBS)-based films with the addition of the bioactive compounds curcumin (CUR) and carvacrol (CAR). Films based on PBS modified with curcumin and carvacrol at different concentration variations (0%/0.1%/1%) were prepared by solvent casting method. The antioxidant, antimicrobial, and antibiofilm properties were investigated against bacteria (Escherichia coli, Staphylococcus aureus) and fungi (Candida albicans). As a result of the modification, the films exhibited free radicals scavenging (DPPH up to 91.47% and ABTS up to 99.21%), as well as antimicrobial (6 log, 4 log, and 2 log reductions for E. coli, S. aureus, and C. albicans, respectively, for samples modified with 1% CUR and 1% CAR) activity. Moreover, antibiofilm activity of modified materials was observed (8.22–87.91% reduction of biofilm, depending on bioactive compounds concentration). PBS films modified with curcumin and carvacrol with observed bifunctional properties have many potential applications as active packaging. Full article

(This article belongs to the Special Issue Novel Materials for Antimicrobial Application)

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21 pages, 13927 KiB

Open AccessArticle

Synthesis and Physicochemical Characterization of Novel Dicyclopropyl-Thiazole Compounds as Nontoxic and Promising Antifungals

by Anna Biernasiuk, Anna Banasiewicz, Maciej Masłyk, Aleksandra Martyna, Monika Janeczko, Angelika Baranowska-Łączkowska, Anna Malm and Krzysztof Z. Łączkowski

Materials 2021, 14(13), 3500; https://doi.org/10.3390/ma14133500 - 23 Jun 2021

Cited by 2 | Viewed by 1579

Abstract

There is a need to search for new antifungals, especially for the treatment of the invasive Candida infections, caused mainly by C. albicans. These infections are steadily increasing at an alarming rate, mostly among immunocompromised patients. The newly synthesized compounds (3a [...] Read more.

There is a need to search for new antifungals, especially for the treatment of the invasive Candida infections, caused mainly by C. albicans. These infections are steadily increasing at an alarming rate, mostly among immunocompromised patients. The newly synthesized compounds (3a–3k) were characterized by physicochemical parameters and investigated for antimicrobial activity using the microdilution broth method to estimate minimal inhibitory concentration (MIC). Additionally, their antibiofilm activity and mode of action together with the effect on the membrane permeability in C. albicans were investigated. Biofilm biomass and its metabolic activity were quantitatively measured using crystal violet (CV) staining and tetrazolium salt (XTT) reduction assay. The cytotoxic effect on normal human lung fibroblasts and haemolytic effect were also evaluated. The results showed differential activity of the compounds against yeasts (MIC = 0.24–500 µg/mL) and bacteria (MIC = 125–1000 µg/mL). Most compounds possessed strong antifungal activity (MIC = 0.24–7.81 µg/mL). The compounds 3b, 3c and 3e, showed no inhibitory (at 1/2 × MIC) and eradication (at 8 × MIC) effect on C. albicans biofilm. Only slight decrease in the biofilm metabolic activity was observed for compound 3b. Moreover, the studied compounds increased the permeability of the membrane/cell wall of C. albicans and their mode of action may be related to action within the fungal cell wall structure and/or within the cell membrane. It is worth noting that the compounds had no cytotoxicity effect on pulmonary fibroblasts and erythrocytes at concentrations showing anticandidal activity. The present studies in vitro confirm that these derivatives appear to be a very promising group of antifungals for further preclinical studies. Full article

(This article belongs to the Special Issue Novel Materials for Antimicrobial Application)

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12 pages, 4152 KiB

Open AccessArticle

Drug Carriers Based on Graphene Oxide and Hydrogel: Opportunities and Challenges in Infection Control Tested by Amoxicillin Release

by Anna Trusek and Edward Kijak

Materials 2021, 14(12), 3182; https://doi.org/10.3390/ma14123182 - 09 Jun 2021

Cited by 14 | Viewed by 2532

Abstract

Graphene oxide (GO) was proposed as an efficient carrier of antibiotics. The model drug, amoxicillin (AMOX), was attached to GO using a peptide linker (Leu-Leu-Gly). GO-AMOX was dispersed in a hydrogel to which the enzyme responsible for releasing AMOX from GO was also [...] Read more.

Graphene oxide (GO) was proposed as an efficient carrier of antibiotics. The model drug, amoxicillin (AMOX), was attached to GO using a peptide linker (Leu-Leu-Gly). GO-AMOX was dispersed in a hydrogel to which the enzyme responsible for releasing AMOX from GO was also added. The drug molecules were released by enzymatic hydrolysis of the peptide bond in the linker. As the selected enzyme, bromelain, a plant enzyme, was used. The antibacterial nature of the carrier was determined by its ability to inhibit the growth of the Enterococcus faecalis strain, which is one of the bacterial species responsible for periodontal and root canal diseases. The prepared carrier contained only biocompatible substances, and the confirmation of its lack of cytotoxicity was verified based on the mouse fibrosarcoma cell line WEHI 164. The proposed type of preparation, as a universal carrier of many different antibiotic molecules, can be considered as a suitable solution in the treatment of inflammation in dentistry. Full article

(This article belongs to the Special Issue Novel Materials for Antimicrobial Application)

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19 pages, 5806 KiB

Open AccessFeature PaperArticle

Collagen-Carboxymethylcellulose Biocomposite Wound-Dressings with Antimicrobial Activity

by Ionela Andreea Neacsu, Sorina-Alexandra Leau, Stefania Marin, Alina Maria Holban, Bogdan-Stefan Vasile, Adrian-Ionut Nicoara, Vladimir Lucian Ene, Coralia Bleotu, Mădălina Georgiana Albu Kaya and Anton Ficai

Materials 2021, 14(5), 1153; https://doi.org/10.3390/ma14051153 - 01 Mar 2021

Cited by 21 | Viewed by 3086

Abstract

Microbial infections associated with skin diseases are frequently investigated since they impact on the progress of pathology and healing. The present work proposes the development of freeze-dried, glutaraldehyde cross-linked, and non-cross-linked biocomposite dressings with a porous structure, which may assist the reepithelization process [...] Read more.

Microbial infections associated with skin diseases are frequently investigated since they impact on the progress of pathology and healing. The present work proposes the development of freeze-dried, glutaraldehyde cross-linked, and non-cross-linked biocomposite dressings with a porous structure, which may assist the reepithelization process through the presence of collagen and carboxymethylcellulose, along with a therapeutic antimicrobial effect, due to silver nanoparticles (AgNPs) addition. Phisyco-chemical characterization revealed the porous morphology of the obtained freeze-dried composites, the presence of high crystalline silver nanoparticles with truncated triangular and polyhedral morphologies, as well as the characteristic absorption bands of collagen, silver, and carboxymethylcellulose. In vitro tests also assessed the stability, functionality, and the degradability rate of the obtained wound-dressings. Antimicrobial assay performed on Gram-negative (Escherichia coli), Gram-positive (Staphyloccocus aureus) bacteria, and yeast (Candida albicans) models demonstrated that composite wound dressings based on collagen, carboxymethylcellulose, and AgNPs are suitable for skin lesions because they prevent the risk of infection and have prospective wound healing capacity. Moreover, the cell toxicity studies proved that the obtained materials can be used in long time treatments, with no cytotoxic effects. Full article

(This article belongs to the Special Issue Novel Materials for Antimicrobial Application)

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12 pages, 3119 KiB

Open AccessFeature PaperArticle

Bacterial Surface Colonization of Sputter-Coated Platinum Films

by Dominika Czerwińska-Główka, Wioletta Przystaś, Ewa Zabłocka-Godlewska, Sebastian Student, Beata Cwalina, Mieczysław Łapkowski and Katarzyna Krukiewicz

Materials 2020, 13(12), 2674; https://doi.org/10.3390/ma13122674 - 12 Jun 2020

Cited by 9 | Viewed by 2292

Abstract

Due to its biocompatibility and advantageous electrochemical properties, platinum is commonly used in the design of biomedical devices, e.g., surgical instruments, as well as electro-medical or orthopedic implants. This article verifies the hypothesis that a thin layer of sputter-coated platinum may possess antibacterial [...] Read more.

Due to its biocompatibility and advantageous electrochemical properties, platinum is commonly used in the design of biomedical devices, e.g., surgical instruments, as well as electro-medical or orthopedic implants. This article verifies the hypothesis that a thin layer of sputter-coated platinum may possess antibacterial effects. The purpose of this research was to investigate the adhesion and growth ability of a model strain of Gram-negative bacteria, Escherichia coli, on a surface of a platinum-coated glass slide. Although some previous literature reports suggests that a thin layer of platinum would inhibit the formation of bacterial biofilm, the results of this study suggest otherwise. The decrease in the number of bacterial cells attached to the platinum-coated glass, which was observed within first three hours of culturing, was found to be a short-time effect, vanishing after 24 h. Consequently, it was shown that a thin layer of sputter-coated platinum did not exhibit any antibacterial effect. For this reason, this study indicates an urgent need for the development of new methods of surface modification that could reduce bacterial surface colonization of platinum-based biomedical devices. Full article

(This article belongs to the Special Issue Novel Materials for Antimicrobial Application)

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15 pages, 1388 KiB

Open AccessArticle

Coumarin Derivatives as New Toxic Compounds to Selected K12, R1–R4 E. coli Strains

by Paweł Kowalczyk, Arleta Madej, Daniel Paprocki, Mateusz Szymczak and Ryszard Ostaszewski

Materials 2020, 13(11), 2499; https://doi.org/10.3390/ma13112499 - 30 May 2020

Cited by 18 | Viewed by 2931

Abstract

Coumarins are natural compounds that were detected in 80 species of plants. They have numerous applications including the medical, food, tobacco, perfumery, and spirit industries. They show anti-swelling and diastolic effects. However, excess consumption of coumarins may adversely affect our health, because they [...] Read more.

Coumarins are natural compounds that were detected in 80 species of plants. They have numerous applications including the medical, food, tobacco, perfumery, and spirit industries. They show anti-swelling and diastolic effects. However, excess consumption of coumarins may adversely affect our health, because they are easily absorbed from the intestines into the lymph and blood, causing cirrhosis of the liver. Peptidomimetics are molecules whose structure and function are similar to those of peptides. They are an important group of compounds with biological, microbiological, anti-inflammatory, and anti-cancer properties. Therefore, studies on new peptidomimetics, which load the effect of native peptides, whose half-life in the body is much longer due to structural modifications, are extremely important. A preliminary study of coumarin analogues and its derivatives as new potential antimicrobial drugs containing carboxylic acid or ester was performed to determine their basic structure related to their biological features against various types of Gram-stained bacteria by lipopolysaccharide (LPS). We hypothesized that the toxicity (antibacterial activity) of coumarin derivatives is dependent on the of LPS in bacteria and nature and position of the substituent which may be carboxylic acid, hydroxyl groups, or esters. In order to verify this hypothesis, we used K12 (smooth) and R1–R4 (rough) Escherichia coli strains which are characterized by differences in the type of LPS, especially in the O-antigen region, the outermost LPS layer. In our work, we synthesized 17 peptidomimetics containing a coumarin scaffold and checked their influence on K12 and R1–R4 E. coli strains possessing smooth and rough LPS. We also measured the damage of plasmid DNA caused by target compounds. The results of our studies clearly support the conclusion that coumarin peptidomimetics are antagonistic compounds to many of the currently used antibiotics. The high biological activity of the selected coumarin peptidomimetic was associated with identification of the so-called magic methyl groups, which substantially change the biochemical properties of target compounds. Investigating the effects of these compounds is particularly important in the era of increasingly common resistance in bacteria. Full article

(This article belongs to the Special Issue Novel Materials for Antimicrobial Application)

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25 pages, 5535 KiB

Open AccessArticle

Bioactive Properties of Nanofibres Based on Concentrated Collagen Hydrolysate Loaded with Thyme and Oregano Essential Oils

by Mariana Daniela Berechet, Carmen Gaidau, Aleksandra Miletic, Branka Pilic, Maria Râpă, Maria Stanca, Lia-Mara Ditu, Rodica Constantinescu and Andrada Lazea-Stoyanova

Materials 2020, 13(7), 1618; https://doi.org/10.3390/ma13071618 - 01 Apr 2020

Cited by 28 | Viewed by 3691

Abstract

This research aimed to obtain biocompatible and antimicrobial nanofibres based on concentrated collagen hydrolysate loaded with thyme or oregano essential oils as a natural alternative to synthesis products. The essential oils were successfully incorporated using electrospinning process into collagen resulting nanofibres with diameter [...] Read more.

This research aimed to obtain biocompatible and antimicrobial nanofibres based on concentrated collagen hydrolysate loaded with thyme or oregano essential oils as a natural alternative to synthesis products. The essential oils were successfully incorporated using electrospinning process into collagen resulting nanofibres with diameter from 471 nm to 580 nm and porous structure. The presence of essential oils in collagen nanofibre mats was confirmed by Attenuated Total Reflectance -Fourier Transform Infrared Spectroscopy (ATR-FTIR), Ultraviolet–visible spectroscopy (UV–VIS) and antimicrobial activity. Scanning Electron Microscopy with Energy Dispersive Spectroscopy analyses allowed evaluating the morphology and constituent elements of the nanofibre networks. Microbiological tests performed against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans showed that the presence of essential oils supplemented the new collagen nanofibres with antimicrobial properties. The biocompatibility of collagen and collagen with essential oils was assessed by in vitro cultivation with NCTC clone 929 of fibroblastic cells and cell viability measurement. The results showed that the collagen and thyme or oregano oil composites have no cytotoxicity up to concentrations of 1000 μg·mL⁻¹ and 500 μg mL⁻¹, respectively. Optimization of electrospinning parameters has led to the obtaining of new collagen electrospun nanofibre mats loaded with essential oils with potential use for wound dressings, tissue engineering or protective clothing. Full article

(This article belongs to the Special Issue Novel Materials for Antimicrobial Application)

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25 pages, 5346 KiB

Open AccessFeature PaperArticle

Nanomagnetite-embedded PLGA Spheres for Multipurpose Medical Applications

by Valentina Grumezescu, Oana Gherasim, Irina Negut, Stefan Banita, Alina Maria Holban, Paula Florian, Madalina Icriverzi and Gabriel Socol

Materials 2019, 12(16), 2521; https://doi.org/10.3390/ma12162521 - 08 Aug 2019

Cited by 10 | Viewed by 3378

Abstract

We report on the synthesis and evaluation of biopolymeric spheres of poly(lactide-co-glycolide) containing different amounts of magnetite nanoparticles and Ibuprofen (PLGA-Fe₃O₄-IBUP), but also chitosan (PLGA-CS-Fe₃O₄-IBUP), to be considered as drug delivery systems. Besides morphological, structural, [...] Read more.

We report on the synthesis and evaluation of biopolymeric spheres of poly(lactide-co-glycolide) containing different amounts of magnetite nanoparticles and Ibuprofen (PLGA-Fe₃O₄-IBUP), but also chitosan (PLGA-CS-Fe₃O₄-IBUP), to be considered as drug delivery systems. Besides morphological, structural, and compositional characterizations, the PLGA-Fe₃O₄-IBUP composite microspheres were subjected to drug release studies, performed both under biomimetically-simulated dynamic conditions and under external radiofrequency magnetic fields. The experimental data resulted by performing the drug release studies evidenced that PLGA-Fe₃O₄-IBUP microspheres with the lowest contents of Fe₃O₄ nanoparticles are optimal candidates for triggered drug release under external stimulation related to hyperthermia effect. The as-selected microspheres and their chitosan-containing counterparts were biologically assessed on macrophage cultures, being evaluated as biocompatible and bioactive materials that are able to promote cellular adhesion and proliferation. The composite biopolymeric spheres resulted in inhibited microbial growth and biofilm formation, as assessed against Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans microbial strains. Significantly improved antimicrobial effects were reported in the case of chitosan-containing biomaterials, regardless of the microorganisms’ type. The nanostructured composite biopolymeric spheres evidenced proper characteristics as prolonged and controlled drug release platforms for multipurpose biomedical applications. Full article

(This article belongs to the Special Issue Novel Materials for Antimicrobial Application)

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16 pages, 7051 KiB

Open AccessFeature PaperArticle

Antimicrobial Wound Dressings as Potential Materials for Skin Tissue Regeneration

by Andrei Paduraru, Cristina Ghitulica, Roxana Trusca, Vasile Adrian Surdu, Ionela Andreea Neacsu, Alina Maria Holban, Alexandra Catalina Birca, Florin Iordache and Bogdan Stefan Vasile

Materials 2019, 12(11), 1859; https://doi.org/10.3390/ma12111859 - 08 Jun 2019

Cited by 46 | Viewed by 4344

Abstract

The most important properties of performant wound dressings are biocompatibility, the ability to retain large amount of exudate and to avoid complications related with persistent infection which could lead to delayed wound healing. This research aimed to obtain and characterize a new type [...] Read more.

The most important properties of performant wound dressings are biocompatibility, the ability to retain large amount of exudate and to avoid complications related with persistent infection which could lead to delayed wound healing. This research aimed to obtain and characterize a new type of antimicrobial dressings, based on zinc oxide/sodium alginate/polyvinyl alcohol (PVA). Zinc oxide nanostructures, obtained with different morphology and grain size by hydrothermal and polyol methods, are used as antimicrobial agents along with sodium alginate, which is used to improve the biocompatibility of the dressing. The nanofiber dressing was obtained through the electrospinning method. Characterization techniques such as X-ray diffraction (XRD) and scanning electron microscopy (SEM) were performed to determine the structural and morphological properties of the obtained powders and composite fibers. Their antimicrobial activity was tested against Gram negative Escherichia coli (E. coli), Gram positive Staphylococcus aureus (S. aureus) bacteria and Candida albicans (C. albicans) yeast strains. The in vitro biocompatibility of the obtained composites was tested on human diploid cells. The obtained results suggest that the composite fibers based on zinc oxide and alginate are suitable for antimicrobial protection, are not toxic and may be useful for skin tissue regeneration if applied as a dressing. Full article

(This article belongs to the Special Issue Novel Materials for Antimicrobial Application)

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Review

Jump to: Research

36 pages, 5826 KiB

Open AccessReview

A Technological Understanding of Biofilm Detection Techniques: A Review

by Spyridon Achinas, Stijn Keimpe Yska, Nikolaos Charalampogiannis, Janneke Krooneman and Gerrit Jan Willem Euverink

Materials 2020, 13(14), 3147; https://doi.org/10.3390/ma13143147 - 15 Jul 2020

Cited by 14 | Viewed by 3813

Abstract

Biofouling is a persistent problem in almost any water-based application in several industries. To eradicate biofouling-related problems in bioreactors, the detection of biofilms is necessary. The current literature does not provide clear supportive information on selecting biofilm detection techniques that can be applied [...] Read more.

Biofouling is a persistent problem in almost any water-based application in several industries. To eradicate biofouling-related problems in bioreactors, the detection of biofilms is necessary. The current literature does not provide clear supportive information on selecting biofilm detection techniques that can be applied to detect biofouling within bioreactors. Therefore, this research aims to review all available biofilm detection techniques and analyze their characteristic properties to provide a comparative assessment that researchers can use to find a suitable biofilm detection technique to investigate their biofilms. In addition, it discusses the confluence of common bioreactor fabrication materials in biofilm formation. Full article

(This article belongs to the Special Issue Novel Materials for Antimicrobial Application)

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16 pages, 1018 KiB

Open AccessReview

Nanomaterials for Wound Healing and Infection Control

by Mara Madalina Mihai, Monica Beatrice Dima, Bogdan Dima and Alina Maria Holban

Materials 2019, 12(13), 2176; https://doi.org/10.3390/ma12132176 - 06 Jul 2019

Cited by 259 | Viewed by 20277

Abstract

Wound healing has been intensely studied in order to develop an “ideal” technique that achieves expeditious recovery and reduces scarring to the minimum, thus ensuring function preservation. The classic approach to wound management is represented by topical treatments, such as antibacterial or colloidal [...] Read more.

Wound healing has been intensely studied in order to develop an “ideal” technique that achieves expeditious recovery and reduces scarring to the minimum, thus ensuring function preservation. The classic approach to wound management is represented by topical treatments, such as antibacterial or colloidal agents, in order to prevent infection and promote a proper wound-healing process. Nanotechnology studies submicroscopic particles (maximum diameter of 100 nm), as well as correlated phenomena. Metal nanoparticles (e.g., silver, gold, zinc) are increasingly being used in dermatology, due to their beneficial effect on accelerating wound healing, as well as treating and preventing bacterial infections. Other benefits include: ease of use, less frequent dressing changes and a constantly moist wound environment. This review highlights recent findings regarding nanoparticle application in wound management. Full article

(This article belongs to the Special Issue Novel Materials for Antimicrobial Application)

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