Hemostatic and antibacterial PVA/Kaolin composite sponges loaded with penicillin–streptomycin for wound dressing applications

AbstractHemorrhage is the major hindrance over the wound healing, which triggers microbial infections and might provoke traumatic death. Herein, new hemostatic and antibacterial PVA/Kaolin composite sponges were crosslinked using a freeze-thawing approach and boosted by penicillin–streptomycin (Pen-Strep). Physicochemical characteristics of developed membranes were analyzed adopting Fourier transformed infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), a thermal gravimetric analyzer (TGA), and differential scanning calorimetry (DSC). Furthermore, the impacts of kaolin concentrations on porosity, swelling behavior, gel fraction, and degradation of the membranes were investigated. SEM analyses revealed a spongy-like structure of hydrogels associated with high dispersion of kaolin inside PVA matrix. The thermal characteristics of PVA/Kaolin were significantly ameliorated compared to the prime PVA. Moreover, the results exhibited significant variations of swelling performance, surface roughness and pore capacity due to the alterations of kaolin contents. Besides, the adhesive strength ability was manifestly enhanced for PVA-K0.1 sponge. Biomedical evaluations including antibacterial activity, blood clotting index and thrombogenicity of the membranes were studied. The contact of PVA/Kaolin to blood revealed notable augmentation in blood clotting. Furthermore, the incorporation of kaolin into PVA presented mild diminution in antibacterial activities. Moreover, PVA/Kaolin composites illustrated no cellular toxicity towards fibroblast cells. These remarkable features substantiate that the PVA-K0.1 sponge could be applied as a multifunctional wound dressing.

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Comprehensive Thermal Characteristics of Different Cultivars of Flaxseed Oil (Linum usittatissimum L.)

Molecules ◽

10.3390/molecules26071958 ◽

2021 ◽

Vol 26 (7) ◽

pp. 1958

Author(s):

Jolanta Tomaszewska-Gras ◽

Mahbuba Islam ◽

Liliana Grzeca ◽

Anna Kaczmarek ◽

Emilia Fornal

Keyword(s):

Differential Scanning Calorimetry ◽

Heating Rate ◽

Fatty Acid Content ◽

Thermal Characteristics ◽

Principal Component ◽

Flaxseed Oil ◽

Scanning Calorimetry ◽

Total Oxidation ◽

Increasing Temperature ◽

Linear Correlations

The aim of this study was to describe the thermal properties of selected cultivars of flaxseed oil by the use of the differential scanning calorimetry (DSC) technique. The crystallization and melting profiles were analyzed depending on different scanning rates (1, 2, 5 °C/min) as well as oxidative induction time (OIT) isothermally at 120 °C and 140 °C, and oxidation onset temperatures (Ton) at 2 and 5 °C/min were measured. The crystallization was manifested as a single peak, differing for a cooling rate of 1 and 2 °C/min. The melting curves were more complex with differences among the cultivars for a heating rate of 1 and 2 °C/min, while for 5 °C/min, the profiles did not differ, which could be utilized in analytics for profiling in order to assess the authenticity of the flaxseed oil. Moreover, it was observed that flaxseed oil was highly susceptible to thermal oxidation, and its stability decreased with increasing temperature and decreasing heating rate. Significant negative linear correlations were found between unsaturated fatty acid content (C18:2, C18:3 n-3) and DSC parameters (OIT, Ton). Principal component analysis (PCA) also established a strong correlation between total oxidation value (TOTOX), peroxide value (PV) and all DSC parameters of thermo-oxidative stability.

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Tantalum doped SiO2-CaO-P2O5 based bioactive glasses: Investigation of in vitro bioactivity and antibacterial activities

Biomedical glasses ◽

10.1515/bglass-2020-0002 ◽

2020 ◽

Vol 6 (1) ◽

pp. 10-22

Author(s):

Zakaria Tabia ◽

Sihame Akhtach ◽

Khalil El Mabrouk ◽

Meriame Bricha ◽

Khalid Nouneh ◽

...

Keyword(s):

Antibacterial Activities ◽

Silica Matrix ◽

Morphological Properties ◽

Metallic Ions ◽

X Ray Diffraction ◽

Bioactive Glasses ◽

E Coli ◽

Fourier Transformed Infrared Spectroscopy ◽

Electron Scanning Microscopy

AbstractMultifunctionality can be achieved for bioactive glasses by endowing them with multiple other properties along with bioactivity. One way to address this topic is by doping these glasses with therapeutic metallic ions. In this work, we put under investigation a series of bioactive glasses doped with tantalum. We aim to study the effect of tantalum, on the structure, bioactivity and antibacterial property of a ternary bioactive glass composition based on SiO2-CaO-P2O5. Fourier Transformed Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD) and Electron Scanning Microscopy (SEM) were used to assess the structural and morphological properties of these glasses and monitor their changes after in vitro acellular bioactivity test. Antibacterial activity was tested against gram positive and negative bacteria. Characterization results confirmed the presence of calcium carbonate crystallites along with the amorphous silica matrix. The assessment of bioactivity in SBF indicated that all compositions showed a fast bioactive response after only six hours of immersion period. However, analytical characterization revealed that tantalum introduced a slight latency in hydroxyapatite deposition at higher concentrations (0.8-1 %mol). Antibacterial test showed that tantalum ions had an inhibition effect on the growth of E. coli and S. aureus. This effect was more pronounced in compositions where mol% of tantalum is superior to 0.4%. These results proved that tantalum could be used, in intermediate proportions, as a promising multifunctional dopant element in bioactive glasses for bone regeneration applications.

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Effect of Silver Ions on the Structural and Antibacterial Properties of Bone Replacement Material

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.795.692 ◽

2013 ◽

Vol 795 ◽

pp. 692-696 ◽

Cited By ~ 2

Author(s):

Nida Iqbal ◽

Mohammed Rafiq Abdul Kadir ◽

Nasrul Humaimi Bin Mahmood ◽

Micheal Moses ◽

Mashitah Binti Mad Salim ◽

...

Keyword(s):

Calcium Phosphates ◽

Bacterial Species ◽

Calcium Nitrate ◽

Antibacterial Properties ◽

Silver Ions ◽

Antibacterial Activities ◽

Silver Addition ◽

Wide Range ◽

Microbial Infections ◽

Inorganic Mineral

Antibacterial materials based on calcium phosphates have wide range of biomedical applications in the prevention of microbial infections. The synthesis of inorganic mineral component of bone i.e. hydroxyapatite was done with the addition of silver (Ag) (5-15 wt %) as antibacterial agent. The wet precipitation synthesis was carried out using diammonium hydrogen phosphate and calcium nitrate as P and Ca precursors. The presence and effect of silver addition on the structure was studied using Fourier Transform-Infrared (FTIR) spectroscopy and Energy Dispersive X-ray (EDX) techniques. The antibacterial properties of all samples were evaluated using Disc Diffusion Technique (DDT) againstS. aureus,B. subtilis, P. aeruginosaandE. coli. Antibacterial activities of samples were found to vary depending on the bacterial species and Ag loading percentage. The antibacterial assay suggested that the addition of Ag ions within hydroxyapatite can be effectively provided the required level of antibacterial activity against bacteria.

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Preparation and Characterization of Ni2+-Montmorillonite/Polyvinyl Alcohol Water-Soluble Nanocomposite Film

Polymers and Polymer Composites ◽

10.1177/096739110501300811 ◽

2005 ◽

Vol 13 (8) ◽

pp. 839-846 ◽

Cited By ~ 4

Author(s):

Li-Ping Wang ◽

Yun-Pu Wang ◽

Fa-Ai Zhang

Keyword(s):

Polyvinyl Alcohol ◽

Photoelectron Spectroscopy ◽

Thermal Characteristics ◽

Water Soluble ◽

Scanning Calorimetry ◽

Xps Spectra ◽

X Ray ◽

Alcohol Water ◽

Ft Ir ◽

Silicate Layers

A new type of nano-composite film was prepared from polyvinyl alcohol, Ni2+-montmorillonite (Ni2+-MMT), defoamer, a levelling agent and a plasticizer. Its thermal characteristics were studied by Differential Scanning Calorimetry (DSC). The intermolecular interactions were measured by Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS), and the tensile strength (TS) and elongation at break (%E) were measured. The microstructures were studied by X-ray diffraction (XRD) and atomic force microscopy (AFM). FT-IR and XPS spectra indicated that cross-linking has taken place between PVA and Ni2+-MMT. XRD and AFM indicate that the PVA molecules had inserted themselves into the silicate layers of MMT, exfoliating them and dispersing them randomly into the PVA matrix. Compared to pure PVA film, the TS of the films was increased and %E decreased when the Ni2+-Montmorillonite was added and the dissolution temperature of the film was also reduced.

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Influence of Rigid Segment Type on Copoly(ether-ester) Properties

Materials ◽

10.3390/ma14164614 ◽

2021 ◽

Vol 14 (16) ◽

pp. 4614

Author(s):

Konrad Walkowiak ◽

Izabela Irska ◽

Agata Zubkiewicz ◽

Zbigniew Rozwadowski ◽

Sandra Paszkiewicz

Keyword(s):

Alternative Energy ◽

Raw Materials ◽

Tensile Modulus ◽

Xrd Analysis ◽

Thermoplastic Elastomers ◽

Polymer Materials ◽

Scanning Calorimetry ◽

Soft Phase ◽

Ecological Awareness ◽

Fourier Transformed Infrared Spectroscopy

The growing ecological awareness of society created the tendency to replace petrochemically based materials with alternative energy carriers and renewable raw materials. One of the most requested groups of polymer materials with significant technological importance is thermoplastic elastomers (TPE). They combine the properties of elastomers such as flexibility with the typical properties of thermoplastics, like easy processing. Herein, one compares the influence of rigid segments on the properties of copoly(ester-ether). Thermoplastic polyesters based on bio-1,6-hexanediol and terephthalic (T), furanic (F), and napthalate (N) diesters, i.e., PHT, PHF, and PHN, were obtained employing melt polycondensation. Additionally, to grant elastic properties of polyesters, systems containing 50 wt.% of bio-based polyTHF®1000 (pTHF) with a molecular mass of 1000 g/mol, have been prepared. The composition and chemical structure have been determined by 1H nuclear magnetic resonance (NMR) and Fourier transformed infrared spectroscopy (FTIR) analyses. The temperatures corresponding to phase transition changes were characterized by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) analyses. The crystalline structure was examined by X-ray diffraction (XRD) analysis. Additionally, the influence of pTHF–rich segment on the tensile properties, water absorption, as well as thermal and thermo-oxidative stability, has been analyzed. It was found that incorporation of soft phase allows creation of thermoplastic elastomers with tensile characteristics comparable to the commercially available ones, by means of elongation at break higher than 500%, low values of tensile modulus, without exhibiting yield point.

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The Influence of the Nature of Redox-Active Moieties on the Properties of Redox-Active Ionic Liquids and on Their Use as Electrolyte for Supercapacitors

Energies ◽

10.3390/en14196344 ◽

2021 ◽

Vol 14 (19) ◽

pp. 6344

Author(s):

Philipp S. Borchers ◽

Patrick Gerlach ◽

Yihan Liu ◽

Martin D. Hager ◽

Andrea Balducci ◽

...

Keyword(s):

Phase Transition ◽

Differential Scanning Calorimetry ◽

Ionic Liquid ◽

Ionic Liquids ◽

Binary Mixtures ◽

Thermal Characteristics ◽

The Other ◽

Scanning Calorimetry ◽

Imidazolium Ionic Liquids ◽

Redox Active

In this work, two new redox-active ionic liquids, one based on 2,2,6,6-tetramethylpiperidine-N-oxide and the other based on 4,4′-bipyridine, are synthesized and characterized. A ferrocene-based redox-active ionic liquid is used for referencing the results. All ionic liquids are formed via salt-metathesis from halogenate to bis(trifluoromethylsulfonyl)imide. Their fundamental thermal characteristics are assessed with differential scanning calorimetry. While the imidazolium ionic liquids show no melting point, the phase transition is well observable for the viologen-based ionic liquid. The properties of the neat redox-active ionic liquids and of binary mixtures containing these ionic liquids (0.1 m) and 1-butyl-1-methyl pyrrolidinium-bis(trifluoromethylsulfonyl)imide have been investigated. Finally, the use of these binary mixtures in combination with activated carbon-based electrodes has been considered in view of the use of these redox-active electrolytes in supercapacitors.

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THE PHYSICOCHEMICAL CHARACTERISTICS OF RECYCLED-PLASTIC PELLETS OBTAINED FROM DISPOSABLE FACE MASK WASTES

Jurnal Sains Materi Indonesia ◽

10.17146/jsmi.2021.23.1.6336 ◽

2021 ◽

Vol 23 (1) ◽

pp. 16

Author(s):

Vienna Saraswaty ◽

Rossy Choerun Nissa ◽

Bonita Firdiana ◽

Akbar Hanif Dawam Abdullah

Keyword(s):

Tensile Strength ◽

Physicochemical Characterization ◽

Face Mask ◽

Physicochemical Characteristics ◽

Scanning Calorimetry ◽

Elongation At Break ◽

Ft Ir ◽

The Government ◽

Plastic Pellets

THE PHYSICOCHEMICAL CHARACTERISTICS OF RECYCLED-PLASTIC PELLETS OBTAINED FROM DISPOSABLE FACE MASK WASTES. The government policy to wear a face mask during the COVID-19 pandemic has increased disposable face mask wastes. Thus, to reduce such wastes, it is necessary to evaluate the physicochemical characteristics of disposable face masks wastes before the recycling process and the recycled products. In this study, physicochemical characterization of the 3-ply disposable face masks and the recycled plastic pellets after disinfection using 0.5% v/v sodium hypochlorite were evaluated. A set of parameters including the characterization of surface morphology by a scanning electron microscope (SEM), functional groups properties by a fourier transform infra-red spectroscopy (FT-IR), thermal behavior by a differential scanning calorimetry (DSC), tensile strength and elongation at break were evaluated. The surface morphological of each layer 3-ply disposable face mask showed that the layers were composed of non-woven fibers. The FT-IR evaluation revealed that 3-ply disposable face mask was made from a polypropylene. At the same time, the DSC analysis found that the polypropylene was in the form of homopolymer. The SEM analysis showed that the recycled plastic pellets showed a rough and uneven surface. The FT-IR, tensile strength and elongation at break of the recycled plastic pellets showed similarity with a virgin PP type CP442XP and a recycled PP from secondary recycling PP (COPLAST COMPANY). In summary, recycling 3-ply disposable face mask wastes to become plastic pellets is recommended for handling disposable face mask wastes problem.

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Impact of environmental agents on non-woven polylactide/natural rubber agrofiber

E3S Web of Conferences ◽

10.1051/e3sconf/202128507034 ◽

2021 ◽

Vol 285 ◽

pp. 07034

Author(s):

Yulia Tertyshnaya ◽

Maksim Zakharov ◽

Alina Ivanitskikh ◽

Anatoliy Popov

Keyword(s):

Natural Rubber ◽

Uv Irradiation ◽

Thermal Characteristics ◽

Degree Of Crystallinity ◽

Distilled Water ◽

Fibrous Materials ◽

Scanning Calorimetry ◽

Melting Temperatures ◽

Environmental Agents ◽

The Degree Of Crystallinity

In the work an eco-friendly non-woven fiber made of polylactide and natural rubber with a rubber content from 0 to 15 wt.% was obtained by electrospinning. The influence of distilled water and UV irradiation on the agrofibers has been investigated. The water sorption test showed that the addition of natural rubber into the polylactide matrix does not significantly affect the degree of water absorption of the fibrous materials, which is in the range of 49-50.6%. Thermal characteristics after 180 days of degradation in distilled water at 22±2 oC and UV irradiation at a wavelength of 365 nm during 100 hours were determined using the differential scanning calorimetry. Changes in the values for glass transition and melting temperatures, and the degree of crystallinity were determined.

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Compatibility Studies of Valsartan with Different Pharmaceutical Excipients

Revista de Chimie ◽

10.37358/rc.19.7.7386 ◽

2019 ◽

Vol 70 (7) ◽

pp. 2590-2600

Author(s):

Ioana Cristina Tita ◽

Lavinia Lupa ◽

Bogdan Tita ◽

Roxana Liana Stan ◽

Laura Vicas

Keyword(s):

Magnesium Stearate ◽

Dosage Forms ◽

Compatibility Studies ◽

Scanning Calorimetry ◽

Pharmaceutical Dosage Forms ◽

Lactose Monohydrate ◽

Pharmaceutical Excipients ◽

Solid Dosage ◽

Fourier Transformed Infrared Spectroscopy ◽

Ft Ir

Compatibility studies between active drugs and excipients are substantial in the pharmaceutical technology. Thermal analysis has been extensively used to obtain information about drug-excipient interactions and to perform pre-formulation studies of pharmaceutical dosage forms. The objective of the present study was to evaluate the compatibility of the valsartan (VALS) with pharmaceutical excipients of common use including diluents, binders, disintegrants, lubricants and solubilising agents. Thermogravimetry (TG), derivative thermogravimetry (DTG), but especially differential scanning calorimetry (DSC) were used for a first screening to find small variations in peak temperature and/or their associated enthalpy for six drug/excipient mixtures (starch, cross caramelose sodique, microcrystalline cellulose 102, povidone K30, lactose monohydrate and magnesium stearate), which indicate some degree of interaction. Additional methods using Fourier transformed infrared spectroscopy (FT-IR) and X-ray powder diffraction (XRPD) confirmed the incompatibility of VALS with starch, povidone K30, lactose monohydrate and magnesium stearate. Those excipients should be avoided in the development of solid dosage forms.

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A handy skin wound dressing prepared by alginate and cationic nanofibrillated cellulose derived from solid residues of herbs

BioResources ◽

10.15376/biores.16.3.5926-5946 ◽

2021 ◽

Vol 16 (3) ◽

pp. 5926-5946

Author(s):

Ting Jiang ◽

Xiaoyan Feng ◽

Rui Xu ◽

Sheng Dong ◽

Meiyan Wu ◽

...

Keyword(s):

Wound Dressing ◽

Cost Effective ◽

Nanofibrillated Cellulose ◽

Antibacterial Activities ◽

Skin Wound ◽

Natural Medicine ◽

Nanofibrous Structure ◽

New Strategy ◽

Physical Interactions ◽

Dressing Materials

Large amounts of solid residues are generated after extraction of active ingredients from herbs for the production of natural medicine, but the residues have not been well utilized. In this work, cationic nanofibrillated cellulose (CCNF) was prepared from the solid residues of Astragali Radix by etherification and homogenization. The CCNF was mixed with sodium alginate (SA) to create a hydrogel dressing by physical interactions between CCNF and SA without any addition of cross-linker. The CCNF-SA dressing exhibited moderate viscosity, good moisture-maintaining property, great antibacterial activities, good cytocompatibility, and clear acceleration of wound healing on rats. Furthermore, this CCNF-SA dressing with nanofibrous structure had moderate air permeability. Therefore, the CCNF-SA hydrogel could be used potentially as a skin wound dressing. Development of cost-effective and bioactive wound dressing materials is of crucial importance to reduce the burden on patients and healthcare systems. Also, this work provides a new strategy for valorization of the solid residues of herbs.

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