The growing popularity of solution blow spinning as a method for the production of fibrous tissue... more The growing popularity of solution blow spinning as a method for the production of fibrous tissue engineering scaffolds and the vast range of polymer–solvent systems available for the method raises the need to study the effect of processing conditions on fiber morphology and develop a method for its qualitative assessment. Rheological approaches to determine polymer solution spinnability and image analysis approaches to describe fiber diameter and alignment have been previously proposed, although in a separate manner and mostly for the widely known, well-researched electrospinning method. In this study, a series of methods is presented to determine the processing conditions for the development of submicron fibrous scaffolds. Rheological methods are completed with extensive image analysis to determine the spinnability window for a polymer–solvent system and qualitatively establish the influence of polymer solution concentration and collector rotational speed on fiber morphology, diam...
International Journal of Biological Macromolecules, 2021
Developing a multifunctional wound dressing that protects, cures and indicates the healing progre... more Developing a multifunctional wound dressing that protects, cures and indicates the healing progress, is a new approach of investigation. Red cabbage extract (RCE), consisting of bioactive compounds that are antioxidant, anti-inflammatory, anti-carcinogenic, bactericidal, antifungal, and antiviral activities, was utilized as a natural pH-sensitive indicator. Chitosan-based hydrogel, encapsulating RCE, was developed to obtain a smart therapeutic pH-sensitive wound dressing as antimicrobial bio-matrix provides a comfortable cushion for wound bed and indicates its status. Methacrylated-chitosan was crosslinked by different concentrations of methylenebisacrylamide (MBAA) by which hydrogel mechanical and morphological properties were tuned. The proposed mechanism for hydrogel formation was confirmed by FT-IR. The coloristic properties of the RCE and the changes in color intensity as a function of pH were confirmed by UV-Vis spectroscopy. The effect of MBAA on the mechanical, swelling, release and morphological properties of hydrogel were investigated. MBAA (2.5% wt/v) in 2% wt/v chitosan showed preferable mechanical (20 KPa), swelling (1294% at pH 8 ± 0.2), and release (prolonged up to 5 days) properties. Hydrogel matrices, loaded on cotton gauze submerged in different pH buffer solutions, showed explicit color changes from green to red as pH changed from 9 to 4.
Abstract Electrospinning is a widely investigated process for forming nanofibers. Nanofibers in d... more Abstract Electrospinning is a widely investigated process for forming nanofibers. Nanofibers in drug delivery systems are extensively tested due to its remarkable properties e.g. small pore size or large surface area. Recent articles have informed about formation of fibers using triaxial electrospinning in drug delivery systems. This paper summarizes the process of triaxial electrospinning and its application in drug delivery. Triaxial electrospinning has advantages in forming complex nanostructures for specific drug delivery applications. This paper summarizes the possibility to use triaxial electrospinning to resolve the problem of limited drug solubility, to protect biomolecules from hostile environment, and to control drug release kinetics, with the possibility of loading of various drugs. There are literature data evidencing the possibility to achieve sustained release with a border case of zero rate order kinetics. There is no doubt that triaxial electrospinning opens a new way to develop sophisticated nanomaterials for achieving the desired functional performances and to expand the applications in the drug delivery area. Triaxial electrospinning method is interdisciplinary area with great potential in nanotechnology.
Non-isothermal crystallization of poly(vinylidene fluoride) during cooling at various rates was i... more Non-isothermal crystallization of poly(vinylidene fluoride) during cooling at various rates was investigated by differential scanning calorimetry (d.s.c.). The data were analysed with the new model of non-isothermal crystallization developed by Ziabicki. The application of this model to experimental data allows separate determination of the rate of steady-state crystallization and the effect of time-dependent mechanisms. It was shown that the measured crystallization rate is higher than the rate of the steady-state process. It is probable that the accelerating factor is the athermal mechanism predicted by Ziabicki's model. The analysis presented of non-isothermal crystallization data gives the possibility of determining the steady-state crystallization rates over the whole temperature range of the crystallization process. The previous method of determination of crystallization rate from isothermal measurements applied to polymers with high crystallization rate, like poly(vinylidene fluoride) or polyethylene, can provide data only for a narrow temperature range lying at the end of the upper branch of the crystallization curve.
The crystallization process of a new polyamide, nylon 1313, from the melt has been thoroughly inv... more The crystallization process of a new polyamide, nylon 1313, from the melt has been thoroughly investigated under isothermal and nonisothermal conditions. During isothermal crystallization, relative crystallinity develops in accordance with the Avrami equation with the exponent n ≈ 2 based on DSC analysis. Under nonisothermal conditions, several different analysis methods were used to elucidate the crystallization process. The Avrami exponent n is greater in the isothermal crystallization process, indicating that the mode of nucleation and the growth of the nonisothermal crystallization for nylon 1313 are more complicated, and that the nucleation mode might include both homogeneous and heterogeneous nucleation simultaneously. The calculated activation energy is 214.25 kJ/mol for isothermal crystallization by Arrhenius form and 135.1 kJ/mol for nonisothermal crystallization by Kissinger method, respectively. In addition, the crystallization ability of nylon 1313 was assessed by using ...
This research work is aimed at studying the effect of ultrasounds on the effectiveness of fiber f... more This research work is aimed at studying the effect of ultrasounds on the effectiveness of fiber fragmentation by taking into account the type of sonication medium, processing time, and various PLLA molecular weights. Fragmentation was followed by an appropriate filtration in order to decrease fibers length distribution. It was evidenced by fiber length determination using SEM that the fibers are shortened after ultrasonic treatment, and the effectiveness of shortening depends on the two out of three investigated parameters, mostly on the sonication medium, and processing time. The gel permeation chromatography (GPC) confirmed that such ultrasonic treatment does not change the polymers' molecular weight. Our results allowed to optimize the ultrasonic fragmentation procedure of electrospun fibers while preliminary viscosity measurements of fibers loaded into hydrogel confirmed their potential in further use as fillers for injectable hydrogels for regenerative medicine applications.
The growing popularity of solution blow spinning as a method for the production of fibrous tissue... more The growing popularity of solution blow spinning as a method for the production of fibrous tissue engineering scaffolds and the vast range of polymer–solvent systems available for the method raises the need to study the effect of processing conditions on fiber morphology and develop a method for its qualitative assessment. Rheological approaches to determine polymer solution spinnability and image analysis approaches to describe fiber diameter and alignment have been previously proposed, although in a separate manner and mostly for the widely known, well-researched electrospinning method. In this study, a series of methods is presented to determine the processing conditions for the development of submicron fibrous scaffolds. Rheological methods are completed with extensive image analysis to determine the spinnability window for a polymer–solvent system and qualitatively establish the influence of polymer solution concentration and collector rotational speed on fiber morphology, diam...
International Journal of Biological Macromolecules, 2021
Developing a multifunctional wound dressing that protects, cures and indicates the healing progre... more Developing a multifunctional wound dressing that protects, cures and indicates the healing progress, is a new approach of investigation. Red cabbage extract (RCE), consisting of bioactive compounds that are antioxidant, anti-inflammatory, anti-carcinogenic, bactericidal, antifungal, and antiviral activities, was utilized as a natural pH-sensitive indicator. Chitosan-based hydrogel, encapsulating RCE, was developed to obtain a smart therapeutic pH-sensitive wound dressing as antimicrobial bio-matrix provides a comfortable cushion for wound bed and indicates its status. Methacrylated-chitosan was crosslinked by different concentrations of methylenebisacrylamide (MBAA) by which hydrogel mechanical and morphological properties were tuned. The proposed mechanism for hydrogel formation was confirmed by FT-IR. The coloristic properties of the RCE and the changes in color intensity as a function of pH were confirmed by UV-Vis spectroscopy. The effect of MBAA on the mechanical, swelling, release and morphological properties of hydrogel were investigated. MBAA (2.5% wt/v) in 2% wt/v chitosan showed preferable mechanical (20 KPa), swelling (1294% at pH 8 ± 0.2), and release (prolonged up to 5 days) properties. Hydrogel matrices, loaded on cotton gauze submerged in different pH buffer solutions, showed explicit color changes from green to red as pH changed from 9 to 4.
Abstract Electrospinning is a widely investigated process for forming nanofibers. Nanofibers in d... more Abstract Electrospinning is a widely investigated process for forming nanofibers. Nanofibers in drug delivery systems are extensively tested due to its remarkable properties e.g. small pore size or large surface area. Recent articles have informed about formation of fibers using triaxial electrospinning in drug delivery systems. This paper summarizes the process of triaxial electrospinning and its application in drug delivery. Triaxial electrospinning has advantages in forming complex nanostructures for specific drug delivery applications. This paper summarizes the possibility to use triaxial electrospinning to resolve the problem of limited drug solubility, to protect biomolecules from hostile environment, and to control drug release kinetics, with the possibility of loading of various drugs. There are literature data evidencing the possibility to achieve sustained release with a border case of zero rate order kinetics. There is no doubt that triaxial electrospinning opens a new way to develop sophisticated nanomaterials for achieving the desired functional performances and to expand the applications in the drug delivery area. Triaxial electrospinning method is interdisciplinary area with great potential in nanotechnology.
Non-isothermal crystallization of poly(vinylidene fluoride) during cooling at various rates was i... more Non-isothermal crystallization of poly(vinylidene fluoride) during cooling at various rates was investigated by differential scanning calorimetry (d.s.c.). The data were analysed with the new model of non-isothermal crystallization developed by Ziabicki. The application of this model to experimental data allows separate determination of the rate of steady-state crystallization and the effect of time-dependent mechanisms. It was shown that the measured crystallization rate is higher than the rate of the steady-state process. It is probable that the accelerating factor is the athermal mechanism predicted by Ziabicki's model. The analysis presented of non-isothermal crystallization data gives the possibility of determining the steady-state crystallization rates over the whole temperature range of the crystallization process. The previous method of determination of crystallization rate from isothermal measurements applied to polymers with high crystallization rate, like poly(vinylidene fluoride) or polyethylene, can provide data only for a narrow temperature range lying at the end of the upper branch of the crystallization curve.
The crystallization process of a new polyamide, nylon 1313, from the melt has been thoroughly inv... more The crystallization process of a new polyamide, nylon 1313, from the melt has been thoroughly investigated under isothermal and nonisothermal conditions. During isothermal crystallization, relative crystallinity develops in accordance with the Avrami equation with the exponent n ≈ 2 based on DSC analysis. Under nonisothermal conditions, several different analysis methods were used to elucidate the crystallization process. The Avrami exponent n is greater in the isothermal crystallization process, indicating that the mode of nucleation and the growth of the nonisothermal crystallization for nylon 1313 are more complicated, and that the nucleation mode might include both homogeneous and heterogeneous nucleation simultaneously. The calculated activation energy is 214.25 kJ/mol for isothermal crystallization by Arrhenius form and 135.1 kJ/mol for nonisothermal crystallization by Kissinger method, respectively. In addition, the crystallization ability of nylon 1313 was assessed by using ...
This research work is aimed at studying the effect of ultrasounds on the effectiveness of fiber f... more This research work is aimed at studying the effect of ultrasounds on the effectiveness of fiber fragmentation by taking into account the type of sonication medium, processing time, and various PLLA molecular weights. Fragmentation was followed by an appropriate filtration in order to decrease fibers length distribution. It was evidenced by fiber length determination using SEM that the fibers are shortened after ultrasonic treatment, and the effectiveness of shortening depends on the two out of three investigated parameters, mostly on the sonication medium, and processing time. The gel permeation chromatography (GPC) confirmed that such ultrasonic treatment does not change the polymers' molecular weight. Our results allowed to optimize the ultrasonic fragmentation procedure of electrospun fibers while preliminary viscosity measurements of fibers loaded into hydrogel confirmed their potential in further use as fillers for injectable hydrogels for regenerative medicine applications.
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