mehran afrashi - Academia.edu (original) (raw)
Papers by mehran afrashi
In this research, the anti-fungal effect of fluconazoleloaded polyvinyl alcohol (PVA) nano-fibers... more In this research, the anti-fungal effect of fluconazoleloaded polyvinyl alcohol (PVA) nano-fibers was compared with that of drug-loaded fabric (DLF) to be used in medical textiles and fibrous pads as a local drug delivery system. The drug-loaded nano-fibers (DLNs) were coated on the fabric surface using the electro-spinning process. The DLF was then prepared by means of the pad-dry method. The characterization of the samples was carried out by SEM, FTIR, and XRD tests. UV-V is spectrophotometry was also used to measure the drug release rate. The anti-fungal effect was studied by the disk diffusion method. The drug release test showed about 75% fluconazole release in 90 min and the disc diffusion test indicated that the DLF has more effect than the DLN due to the fast drug release.
Bulletin of Materials Science, 2021
In this study, the antifungal activity of both fluconazole and ketoconazole was compared. The dru... more In this study, the antifungal activity of both fluconazole and ketoconazole was compared. The drugs were loaded into the polycaprolactone (PCL)/polyvinylpyrrolidone (PVP) nanofibrous mats and the effect of the drug-loaded samples on Candida albicans ( Ca ) were investigated by disc diffusion method. Furthermore, the characterization of nanofibrous mats was performed by field emission scanning electron microscopy, Fourier transform infrared (FT-IR) and contact angle tests. The mean diameter of nanofibres was 656 nm and it decreased with the addition of drugs into the electrospinning solutions, because the viscosity of solutions were decreased while electron conductivity of solutions was increased. With increase in the amount of the drug from 5 to 15%, the hydrophilicity increased. FT-IR revealed both drugs were physically embedded in the nanofibres and confirmed their presence in the composition. In addition, the degradation behaviour of samples was significant due to by the amount and the dissolution of PVP and approximately 40% loss weight occurred after 22 days. In the disc diffusion tests, both drug-loaded samples had antifungal effect on sensitive isolates of Ca , while for resistant of isolate the ketoconazole had more effective than fluconazole. Overall, the study highlights the ability of antifungal drug-loaded PVP/PCL nanofibrous mats as potential wound dressing materials and local delivery systems.
Fashion and Textiles, 2018
Nanofibers are of great importance due to their high surface to volume ratio, porosity, and good ... more Nanofibers are of great importance due to their high surface to volume ratio, porosity, and good mechanical performance in a wide variety of applications (Ciera 2011). They are used in vast areas such as tissue engineering (Semnani et al. 2017), wound dressing (Vargas et al. 2010), drug delivery systems (Hu et al. 2014; Zamani et al. 2010), filtration (Su et al. 2017), and self-cleaning surfaces (Huang et al. 2017). There are different methods for producing nanofibers such as drawing, template synthesis, phase separation, self-assembling, and electrospinning (Yoon et al. 2009; Zhang et al. 2005). In comparison with electrospinning, other methods can produce limited amount of nanofibers. In addition, these methods have more disadvantages. Drawing is a discrete method, self-assembling is complicated, phase separation is limited to special polymers, and template synthesis has fiber diameter limit (Caruso et al. 2001). On
International Journal of Mechanical Sciences, 2018
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service... more This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Highlights The static and dynamic responses of nano-bridges with circular cross-section are analyzed in detail. It is found that both the pull-in voltage and the fundamental frequency change prominently with the variation of length-scale and surface effects. The impact of couple stress and temperature rise on the threshold voltage changes with the change of Poisson's ratio.
Journal of Non-Crystalline Solids, 2019
Nowadays, various materials have been used as drug delivery systems (DDSs). In this study, Poly (... more Nowadays, various materials have been used as drug delivery systems (DDSs). In this study, Poly (vinyl alcohol) nanofibers and films were used as an organic drug carriers and silica-aerogel as a mineral drug carrier. The physicochemical properties and also drug release of prepared samples were investigated from appropriate tests. The results of low-temperature N 2 adsorption/desorption analysis showed the drug molecules have been trapped in the aerogel pores. The results of drug release showed the drug loaded samples, especially the silica aerogel, have a faster release, due to a high surface area and high porosity rather than the crystalline form of the drug. About 80% of the fluconazole loaded on silica aerogel was released in 60 min, while this amount of the pure fluconazole was released in 225 min. As well as, in vitro test was performed by disc diffusion method that the drug loaded silica aerogel and Poly (vinyl alcohol) film showed a significant effect on the destruction of the fungal.
Current drug delivery, Jan 26, 2018
Eugenol, as the major phenolic component of clove essential oil due to its desired properties in ... more Eugenol, as the major phenolic component of clove essential oil due to its desired properties in medical field, was loaded into polyacrylonitrile (PAN) nanofibers with various percentages. Our main purpose in this study was to determine the in vitro antifungal activity of eugenol loaded on PAN nanofibers against Candida albicans as the most common causative agent for candidiasis. Also, the surface morphology and the mechanical properties of nanofibers were studied by scanning electron microscope (SEM) and a tensile tester, respectively. The average diameters of nanofibers in pure PAN nanofibers were found to be 127 nm. The results showed that the average diameter of nanofibers after increasing the eugenol ratio (from 127 to 179-218 nm) was increased. Drug release profile of the samples was gradual and was completed after 150 hours. According to the results, these nanofiber mats loaded with eugenol can be used for treating cutaneous mucocutaneous candidiasis in high risk patients asp...
Journal of materials science. Materials in medicine, Jan 27, 2017
Polymer-based drug delivery systems are suitable to optimize the therapeutic properties of drugs ... more Polymer-based drug delivery systems are suitable to optimize the therapeutic properties of drugs and to render them safer, more effective and reliable. Long-term or repeated use of oral administration of fluconazole for treating chronic candidiasis in the patient and partially abandoned treatment lead to the resistant strains of the fungus Candida albicans and severity of the disease. In this study, the use of nanofibers and microfibers containing fluconazole for local drug delivery to increase the efficiencies and reduce the side effects caused by taking the drug was studied. Morphology, microstructure and chemical composition of PVA nanofibers containing fluconazole were characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). As well as, the DSC test was indicated presence of fluconazole in PVA fibrous mats. The rate of drug release was investigated by UV-Vis spectrophotometery and swelling technique. SEM images showed that the nanof...
International Journal of Engineering Science, 2016
Double-sided nano-devices can potentially be used as tuning switches and variable capacitors. In ... more Double-sided nano-devices can potentially be used as tuning switches and variable capacitors. In this paper, the pull-in behavior of double-sided cantilever nano-wires, including the Casimir and partial electrostatic attractions are developed. To increase the tunability, only a piece of substrate plates is electrostatically actuated and conductors' voltage can be different. Herein, the governing nonlinear equation is derived via extended Hamilton's principle. The Galerkin method is used to discretize the differential EOM and the stepby-step linearization method is employed to solve them numerically. The validity of the presented model is confirmed by comparing the theoretical results with the experimental reported ones. The influence of geometrical parameters, i.e. stationary electrodes distance (initial gaps), non-actuated piece length/location as well as wire diameter and length on the instability is investigated. Furthermore, the effect of surface elasticity, residual surface tension and length-scale on the free vibration is examined. It is concluded that the geometric configuration characteristics play significant roles in the pull-in deflection and voltage of nano-structures, which should be considered in applying design and tuning applications.
Journal of Advanced Materials In Engineering, 2019
In this study, adsorption of fluconazole on silica aerogel was performed successfully by the imme... more In this study, adsorption of fluconazole on silica aerogel was performed successfully by the immersion method in the 1% solution of fluconazole-ethanol at the ambient condition and without using the supercritical method. The hydrophobic and hydrophilic silica aerogels were synthesized by the two-stage sol-gel method and dried at the ambient temperature. This method had most of drug loading at 24 h. It was 1.92% and 1.98% for the hydrophilic and hydrophobic silica aerogels, respectively. Physical properties of the synthesized aerogels were studied by the nitrogen absorption and desorption tests. The presence of fluconazole and the chemical structure of the samples were determined by fourier-transform infrared spectroscopy (FTIR). As well, the loading and release of the drug were investigated using a spectrophotometer. The results showed the structure of the synthesized aerogels had a
Materials Research Express, 2019
In this research, the anti-fungal effect of fluconazoleloaded polyvinyl alcohol (PVA) nano-fibers... more In this research, the anti-fungal effect of fluconazoleloaded polyvinyl alcohol (PVA) nano-fibers was compared with that of drug-loaded fabric (DLF) to be used in medical textiles and fibrous pads as a local drug delivery system. The drug-loaded nano-fibers (DLNs) were coated on the fabric surface using the electro-spinning process. The DLF was then prepared by means of the pad-dry method. The characterization of the samples was carried out by SEM, FTIR, and XRD tests. UV-V is spectrophotometry was also used to measure the drug release rate. The anti-fungal effect was studied by the disk diffusion method. The drug release test showed about 75% fluconazole release in 90 min and the disc diffusion test indicated that the DLF has more effect than the DLN due to the fast drug release.
Bulletin of Materials Science, 2021
In this study, the antifungal activity of both fluconazole and ketoconazole was compared. The dru... more In this study, the antifungal activity of both fluconazole and ketoconazole was compared. The drugs were loaded into the polycaprolactone (PCL)/polyvinylpyrrolidone (PVP) nanofibrous mats and the effect of the drug-loaded samples on Candida albicans ( Ca ) were investigated by disc diffusion method. Furthermore, the characterization of nanofibrous mats was performed by field emission scanning electron microscopy, Fourier transform infrared (FT-IR) and contact angle tests. The mean diameter of nanofibres was 656 nm and it decreased with the addition of drugs into the electrospinning solutions, because the viscosity of solutions were decreased while electron conductivity of solutions was increased. With increase in the amount of the drug from 5 to 15%, the hydrophilicity increased. FT-IR revealed both drugs were physically embedded in the nanofibres and confirmed their presence in the composition. In addition, the degradation behaviour of samples was significant due to by the amount and the dissolution of PVP and approximately 40% loss weight occurred after 22 days. In the disc diffusion tests, both drug-loaded samples had antifungal effect on sensitive isolates of Ca , while for resistant of isolate the ketoconazole had more effective than fluconazole. Overall, the study highlights the ability of antifungal drug-loaded PVP/PCL nanofibrous mats as potential wound dressing materials and local delivery systems.
Fashion and Textiles, 2018
Nanofibers are of great importance due to their high surface to volume ratio, porosity, and good ... more Nanofibers are of great importance due to their high surface to volume ratio, porosity, and good mechanical performance in a wide variety of applications (Ciera 2011). They are used in vast areas such as tissue engineering (Semnani et al. 2017), wound dressing (Vargas et al. 2010), drug delivery systems (Hu et al. 2014; Zamani et al. 2010), filtration (Su et al. 2017), and self-cleaning surfaces (Huang et al. 2017). There are different methods for producing nanofibers such as drawing, template synthesis, phase separation, self-assembling, and electrospinning (Yoon et al. 2009; Zhang et al. 2005). In comparison with electrospinning, other methods can produce limited amount of nanofibers. In addition, these methods have more disadvantages. Drawing is a discrete method, self-assembling is complicated, phase separation is limited to special polymers, and template synthesis has fiber diameter limit (Caruso et al. 2001). On
International Journal of Mechanical Sciences, 2018
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service... more This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Highlights The static and dynamic responses of nano-bridges with circular cross-section are analyzed in detail. It is found that both the pull-in voltage and the fundamental frequency change prominently with the variation of length-scale and surface effects. The impact of couple stress and temperature rise on the threshold voltage changes with the change of Poisson's ratio.
Journal of Non-Crystalline Solids, 2019
Nowadays, various materials have been used as drug delivery systems (DDSs). In this study, Poly (... more Nowadays, various materials have been used as drug delivery systems (DDSs). In this study, Poly (vinyl alcohol) nanofibers and films were used as an organic drug carriers and silica-aerogel as a mineral drug carrier. The physicochemical properties and also drug release of prepared samples were investigated from appropriate tests. The results of low-temperature N 2 adsorption/desorption analysis showed the drug molecules have been trapped in the aerogel pores. The results of drug release showed the drug loaded samples, especially the silica aerogel, have a faster release, due to a high surface area and high porosity rather than the crystalline form of the drug. About 80% of the fluconazole loaded on silica aerogel was released in 60 min, while this amount of the pure fluconazole was released in 225 min. As well as, in vitro test was performed by disc diffusion method that the drug loaded silica aerogel and Poly (vinyl alcohol) film showed a significant effect on the destruction of the fungal.
Current drug delivery, Jan 26, 2018
Eugenol, as the major phenolic component of clove essential oil due to its desired properties in ... more Eugenol, as the major phenolic component of clove essential oil due to its desired properties in medical field, was loaded into polyacrylonitrile (PAN) nanofibers with various percentages. Our main purpose in this study was to determine the in vitro antifungal activity of eugenol loaded on PAN nanofibers against Candida albicans as the most common causative agent for candidiasis. Also, the surface morphology and the mechanical properties of nanofibers were studied by scanning electron microscope (SEM) and a tensile tester, respectively. The average diameters of nanofibers in pure PAN nanofibers were found to be 127 nm. The results showed that the average diameter of nanofibers after increasing the eugenol ratio (from 127 to 179-218 nm) was increased. Drug release profile of the samples was gradual and was completed after 150 hours. According to the results, these nanofiber mats loaded with eugenol can be used for treating cutaneous mucocutaneous candidiasis in high risk patients asp...
Journal of materials science. Materials in medicine, Jan 27, 2017
Polymer-based drug delivery systems are suitable to optimize the therapeutic properties of drugs ... more Polymer-based drug delivery systems are suitable to optimize the therapeutic properties of drugs and to render them safer, more effective and reliable. Long-term or repeated use of oral administration of fluconazole for treating chronic candidiasis in the patient and partially abandoned treatment lead to the resistant strains of the fungus Candida albicans and severity of the disease. In this study, the use of nanofibers and microfibers containing fluconazole for local drug delivery to increase the efficiencies and reduce the side effects caused by taking the drug was studied. Morphology, microstructure and chemical composition of PVA nanofibers containing fluconazole were characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). As well as, the DSC test was indicated presence of fluconazole in PVA fibrous mats. The rate of drug release was investigated by UV-Vis spectrophotometery and swelling technique. SEM images showed that the nanof...
International Journal of Engineering Science, 2016
Double-sided nano-devices can potentially be used as tuning switches and variable capacitors. In ... more Double-sided nano-devices can potentially be used as tuning switches and variable capacitors. In this paper, the pull-in behavior of double-sided cantilever nano-wires, including the Casimir and partial electrostatic attractions are developed. To increase the tunability, only a piece of substrate plates is electrostatically actuated and conductors' voltage can be different. Herein, the governing nonlinear equation is derived via extended Hamilton's principle. The Galerkin method is used to discretize the differential EOM and the stepby-step linearization method is employed to solve them numerically. The validity of the presented model is confirmed by comparing the theoretical results with the experimental reported ones. The influence of geometrical parameters, i.e. stationary electrodes distance (initial gaps), non-actuated piece length/location as well as wire diameter and length on the instability is investigated. Furthermore, the effect of surface elasticity, residual surface tension and length-scale on the free vibration is examined. It is concluded that the geometric configuration characteristics play significant roles in the pull-in deflection and voltage of nano-structures, which should be considered in applying design and tuning applications.
Journal of Advanced Materials In Engineering, 2019
In this study, adsorption of fluconazole on silica aerogel was performed successfully by the imme... more In this study, adsorption of fluconazole on silica aerogel was performed successfully by the immersion method in the 1% solution of fluconazole-ethanol at the ambient condition and without using the supercritical method. The hydrophobic and hydrophilic silica aerogels were synthesized by the two-stage sol-gel method and dried at the ambient temperature. This method had most of drug loading at 24 h. It was 1.92% and 1.98% for the hydrophilic and hydrophobic silica aerogels, respectively. Physical properties of the synthesized aerogels were studied by the nitrogen absorption and desorption tests. The presence of fluconazole and the chemical structure of the samples were determined by fourier-transform infrared spectroscopy (FTIR). As well, the loading and release of the drug were investigated using a spectrophotometer. The results showed the structure of the synthesized aerogels had a
Materials Research Express, 2019