Zoha Babaei afrapoli; Reza Faridi Majidi; Babak Negahdari; Gholamreza Tavoosidana
Abstract
In this study the influence of dicarboxy acetone (DCA), as an oxidation product of sodium citrate, was evaluated by ‘reversed Turkevich’ method in this study. Gold nanoparticles (GNPs) were synthesized systematically at various sodium citrate to HAuCl4 molar ratio and temperature. TheseThe ...
Read More
In this study the influence of dicarboxy acetone (DCA), as an oxidation product of sodium citrate, was evaluated by ‘reversed Turkevich’ method in this study. Gold nanoparticles (GNPs) were synthesized systematically at various sodium citrate to HAuCl4 molar ratio and temperature. TheseThe GNPs were characterized by UV-vis spectroscopy, DLS and TEM techniques. The results showed that by reversing the order of reagents addition we could synthesize GNPs were obtained in range of 12-51 nm. All of these GNPs samples were monodisperse and have had the same pattern of narrow size distribution in contrast to traditional Turkevich method in which GNPs larger than 40 nm became unstable. Moreover, Sodium citrate to HAuCl4 molar ratio and temperature had a significant role in size controlling and monodispersity of GNPs. By increasing sodium citrate to HAuCl4 molar ratio,s the size of GNPs reduced drastically. Since, temperature had a central role on the production rate of DCA, so its influence on monodispersity of GNPs was more considerable than the size of them.
Seyedeh Sara Esnaashari; Majid Naghibzadeh; Mahdi Adabi; Reza Faridi Majidi
Abstract
Objective(s): This paper investigates the validity of Artificial Neural Networks (ANN) model in the prediction of electrospun kefiran nanofibers diameter using 4 effective parameters involved in electrospinning process. Polymer concentration, applied voltage, flow rate and nozzle to collector distance ...
Read More
Objective(s): This paper investigates the validity of Artificial Neural Networks (ANN) model in the prediction of electrospun kefiran nanofibers diameter using 4 effective parameters involved in electrospinning process. Polymer concentration, applied voltage, flow rate and nozzle to collector distance were used as variable parameters to design various sets of electrospinning experiments for production of electrospun kefiran nanofibers. Methods: The Scanning Electron Microscopy (SEM) was used to investigate the morphology and evaluate the size of the nanofiber. Data set was drawn using k fold cross-validation method, which was the most suitable scheme for the volume of the data in this work. Data were partitioned into the five series and trained and tested via ANN method. Results: The Scanning Electron Microscopy (SEM) images of the generated nanofiber samples were confirmed that all of the samples were fine and defect-free. Our results indicated that the network including four input variables, three hidden layers with 10, 18 and 9 nodes in each layer, respectively, and one output layer obtained the highest efficiency in the testing set. The mean squared error (MSE) and linear regression (R) between observed and predicted nanofibers diameter were 0.0452 and 0.950, respectively. Conclusions: The results demonstrated that the proposed neural network was appropriately performed in assessing the input parameters and prediction of nanofibers diameter.
Hadi Samadian; Hamid Mobasheri; Saeed Hasanpour; Reza Faridi Majidi
Abstract
Objective(s): Since the electric field is the main driving force in electrospinning systems, the modeling and analysis of electric field distribution are critical to the nanofibers production. The aim of this study was modeling of the electric field and investigating the various parameters on polyacrylonitrile ...
Read More
Objective(s): Since the electric field is the main driving force in electrospinning systems, the modeling and analysis of electric field distribution are critical to the nanofibers production. The aim of this study was modeling of the electric field and investigating the various parameters on polyacrylonitrile (PAN) nanofibers morphology and diameter. Methods: The electric field profile at the nozzle and electrospinning zone was evaluated by Finite Element Method. The morphology and diameter of nanofibers were examined by Scanning electron microscopy (SEM). Results: The results of the electric field analysis indicated that the electric field was concentrated at the tip of the nozzle. Moreover, in the spinning direction, the electric field was concentrated at the surface of the spinneret and decayed rapidly toward the surface of the collector. Increasing polymer solution concentration from 7 to 11wt.% led to increasing nanofibers diameter form 77.76 ± 19.44 to 202.42 ± 36.85. Conclusions: Base on our results, it could be concluded that concentration of the electric field at the tip of the nozzle is high and initiates jet and nanofibers formation. PAN nanofibers can be transformed to carbon nanofibers which have various applications in biomedicine.
Saman Firoozi; Mohammad Ali Derakhshan; Roya Karimi; Ali Rashti; Babak Negahdari; Reza Faridi Majidi; Samaneh Mashaghi; Hossien Ghanbari
Abstract
Objective(s): Tissue engineering represents a new approach to solve the current complications of the heart valve replacements by offering viable valve prosthesis with growth and remodeling capability. In this project, electrospinning and dip coating techniques were used to fabricate heart valve constructs ...
Read More
Objective(s): Tissue engineering represents a new approach to solve the current complications of the heart valve replacements by offering viable valve prosthesis with growth and remodeling capability. In this project, electrospinning and dip coating techniques were used to fabricate heart valve constructs from medical grade polyurethane (PU). Methods: First, a mold of tricuspid valve was dip coated in a PU solution, except for its valvular parts. Then, PU nanofibers were electrospun on the dip coated mold to form the valves. The morphology and diameter of nanofibers were investigated by SEM and contact angle measurements were done to evaluate the wettability of scaffolds. Thereafter, a tensile tester machine was used to assess mechanical properties of nanofibrous scaffolds. Then, the HUVEC cell line was cultured on the surface of scaffolds. Results: The SEM images showed the proper nanofibrous structure of the prepared scaffolds. Also, the obtained structure demonstrated appropriate tensile properties. Based on direct and indirect MTT, DAPI staining and SEM results, nanofibers were biocompatible and cells attached to the surface of the scaffolds, properly. Conclusions: This study demonstrated polyurethane-based nanofibrous scaffolds for engineering artificial heart valve. The presented scaffold provides temporary support for cells prior to generation of extracellular matrix (ECM).
Safieh Boroumand; Sara Hosseini; Mohhamad Salehi; Reza Faridi Majidi
Abstract
Objectives: Postsurgical adhesion is one of the common complications after surgery. Some anti-adhesion barriers are commercially available which are not customary used by physicians as much as expected because of ineffectiveness. Recently, nanofibers have been introduced as anti-adhesion barriers with ...
Read More
Objectives: Postsurgical adhesion is one of the common complications after surgery. Some anti-adhesion barriers are commercially available which are not customary used by physicians as much as expected because of ineffectiveness. Recently, nanofibers have been introduced as anti-adhesion barriers with the potential of drug delivery. In the light of role of inflammation and oxidative stress in adhesion formation, it is supposed that curcumin as an anti-oxidant and anti-inflammatory agent is able to prevent postsurgical adhesions. Methods: In the present study, curcumin-loaded nanofibrous (Cur-PCL) sheets were prepared using electrospinning and evaluated for its anti-adhesion profile in a mice model. Scanning Electron Microscopy (SEM), Attenuated Total Reflectance Fourier Transformed Infrared Spectroscopy (ATR-FTIR), drug release and degradation investigations and also, in vivo studies were performed. Results: curcumin-loaded Cur-PCL nanofibers were successfully prepared and shown significant prevention of postsurgical adhesion formation in mice model. Release study indicated that after 30 days, about 30% of the drug is released from the electrospun nanofibers. In vivo experiments showed that postsurgical adhesion has been reduced about 50% compared to the control group. Conclusions: Cur-PCL curcumin-loaded nanofibers have the potential to decrease postsurgical adhesion formation as a barrier. This system supports the sustained release of curcumin from the nanofibers.
)
)
)
)