Department of Biomedical Engineering (1990 - Present)
Chemical Engineering
Chemical Engineering, McGill, Montreal, Canada
Chemical Engineering
Chemical Engineering, McGill, Montreal, Canada
chemical engineering
, Iran University of Science and Technology,
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Professor Ebrahim Vasheghani-Farahani obtained his PhD degree in chemical engineering from McGill University, Canada in 1990 and joined immediately to Chemical Engineering Department of Tarbiat Modares University (TMU) in Tehran, Iran. In addition to academic affairs, he served in several administrative positions at Tarbiat Modares University, Ministry of Science, Research and Technology of Iran and Islamic Azad University. He has been awarded two times as outstanding professor in TMU and is a fellow member of the Academy of Science of Iran (Chemical Engineering Branch). His current research interests include preparation and application of hydrogels in drug delivery systems, cell therapy and tissue engineering.
Midazolam is considered as one of the best first-line drugs in managing status epilepticus in children who require emergency drug treatment. Due to poor water solubility, oral bioavailability of midazolam is relatively low. To improve its dissolution and absorption, midazolam nano-suspensions were formulated with different stabilizers using the ultrasonic technique. A combination of Tween 80 and Poloxamer (TP) was considered as one stabilizer and 3-methyl chitosan (TMC) as another stabilizer. The ratio of the stabilizers was selected as an independent variable, and their effects on the particle size and the zeta potential were evaluated by the simplex lattice mixture method. The freeze-dried optimized midazolam nano-suspension powder was ch
Objective: Multiple myeloma (MM) is an incurable plasma cell malignancy. Several genetic and epigenetic changes affect numerous critical genes expression status in this disorder. CDKN2A gene is expressed at low level in almost all cases with MM disease. The mechanism of this gene down-regulation has remained controversial. In the present study, we targeted EZH2 by microRNA-124 (miR-124) in L-363 cells and assessed following possible impact on CDKN2A gene expression and phenotypic changes.Materials and Methods: In this experimental study, growth inhibitory effects of miR-124 were measured by MTT assay in L-363 cell line. Likewise, cell cycle assay was measured by flowcytometery. The expression levels of EZH2 and CDKN2A were evaluated by real
Poly (l-lactide)-graft-chondroitin sulfate (PLLA-g-CS) copolymers were synthesized with different l-lactide contents via ring-opening polymerization. Chemical structure of the synthesized copolymers was confirmed by FTIR and HNMR analyses. The degree of polymerization and substitution of PLLA was found to be 0.56 and 2.98, respectively. Nisin was loaded in PLLA-g-CS nanogels at 37 and 42??C. The hydrodynamic radius of the nanogels was 181 and 399?nm, respectively. The release profile was studied at two different temperatures and pHs over 7?days. The results indicated a variation of the cumulative release of nisin from 25 to 98% depending on the pH and temperature of release media. Cytotoxicity test of nisin loaded nanogels on human dermis f
In the present study, preparation of blend hydrogels of tyramine conjugated gum tragacanth and poly (vinyl alcohol) was carried out by electron beam irradiation, and modification of hydrogel properties with poly (vinyl alcohol) was demonstrated. Gel content, swelling behavior, pore size and mechanical and rheological properties of hydrogels prepared at 14, 28 and 56 kilogray (kGy) with different ratios of polymers were investigated. Gel content increased from 67 ? 2% for pure tyramine conjugated gum tragacanth hydrogel to >92% for blend hydrogels. However, the corresponding equilibrium swelling degree decreased from 35.21 ? 1.51 to 9.14 ? 1.66 due to the higher crosslink density of blend hydrogel. The mechanical strength of the
Mesenchymal stem cells with differentiation ability to diverse cells play a crucial role in tissue engineering. Tracking the fate of these cells during the regeneration of tissue helps to obtain more information about their function. In this study, histidine conjugated β-cyclodextrin as a cell-penetrating carrier with drug loading ability was attached to QDs nanoparticle (QD-βCD-His) for stem cell labeling. Traceability of QD-βCD-His labeled human adipose stem cells (hASCs) was monitored in 2D cell culture and 3D temperature-sensitive chitosan hydrogel scaffold. Dexamethason (Dex) as an osteoinductive drug was loaded into QD-βCD-His nano-carrier (QD-βCD-His@Dex) to induce bone differentiation of labeled cells. Overall results indicated
Nanogels, or nanostructured hydrogels, are one of the most interesting materials in biomedical engineering. Nanogels are widely used in medical applications, such as in cancer therapy, targeted delivery of proteins, genes and DNAs, and scaffolds in tissue regeneration. One salient feature of nanogels is their tunable responsiveness to external stimuli. In this review, thermosensitive nanogels are discussed, with a focus on moieties in their chemical structure which are responsible for thermosensitivity. These thermosensitive moieties can be classified into four groups, namely, polymers bearing amide groups, ether groups, vinyl ether groups and hydrophilic polymers bearing hydrophobic groups. These novel thermoresponsive nanogels provide eff
Electrospun scaffolds are potentially interesting in bone tissue engineering due to a strong structural similarity to the natural bone matrix. To investigate the osteogenic behavior of cells on the scaffolds, dynamic culture of cells is essential to simulate the biological environment. In the present study, human mesenchymal stem cells (hMSCs) were cultured on multilayer nanohydroxyapatite-polycaprolactone electrospun scaffolds at different configurations (horizontal with or without pressure and parallel with the medium flow) and flow rates in a perfusion bioreactor. Alkaline phosphatase (ALP) activity, cell viability, Ca deposition and RUNX2 expression were determined in three different dynamic states, and compared with static culture afte
In the present study, gamma irradiation was applied to promote the mechanical properties of enzyme-mediated in situ forming hydrogels prepared with tyramine-functionalized gum tragacanth (TA-GT). For this purpose, after gamma irradiation of powder or hydrocolloid solution of gum tragacanth (GT), the physiochemical and rheological properties of GT solution, and resultant hydrogel was investigated. In situ forming hydrogels were prepared via horseradish peroxidase catalyzed coupling reaction of TA-GT in the presence of hydrogen peroxide. Gamma irradiation led to a decrease in GT molecular weight and solution viscosity. Also, the solubility of GT improved and the separation of water soluble/swellable part of gum samples became easier, using ga
In this study, poly(3-hydroxybutyrate) (PHB) production was investigated for the first time using high cell density cultivation of Methylocystis hirsuta from natural gas. Various carbon sources including acetate, ethanol and glucose were used in a loop bioreactor. Then, effects of magnesium and phosphorus contents on PHB production were investigated. Results revealed that the bacterial strain had the capability to grow on various substrates. Furthermore, the cell dry mass (CDM) reached to 4.5 g/L with a PHB content of 85% (w/w) using a ratio of 1:1 of methanol:ethanol. Deficiencies of magnesium and phosphorus were shown to play a key role to achieve high cell densities in bioreactors. In addition, PHB was produced in a bubble column biore
BackgroundPhenamil (PH) is a small molecule that induces bone formation through upregulation of the TRB3 gene in the bone-regeneration process. β-Cyclodextrins (βCDs) with hydrophilic surfaces and a relatively hydrophobic cavity can form inclusion complexes with primarily hydrophobic small molecules such as PH, and increase their apparent solubility and dissolution rate. The hydrophilic surface of βCDs prevents their interaction with the hydrophobic lipids of the cell membrane for penetration. Therefore, binding of penetrative groups, such as lysine, arginine, and histidine (His), to βCDs for cell penetration is required.AimThe aim of this study was to investigate the effect of His-conjugated βCD on cellular uptake of PH for bone diffe
In this study, a preformed particle gel (PPG) was synthesized from sulfonated polyacrylamide and chromium metal cross-linker with specific concentration. The main characteristics of PPG, such as gelation time, gel fraction, swelling properties and salt sensitivity factor were investigated. The gel fraction of 94.1% practically indicated an appropriate conversion of gelant to the gel. The equilibrium swelling ratios of particle gels in distilled water and formation water at 80??C were 470.49 and 12.61, respectively. Additionally, the rheological properties of gel were studied by a dynamic rheometer. The ultimate storage modulus of gel was measured 35.4?kPa. The linear viscoelastic behavior was observed at strain between 1 and 82
In the present study, an enzyme catalyzed in situ forming hydrogel based on chemically modified tragacanth was prepared and then evaluated for use in cartilage tissue engineering. For this purpose, firstly tyramine was conjugated on the galacturonic acid methyl ester units of gum tragacanth (GT) via ammonolysis of methyl ester groups in heterogeneous media. Then, the hydrogel was prepared by mixing of functionalized polymer, horseradish peroxidase (HRP) and hydrogen peroxide using a double syringe equipped with a mixing chamber. Then, cell viability of the encapsulated human mesenchymal stem cells (hMSCs) and in vitro chondrocyte differentiation of them, incubated in the presence of differentiation medium, were investigated. After mixing of
Nanotechnology based drug delivery systems have been explored extensively in cancer therapy over the past decades. Among the vast number of different materials used in nanocarrier systems, natural biopolymers are most frequently used in the encapsulation of chemotherapeutic drugs. However, the low solubility of these agents within biological fluid has decreased their efficacy for inhibiting the growth of cancer cells. Herein, we have developed a new biodegradable and biocompatible drug delivery system based on Dextran. Specifically, we have prepared lipid-conjugated dextran through esterification process using stearic acid (SA) and cholesterol (Chol). In vitro toxicity studies of unloaded and rapamycin loaded nanocarriers with U87 MG cell l
Background aimsAdipose tissue–derived mesenchymal stromal cells (AT-MSCs), widely known as multipotent progenitors, release several cytokines that support cell survival and repair. There are in vitro and in vivo studies reporting the regenerative role of AT-MSCs possibly mediated by their protective effects on functional islet cells as well as their capacity to differentiate into insulin-producing cells (IPCs).MethodsOn such a basis, our goal in the present study was to use three different models including direct and indirect co-cultures and islet-derived conditioned medium (CM) to differentiate AT-MSCs into IPCs and to illuminate the molecular mechanisms of the beneficial impact of AT-MSCs on pancreatic islet functionality. Furthermore,
Nanocarrier-based drug delivery systems have been explored extensively in cancer therapy. Among the vast number of different nanocarrier systems applied to deliver chemotherapeutics to cancer tumor, intelligent systems which deliver drug to various sites in the body have attracted considerable attentions. Finding a specific stimulant that triggers the carrier to release its payload in the target tissue is a key parameter for efficacy of delivery systems. Acidic pH of cancer tumor helps a pH-sensitive carrier to release drug at the tumor site. In this study, a pH-sensitive mixed micellar system was developed using Dextran-Stearic Acid (Dex-SA) and Dextran-Histidine (Dex-His) conjugated polymers to deliver doxorubicin (DOX) to cancer cells. D
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