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Papers by Meisam Valizadeh Kiamahalleh

Journal of Pharmaceutical Sciences, 2017

An efficient drug delivery system was introduced. The carrier was synthesized by combination of a... more An efficient drug delivery system was introduced. The carrier was synthesized by combination of an ordered mesoporous carbon (CMK3) and a thermosensitive polymer, Poly(N-isopropylacrylamide), known as PNIPAAm. The polymers with two different chain lengths (PNIPAAMm-100n and PNIPAAm 400n) were synthesized and each of the polymers was embedded in CMK3 to form composite materials. Nitrogen adsorption isotherm and scanning electron microscopy of the samples showed a uniform embedding of PNIPAAMm-100n but a non-uniform embedding of PNIPAAMm-400n. The latter observation is attributed to large intra-molecular interactions of PNIPAAMm-400n and their aggregation on the external surface of the porous structure. Doxorubicin (DOX) was used as the model drug and was loaded onto the samples. The ultimate loading capacities for the polymer-embedded samples were reduced. However, the loading rates and the release capacities were significantly improved. Thermosensitivity of the polymer was introduced as the governing drug release mechanism; regardless of the polymer chain length, drug release at 37 °C was significantly higher than 4 °C. Cytotoxicity results confirmed materials&amp;amp;amp;amp;amp;#39; biocompatibility for future biological tests. It is clearly shown that the properly-synthesized composite of ordered mesoporous carbon and thermosensitive polymer can be used as an efficient carrier for drug loading and release experiments. The loading and release profiles can be controlled by tailoring the polymer chain length.

Journal of Chromatography B, 2016

Curcumin is a hydrophobic polyphenolic compound derived from turmeric rhizome, which consists abo... more Curcumin is a hydrophobic polyphenolic compound derived from turmeric rhizome, which consists about 2-5% of the total rhizome content and is a more valuable component of turmeric. For reducing the drawbacks of conventional extraction (using organic solvents) of curcumin, the water as a clean solvent was used for extracting curcumin. Subcritical water extraction (SWE) experimental setup was fabricated in a laboratory scale and the influences of some parameters (e.g. extraction temperature, particle size, retention time and pressure) on the yield of extraction were investigated. Optimum extraction conditions such as SWE pressure of 10bar, extractive temperature of 140°C, particle size of 0.71mm and retention time of 14min were defined. The maximum amount of curcumin extracted at the optimum condition was 3.8wt%. The yield of curcumin extraction was more than 76wt% with regards to the maximum possible curcumin content of turmeric, as known to be 5%. The scanning electron microscope (SEM) images from the outer surface of turmeric, before and after extraction, clearly demonstrated the effect of each parameter; changes in porosity and hardness of turmeric that is directly related to the amount of extracted curcumin in process optimization of the extraction parameters.

carbon, 2010

Correspondnig Author: Sharif Hussein Sharif Zein, Department of Chemical Engineering, Universiti ... more Correspondnig Author: Sharif Hussein Sharif Zein, Department of Chemical Engineering, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang, Malaysia E-mail: chhussein@eng.usm.my Tel.:+604 599 6442 1 ... Multiwalled Carbon Nanotubes Filled ...

Nanostructured Ceramic Oxides for Supercapacitor Applications, 2014

Journal of Biomedical Materials Research Part A, 2016

Providing a controllable and definable three-dimensional (3D) microenvironment for chondrogenic d... more Providing a controllable and definable three-dimensional (3D) microenvironment for chondrogenic differentiation of mesenchymal stem cells (MSCs) remains a great challenge for cartilage tissue engineering. In this work, poly (N-isopropylacrylamide) (PNIPAAm) polymers with the degrees of polymerization of 100 and 400 (NI100 and NI400) were prepared and the polymer solutions were introduced into the pre-prepared chitosan porous scaffolds (CS) to form hybrids (CSNI100 and CSNI400, respectively). SEM images indicated that the PNIPAAm gel partially occupied chitosan pores while the interconnected porous structure of chitosan was preserved. MSCs were incorporated within the hybrid and cell proliferation and chondrogenic differentiation were monitored. After seven-day incubation of the cell-laden constructs in a growth medium, the cell viability in CSNI100 and CSNI400 were 54% and 108% higher than that in CS alone, respectively. Glycosaminoglycan and total collagen contents increased 2.6 and 2.5 folds after 28-day culture of cell-laden CSNI400 in the chondrogenic medium. These results suggest that the hybrid structure composed of the chitosan porous scaffold and the well-defined PNIPAAm hydrogel, in particular CSNI400, is suitable for 3D stem cell culture and cartilage tissue engineering. This article is protected by copyright. All rights reserved.

Materials science & engineering. C, Materials for biological applications, 2016

Poly (N-isopropylacrylamide) (PNIPAAm) is a thermosensitive polymer with various biomedical appli... more Poly (N-isopropylacrylamide) (PNIPAAm) is a thermosensitive polymer with various biomedical applications. We examined molecular weight (MW)-dependent cytotoxicity of PNIPAAm. Our results indicated that low-MW PNIPAAm (degree of polymerization (DP)=35) is inherently toxic to cells. Moderate-MW PNIPAAms with their DP between 100 and 200 are non-cytotoxic. When cells are seeded on top of a polymer-coated surface, PNIPAAm with a higher MW (DP=400) shows non/low cytotoxicity, while when monolayer cells are exposed to the polymer solution, cell viability drops drastically. This may be due to lack of nutrient and oxygen rather than intrinsic toxicity of the polymer.

KSCE Journal of Civil Engineering, 2013

Rice straw can be used in the production of energy or organic fertilizer. However, one of the mai... more Rice straw can be used in the production of energy or organic fertilizer. However, one of the main problems in the transformation of rice straw is its low-biodegradability. This study reports a comparison on the effectiveness of the Sodium Hydroxide (NaOH) and Potassium Hydroxide (KOH) pre-treatment methods on the enhancement of rice straw solubilization to increase its biodegradability. Laboratory-scale experiments were carried out in reflux completely mixed reactors of 500 mL capacity. The Response Surface Method (RSM) was used to optimize experimental conditions. The respective optimum conditions determined from RSM for NaOH and KOH were as follows: concentration of 29.99 and 30 g/L, reaction time of 165.7 and 151.23 min, and temperature of 164.37 and 200°C. The actual and predicted results are clearly indicated that the solubility of rice straw is significantly increased under NaOH pretreatment in comparison with KOH. The actual results of solubility of rice straw under optimum conditions are compared well with the maximum predicted values.

Journal of Applied Sciences, 2011

Abstract: Nickel-manganese oxide/Poly (3, 4-ethylenedioxythiophene)(NMO/MWCNTs/PEDOT) nanocomposi... more Abstract: Nickel-manganese oxide/Poly (3, 4-ethylenedioxythiophene)(NMO/MWCNTs/PEDOT) nanocomposites have been prepared from emulsification of as-prepared NMO/MWCNT and aqueous acetonitrile solutions of EDOT by oxidation using Ferric chloride. The uniform coating of PEODOT on NMO/MWCNTs nanocomposite was confirmed by Energy dispersive x-ray (EDX) and scanning electron microscope (SEM) images.

ABSTRACT A municipal solid waste produced in urban and rural communities is a serious pollution s... more ABSTRACT A municipal solid waste produced in urban and rural communities is a serious pollution source of water resource in developing country. One of the main problem in treatment of organic solid waste is its non-readily biodegradability due to the complexity of organic material especially hemicellolluse. This study reports Sodium Hydroxide (NaOH) thermochemical pretreatment of rice straw as a indicators of cellulosic compound to enhance its biodegradability.

Abstract A municipal solid waste produced in urban and rural communities is a serious pollution s... more Abstract A municipal solid waste produced in urban and rural communities is a serious pollution source of water resource in developing country. One of the main problem in treatment of organic solid waste is its non-readily biodegradability due to the complexity of organic material especially hemicellolluse. This study reports Sodium Hydroxide (NaOH) thermochemical pretreatment of rice straw as a indicators of cellulosic compound to enhance its biodegradability.

Electrode materials are the most important factors to verify the properties of the electrochemica... more Electrode materials are the most important factors to verify the properties of the electrochemical supercapacitor. In this paper, the storage principles and characteristics of electrode materials, including carbon-based materials, transition metal oxides and conducting polymers for supercapacitors are depicted in detail. Other factors such as electrode separator and electrolyte are briefly investigated. Recently, several works are conducted on application of multiwalled carbon nanotubes (MWCNTs) and MWCNTs-based electrode materials for supercapacitors. MWCNTs serve in experimental supercapacitor electrode materials result in specific capacitance (SC) value as high as 135 Fg -1. Addition of pseudocapacitive materials such as transition metal oxides and conducting polymers in the MWCNTs results in electrochemical performance improvement (higher capacitance and conductivity). The nanocomposites of MWCNTs and pseudocapacitive materials are the most promising electrode materials for supercapacitors because of their good electrical conductivity, low cost and high mass density. © 2012 World Scientific Publishing Company.

Urban waters: Resource or Risk?, Jan 1, 2011

A novel ternary nanocomposite of nickel-manganese oxides/multi-walled carbon nanotubes (NMO/MWCNT... more A novel ternary nanocomposite of nickel-manganese oxides/multi-walled carbon nanotubes (NMO/MWCNTs) coated with poly (3,4-ethylenedioxythiophene)(PEDOT) was prepared by chemical oxidation method. The filling of NMO particles inside MWCNTs and the uniform coating of NMO/MWCNTs with PEDOT intensified the capacitive behavior of MWCNTs. The lowest IR drop (0.1 V) and highest specific capacitance (SC) values of 526.55 F/g of NMO/MWCNTs/PEDOT imply it as highly efficient hybrid supercapacitor materials in 6 M KOH electrolyte.

Improving the electrochemical stability of manganese oxide/multiwalled carbon nanotubes (MnO2/MWC... more Improving the electrochemical stability of manganese oxide/multiwalled carbon nanotubes (MnO2/MWCNTs) nanocomposites is of great importance to many electrochemical supercapacitor applications. In this study, the electrochemical properties of MnO2 filled inside the cavity of MWCNTs were investigated for the first time. The prepared nanocomposite was characterized by means of X-ray photoelectron spectroscopy (XPS), X-ray diffraction patterns (XRD), transmission electron microscopy (TEM) images, scanning electron microscopy (SEM) together with energy dispersive X-ray spectroscopy (EDX) and thermogravimetric analyses (TGA). Electrochemical characterization has been performed using cyclic voltammetry (CV), galvanostatic charging/discharging (CD) test. The TEM image, XRD analysis confirmed the high structural stability and CD test complied the high electrochemical stability of the prepared nanocomposite. Besides, MnO2/MWCNTs nanocomposite supercapacitor showed superior cycling stability in the potential range of 0-1.0V due to the filling of the electroactive material inside the tubes and retained 96% of initial capacitance even over 200 cycles.