Showing papers by "Mansour Youseffi published in 2017"

In Vitro Growth of Human Keratinocytes and Oral Cancer Cells into Microtissues: An Aerosol-Based Microencapsulation Technique

Abstract: Cells encapsulation is a micro-technology widely applied in cell and tissue research, tissue transplantation, and regenerative medicine. In this paper, we proposed a growth of microtissue model for the human keratinocytes (HaCaT) cell line and an oral squamous cell carcinoma (OSCC) cell line (ORL-48) based on a simple aerosol microencapsulation technique. At an extrusion rate of 20 μL/min and air flow rate of 0.3 L/min programmed in the aerosol system, HaCaT and ORL-48 cells in alginate microcapsules were encapsulated in microcapsules with a diameter ranging from 200 to 300 μm. Both cell lines were successfully grown into microtissues in the microcapsules of alginate within 16 days of culture. The microtissues were characterized by using a live/dead cell viability assay, field emission-scanning electron microscopy (FE-SEM), fluorescence staining, and cell re-plating experiments. The microtissues of both cell types were viable after being extracted from the alginate membrane using alginate lyase. However, the microtissues of HaCaT and ORL-48 demonstrated differences in both nucleus size and morphology. The microtissues with re-associated cells in spheroids are potentially useful as a cell model for pharmacological studies.

Electrocardiograph (ECG) Circuit Design and Software-based Processing using LabVIEW

Abstract: The efficiency and acquisition of a clean (diagnosable) ECG signal dependent upon the proper selection of electronic components and the techniques used for noise elimination. Given that the human body and the lead cables act as antennas, hence picking up noises from the surroundings, thus a major part in the design of an ECG device is to apply various techniques for noise reduction at the early stage of the transmission and processing of the signal. This paper, therefore, covers the design and development of a Single Chanel 3-Lead Electrocardiograph and a Software-based processing environment. Main design characteristics include reduction of common mode voltages, good protection for the patient, use of the ECG device for both monitoring and automatic extraction (measurements) of the ECG components by the software. The hardware consisted of a lead selection stage for the user to select the bipolar lead for recording, a pre-amplification stage for amplifying the differential potentials while rejecting common mode voltages, an electrical isolation stage from three filtering stages with different bandwidths for noise attenuation, a power line interference reduction stage and a final amplification stage. A program in LabVIEW was developed to further improve the quality of the ECG signal, extract all its features and automatically calculate the main ECG output waveforms. The program had two main sections: The filtering section for removing power line interference, wideband noises and baseline wandering, and the analysis section for automatically extracting and measuring all the features of the ECG in real time. A Front Panel Environment was, therefore, developed for the user interface. The present system produced ECG tracings without the influence of noise/artefacts and provided accurate detection and measurement of all the components of the ECG signal.

Fabrication and characterizations of hydrogels for cartilage repair

Abstract: Articular cartilage is a vascular tissue with limited repair capabilities leaving an afflicted person in extreme pain The tissue experiences numerous forces throughout its lifetime This study focuses on development of a novel hydrogel composed of chitosan and glycerophosphate for articular cartilage repair The aim of this study was to investigate the mechanical properties and swelling behaviour of a novel hydrogel composed of chitosan and glycerophosphate for cartilage repair The mechanical properties were measured for compression forces Mach mechanical testing system was used to obtain storage and loss modulus for each hydrogel sample to achieve viscoelastic properties of fabricated hydrogels Two swelling tests were carried out to compare water retaining capabilities of the samples The hydrogel samples were made of five different concentrations of glycerophosphate cross linked with chitosan Each sample with different glycerophosphate concentration underwent sinusoidal compression forces at three different frequencies Hz Hz and Hz The result of mechanical testing was obtained as storage and loss modulus Storage modulus represents the elastic component and loss modulus represents the viscosity of the samples The results obtained for Hz were of interest because the knee experiences frequency of Hz during walking

The Effect of WIN55, 212-2 on Protein S100, Matrix Metalloproteinase-2 and Nitric Oxide Expression of Chondrocyte Monolayer

Abstract: Articular cartilage is highly capable of withstanding repeated loading, considerable stress, and friction. However, unlike other types of connective tissue, it has very low capacity to repair due to the lack of nerves, blood vessels and lymphatics [1]. It was shown in previous studies [2] that treating primary chondrocyte monolayers with 1 μM of WIN55, 212-2 increased the rate of wound closure and cell proliferation and those treating primary chondrocyte monolayers with 2 μM of the same synthetic cannabinoid decreased rate of wound closure and cell proliferation. Moreover, both treatments notably reduced cell lengths, but by different percentages. These results prompted further investigation of the effect of WIN55, 212-2 (WIN-2) on chondrocyte protein expression. Understanding the mechanisms regulating cellular behaviour, e.g. proliferation, migration, morphology, phenotype and cell adhesion is crucial for tissue engineering [3]. Cells receptor membranes bind to their ligands by expressing different types of integrins depending on the extracellular matrix [4]. Furthermore, functionality of cells relies in part on the extra cellular matrix (ECM) protein surrounding the cell [5]. For instance, collagen type-II rich ECM promotes chondrocyte proliferation and differentiation [6].