Showing papers by "Mansour Youseffi published in 2016"

Valves and tubes including valves

Abstract: A valve (20) for the sealing cuff (10) of a tracheal tube has a valve member (40) urged against a valve seal (36, 37) by an MRI-safe resilient member (42) of neoprene or nitrile. The valve includes a two-part actuator (70) by which the valve member is displaced. Before use, during storage, the valve member is in a closed position with the resilient member relatively relaxed. When the valve is opened for the first time by inserting a syringe or the like, the two-part actuator arrangement is moved forwards to unseat the valve member to allow flow. This causes inclined surfaces (88) and (92) on the two parts (72) and (73) of the actuator to rotate the forward part slightly. When the syringe is removed to allow the valve to close, the forward part of the actuator latches on a surface (34) of the housing (21) in an operational position where the valve is closed.

Characterisation of encapsulated cells in calcium alginate microcapsules

Abstract: Polysaccharides including agarose, chitosan, alginate and collagen are group of natural polymers applied for microencapsulation of cells. This study focused on the characterisation of calcium alginate microcapsules and encapsulated human keratinocytes cell lines. The synthesised calcium alginate were characterised using Fourier Transform Infrared Spectroscopy (FTIR) in wavelength ranging from 600–4000 cm−1 and Field Emission Scanning Electron Microscopy (FESEM). Cells restructuring in the calcium alginate microcapsules influenced the functional groups and chemistry contents of the cells.

Investigation of electroporation technique on cell propertiescultured on self-assembled monolayer

Abstract: Electroporation (EP) is a method of controlling cell function by using pulses of electrical fields to create pore through a cell membrane and causes other substance around it to be absorbed into the cell. Where this method had been led to a variety of medical applications. While, micro contact printing (μCP) is a quite useful technique for patterning extracellular matrix as an adhesion molecule for cells that works for controlling the cell growth. This study focuses on a comparison of a cancer cell (HeLa cancer cell) cultured on two different type of substrates which is a protein surface and empty surface. In order to see the effect of cell proliferation of cancer cell with protein solution, which is in this experiment we used fibronectin for the protein solution and the preliminary result show a positive respond to the protein solution that act as self-assembled monolayer.

Growth of microtissues in microencapsules formed using microextrusion and vibration

Abstract: Microencapsulation technology had been widely used in biological study, drug delivery, cosmetic and also food industry. Previous methods developed for microencapsulation is complex in terms of their design and handling. A simple micro extruder device with vibration mode was developed to microencapsulate HaCaT cells in calcium alginate capsules at 10 to 60 Hz. The microencapsulated cells proliferated and formed into microtissues. Alginate lyase was applied to remove the microtissues from the encapsulation and for studying the cell adhesion in the microtissues. DAPI and live/dead cell stainings were applied to study the organisation and viability of cells, respectively. Via the nuclei staining, it was found that the distance between cells reduced as the incubation period increased. After 15 days of culture, the cells were viable as indicated by the fluorescence green expression of Calcein-AM. Replating experiment indicated that the cells from the microtissues were able to migrate and has the tendency to form monolayer of cells on the culture flask.