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Stem Cell Biotechnology
Stem cell has been an exciting discovery for biotechnology research involving cellular manipulation for the medical field. Stem cell or progenitor cell, has the ability to differentiate itself into numerous specialized cells and this opens up a lot of possibility on how researchers can engineer the stem cells to factory-produce the cells that they desire. Some examples of stem cell that we know are embryonic stem cell, bone marrow stem cell, and stem cells extracted from the umbilical cord. To be able to study the stem cells, they first need to be identified among the cells and the technique used is the identification of cell marker. In Mesenchymal stem cells, CD105, CD166, CD44, CD90 are example of cell markers used to identify the stem cells. Once the stem cells are identified, they can be isolated using magnetic separation involving the recognition of the primary and secondary antibodies. RNA interference, transcriptome analysis, proteomics are then used to study the correlation between different types of stem cells and possible treatment emerging from it.

Bioprinting Stem Cell
Bioprinting is a robust technology used nowadays in assessing biotechnology research of stem cells development in vitro and also in vivo. Bioprinting enables the deposition of living stem cells to another specialized cells via lasers and acoustic technology. This is mainly done for genomics analysis and also to study the regenerating ability of stem cell tissues that can aid the repair of wounded cells and tissues. Extrusion, Inkjet, Stereolithography and laser-assisted are among the techniques used in bioprinting.

Extrusion method
Extrusion bioprinting prints bioink onto a substrate using a dispenser through 3 different methods; pneumatic dispensing, piston-driven dispensing and screw-driven dispensing. Each type of dispenser uses different type of force to push the bioink through the nozzle of the dispenser. The pneumatic dispenser is connected to a small tube, allowing air pressure to push the bioink through the nozzle. Piston-driven dispenser uses normal force while the screw-driven dispenser uses a rotational force to achieve the same purpose.

Inkjet method
This method is used to print a low-viscosity bioink. Three techniques involving inkjet bioprinting method are drop-on-demand inkjet, continuous-inkjet and electro-hydrodynamic jet. For drop-on-demand inkjet bioprinting, there are two sub-techniques using thermal and piezoelectric actuator. Both the electric and thermal actuator are installed at the nozzle of the dispenser to create droplets of bioink by altering the temperature and voltage of the nozzle.

Stereolithography
Microscale cell patterning is an application of bioprinting that can be achieved using stereolithography. Beam projector is used in stereolithography to project visible light onto a light-sensitive polymers of bioink and substrate to shape the bioink into a desired pattern.

Laser-assisted
Laser-assisted bioprinting or laser-induced forward transfer (LIFT) is the application of tissue engineering that involves the transfer of bioink in either liquid or solid state onto a substrate using a laser pulse. The laser is pulsed through layers of slide, laser absorbing layer and bioink to produce droplets of bioink.

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