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2017
Journal Article
Titel
Laser Assisted Bioprinting (LAB) without sacrificial metal layer for contamination free assembly of cell cultures
Titel Supplements
Abstract
Abstract
The fabrication of complex tissue structures via cell-by-cell assembly enables a wide range of applications in tissue engineering and stem cell research. With Laser-Assisted Bioprinting (LAB) - using the Laser Induced Forward Transfer (LIFT) process - a high spatial resolution and a high transfer rate can be achieved. LIFT allows for transferring a wide variety of biological materials, like cells or proteins resulting in ideal conditions for the fabrication of complex tissue structures. In this study a new LIFT process omitting a sacrificial metal layer is investigated. This is desirable to allow for a contamination free cell transfer without uncontrolled nano-particles coming from the absorber material, within the cell culture medium. To omit the metallic layer without increasing the radiation-induced strain on the cells, the cell surrounding hydrogel matrix itself is used as an absorbing material. A laser wavelength close to the absorption peak of the symmetric and asymmetric stretch vibrations of water is under investigation for LIFT. Preliminary results using a 3.0 mm wavelength laser source and a tophat-like beam shape show that gelatine based hydrogel can be transferred at transfer rates of 1000 drops per second. The estimated laser penetration depth < 2 mm should result in a sufficiently thin absorption layer compared to the full thickness of the hydrogel of about 50 mm therefor the underneath cells should stay unharmed. Further reduction of laser influence on the cell could be achieved by beam shaping the laser radiation. In future experiments the influence of NIR irradiation on cell transfer and survival rate as well as the use of donut or tophat beam shapes will be evaluated.