A Novel Automation System for Microplasma Surface Patterning and Biologics Printing

In the field of tissue engineering, regenerative medicine, and life sciences, the topological biochemical cues regulate cell attachment and alignment within the construct. In a native biological system, these cues are inherent. However, most of the biological materials utilized in the fabrication of tissue construct do not possess the appropriate cues required to develop an architecture to support the cell attachment and growth of a functional tissue Therefore the ability to manipulate structural and biochemical cues plays an important role in biofabrication process, and it is a key element to evaluate a engineered cellular model. Plasma surface functionalization and biologics printing have been investigated and validated as two effective techniques to guide cell functions by creating microenvironments. The objective of this work is to develop a novel dual functional platform for freeform microplasma surface patterning and biologics printing process as well as to study the underlying process science and the process induced cellular functions. The microplasma jet system was assembled by two parts. The upper part is a plastic NPT connector surrounding an extending high voltage copper electrode. The lower part is a dielectric Pasteur pipette connected with a capillary micro-scale nozzle tip. The lower part is interchangeable and the diameter of the tip ranges from 50 μm to 1 mm. With up to 20 kV output capability, a high-voltage power supply was connected to the copper electrode through the NPT connector which also served as gas inlet. A high-voltage probe linked to an oscilloscope is used to monitor the real time voltage. The whole microplasma jet system was set up on automation platform, which allows X-Y-Z motion control and switch control. This integrated system operates at atmospheric pressured environment. All tissue constructs could be fabricated at room temperature without the use of a mask. Clear polystyrene microplates were used as plasma treatment substrates. After O²-He mixed microplasma treatment, 7F2 mouse osteoblastic cells were cultured in the microplates for cell biology studies. We demonstrated the capability of our dual functional platform by applying microplasma in the polystyrene wells and control group (without any treatment) in other wells of the same microplate substrate. The results show that the microplasma treatment changed the surface properties and improved cell attachment. This dual functional freeform system allows for surface patterning and printing of cells, proteins, growth factors, etc. to fabricate three-dimensional tissue constructs.