In this project, we proposed an inkjet printer technique in combination with graphene oxide (GO) micropatterns, offering a general strategy to enhance the transplantation system of a bio-subretinal chip and treatment of functional recovery. To achieve cell-to-chip adhesion efficacy and enhance performance in a biological environment while retaining functions of the desired device, we developed a simple and rapid method to pattern cells on the retinal chip. We employed the inkjet printer technology to create biological material interface for cell micropatterning. This novel approach precisely controls the GO microscale patterns and successfully increases the cell adhesion density on the retinal chip. The development of surface coating technology would pave the way to the development of the first fully integrated and encapsulated retinal prostheses with biocompatible on-chip electrodes for long-term implantation. The bio-subretinal chip is distinct from other retinal prostheses designs in that it directly receives the projected image signal and transduces it into electrical stimulation pulses to stimulate the remaining retina neurons, such as bipolar or ganglion cells, to regenerate the visual neural pulses for transmission to the visual cortex. Thus, we conclude that we established a bio-subretinal chip, which could be effectively applied in retina-tissue engineering and therapy.
The retina in vivo is tremendously complex tissue composed of various cell types beyond RPEs situated in a complex 3D environment. However, it is not easy to conduct this by experiments because of the limitations of clinical retinal biopsies acquisition and primary retinal cultures. The development of novel approaches to improve the therapeutic outcomes of retinal diseases is still urgently needed. Thus, in this project, we first use the artificial retinal chip developed by Prof. Chung-Yu Wu’s research team at the NCTU that use electronic components to replace photoreceptors, followed by the combination of retinal cells to form an implantable bio-subretinal chip. This multi-modality approach will provide a novel platform of bio-subretinal prosthesis to recover vision perception.
Further, the proposed approach involves a general route toward improving functionalization of subretinal bio-chip by the integration of GO micropatterns, thus having broader implications on many different technologies that utilize GO as a template material.
Finally, to our knowledge, this is the first demonstration of “printed GO micropatterns” in retinal prostheses and at showcasing its enormous potential. Although numerous studies have employed novel surfaces to improve cell functionalization of the implanted device, there are still difficulties associated in achieving cell functionalization for a subretinal chip because of the presence of multiple independent microelectrodes in the chip. Thus, it would be interesting to obtain a printed GO that could pattern cells onto the microelectrodes of the chip, and simultaneously preserves its functionalization for further implantation.