Biohybrid Retinal Implant: Research and Development Update in 2005

Abstract

Since the mid-90's, our research group has been developing a biohybrid retinal implant, which is a visual prosthesis that combines microelectromechanical system (MEMS) technology and regenerative medicine. In this implant, the neural axons attached on the MEMS are guided toward the central nervous system (CNS) by a peripheral nerve graft. Because neurons form functional connections between the MEMS and the CNS, electrical stimulation causes the neurons in the biohybrid retinal implant to send visual information to the CNS. Our recent research has included the first prototype of bio-MEMS, the development of various micro/nanoelectrode arrays, in vitro nerve cell culture and axon guidance experiments on the fabricated electrode array, in vivo electrical stimulation experiments, and various computer simulations including the psychophysical evaluation of reading ability with a visual prosthesis simulator.

Will microfluidics enable functionally integrated biohybrid robots?

“…Biohybrid technologies to recognize and sense mechanical stimuli have been shown through cells specialized in tactile or auditory perception ( 16 , 36 ), while the optical reactivity of certain cell types and organisms has opened perspectives on biological vision and the control of robots ( 37 – 39 ). At the beginning of the millennium, retina prostheses composed of living cells and engineered materials have started research in biohybrid technologies to restore vision ( 40 – 42 ), and these have been strongly fostered by micro- and nano-technological advancements. Optogenetic genome modification imposes photosensitivity to cells.…”

Prosthetic interfaces with the visual system: biological issues

“…In some cases, subjects were able to perceive discrete colored dots; however, the surgical difficulty of the deep brain approach to the LGN has hampered prosthetic design. A visual prosthetic design projecting to the LGN has been proposed (Yagi et al 1999(Yagi et al , 2005.…”

“…(Matsuzawa et al 1994, Fromherz 2003. A 'bio-hybrid' prosthesis has been proposed 1.0 mC cm −2 0.4-0.6 mC cm −2 0.1 mC cm −2 0.2-7.7 mC cm −2 density/phase where a silicon chip would stimulate cultured retinal ganglion cells which would then form synaptic projections to a blind patient's LGN neurons (Yagi et al 1999(Yagi et al , 2005. In the neonatal mouse, retinal neurons will grow into sculptured devices and can be electrically stimulated with current (Peterman et al 2003b, Leng et al 2004.…”

An electroactive hybrid biointerface for enhancing neuronal differentiation and axonal outgrowth on bio-subretinal chip

“…An urgent demand for improving this issue has urged scientists to develop biohybrid retinal prostheses [ 10 ], which integrate electroactive retinal nerve cells with synthetic electrodes to enhance bioelectrode interface compatibility while providing unique opportunities for tissue regeneration. In addition, biohybrid retinal prostheses and residual retinal cells within the body can interconnect through axons of neurons to improve the electrical pulse transmission efficiency [ 11 , 12 ]. However, conventional metal electrodes exhibit low charge injection and capacitance, resulting in abnormal electrochemical reactions during electrical stimulation and transmission [ [13] , [14] , [15] ].…”