Electrical stimulation of retinal ganglion cells with diamond and the development of an all diamond retinal prosthesis

Hadjinicolaou, Alexander; Leung, Ronald T; Garrett, David J.; Ganesan, Kumaravelu; Fox, Kate; Nayagam, David A. X.; Shivdasani, Mohit N.; Meffin, Hamish; Ibbotson, M.; Prawer, S.; O’Brien, Brendan J.

doi:10.1016/j.biomaterials.2012.04.063

Cited by 108 publications

(96 citation statements)

References 35 publications

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“…[29] Some examples of application include graphene for cell scaffolds, [30] carbon fibre dopamine sensors, [31] carbon fibre neural recording devices, [25,32] carbon nanotube neural recording devices, [33] carbon nanotube/agarose hybrid materials for tissue engineering, [34] and nitrogendoped diamond stimulating electrodes. [35] Two recent publications describe graphene oxide (GO) conductive polymer hybrid films as successful neural interfacing electrodes. [36,37] The more recent of the two, by Tian et al, describes electrochemical deposition of a PEDOT/GO hybrid film onto gold wires (100 µm diameter).…”

Section: Introductionmentioning

confidence: 99%

Soft, Flexible Freestanding Neural Stimulation and Recording Electrodes Fabricated from Reduced Graphene Oxide

Apollo

Maturana

Tong

et al. 2015

Adv Funct Materials

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123

139

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. (2015). Soft, flexible freestanding neural stimulation and recording electrodes fabricated from reduced graphene oxide. Advanced Functional Materials, 25 (23), 3551-3559. Soft, flexible freestanding neural stimulation and recording electrodes fabricated from reduced graphene oxide AbstractThere is an urgent need for conductive neural interfacing materials that exhibit mechanically compliant properties, while also retaining high strength and durability under physiological conditions. Currently, implantable electrode systems designed to stimulate and record neural activity are composed of rigid materials such as crystalline silicon and noble metals. While these materials are strong and chemically stable, their intrinsic stiffness and density induce glial scarring and eventual loss of electrode function in vivo. Conductive composites, such as polymers and hydrogels, have excellent electrochemical and mechanical properties, but are electrodeposited onto rigid and dense metallic substrates. In the work described here, strong and conductive microfibers (40-50 μm diameter) wet-spun from liquid crystalline dispersions of graphene oxide are fabricated into freestanding neural stimulation electrodes. The fibers are insulated with parylene-C and laser-treated, forming "brush" electrodes with diameters over 3.5 times that of the fiber shank. The fabrication method is fast, repeatable, and scalable for high-density 3D array structures and does not require additional welding or attachment of larger electrodes to wires. The electrodes are characterized electrochemically and used to stimulate live retina in vitro. Additionally, the electrodes are coated in a water-soluble sugar microneedle for implantation into, and subsequent recording from, visual cortex. AbstractThere is an urgent need for conductive neural interfacing materials that exhibit mechanicallycompliant properties while also retaining high strength and durability in physiological conditions. Currently, implantable electrode systems designed to stimulate and record neural activity are comprised of rigid materials such as crystalline silicon and noble metals. While these materials are strong and chemically stable, their intrinsic stiffness and density induce glial scarring and eventual loss of electrode function in vivo. Conductive composites, such as polymers and hydrogels, have excellent electrochemical and mechanical properties, but are electrodeposited onto rigid and dense metallic substrates. In the work described here, strong and conductive microfibres (40-50 µm diameter) wet-spun from liquid crystalline dispersions of graphene oxide are fabricated into freestanding neural stimulation electrodes. The fibres were insulated with parylene-C and laser-treated, forming "brush" electrodes with diameters over 3.5 times that of the fibre shank. The fabrication method is fast, repeatable, and scalable for high density 3-D array structures and does not require additional welding or attachment of larger electrodes to wires. The electrodes are characterized electroch...

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Section: Introductionmentioning

confidence: 99%

Soft, Flexible Freestanding Neural Stimulation and Recording Electrodes Fabricated from Reduced Graphene Oxide

Apollo

Maturana

Tong

et al. 2015

Adv Funct Materials

Self Cite

123

139

View full text Add to dashboard Cite

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“…102,103 Special electrode coatings can increase the amount of charge that can be injected while minimizing the damage done to the local surrounding tissue. [104][105][106][107][108][109] A further challenge is the development of high-channel count stimulators, which currently only exist in research labs. 110 ICMS has the potential to drive very high-resolution sensory signals directly into the brain, and although clinical experiments using this technology will rapidly push the field forward, it is likely that it will be many years before this approach will be used regularly in a clinical setting.…”

Section: -99mentioning

confidence: 99%

Neuroprosthetic technology for individuals with spinal cord injury

Collinger¹,

Foldes

Bruns

et al. 2013

The Journal of Spinal Cord Medicine

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Context: Spinal cord injury (SCI) results in a loss of function and sensation below the level of the lesion. Neuroprosthetic technology has been developed to help restore motor and autonomic functions as well as to provide sensory feedback. Findings: This paper provides an overview of neuroprosthetic technology that aims to address the priorities for functional restoration as defined by individuals with SCI. We describe neuroprostheses that are in various stages of preclinical development, clinical testing, and commercialization including functional electrical stimulators, epidural and intraspinal microstimulation, bladder neuroprosthesis, and cortical stimulation for restoring sensation. We also discuss neural recording technologies that may provide command or feedback signals for neuroprosthetic devices. Conclusion/clinical relevance: Neuroprostheses have begun to address the priorities of individuals with SCI, although there remains room for improvement. In addition to continued technological improvements, closing the loop between the technology and the user may help provide intuitive device control with high levels of performance.

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“…Depending on the implant and the study being performed, remove extraneous components before further dissection. NOTE: In the present example, the epiretinal array being evaluated consisted of a prototype hermetic diamond electrode and electronics package housed within a conformal silicone carrier (produced in house; refer to 20 ). 1.…”

Section: Electrode Removal and Dissectionmentioning

confidence: 99%

“…In our companion article, we described a method for assessing the localized histopathology of the eye surrounding an implant positioned in the suprachoroidal space 16 The epiretinal location is the most commonly utilised position for locating a visual prosthesis. Electrode arrays situated here are typically affixed to the retina with a metal tack that penetrates all the layers of the eye [17][18][19][20] . Prior to the techniques described in the present manuscript, it was difficult to accurately assess the retinal and other tissues immediately surrounding a tack.…”

Section: Introductionmentioning

confidence: 99%

Techniques for Processing Eyes Implanted with a Retinal Prosthesis for Localized Histopathological Analysis: Part 2 Epiretinal Implants with Retinal Tacks

Nayagam

Durmo²,

McGowan

et al. 2015

JoVE

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Retinal prostheses for the treatment of certain forms of blindness are gaining traction in clinical trials around the world with commercial devices currently entering the market. In order to evaluate the safety of these devices, in preclinical studies, reliable techniques are needed. However, the hard metal components utilised in some retinal implants are not compatible with traditional histological processes, particularly in consideration for the delicate nature of the surrounding tissue. Here we describe techniques for assessing the health of the eye directly adjacent to a retinal implant secured epiretinally with a metal tack.Retinal prostheses feature electrode arrays in contact with eye tissue. The most commonly used location for implantation is the epiretinal location (posterior chamber of the eye), where the implant is secured to the retina with a metal tack that penetrates all the layers of the eye. Previous methods have not been able to assess the proximal ocular tissue with the tack in situ, due to the inability of traditional histological techniques to cut metal objects. Consequently, it has been difficult to assess localized damage, if present, caused by tack insertion.Therefore, we developed a technique for visualizing the tissue around a retinal tack and implant. We have modified an established technique, used for processing and visualizing hard bony tissue around a cochlear implant, for the soft delicate tissues of the eye. We orientated and embedded the fixed eye tissue, including the implant and retinal tack, in epoxy resin, to stabilise and protect the structure of the sample. Embedded samples were then ground, polished, stained, and imaged under various magnifications at incremental depths through the sample. This technique allowed the reliable assessment of eye tissue integrity and cytoarchitecture adjacent to the metal tack.

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Electrical stimulation of retinal ganglion cells with diamond and the development of an all diamond retinal prosthesis

Cited by 108 publications

References 35 publications

Soft, Flexible Freestanding Neural Stimulation and Recording Electrodes Fabricated from Reduced Graphene Oxide

Soft, Flexible Freestanding Neural Stimulation and Recording Electrodes Fabricated from Reduced Graphene Oxide

Neuroprosthetic technology for individuals with spinal cord injury

Techniques for Processing Eyes Implanted with a Retinal Prosthesis for Localized Histopathological Analysis: Part 2 Epiretinal Implants with Retinal Tacks

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