Controlled delivery for neuro-bionic devices

Yue, Zhilian; Moulton, Simon E.; Cook, Mark; O’Leary, Stephen; Wallace, Gordon G.

doi:10.1016/j.addr.2012.06.002

Cited by 51 publications

(37 citation statements)

References 88 publications

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“…CPs are able to reversibly "switch" from an oxidized state to a reduced state following electrical stimulation. This change results in a number of immediate physical and electrical transitions within the polymer due to changes to the electronic configuration of the backbone and the mass transport of ions into or out of the film [179,303,304]. These transitions, which manifest in the form of changes to polymer conductivity, volume, and elasticity, may be harnessed to create controlled drug-releasing mechanisms [179,304] including through (1) the drug incorporation into the coating as the dopant itself, leading to release through ionic repulsion as the polymer reduces [179,303,304]; (2) the volume change of the film releasing loosely bound macromolecules such as proteins from the coating surface [223,224]; and (3) the volume change creating a "squeezing" action as the coating shrinks, expelling drug trapped within nanoreservoirs in the coating [305].…”

Section: Mechanismmentioning

confidence: 99%

Nanostructured Coatings for Improved Charge Delivery to Neurons

Kozai

Alba

Zhang

et al. 2014

Nanotechnology and Neuroscience: Nano-Electronic, Photonic and Mechanical Neuronal Interfacing

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This chapter explores the variability and limitations of traditional stimulation electrodes by first appreciating how electrical potential differences lead to efficacious activation of nearby neurons and examining the basic electrochemical mechanisms of charge transfer at an electrode/electrolyte interface. It then covers the advantages and current challenges of emerging micro-/nanostructured electrode materials for next-generation neural stimulation microelectrodes. Introduction to Electrical Stimulation of NeuronsStimulation electrodes have many clinical applications. The most common clinically approved stimulator is the artificial cardiac pacemaker, which is implanted into patients with a slow or arrhythmic heartbeat [1]. Artificial pacemakers use electrodes placed directly in contact with the heart muscles to regulate heart rate by delivering a timed series of electrical pulses. Another common stimulation device implanted into many adults and children is the cochlear implant [2]. Cochlear duct electrodes are designed as a series of stimulation contacts arranged along a flexible silicone carrier (Fig. 4.1a). These electrodes are placed into the cochlea where they directly electrically stimulate nerve cells, bypassing damaged hair cells that transduce acoustic vibrations into electrical impulses in the underlying nerve cells. (Fig. 4.1b). Electrical stimulation in these deep brain structures, such as the basal ganglia, has been used to treat symptoms of Parkinson's disease including tremor and bradykinesia, as well as other movement disorders such as dystonia [3][4][5]. In addition, DBS is being studied as a treatment for stroke, chronic pain, major depression, and chronic obesity [6-10]. For epilepsy and major depression, vagal nerve stimulation offers an alternative that does not require brain surgery [11,12]. In the extremities, functional electrical stimulation (FES) is used to deliver electrical current to activate nerves or muscles in disabled patients. FES has been applied to aid in standing, walking, and basic handgrips and for restoring bowel and bladder function [13][14][15]. Many other electrical stimulation applications exist, including the restoration of somatosensation and vision, the treatment of hypertension and gastroparesis, and the promotion of nerve regeneration [16][17][18][19].While these neurostimulation devices have demonstrated some success in bypassing, replacing, or treating damaged neural circuits, they are far from being able to reliably restore natural function in all patients. In order to understand the variability and limitations of traditional stimulation electrodes, we must first appreciate how electrical potential differences lead to efficacious activation of nearby neurons and examine the basic electrochemical mechanisms of charge transfer at an electrode/electrolyte interface. This chapter will first lay out our current knowledge of these areas and afterwards will cover the advantages and current challenges of emerging micro-/nanostructured electrode materials for ...

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Section: Mechanismmentioning

confidence: 99%

Nanostructured Coatings for Improved Charge Delivery to Neurons

Kozai

Alba

Zhang

et al. 2014

Nanotechnology and Neuroscience: Nano-Electronic, Photonic and Mechanical Neuronal Interfacing

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“…More specifically, the implanted devices will predict and anticipate, for instance, epileptic seizure onsets within a probabilistic framework, thereby enabling a portion of the device to automatically activate a therapeutic response (drug delivery, electric stimulation, optic display, etc. ), in order to deter the course of neurological disturbances (Yue et al 2013). These devices will operate in a continuous-time closed control loop where therapy is responsive to probabilistic severity measurements; in other words, the therapeutic response will be graded from benign to severe as the situation warrants (Osorio et al 2001).…”

Section: Automated Therapeutic Activation: Novel Ethical Issues Aheadmentioning

confidence: 99%

“…Currently, predictive brain technologies are being developed to include automated therapeutic responses: for example, a drug delivery system that is not self-administered by the patient but is instead preprogrammed (Yue et al 2013). Theoretically, these predictive technologies could be used for a range of other pathologies where evidence shows that brain disturbances or changes occur before the onset of preventable symptoms.…”

mentioning

confidence: 99%

“…For instance, the current frequency of Parkinson's disease in Australia is 1 in 350 persons; the incidence is forecast to increase by 80% in the next 20 years as a result of the aging population (Parkinson's Australia 2011). Novel generations of implantable brain technologies promise to improve existing treatments, as well as to expand the range of new treatments available for other common neurological and psychiatric conditions (Yue et al 2013).…”

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confidence: 99%

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A Threat to Autonomy? The Intrusion of Predictive Brain Implants

Gilbert

2015

AJOB Neuroscience

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The world's first-in-human clinical trial using invasive intelligent brain devices-devices that predict specific neuronal events directly to the implanted person-has been completed with significant success. Predicting brain activity before specific outcomes occur brings a raft of unprecedented applications, especially when implants offer advice on how to respond to the neuronal events forecasted. Although these novel predictive and advisory implantable devices offer great potential to positively affect patients following surgery by enhancing quality of life (e.g., provide control over symptoms), substantial ethical concerns remain. The invasive nature of these novel devices is not unique; however, the inclusion of predictive and advisory functionalities within the implants, involving permanent monitoring of brain activity in real time, raises new ethical issues to explore, especially in relation to concerns for patient autonomy. What might be the effects of ongoing monitoring of predictive and advisory brain technologies on a patient's postoperative sense of autonomy? The role played by predictive and advisory implantable brain devices on patient's feelings of autonomy following surgery is completely unknown. The first section of this article addresses this shortcoming by reporting on a pilot study that we conducted with one of the patients implanted with one of these novel brain devices. The second section examines how overreliance on predictive and advisory brain technologies may threaten patients' autonomy. The third section looks into ethical problems concerning how devices delivering automated therapeutic responses might, hypothetically speaking, be used to monitor and control individual's autonomy through inhibition of undesirable behaviors.

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“…There is also the benefit of precise control over the amount of reagents or factors added to the cells and low cost associated with the devices owing to the small volume of expensive reagents required for the devices. There has been some application of microtechnology to in vivo implantable devices for nerve regeneration, such as those that incorporate microfluidic chips into nerve implants in order to provide precise delivery of a target drug or enable monitoring of regeneration [20][21][22][23][24]. However, the majority of neuronal LOC devices are in vitro devices, in contrast to in vivo cell or whole-organism devices, and will be the primary focus of this review.…”

Section: Introductionmentioning

confidence: 99%

Investigation of nerve injury through microfluidic devices

Siddique

Thakor

2014

J. R. Soc. Interface.

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Traumatic injuries, both in the central nervous system (CNS) and peripheral nervous system (PNS), can potentially lead to irreversible damage resulting in permanent loss of function. Investigating the complex dynamics involved in these processes may elucidate the biological mechanisms of both nerve degeneration and regeneration, and may potentially lead to the development of new therapies for recovery. A scientific overview on the biological foundations of nerve injury is presented. Differences between nerve regeneration in the central and PNS are discussed. Advances in microtechnology over the past several years have led to the development of invaluable tools that now facilitate investigation of neurobiology at the cellular scale. Microfluidic devices are explored as a means to study nerve injury at the necessary simplification of the cellular level, including those devices aimed at both chemical and physical injury, as well as those that recreate the post-injury environment.

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Controlled delivery for neuro-bionic devices

Cited by 51 publications

References 88 publications

Nanostructured Coatings for Improved Charge Delivery to Neurons

Nanostructured Coatings for Improved Charge Delivery to Neurons

A Threat to Autonomy? The Intrusion of Predictive Brain Implants

Investigation of nerve injury through microfluidic devices

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