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1.
Nature ; 614(7948): 456-462, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36792740

RESUMO

Stretchable hybrid devices have enabled high-fidelity implantable1-3 and on-skin4-6 monitoring of physiological signals. These devices typically contain soft modules that match the mechanical requirements in humans7,8 and soft robots9,10, rigid modules containing Si-based microelectronics11,12 and protective encapsulation modules13,14. To make such a system mechanically compliant, the interconnects between the modules need to tolerate stress concentration that may limit their stretching and ultimately cause debonding failure15-17. Here, we report a universal interface that can reliably connect soft, rigid and encapsulation modules together to form robust and highly stretchable devices in a plug-and-play manner. The interface, consisting of interpenetrating polymer and metal nanostructures, connects modules by simply pressing without using pastes. Its formation is depicted by a biphasic network growth model. Soft-soft modules joined by this interface achieved 600% and 180% mechanical and electrical stretchability, respectively. Soft and rigid modules can also be electrically connected using the above interface. Encapsulation on soft modules with this interface is strongly adhesive with an interfacial toughness of 0.24 N mm-1. As a proof of concept, we use this interface to assemble stretchable devices for in vivo neuromodulation and on-skin electromyography, with high signal quality and mechanical resistance. We expect such a plug-and-play interface to simplify and accelerate the development of on-skin and implantable stretchable devices.


Assuntos
Eletromiografia , Eletrônica Médica , Nanoestruturas , Maleabilidade , Polímeros , Próteses e Implantes , Dispositivos Eletrônicos Vestíveis , Humanos , Nanoestruturas/química , Polímeros/química , Pele , Monitorização Fisiológica , Eletrônica Médica/instrumentação , Eletrônica Médica/métodos , Eletromiografia/instrumentação
2.
J Med Internet Res ; 22(5): e15977, 2020 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-32449685

RESUMO

BACKGROUND: The disproportionately high prevalence of HIV among men who have sex with men (MSM) is a global concern. Despite the increasing utilization of electronic health (eHealth) technology in the delivery of HIV prevention interventions, few studies have systematically explored its effectiveness and association with various intervention characteristics. OBJECTIVE: This study aimed to conduct a meta-analysis of the effectiveness of eHealth technology-based interventions for promoting HIV-preventive behaviors among MSM and to determine effectiveness predictors within a framework integrating design and implementation features. METHODS: A systematic literature search using terms related to eHealth technology, HIV, the MSM population, and an experimental study design was performed using 5 databases (ie, MEDLINE, PsycINFO, EMBASE, Web of Science, and ProQuest Dissertations & Theses) and other sources (eg, bibliographies of relevant reviews and JMIR Publications). First, primary meta-analyses were conducted to estimate the effectiveness of eHealth interventions (d+) in changing 3 HIV-preventive behaviors among MSM: unprotected anal intercourse (UAI), HIV testing, and multiple sex partnership (MSP). Moderation analyses were then conducted to examine a priori effectiveness predictors including behavioral treatment components (eg, theory use, tailoring strategy use, navigation style, and treatment duration), eHealth technology components (eg, operation mode and modality type), and intervention adherence. RESULTS: A total of 46 studies were included. The overall effect sizes at end point were small but significant for all outcomes (UAI: d+=-.21, P<.001; HIV testing: d+=.38, P<.001; MSP: d+=-.26, P=.02). The intervention effects on UAI were significantly larger when compared with preintervention groups than with concurrent groups. Greater UAI reductions were associated with the increased use of tailoring strategies, provision of feedback, and tunneling navigation in interventions with a concurrent group, whereas reductions were associated with the use of self-paced navigation in interventions with a preintervention group. Greater uptake of HIV testing was associated with longer treatment duration; computer-mediated communication; and the use of messaging, social media, or a combined technology modality. Higher intervention adherence consistently predicted larger effects on UAI and HIV testing. CONCLUSIONS: This study provided empirical evidence for the effectiveness of eHealth interventions in promoting HIV-preventive behaviors among MSM. Features of treatment content and eHealth technology might best predict the intervention effects on UAI and HIV testing, respectively. Most importantly, intervention adherence tended to play an important role in achieving better effectiveness. The findings could help inform the development of efficacious interventions for HIV prevention in the future.


Assuntos
Eletrônica Médica/métodos , Infecções por HIV/prevenção & controle , Homossexualidade Masculina/estatística & dados numéricos , Humanos , Masculino
3.
Acc Chem Res ; 51(2): 309-318, 2018 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-29381054

RESUMO

Nanobioelectronics represents a rapidly developing field with broad-ranging opportunities in fundamental biological sciences, biotechnology, and medicine. Despite this potential, seamless integration of electronics has been difficult due to fundamental mismatches, including size and mechanical properties, between the elements of the electronic and living biological systems. In this Account, we discuss the concept, development, key demonstrations, and future opportunities of mesh nanoelectronics as a general paradigm for seamless integration of electronics within synthetic tissues and live animals. We first describe the design and realization of hybrid synthetic tissues that are innervated in three dimensions (3D) with mesh nanoelectronics where the mesh serves as both as a tissue scaffold and as a platform of addressable electronic devices for monitoring and manipulating tissue behavior. Specific examples of tissue/nanoelectronic mesh hybrids highlighted include 3D neural tissue, cardiac patches, and vascular constructs, where the nanoelectronic devices have been used to carry out real-time 3D recording of electrophysiological and chemical signals in the tissues. This novel platform was also exploited for time-dependent 3D spatiotemporal mapping of cardiac tissue action potentials during cell culture and tissue maturation as well as in response to injection of pharmacological agents. The extension to simultaneous real-time monitoring and active control of tissue behavior is further discussed for multifunctional mesh nanoelectronics incorporating both recording and stimulation devices, providing the unique capability of bidirectional interfaces to cardiac tissue. In the case of live animals, new challenges must be addressed, including minimally invasive implantation, absence of deleterious chronic tissue response, and long-term capability for monitoring and modulating tissue activity. We discuss each of these topics in the context of implantation of mesh nanoelectronics into rodent brains. First, we describe the design of ultraflexible mesh nanoelectronics with size features and mechanical properties similar to brain tissue and a novel syringe-injection methodology that allows the mesh nanoelectronics to be precisely delivered to targeted brain regions in a minimally invasive manner. Next, we discuss time-dependent histology studies showing seamless and stable integration of mesh nanoelectronics within brain tissue on at least one year scales without evidence of chronic immune response or glial scarring characteristic of conventional implants. Third, armed with facile input/output interfaces, we describe multiplexed single-unit recordings that demonstrate stable tracking of the same individual neurons and local neural circuits for at least 8 months, long-term monitoring and stimulation of the same groups of neurons, and following changes in individual neuron activity during brain aging. Moving forward, we foresee substantial opportunities for (1) continued development of mesh nanoelectronics through, for example, broadening nanodevice signal detection modalities and taking advantage of tissue-like properties for selective cell targeting and (2) exploiting the unique capabilities of mesh nanoelectronics for tackling critical scientific and medical challenges such as understanding and potentially ameliorating cell and circuit level changes associated with natural and pathological aging, as well as using mesh nanoelectronics as active tissue scaffolds for regenerative medicine and as neuroprosthetics for monitoring and treating neurological diseases.


Assuntos
Equipamentos e Provisões Elétricas , Eletrônica Médica/instrumentação , Eletrônica Médica/métodos , Engenharia Tecidual/métodos , Animais , Encéfalo/metabolismo , Humanos , Camundongos , Neurônios/metabolismo , Primatas , Ratos
4.
Acc Chem Res ; 51(7): 1581-1589, 2018 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-29897228

RESUMO

The field of bioelectronics involves the fascinating interplay between biology and human-made electronics. Applications such as tissue engineering, biosensing, drug delivery, and wearable electronics require biomimetic materials that can translate the physiological and chemical processes of biological systems, such as organs, tissues. and cells, into electrical signals and vice versa. However, the difference in the physical nature of soft biological elements and rigid electronic materials calls for new conductive or electroactive materials with added biomimetic properties that can bridge the gap. Soft electronics that utilize organic materials, such as conjugated polymers, can bring many important features to bioelectronics. Among the many advantages of conjugated polymers, the ability to modulate the biocompatibility, solubility, functionality, and mechanical properties through side chain engineering can alleviate the issues of mechanical mismatch and provide better interface between the electronics and biological elements. Additionally, conjugated polymers, being both ionically and electrically conductive through reversible doping processes provide means for direct sensing and stimulation of biological processes in cells, tissues, and organs. In this Account, we focus on our recent progress in molecular engineering of conjugated polymers with tunable biomimetic properties, such as biocompatibility, responsiveness, stretchability, self-healing, and adhesion. Our approach is general and versatile, which is based on functionalization of conjugated polymers with long side chains, commonly polymeric or biomolecules. Applications for such materials are wide-ranging, where we have demonstrated conductive, stimuli-responsive antifouling, and cell adhesive biointerfaces that can respond to external stimuli such as temperature, salt concentration, and redox reactions, the processes that in turn modify and reversibly switch the surface properties. Furthermore, utilizing the advantageous chemical, physical, mechanical and functional properties of the grafts, we progressed into grafting of the long side chains onto conjugated polymers in solution, with the vision of synthesizing solution-processable conjugated graft copolymers with biomimetic functionalities. Examples of the developed materials to date include rubbery and adhesive photoluminescent plastics, biomolecule-functionalized electrospun biosensors, thermally and dually responsive photoluminescent conjugated polymers, and tunable self-healing, adhesive, and stretchable strain sensors, advanced functional biocidal polymers, and filtration membranes. As outlined in these examples, the applications of these biomimetic, conjugated polymers are still in the development stage toward truly printable, organic bioelectronic devices. However, in this Account, we advocate that molecular engineering of conjugated polymers is an attractive approach to a versatile class of organic electronics with both ionic and electrical conductivity as well as mechanical properties required for next-generation bioelectronics.


Assuntos
Materiais Biomiméticos/química , Polímeros/química , Materiais Biocompatíveis/síntese química , Materiais Biocompatíveis/química , Materiais Biomiméticos/síntese química , Engenharia Química , Condutividade Elétrica , Eletrônica Médica/métodos , Maleabilidade , Polímeros/síntese química , Dispositivos Eletrônicos Vestíveis
5.
Neural Comput ; 30(9): 2472-2499, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29949460

RESUMO

A hippocampal prosthesis is a very large scale integration (VLSI) biochip that needs to be implanted in the biological brain to solve a cognitive dysfunction. In this letter, we propose a novel low-complexity, small-area, and low-power programmable hippocampal neural network application-specific integrated circuit (ASIC) for a hippocampal prosthesis. It is based on the nonlinear dynamical model of the hippocampus: namely multi-input, multi-output (MIMO)-generalized Laguerre-Volterra model (GLVM). It can realize the real-time prediction of hippocampal neural activity. New hardware architecture, a storage space configuration scheme, low-power convolution, and gaussian random number generator modules are proposed. The ASIC is fabricated in 40 nm technology with a core area of 0.122 mm[Formula: see text] and test power of 84.4 [Formula: see text]W. Compared with the design based on the traditional architecture, experimental results show that the core area of the chip is reduced by 84.94% and the core power is reduced by 24.30%.


Assuntos
Eletrônica Médica/instrumentação , Hipocampo/citologia , Modelos Neurológicos , Neurônios/fisiologia , Dinâmica não Linear , Potenciais de Ação/fisiologia , Algoritmos , Animais , Eletrônica Médica/métodos , Humanos , Rede Nervosa/fisiologia , Redes Neurais de Computação , Próteses Neurais
6.
Behav Res Methods ; 50(1): 228-235, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28233251

RESUMO

Vision occlusion spectacles are a highly valuable instrument for visual-perception-action research in a variety of disciplines. In sports, occlusion spectacles have enabled invaluable knowledge to be obtained about the superior capability of experts to use visual information to guide actions within in-situ settings. Triggering the spectacles to occlude a performer's vision at a precise time in an opponent's action or object flight has been problematic, due to experimenter error in using a manual buttonpress approach. This article describes a new laser curtain wireless trigger for vision occlusion spectacles that is portable and fast in terms of its transmission time. The laser curtain can be positioned in a variety of orientations to accept a motion trigger, such as a cricket bowler's arm that distorts the lasers, which then activates a wireless signal for the occlusion spectacles to change from transparent to opaque, which occurs in only 8 ms. Results are reported from calculations done in an electronics laboratory, as well as from tests in a performance laboratory with a cricket bowler and a baseball pitcher, which verified this short time delay before vision occlusion. In addition, our results show that occlusion consistently occurred when it was intended-that is, near ball release and during mid-ball-flight. Only 8% of the collected data trials were unusable. The laser curtain improves upon the limitations of existing vision occlusion spectacle triggers, indicating that it is a valuable instrument for perception-action research in a variety of disciplines.


Assuntos
Beisebol , Equipamentos e Provisões Elétricas , Óculos , Lasers , Visão Ocular/fisiologia , Percepção Visual/fisiologia , Beisebol/fisiologia , Beisebol/psicologia , Eletrônica Médica/instrumentação , Eletrônica Médica/métodos , Humanos , Masculino , Orientação
7.
Proc Natl Acad Sci U S A ; 111(22): 7974-9, 2014 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-24843161

RESUMO

The ability to implant electronic systems in the human body has led to many medical advances. Progress in semiconductor technology paved the way for devices at the scale of a millimeter or less ("microimplants"), but the miniaturization of the power source remains challenging. Although wireless powering has been demonstrated, energy transfer beyond superficial depths in tissue has so far been limited by large coils (at least a centimeter in diameter) unsuitable for a microimplant. Here, we show that this limitation can be overcome by a method, termed midfield powering, to create a high-energy density region deep in tissue inside of which the power-harvesting structure can be made extremely small. Unlike conventional near-field (inductively coupled) coils, for which coupling is limited by exponential field decay, a patterned metal plate is used to induce spatially confined and adaptive energy transport through propagating modes in tissue. We use this method to power a microimplant (2 mm, 70 mg) capable of closed-chest wireless control of the heart that is orders of magnitude smaller than conventional pacemakers. With exposure levels below human safety thresholds, milliwatt levels of power can be transferred to a deep-tissue (>5 cm) microimplant for both complex electronic function and physiological stimulation. The approach developed here should enable new generations of implantable systems that can be integrated into the body at minimal cost and risk.


Assuntos
Eletrônica Médica/instrumentação , Eletrônica Médica/métodos , Miniaturização/métodos , Modelos Teóricos , Próteses e Implantes , Tecnologia sem Fio/instrumentação , Animais , Córtex Cerebral , Fontes de Energia Elétrica , Campos Eletromagnéticos , Desenho de Equipamento , Ventrículos do Coração , Humanos , Óptica e Fotônica/instrumentação , Óptica e Fotônica/métodos , Coelhos , Semicondutores , Pele , Suínos
8.
Proc Natl Acad Sci U S A ; 109(49): 19910-5, 2012 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-23150574

RESUMO

Curved surfaces, complex geometries, and time-dynamic deformations of the heart create challenges in establishing intimate, nonconstraining interfaces between cardiac structures and medical devices or surgical tools, particularly over large areas. We constructed large area designs for diagnostic and therapeutic stretchable sensor and actuator webs that conformally wrap the epicardium, establishing robust contact without sutures, mechanical fixtures, tapes, or surgical adhesives. These multifunctional web devices exploit open, mesh layouts and mount on thin, bio-resorbable sheets of silk to facilitate handling in a way that yields, after dissolution, exceptionally low mechanical moduli and thicknesses. In vivo studies in rabbit and pig animal models demonstrate the effectiveness of these device webs for measuring and spatially mapping temperature, electrophysiological signals, strain, and physical contact in sheet and balloon-based systems that also have the potential to deliver energy to perform localized tissue ablation.


Assuntos
Materiais Biocompatíveis , Eletrônica Médica/instrumentação , Técnicas Eletrofisiológicas Cardíacas/instrumentação , Coração/fisiologia , Pericárdio/anatomia & histologia , Próteses e Implantes , Animais , Catéteres , Eletrônica Médica/métodos , Desenho de Equipamento/métodos , Coração/anatomia & histologia , Teste de Materiais , Nanotecnologia/métodos , Coelhos , Semicondutores , Seda , Temperatura
9.
Angew Chem Int Ed Engl ; 54(43): 12562-76, 2015 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-26420480

RESUMO

Thin-film transistors can be used as high-performance bioelectronic devices to accomplish tasks such as sensing or controlling the release of biological species as well as transducing the electrical activity of cells or even organs, such as the brain. Organic, graphene, or zinc oxide are used as convenient printable semiconducting layers and can lead to high-performance low-cost bioelectronic sensing devices that are potentially very useful for point-of-care applications. Among others, electrolyte-gated transistors are of interest as they can be operated as capacitance-modulated devices, because of the high capacitance of their charge double layers. Specifically, it is the capacitance of the biolayer, being lowest in a series of capacitors, which controls the output current of the device. Such an occurrence allows for extremely high sensitivity towards very weak interactions. All the aspects governing these processes are reviewed here.


Assuntos
Técnicas Biossensoriais/métodos , Eletrônica Médica/métodos , Impressão/métodos , Transistores Eletrônicos , Animais , Técnicas Biossensoriais/instrumentação , Capacitância Elétrica , Eletrólitos/química , Eletrônica Médica/instrumentação , Desenho de Equipamento , Grafite/química , Humanos , Impressão/instrumentação , Termodinâmica , Óxido de Zinco/química
10.
Biochim Biophys Acta ; 1830(9): 4286-7, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23079584

RESUMO

BACKGROUND: This issue of "Biochimica et Biophysica Acta - General Subjects" is dedicated to organic bioelectronics, an interdisciplinary field that has been growing at a fast pace. Bioelectronics creates tremendous promise, excitement, and hype. The application of organic electronic materials in bioelectronics offers many opportunities and is fuelled by some unique features of these materials, such as the ability to transport ions. SCOPE OF REVIEW: This is a perspective on the history and current status of the field. MAJOR CONCLUSIONS: Organic bioelectronics currently encompasses many different applications, including neural interfaces, tissue engineering, drug delivery, and biosensors. The interdisciplinary nature of the field necessitates collaborations across traditional scientific boundaries. GENERAL SIGNIFICANCE: Organic bioelectronics is a young and exciting interdisciplinary field. This article is part of a Special Issue entitled Organic Bioelectronics - Novel Applications in Biomedicine.


Assuntos
Técnicas Biossensoriais/instrumentação , Biotecnologia/instrumentação , Sistemas de Liberação de Medicamentos/instrumentação , Eletrônica Médica/instrumentação , Engenharia Tecidual/instrumentação , Técnicas Biossensoriais/métodos , Biotecnologia/métodos , Sistemas de Liberação de Medicamentos/métodos , Eletrônica Médica/métodos , Humanos , Engenharia Tecidual/métodos
11.
Biochim Biophys Acta ; 1830(9): 4381-90, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23246813

RESUMO

BACKGROUND: The gastrointestinal epithelium provides a physical and biochemical barrier to the passage of ions and small molecules; however this barrier may be breached by pathogens and toxins. The effect of individual pathogens/toxins on the intestinal epithelium has been well characterized: they disrupt barrier tissue in a variety of ways, such as by targeting tight junction proteins, or other elements of the junctions between adjacent cells. A variety of methods have been used to characterize disruption in barrier tissue, such as immunofluorescence, permeability assays and electrical measurements of epithelia resistance, but these methods remain time consuming, costly and ill-suited to diagnostics or high throughput toxicology. METHODS: The advent of organic electronics has created a unique opportunity to interface the worlds of electronics and biology, using devices such as the organic electrochemical transistor (OECT), whose low cost materials and potential for easy fabrication in high throughput formats represent a novel solution for assessing epithelial tissue integrity. RESULTS: In this study, OECTs were integrated with gastro-intestinal cell monolayers to study the integrity of the gastrointestinal epithelium, providing a very sensitive way to detect minute changes in ion flow across the cell layer due to inherent amplification by the transistor. MAJOR CONCLUSIONS: We validate the OECT against traditional methods by monitoring the effect of toxic compounds on epithelial tissue. We show a systematic characterization of this novel method, alongside existing methods used to assess barrier tissue function. GENERAL SIGNIFICANCE: The toxic compounds induce a dramatic disruption of barrier tissue, and the OECT measures this disruption with increased temporal resolution and greater or equal sensitivity when compared with existing methods. This article is part of a Special Issue entitled Organic Bioelectronics - Novel Applications in Biomedicine.


Assuntos
Eletrônica Médica/instrumentação , Mucosa Intestinal/metabolismo , Toxicologia/instrumentação , Transistores Eletrônicos , Células CACO-2 , Linhagem Celular Tumoral , Eletrônica Médica/métodos , Trato Gastrointestinal/metabolismo , Humanos , Proteínas de Membrana/metabolismo , Junções Íntimas/metabolismo , Toxicologia/métodos
12.
Biochim Biophys Acta ; 1830(9): 4321-8, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22982010

RESUMO

BACKGROUND: Organic bioelectronic devices consisting of alternating poly(3,4-ethylenedioxythiophene) (PEDOT) and reduced graphite oxide (rGO) striped microelectrode arrays were fabricated by lithography technology. It has been demonstrated that the organic bioelectronic devices can be used to spatially and temporally manipulate the location and proliferation of the neuron-like pheochromocytoma cells (PC-12 cells). METHODS: By coating an electrically labile contact repulsion layer of poly(l-lysine-graft-ethylene glycol) (PLL-g-PEG) on the PEDOT electrode, the location and polarity of the PC-12 cells were confined to the rGO electrodes. RESULTS: The outgrowth of spatially confined bipolar neurites was found to align along the direction of the 20µm wide electrode. The location of the PC-12 cells can also be manipulated temporally by applying electrical stimulation during the neurite differentiation of PC-12 cells, allowing the PC-12 cells to cross over the boundary between the PEDOT and the rGO regions and construct neurite networks in an unconfined manner where the contact repulsive coating of PLL-g-PEG was removed. CONCLUSIONS: This adsorption and desorption of the PLL-g-PEG without and with electrical stimulation can be attributed to the tunable surface properties of the PEDOT microelectrodes, whose surface charge can switch from being negative to positive under electrical stimulation. GENERAL SIGNIFICANCE: The electrically tunable organic bioelectronics reported here could potentially be applied to tissue engineering related to the development and regeneration of mammalian nervous systems. The spatial and temporal control in this device would also be used to study the synapse junctions of neuron-neuron contacts in both time and space domains. This article is part of a Special Issue entitled Organic Bioelectronics - Novel Applications in Biomedicine.


Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes/química , Eletrônica Médica/métodos , Microeletrodos , Neurônios/fisiologia , Polietilenoglicóis/química , Polilisina/análogos & derivados , Polímeros/química , Animais , Linhagem Celular Tumoral , Estimulação Elétrica/métodos , Terapia por Estimulação Elétrica/métodos , Eletricidade , Grafite/química , Neuritos/fisiologia , Neurônios/citologia , Óxidos/química , Células PC12 , Polilisina/química , Ratos , Engenharia Tecidual/métodos
13.
Biochim Biophys Acta ; 1830(9): 4334-44, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23220700

RESUMO

BACKGROUND: A major challenge when creating interfaces for the nervous system is to translate between the signal carriers of the nervous system (ions and neurotransmitters) and those of conventional electronics (electrons). SCOPE OF REVIEW: Organic conjugated polymers represent a unique class of materials that utilizes both electrons and ions as charge carriers. Based on these materials, we have established a series of novel communication interfaces between electronic components and biological systems. The organic electronic ion pump (OEIP) presented in this review is made of the polymer-polyelectrolyte system poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). The OEIP translates electronic signals into electrophoretic migration of ions and neurotransmitters. MAJOR CONCLUSIONS: We demonstrate how spatio-temporally controlled delivery of ions and neurotransmitters can be used to modulate intracellular Ca(2+) signaling in neuronal cells in the absence of convective disturbances. The electronic control of delivery enables strict control of dynamic parameters, such as amplitude and frequency of Ca(2+) responses, and can be used to generate temporal patterns mimicking naturally occurring Ca(2+) oscillations. To enable further control of the ionic signals we developed the electrophoretic chemical transistor, an analog of the traditional transistor used to amplify and/or switch electronic signals. Finally, we demonstrate the use of the OEIP in a new "machine-to-brain" interface by modulating brainstem responses in vivo. GENERAL SIGNIFICANCE: This review highlights the potential of communication interfaces based on conjugated polymers in generating complex, high-resolution, signal patterns to control cell physiology. We foresee widespread applications for these devices in biomedical research and in future medical devices within multiple therapeutic areas. This article is part of a Special Issue entitled Organic Bioelectronics-Novel Applications in Biomedicine.


Assuntos
Interfaces Cérebro-Computador , Encéfalo/efeitos dos fármacos , Encéfalo/fisiologia , Eletrônica Médica/métodos , Neurônios/efeitos dos fármacos , Neurônios/fisiologia , Humanos , Íons/metabolismo , Neurotransmissores/metabolismo , Poliestirenos , Transdução de Sinais , Tiofenos , Transistores Eletrônicos
14.
Biochim Biophys Acta ; 1830(9): 4365-73, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23220699

RESUMO

BACKGROUND: There is no doubt that future discoveries in the field of biochemistry will depend on the implementation of novel biosensing techniques, able to record biophysiological events with minimal biological interference. In this respect, organic electronics may represent an important new tool for the analysis of structures ranging from single molecules up to cellular events. Specifically, organic field-effect transistors (OFET) are potentially powerful devices for the real-time detection/transduction of bio-signals. Despite this interest, up to date, the experimental data useful to support the development of OFET-based biosensors are still few and, in particular, n-type (electron-transporting) devices, being fundamental to develop highly-performing circuits, have been scarcely investigated. METHODS: Here, films of N,N'-1H,1H-perfluorobutyldicyanoperylene-carboxydi-imide (PDIF-CN2) molecules, a recently-introduced and very promising n-type semiconductor, have been evaporated on glass and silicon dioxide substrates to test the biocompatibility of this compound and its capability to stay electrically-active even in liquid environments. RESULTS: We found that PDIF-CN2 transistors can work steadily in water for several hours. Biocompatibility tests, based on in-vitro cell cultivation, remark the need to functionalize the PDIF-CN2 hydrophobic surface by extra-coating layers (i.e. poly-l-lysine) to favor the growth of confluent cellular populations. CONCLUSIONS: Our experimental data demonstrate that PDIF-CN2 compound is an interesting organic semiconductor to develop electronic devices to be used in the biological field. GENERAL SIGNIFICANCE: This work contributes to define a possible strategy for the fabrication of low-cost and flexible biosensors, based on complex organic complementary metal-oxide-semiconductor (CMOS) circuitry including both p- (hole-transporting) and n-type transistors. This article is part of a Special Issue entitled Organic Bioelectronics-Novel Applications in Biomedicine.


Assuntos
Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/estatística & dados numéricos , Eletrônica Médica/instrumentação , Eletrônica Médica/métodos , Imidas/química , Perileno/análogos & derivados , Semicondutores , Transistores Eletrônicos , Animais , Células CHO , Adesão Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Cricetinae , Teste de Materiais/métodos , Metais/química , Nitrilas/química , Óxidos/química , Perileno/química , Água/química
15.
Biochim Biophys Acta ; 1830(9): 4294-304, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23291427

RESUMO

BACKGROUND: An exciting direction in nanomedicine would be to analyze how living cells respond to conducting polymers. Their application for tissue regeneration may advance the performance of drug eluting stents by addressing the delayed stent re-endothelialization and late stent thrombosis. METHODS: The suitability of poly (3, 4-ethylenedioxythiophene) (PEDOT) thin films for stents to promote cell adhesion and proliferation is tested in correlation with doping and physicochemical properties. PEDOT doped either with poly (styrenesulfonate) (PSS) or tosylate anion (TOS) was used for films' fabrication by spin coating and vapor phase polymerization respectively. PEGylation of PEDOT: TOS for reduced immunogenicity and biofunctionalization of PEDOT: PSS with RGD peptides for induced cell proliferation was further applied. Atomic Force Microscopy and Spectroscopic Ellipsometry were implemented for nanotopographical, structural, optical and conductivity measurements in parallel with wettability and protein adsorption studies. Direct and extract testing of cell viability and proliferation of L929 fibroblasts on PEDOT samples by MTT assay in line with SEM studies follow. RESULTS: All PEDOT thin films are cytocompatible and promote human serum albumin adsorption. PEDOT:TOS films were found superior regarding cell adhesion as compared to controls. Their nanotopography and hydrophilicity are significant factors that influence cytocompatibility. PEGylation of PEDOT:TOS increases their conductivity and hydrophilicity with similar results on cell viability with bare PEDOT:TOS. The biofunctionalized PEDOT:PSS thin films show enhanced cell proliferation. CONCLUSIONS: The application of PEDOT polymers has evolved as a new perspective to advance stents. GENERAL SIGNIFICANCE: In this work, nanomedicine involving nanotools and novel nanomaterials merges with bioelectronics to stimulate tissue regeneration for cardiovascular implants. This article is part of a Special Issue entitled Organic Bioelectronics - Novel Applications in Biomedicine.


Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes/química , Sistema Cardiovascular/efeitos dos fármacos , Eletrônica Médica/instrumentação , Nanomedicina/instrumentação , Polímeros/química , Próteses e Implantes , Regeneração/fisiologia , Adesão Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Eletrônica Médica/métodos , Fibroblastos/efeitos dos fármacos , Humanos , Interações Hidrofóbicas e Hidrofílicas , Microscopia de Força Atômica/métodos , Albumina Sérica/metabolismo , Análise Espectral/métodos , Molhabilidade/efeitos dos fármacos
16.
Sensors (Basel) ; 14(12): 23843-70, 2014 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-25615728

RESUMO

With the development of communication technologies, the use of wireless systems in biomedical implanted devices has become very useful. Bio-implantable devices are electronic devices which are used for treatment and monitoring brain implants, pacemakers, cochlear implants, retinal implants and so on. The inductive coupling link is used to transmit power and data between the primary and secondary sides of the biomedical implanted system, in which efficient power amplifier is very much needed to ensure the best data transmission rates and low power losses. However, the efficiency of the implanted devices depends on the circuit design, controller, load variation, changes of radio frequency coil's mutual displacement and coupling coefficients. This paper provides a comprehensive survey on various power amplifier classes and their characteristics, efficiency and controller techniques that have been used in bio-implants. The automatic frequency controller used in biomedical implants such as gate drive switching control, closed loop power control, voltage controlled oscillator, capacitor control and microcontroller frequency control have been explained. Most of these techniques keep the resonance frequency stable in transcutaneous power transfer between the external coil and the coil implanted inside the body. Detailed information including carrier frequency, power efficiency, coils displacement, power consumption, supplied voltage and CMOS chip for the controllers techniques are investigated and summarized in the provided tables. From the rigorous review, it is observed that the existing automatic frequency controller technologies are more or less can capable of performing well in the implant devices; however, the systems are still not up to the mark. Accordingly, current challenges and problems of the typical automatic frequency controller techniques for power amplifiers are illustrated, with a brief suggestions and discussion section concerning the progress of implanted device research in the future. This review will hopefully lead to increasing efforts towards the development of low powered, highly efficient, high data rate and reliable automatic frequency controllers for implanted devices.


Assuntos
Fontes de Energia Elétrica , Eletrônica Médica/métodos , Próteses e Implantes , Processamento de Sinais Assistido por Computador , Amplificadores Eletrônicos , Humanos , Ondas de Rádio , Software , Telemetria/métodos
18.
Clin Gastroenterol Hepatol ; 11(10): 1342-8, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23639605

RESUMO

BACKGROUND & AIMS: Recent reductions in mortality after acute upper gastrointestinal hemorrhage among patients with cirrhosis have been attributed to early and aggressive use of guideline-recommended pharmacologic agents, antibiotics, and endoscopic therapy. Studies have shown, however, that adherence to recommended guidelines is low. We investigated whether use of a standardized electronic order set would improve adherence to treatment and timeliness of delivery. METHODS: We performed a prospective observational study, implementing an electronic order set for 123 patients with known or suspected cirrhosis who presented with symptoms/signs of upper gastrointestinal hemorrhage at Parkland Memorial Hospital (in Dallas, TX) from July 2011 through June 2012. The order set included standard nursing orders, laboratory tests, medications, orders for consultative services, and a brief evidence-based review of the benefits of octreotide and antibiotics in patients with cirrhosis. Primary outcomes included overall adherence to the administration of octreotide and antibiotics and the performance of upper endoscopy, as well as time to these interventions. RESULTS: Administration of antibiotics increased in patients for whom the order set was used (100% vs 89% for whom it was not used; P = .01); the use of the order set significantly reduced the time to administration of antibiotics (3 h 28 min vs 10 h 4 min; P < .001). The time to administration of octreotide also significantly was reduced for patients for whom the order set was used (2 h 16 min vs 6 h 21 min; P < .002). Although all patients underwent endoscopy, there was no significant difference in the time to procedure between patients for whom the order set was used and not used (17 h 54 min vs 18 h 5 min; P = .95). CONCLUSIONS: The use of a standardized electronic order set improved not only overall adherence, but also the timeliness of administration of recommended therapies for patients with known or suspected cirrhosis presenting with upper gastrointestinal hemorrhage.


Assuntos
Eletrônica Médica/métodos , Hemorragia Gastrointestinal/diagnóstico , Hemorragia Gastrointestinal/terapia , Fidelidade a Diretrizes/estatística & dados numéricos , Cirrose Hepática/complicações , Adesão à Medicação/estatística & dados numéricos , Sistemas de Alerta , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Resultado do Tratamento
19.
Ann Neurol ; 71(2): 157-68, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22367987

RESUMO

Therapeutic devices provide new options for treating drug-resistant epilepsy. These devices act by a variety of mechanisms to modulate neuronal activity. Only vagus nerve stimulation (VNS), which continues to develop new technology, is approved for use in the United States. Deep brain stimulation of anterior thalamus for partial epilepsy recently was approved in Europe and several other countries. Responsive neurostimulation, which delivers stimuli to 1 or 2 seizure foci in response to a detected seizure, recently completed a successful multicenter trial. Several other trials of brain stimulation are in planning or underway. Transcutaneous magnetic stimulation (TMS) may provide a noninvasive method to stimulate cortex. Controlled studies of TMS are split on efficacy, which may depend on whether a seizure focus is near a possible region for stimulation. Seizure detection devices in the form of shake detectors via portable accelerometers can provide notification of an ongoing tonic-clonic seizure, or peace of mind in the absence of notification. Prediction of seizures from various aspects of electroencephalography (EEG) is in early stages. Prediction appears to be possible in a subpopulation of people with refractory seizures, and a clinical trial of an implantable prediction device is underway. Cooling of neocortex or hippocampus reversibly can attenuate epileptiform EEG activity and seizures, but engineering problems remain in its implementation. Optogenetics is a new technique that can control excitability of specific populations of neurons with light. Inhibition of epileptiform activity has been demonstrated in hippocampal slices, but use in humans will require more work. In general, devices provide useful palliation for otherwise uncontrollable seizures, but with a different risk profile than with most drugs. Optimizing the place of devices in therapy for epilepsy will require further development and clinical experience.


Assuntos
Epilepsia/fisiopatologia , Epilepsia/terapia , Neuroestimuladores Implantáveis/estatística & dados numéricos , Crioterapia/instrumentação , Crioterapia/métodos , Estimulação Encefálica Profunda/instrumentação , Estimulação Encefálica Profunda/métodos , Eletrodiagnóstico/instrumentação , Eletrodiagnóstico/métodos , Eletroencefalografia/instrumentação , Eletroencefalografia/métodos , Eletrônica Médica/instrumentação , Eletrônica Médica/métodos , Epilepsia/diagnóstico , Humanos , Estimulação Magnética Transcraniana/instrumentação , Estimulação Magnética Transcraniana/métodos , Estimulação Elétrica Nervosa Transcutânea/instrumentação , Estimulação Elétrica Nervosa Transcutânea/métodos , Estimulação do Nervo Vago/instrumentação , Estimulação do Nervo Vago/métodos
20.
Biomaterials ; 301: 122271, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37619262

RESUMO

In the past few decades, stem cell-based regenerative engineering has demonstrated its significant potential to repair damaged tissues and to restore their functionalities. Despite such advancement in regenerative engineering, the clinical translation remains a major challenge. In the stance of personalized treatment, the recent progress in bioelectronic medicine likewise evolved as another important research domain of larger significance for human healthcare. Over the last several years, our research group has adopted biomaterials-based regenerative engineering strategies using innovative bioelectronic stimulation protocols based on either electric or magnetic stimuli to direct cellular differentiation on engineered biomaterials with a range of elastic stiffness or functional properties (electroactivity/magnetoactivity). In this article, the role of bioelectronics in stem cell-based regenerative engineering has been critically analyzed to stimulate futuristic research in the treatment of degenerative diseases as well as to address some fundamental questions in stem cell biology. Built on the concepts from two independent biomedical research domains (regenerative engineering and bioelectronic medicine), we propose a converging research theme, 'Regenerative Bioelectronics'. Further, a series of recommendations have been put forward to address the current challenges in bridging the gap in stem cell therapy and bioelectronic medicine. Enacting the strategic blueprint of bioelectronic-based regenerative engineering can potentially deliver the unmet clinical needs for treating incurable degenerative diseases.


Assuntos
Eletrônica Médica , Medicina de Precisão , Medicina de Precisão/instrumentação , Medicina de Precisão/métodos , Nanoestruturas , Eletrônica Médica/instrumentação , Eletrônica Médica/métodos , Materiais Biocompatíveis/química , Magnetismo
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