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1.
Adv Sci (Weinh) ; : e2103331, 2021 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-34747140

RESUMO

Nutrients play critical roles in maintaining core physiological functions and in preventing diseases. Technologies for delivering these nutrients and for monitoring their concentrations can help to ensure proper nutritional balance. Eccrine sweat is a potentially attractive class of biofluid for monitoring purposes due to the ability to capture sweat easily and noninvasively from nearly any region of the body using skin-integrated microfluidic technologies. Here, a miniaturized system of this type is presented that allows simple, rapid colorimetric assessments of the concentrations of multiple essential nutrients in sweat, simultaneously and without any supporting electronics - vitamin C, calcium, zinc, and iron. A transdermal patch integrated directly with the microfluidics supports passive, sustained delivery of these species to the body throughout a period of wear. Comparisons of measurement results to those from traditional lab analysis methods demonstrate the accuracy and reliability of this platform. On-body tests with human subjects reveal correlations between the time dynamics of concentrations of these nutrients in sweat and those of the corresponding concentrations in blood. Studies conducted before and after consuming certain foods and beverages highlight practical capabilities in monitoring nutritional balance, with strong potential to serve as a basis for guiding personalized dietary choices.

2.
ACS Sens ; 6(8): 2787-2801, 2021 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-34351759

RESUMO

Skin-interfaced wearable systems with integrated colorimetric assays, microfluidic channels, and electrochemical sensors offer powerful capabilities for noninvasive, real-time sweat analysis. This Perspective details recent progress in the development and translation of novel wearable sensors for personalized assessment of sweat dynamics and biomarkers, with precise sampling and real-time analysis. Sensor accuracy, system ruggedness, and large-scale deployment in remote environments represent key opportunity areas, enabling broad deployment in the context of field studies, clinical trials, and recent commercialization. On-body measurements in these contexts show good agreement compared to conventional laboratory-based sweat analysis approaches. These device demonstrations highlight the utility of biochemical sensing platforms for personalized assessment of performance, wellness, and health across a broad range of applications.


Assuntos
Suor , Dispositivos Eletrônicos Vestíveis , Microfluídica , Pele
3.
Sci Adv ; 7(12)2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33731359

RESUMO

Three-dimensional (3D), submillimeter-scale constructs of neural cells, known as cortical spheroids, are of rapidly growing importance in biological research because these systems reproduce complex features of the brain in vitro. Despite their great potential for studies of neurodevelopment and neurological disease modeling, 3D living objects cannot be studied easily using conventional approaches to neuromodulation, sensing, and manipulation. Here, we introduce classes of microfabricated 3D frameworks as compliant, multifunctional neural interfaces to spheroids and to assembloids. Electrical, optical, chemical, and thermal interfaces to cortical spheroids demonstrate some of the capabilities. Complex architectures and high-resolution features highlight the design versatility. Detailed studies of the spreading of coordinated bursting events across the surface of an isolated cortical spheroid and of the cascade of processes associated with formation and regrowth of bridging tissues across a pair of such spheroids represent two of the many opportunities in basic neuroscience research enabled by these platforms.

4.
Proc Natl Acad Sci U S A ; 118(5)2021 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-33468630

RESUMO

Precise, quantitative measurements of the hydration status of skin can yield important insights into dermatological health and skin structure and function, with additional relevance to essential processes of thermoregulation and other features of basic physiology. Existing tools for determining skin water content exploit surrogate electrical assessments performed with bulky, rigid, and expensive instruments that are difficult to use in a repeatable manner. Recent alternatives exploit thermal measurements using soft wireless devices that adhere gently and noninvasively to the surface of the skin, but with limited operating range (∼1 cm) and high sensitivity to subtle environmental fluctuations. This paper introduces a set of ideas and technologies that overcome these drawbacks to enable high-speed, robust, long-range automated measurements of thermal transport properties via a miniaturized, multisensor module controlled by a long-range (∼10 m) Bluetooth Low Energy system on a chip, with a graphical user interface to standard smartphones. Soft contact to the surface of the skin, with almost zero user burden, yields recordings that can be quantitatively connected to hydration levels of both the epidermis and dermis, using computational modeling techniques, with high levels of repeatability and insensitivity to ambient fluctuations in temperature. Systematic studies of polymers in layered configurations similar to those of human skin, of porcine skin with known levels of hydration, and of human subjects with benchmarks against clinical devices validate the measurement approach and associated sensor hardware. The results support capabilities in characterizing skin barrier function, assessing severity of skin diseases, and evaluating cosmetic and medication efficacy, for use in the clinic or in the home.


Assuntos
Eletrônica , Pele/patologia , Água , Tecnologia sem Fio , Adolescente , Adulto , Pré-Escolar , Análise de Elementos Finitos , Humanos , Temperatura
5.
Sci Adv ; 6(49)2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33277263

RESUMO

Therapeutic compression garments (TCGs) are key tools for the management of a wide range of vascular lower extremity conditions. Proper use of TCGs involves application of a minimum and consistent pressure across the lower extremities for extended periods of time. Slight changes in the characteristics of the fabric and the mechanical properties of the tissues lead to requirements for frequent measurements and corresponding adjustments of the applied pressure. Existing sensors are not sufficiently small, thin, or flexible for practical use in this context, and they also demand cumbersome, hard-wired interfaces for data acquisition. Here, we introduce a flexible, wireless monitoring system for tracking both temperature and pressure at the interface between the skin and the TCGs. Detailed studies of the materials and engineering aspects of these devices, together with clinical pilot trials on a range of patients with different pathologies, establish the technical foundations and measurement capabilities.

6.
Sci Transl Med ; 12(574)2020 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-33328330

RESUMO

Precise form-fitting of prosthetic sockets is important for the comfort and well-being of persons with limb amputations. Capabilities for continuous monitoring of pressure and temperature at the skin-prosthesis interface can be valuable in the fitting process and in monitoring for the development of dangerous regions of increased pressure and temperature as limb volume changes during daily activities. Conventional pressure transducers and temperature sensors cannot provide comfortable, irritation-free measurements because of their relatively rigid construction and requirements for wired interfaces to external data acquisition hardware. Here, we introduce a millimeter-scale pressure sensor that adopts a soft, three-dimensional design that integrates into a thin, flexible battery-free, wireless platform with a built-in temperature sensor to allow operation in a noninvasive, imperceptible fashion directly at the skin-prosthesis interface. The sensor system mounts on the surface of the skin of the residual limb, in single or multiple locations of interest. A wireless reader module attached to the outside of the prosthetic socket wirelessly provides power to the sensor and wirelessly receives data from it, for continuous long-range transmission to a standard consumer electronic device such as a smartphone or tablet computer. Characterization of both the sensor and the system, together with theoretical analysis of the key responses, illustrates linear, accurate responses and the ability to address the entire range of relevant pressures and to capture skin temperature accurately, both in a continuous mode. Clinical application in two prosthesis users demonstrates the functionality and feasibility of this soft, wireless system.


Assuntos
Membros Artificiais , Fontes de Energia Elétrica , Desenho de Prótese , Pele , Temperatura
7.
J Control Release ; 321: 174-183, 2020 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-32035908

RESUMO

High rates of restenosis and neointimal formation have driven increasing interest in the application of drug eluting balloons (DEB) as counteractive measures for intraluminal drug delivery. The use of DEBs eliminates the need for stents so that serious side effects including in-stent restenosis and stent thrombosis can be avoided and long-term medication of anti-platelet agent is not needed. Despite their benefits, DEBs have poor drug delivery efficiency due to short balloon inflation times (30-60 s) that limit the passive drug diffusion from the balloon surface to the luminal lesion. To increase drug delivery efficiency, a microneedle DEB (MNDEB) was developed by a conformal transfer molding process using a thin polydimethylsiloxane mold bearing a negative array of MNs of 200 µm in height. A MN array composed of UV curable resin was formed onto the surface of DEB, and drugs were coated onto the structure. The mechanical properties of the MN array were investigated and MN penetration into luminal vasculature was confirmed in vivo. An increase in drug delivery efficiency compared to a standard DEB was demonstrated in an in vivo test in a rabbit aorta. Finally, the superior therapeutic efficacy of MNDEBs was evaluated using an atherosclerosis rabbit model.


Assuntos
Angioplastia Coronária com Balão , Fármacos Cardiovasculares , Stents Farmacológicos , Preparações Farmacêuticas , Animais , Materiais Revestidos Biocompatíveis , Paclitaxel , Desenho de Prótese , Coelhos , Stents , Resultado do Tratamento
8.
Proc Natl Acad Sci U S A ; 114(39): E8254-E8263, 2017 09 26.
Artigo em Inglês | MEDLINE | ID: mdl-28894005

RESUMO

The transmembrane semaphorin Sema-1a acts as both a ligand and a receptor to regulate axon-axon repulsion during neural development. Pebble (Pbl), a Rho guanine nucleotide exchange factor, mediates Sema-1a reverse signaling through association with the N-terminal region of the Sema-1a intracellular domain (ICD), resulting in cytoskeletal reorganization. Here, we uncover two additional Sema-1a interacting proteins, varicose (Vari) and cheerio (Cher), each with neuronal functions required for motor axon pathfinding. Vari is a member of the membrane-associated guanylate kinase (MAGUK) family of proteins, members of which can serve as scaffolds to organize signaling complexes. Cher is related to actin filament cross-linking proteins that regulate actin cytoskeleton dynamics. The PDZ domain binding motif found in the most C-terminal region of the Sema-1a ICD is necessary for interaction with Vari, but not Cher, indicative of distinct binding modalities. Pbl/Sema-1a-mediated repulsive guidance is potentiated by both vari and cher Genetic analyses further suggest that scaffolding functions of Vari and Cher play an important role in Pbl-mediated Sema-1a reverse signaling. These results define intracellular components critical for signal transduction from the Sema-1a receptor to the cytoskeleton and provide insight into mechanisms underlying semaphorin-induced localized changes in cytoskeletal organization.


Assuntos
Citoesqueleto/metabolismo , Proteínas de Drosophila/metabolismo , Filaminas/metabolismo , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Guanilato Ciclase/metabolismo , Proteínas de Membrana/metabolismo , Semaforinas/metabolismo , Transdução de Sinais/fisiologia , Motivos de Aminoácidos , Animais , Citoesqueleto/genética , Proteínas de Drosophila/genética , Drosophila melanogaster , Filaminas/genética , Fatores de Troca do Nucleotídeo Guanina/genética , Guanilato Ciclase/genética , Proteínas de Membrana/genética , Domínios Proteicos , Semaforinas/genética
9.
Int J Dev Neurosci ; 55: 34-40, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27637927

RESUMO

Plexins (Plexs) are a large family of phylogenetically conserved guidance receptors that bind specifically to semaphorins (Semas), another large family of guidance molecules. In the Drosophila embryonic central nervous system (CNS), the secreted semaphorins Sema-2a and Sema-2b both act as ligands for PlexB, but mediate mutually independent and opposite functions (repulsive and attractive guidance, respectively). PlexB is also known to regulate motor axon guidance in the embryonic peripheral nervous system (PNS). However, it is unclear whether the mechanisms of ligand regulation of PlexB seen in the CNS are similar or the same as those that exist in PNS motor axon guidance. Here, we find that two distinct modes of ligand regulation underlie differential roles of PlexB in PNS motor axon pathfinding during embryonic development. Epistasis analyses in the intersegmental nerve b (ISNb) pathway suggest that PlexB serves as a receptor for both Sema-2a and Sema-2b and integrates their mutually dependent but opposite guidance functions. Furthermore, we present evidence that PlexB mediates not only Sema-2a/2b-dependent guidance functions, but also Sema-2a/2b-independent target recognition in establishing the segmental nerve a (SNa) motor axon pathway. These results demonstrate that a single guidance receptor can elicit diverse effects on the establishment of neuronal connectivity via regulation of its ligands themselves.


Assuntos
Axônios/fisiologia , Sistema Nervoso Central/citologia , Proteínas de Drosophila/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Neurônios Motores/citologia , Proteínas do Tecido Nervoso/metabolismo , Receptores de Superfície Celular/metabolismo , Transdução de Sinais/fisiologia , Animais , Animais Geneticamente Modificados , Sistema Nervoso Central/embriologia , Drosophila , Proteínas de Drosophila/genética , Embrião não Mamífero , Regulação da Expressão Gênica no Desenvolvimento/genética , Proteínas do Tecido Nervoso/genética , Receptores de Superfície Celular/genética , Transdução de Sinais/genética
10.
Dev Biol ; 418(2): 258-67, 2016 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-27565025

RESUMO

Plexins (Plexs) comprise a large family of cell surface receptors for semaphorins (Semas) that function as evolutionarily conserved guidance molecules. GTPase activating protein (GAP) activity for Ras family small GTPases has been implicated in plexin signaling cascades through its RasGAP domain. However, little is known about how Ras family GTPases are controlled in vivo by plexin signaling. Here, we found that Drosophila Rap1, a member of the Ras family of GTPases, plays an important role controlling intersegmental nerve b motor axon guidance during neural development. Gain-of-function studies using dominant-negative and constitutively active forms of Rap1 indicate that Rap1 contributes to axonal growth and guidance. Genetic interaction analyses demonstrate that the Sema-1a/PlexA-mediated repulsive guidance function is regulated positively by Rap1. Furthermore, neuronal expression of mutant PlexA robustly restored defasciculation defects in PlexA null mutants when the catalytic arginine fingers of the PlexA RasGAP domain critical for GAP activity were disrupted. However, deleting the RasGAP domain abolished the ability of PlexA to rescue the PlexA guidance phenotypes. These findings suggest that PlexA-mediated motor axon guidance is dependent on the presence of the PlexA RasGAP domain, but not on its GAP activity toward Ras family small GTPases.


Assuntos
Orientação de Axônios/fisiologia , Proteínas de Drosophila/fisiologia , Drosophila melanogaster/crescimento & desenvolvimento , Drosophila melanogaster/fisiologia , Proteínas Monoméricas de Ligação ao GTP/fisiologia , Proteínas do Tecido Nervoso/fisiologia , Receptores de Superfície Celular/fisiologia , Proteínas de Ligação a Telômeros/fisiologia , Proteínas Ativadoras de ras GTPase/fisiologia , Animais , Animais Geneticamente Modificados , Orientação de Axônios/genética , Proteínas de Drosophila/deficiência , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Genes de Insetos , Proteínas Monoméricas de Ligação ao GTP/deficiência , Proteínas Monoméricas de Ligação ao GTP/genética , Neurônios Motores/fisiologia , Mutagênese , Proteínas do Tecido Nervoso/deficiência , Proteínas do Tecido Nervoso/genética , Receptores de Superfície Celular/deficiência , Receptores de Superfície Celular/genética , Proteínas de Ligação a Telômeros/deficiência , Proteínas de Ligação a Telômeros/genética , Regulação para Cima , Proteínas Ativadoras de ras GTPase/deficiência , Proteínas Ativadoras de ras GTPase/genética
11.
J Nanosci Nanotechnol ; 16(6): 6223-30, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27427694

RESUMO

The copper ferrocyanide functionalized core-shell magnetic silica composite (mag@silica-CuFC) was prepared and was found to be easily separated from aqueous solutions by using magnetic field. The synthesized mag@silica-CuFC composite has a high sorption ability of Cs owing to its strong affinity for Cs as well as the high surface area of the supports. Cs sorption on the mag@silica-CuFC composite quickly reached the sorption equilibrium after 2 h of contact time. The effect of the presence of salts with a high concentration of up to 3.5 wt% on the efficiency of Cs sorption onto the composites was also studied. The maximum sorption ability was found to be maintained in the presence of up to 3.5 wt% of NaCl in the solution. Considering these results, the mag@silica-CuFC composite has great potential for use as an effective sorbent for the selective removal of radioactive Cs ions.


Assuntos
Césio/isolamento & purificação , Ferrocianetos/química , Imãs/química , Resíduos Radioativos/análise , Dióxido de Silício/química , Adsorção , Césio/química , Cinética , Nanopartículas/química , Porosidade , Cloreto de Sódio/química , Água/química
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