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1.
Small ; 16(7): e1904758, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31909565

RESUMO

Conductive, stretchable, environmentally-friendly, and strain-sensitive elastomers are attracting immense research interest because of their potential applications in various areas, such as human-machine interfaces, healthcare monitoring, and soft robots. Herein, a binary networked elastomer is reported based on a composite hydrogel of polyvinyl alcohol (PVA) and polyethyleneimine (PEI), which is demonstrated to be ultrastretchable, mechanically robust, biosafe, and antibacterial. The mechanical stretchability and toughness of the hydrogels are optimized by tuning the constituent ratio and water content. The optimal hydrogel (PVA2 PEI1 -75) displays an impressive tensile strain as high as 500% with a corresponding tensile stress of 0.6 MPa. Furthermore, the hydrogel elastomer is utilized to fabricate piezoresistive sensors. The as-made strain sensor displays seductive capability to monitor and distinguish multifarious human motions with high accuracy and sensitivity, like facial expressions and vocal signals. Therefore, the elastomer reported in this study holds great potential for sensing applications in the era of the Internet of Things (IoTs).

2.
ACS Appl Mater Interfaces ; 11(48): 44933-44940, 2019 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-31675212

RESUMO

High-throughput screening and fast identification of single bacterial cells are crucial for clinical diagnosis, bioengineering, and fermentation engineering. Although single-cell technologies have been developed extensively in recent years, the single-cell technologies for bacteria still need further exploration. In this study, we demonstrate an identification and screening technology for single bacterial cells based on a large-scale nanobowl array, which is well-ordered and size-adjustable for use with different kinds of bacteria. When the culture medium with monodispersed bacteria was placed on the nanobowl array, it successfully enabled loading of single bacterium into a single nanobowl. Because of the limitative size and depth of the nanobowls, mixture of different bacteria species could be screened according to their sizes. In addition, with the help of a low electrical current, the bacteria can be further screened according to their intrinsic surface charges. If combined with micromanipulation technology, high-throughput single bacterial selection can be achieved in future.

3.
Toxicol Mech Methods ; 29(8): 569-579, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31161897

RESUMO

The present study investigated the alterations in nerve function and its potential mechanism of offspring result from the decabromodiphenyl ether (BDE209) orally gavage (0, 1.5, and 225 mg/kg.d body weight) in pregnant and lactating mice. Weight gain and litter size of maternal mice and body weight of offspring were examined. Learning and memory abilities of offspring were tested by the Morris water maze experiment. Thyroid hormones (THs) concentrations in peripheral blood of offspring were detected by the chemiluminescence enzyme immunoassay. Relative mRNA expression of type 1 iodothyronine deiodinase (dio1), type 2 iodothyronine deiodinase (dio2), and type 3 iodothyronine deiodinase (dio3) in the livers and brains of offspring were measured by QRT-PCR (quantitative real-time polymerase chain reaction). Protein expression of dio3 in the livers and brains of offspring was measured by Western blot. All indexes of offspring were tested at postnatal day (PND) 21 and PND 60, respectively. As a result, administration of BDE209 decreased weight gain and litter size of maternal mice, and reduced body weight of offspring mice, prolonged escape latency and declined guardant time of offspring in the Morris water maze experiment. Moreover, BDE209 elevated serum levels of total thyroxine (T4), total triiodothyronine (T3), free T4, and free T3 in offspring. In addition, maternal exposure to BDE209 inhibited dio1, dio2, dio3 mRNA expression in the livers of offspring, while elevated dio1 mRNA expression and reduced dio3 mRNA expression in the brains of offspring. BDE209 also inhibited the protein expression of dio3 in the livers and brains of offspring. These results indicate that BDE209 exposure to pregnant and lactating mice can cause disruption in serum THs of offspring by altering mRNA and protein expression of iodothyronine deiodinases, which might consequently result in neurologic impairment of offspring mice.


Assuntos
Poluentes Ambientais/toxicidade , Éteres Difenil Halogenados/toxicidade , Iodeto Peroxidase/genética , Exposição Materna/efeitos adversos , Neurônios/efeitos dos fármacos , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Transcrição Genética/efeitos dos fármacos , Animais , Animais Recém-Nascidos , Feminino , Lactação , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Camundongos Endogâmicos ICR , Gravidez , Natação , Hormônios Tireóideos/sangue
4.
Adv Sci (Weinh) ; 6(6): 1801625, 2019 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-30937259

RESUMO

Implantable medical electronic devices are usually powered by batteries or capacitors, which have to be removed from the body after completing their function due to their non-biodegradable property. Here, a fully bioabsorbable capacitor (BC) is developed for life-time implantation. The BC has a symmetrical layer-by-layer structure, including polylactic acid (PLA) supporting substrate, PLA nanopillar arrays, self-assembled zinc oxide nanoporous layer, and polyvinyl alcohol/phosphate buffer solution (PVA/PBS) hydrogel. The as-fabricated BC can not only work normally in air but also in a liquid environment, including PBS and the animal body. Long-term normal work time is achieved to 30 days in PBS and 50 days in Sprague-Dawley (SD) rats. The work time of BC in the liquid environment is tunable from days to weeks by adopting different encapsulations along BC edges. Capacitance retention of 70% is achieved after 3000 cycles. Three BCs in series can light up 15 green light-emitting diodes (LEDs) in vivo. Additionally, after completing its mission, the BC can be fully degraded in vivo and reabsorbed by a SD rat. Considering its performance, the developed BC has a great potential as a fully bioabsorbable power source for transient electronics and implantable medical devices.

5.
ACS Appl Mater Interfaces ; 10(40): 34302-34310, 2018 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-30209940

RESUMO

With the advantages of being lightweight, flexible, and wearable, wire-shaped supercapacitors have received tremendous attention in wearable and portable power sources in recent years. Considering the demands for large-scale applications, it is necessary to explore a facile and convenient preparation approach for wire-shaped supercapacitors. Herein, we reported a simple approach to fabricate wire-shaped electrodes by a dipping method, which possessed a nitric acid-activated graphite fiber core and an activated carbon-coating layer structure. Parallel and symmetric all-solid-state wire-shaped supercapacitors (PWSCs) based on the electrodes were fabricated. The as-fabricated PWSC showed high energy density (6.60 W h/kg, 8.08 mW h/cm, and 1 mV/s) and power density (253 mW/kg, 0.31 mW/cm, and 100 mV/s) and excellent flexibility. Furthermore, this wire-shaped supercapacitor may bring broader application prospects for energy storage devices in future wearable electronic areas.

6.
Adv Mater ; 30(32): e1801895, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29947102

RESUMO

Implantable medical devices provide an effective therapeutic approach for neurological and cardiovascular diseases. With the development of transient electronics, a new power source with biocompatibility, controllability, and bioabsorbability becomes an urgent demand for medical sciences. Here, various fully bioabsorbable natural-materials-based triboelectric nanogenerators (BN-TENGs), in vivo, are developed. The "triboelectric series" of five natural materials is first ranked, it provides a basic knowledge for materials selection and device design of the TENGs and other energy harvesters. Various triboelectric outputs of these natural materials are achieved by a single material and their pairwise combinations. The maximum voltage, current, and power density reach up to 55 V, 0.6 µA, and 21.6 mW m-2 , respectively. The modification of silk fibroin encapsulation film makes the operation time of the BN-TENG tunable from days to weeks. After completing its function, the BN-TENG can be fully degraded and resorbed in Sprague-Dawley rats, which avoids a second operation and other side effects. Using the proposed BN-TENG as a voltage source, the beating rates of dysfunctional cardiomyocyte clusters are accelerated and the consistency of cell contraction is improved. This provides a new and valid solution to treat some heart diseases such as bradycardia and arrhythmia.


Assuntos
Nanoestruturas , Implantes Absorvíveis , Animais , Fontes de Energia Elétrica , Desenho de Equipamento , Nanotecnologia , Ratos , Ratos Sprague-Dawley
7.
Adv Healthc Mater ; 7(10): e1701298, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29388350

RESUMO

In the past 10 years, the development of nanogenerators (NG) has enabled different systems to operate without external power supply. NG have the ability to harvest the mechanical energies in different forms. Human body motions and activities can also serve as the energy source to drive NG and enable self-powered healthcare system. In this review, a summary of several major actual applications of NG in the biomedical fields is made including the circulatory system, the neural system, cell modulation, microbe disinfection, and biodegradable electronics. Nevertheless, there are still many challenges for NG to be actually adopted in clinical applications, including the miniaturization, duration, encapsulation, and output performance. It is also very important to further combine the NG development more precisely with the medical principles. In future, NG can serve as highly promising complementary or even alternative power suppliers to traditional batteries for the healthcare electronics.


Assuntos
Fontes de Energia Elétrica , Movimento , Nanotecnologia , Dispositivos Eletrônicos Vestíveis , Humanos
8.
ACS Appl Mater Interfaces ; 9(33): 27396-27401, 2017 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-28782357

RESUMO

On the basis of the unique physicochemical properties of graphene quantum dots (GQDs), we developed a novel type of theranostic agent by loading anticancer drug doxorubicin (DOX) to GQD's surface and conjugating Cy5.5 (Cy) dye to GQD though a cathepsin D-responsive (P) peptide. Such type of agents demonstrated superior therapeutic performance both in vitro and in vivo because of the improved tissue penetration and cellular uptake. More importantly, they are capable of functioning as probes for programmed tracking the delivery and release of anticancer drug as well as drug-induced cancer cell apoptosis through GQD's, DOX's, and Cy's charateristic fluorescence, respectively.


Assuntos
Pontos Quânticos , Antineoplásicos , Doxorrubicina , Sistemas de Liberação de Medicamentos , Grafite
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