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1.
Biomed Microdevices ; 21(3): 64, 2019 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-31273462

RESUMO

Sample deposition based on micro-droplet ejection has broad application prospects in the field of biomedicine. Ejection of RPMI-1640 medium (with and without cells) is investigated experimentally using a home-build electrohydrodynamic (EHD) ejection system, consisting of a liquid supplier and a nozzle, a high voltage source, a droplet collector, and a high speed photography module. High electric voltage is applied between the nozzle and the droplet collector. The liquid surface is electrically charged and the ejection takes place when electric force overcomes the surface tension. The ejection process is studied by using high speed photography and image processing. At low voltage, a stable ejection state is established with ejection frequency ranging from a few to a few tens of Hertz. At high voltage, another stable ejection state is reached with ejection frequency as high as 1300 Hz. At the transition voltage range, the ejection exhibits a periodic behaviour. During each cycle, the meniscus rapidly oscillates with gradually increased amplitude, and with several non-uniform droplets ejected at the final stage of the cycle. Human peripheral blood mononuclear cells, after ejection, shows survival rates higher than 79%, manifesting EHD ejection as a promising technique for cell printing.


Assuntos
Meios de Cultura , Técnicas Citológicas/instrumentação , Eletricidade , Hidrodinâmica , Cinética , Impressão/instrumentação
2.
Environ Sci Process Impacts ; 21(8): 1342-1352, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31049512

RESUMO

In this study, we investigated the airborne particles released during paper printing and paper shredding processes in an attempt to characterize and differentiate these particles. Particle characteristics were studied with real time instruments (RTIs) to measure concentrations and with samplers to collect particles for subsequent microscopy and cytotoxicity analysis. The particles released by paper shredding were evaluated for cytotoxicity by using in vitro human lung epithelial cell models. A substantial amount of particles were released during both the shredding and printing processes. We found that the printing process caused substantial release of particles with sizes of less than 300 nm in the form of metal granules and graphite. These released particles contained various elements including Al, Ca, Cu, Fe, Mg, N, K, P, S and Si. The particles released by the paper shredding processes were primarily nanoparticles and had a peak size between 27.4 nm and 36.5 nm. These paper particles contained elements including Al, Br Ca, Cl, Cr, Cu, Fe, Mg, N, Na, Ni P, S and Si, as determined by scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDS) and single-particle inductively coupled plasma-mass spectroscopy (SP-ICP-MS) analysis. Although various metals were identified in the paper particles, these particles did not elicit cytotoxicity to simian virus-transformed bronchial epithelial cells (BEAS2B) and immortalized normal human bronchial epithelial cells (HBE1). However, future studies should investigate other cytotoxicity effects of these paper particles in various types of lung cells to identify potential health effects of the particles.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar em Ambientes Fechados/análise , Monitoramento Ambiental/métodos , Papel , Material Particulado/análise , Impressão , Grafite/análise , Humanos , Metais/análise , Tamanho da Partícula , Impressão/instrumentação
3.
Lab Chip ; 19(9): 1644-1656, 2019 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-30924821

RESUMO

Lab-on-a-chip devices, capable of culturing living cells in continuously perfused, micrometer-sized channels, have been intensively investigated to model physiological microenvironments for cell-related testing and evaluation applications. Various chemical, physical, and/or biological culture cues are usually expected in a designed chip to mimic the in vivo environment with defined spatial heterogeneity of cells and biomaterials. To create such heterogeneity within a given chip, typical methods rely heavily on sophisticated fabrication and cell seeding processes, and chips fabricated with these methods are difficult to readily adapt for other applications. In this study, laser-induced forward transfer (LIFT)-based printing has been implemented to create heterogeneous cellular patterns in a lab-on-a-chip device to achieve the efficiency in creating heterogeneous cellular patterns as well as the flexibility in adapting different evaluation configurations in lab-on-a-chip devices. Two applications, parallel evaluation of cellular behavior and targeted drug delivery to cancer cells, have been implemented as proof-of-concept demonstrations of the proposed fabrication method. For the first application, the morphology of cells in different extracellular matrix (ECM) materials cultured under varying conditions has been investigated. It is found that less stiff ECM and dynamic culturing are preferred for spreading of fibroblasts. For the second application, different drug carriers have been utilized for targeted delivery of anticancer drugs to breast cancer cells. It is found that targeted drug delivery is important to realize effective chemotherapy and drug release rate from drug carriers affects the chemotherapy effect. Consequently, the proposed laser printing-based method enables direct creation of heterogeneous cellular patterns within lab-on-a-chip devices which improves the efficiency and versatility of cell-related sensing and evaluation using lab-on-a-chip devices.


Assuntos
Dispositivos Lab-On-A-Chip , Lasers , Impressão/instrumentação , Portadores de Fármacos/metabolismo , Matriz Extracelular/metabolismo , Humanos , Tinta , Células MCF-7
4.
Langmuir ; 35(5): 1379-1390, 2019 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-30086642

RESUMO

Motivated by the lack of adventitious protein adsorption on zwitterionic polymer brushes that promise low noise and hence high analytical sensitivity for surface-based immunoassays, we explored their use as a substrate for immunoassay fabrication by the inkjet printing of antibodies. We observed that a poly(sulfobetaine)methacrylate brush on glass is far too hydrophilic to enable the noncovalent immobilization of antibodies by inkjet printing. To circumvent this limitation, we developed a series of hybrid zwitterionic-cationic surface coatings with tunable surface wettability that are suitable for the inkjet printing of antibodies but also have low protein adsorption. We show that in a microarray format in which both the capture and detection antibodies are discretely printed as spots on these hybrid brushes, a point-of-care sandwich immunoassay can be carried out with an analytical sensitivity and dynamic range that is similar to or better than those of the same assay fabricated on a PEG-like brush. We also show that the hybrid polymer brushes do not bind anti-PEG antibodies that are ubiquitous in human blood, which can be a problem with immunoassays fabricated on PEG-like coatings.


Assuntos
Imunoensaio/métodos , Metacrilatos/química , Animais , Anticorpos Imobilizados/imunologia , Bovinos , Humanos , Interleucina-6/sangue , Interleucina-6/imunologia , Metacrilatos/síntese química , Testes Imediatos , Impressão/instrumentação , Coelhos , Molhabilidade
5.
Sci Rep ; 8(1): 16763, 2018 11 13.
Artigo em Inglês | MEDLINE | ID: mdl-30425325

RESUMO

Soft lithography-based patterning techniques have been developed to investigate biological and chemical phenomena. Until now, micropatterning with various materials required multiple procedural steps such as repeating layer-by-layer patterning, aligning of stamps, and incubating printed inks. Herein, we describe a facile micropatterning method for producing chemically well-defined surface architectures by combining microcontact (µCP) and microfluidic vacuum-assisted degas-driven flow guided patterning (DFGP) with a poly(dimethylsiloxane) (PDMS) stamp. To demonstrate our concept, we fabricated a bi-composite micropatterned surface with different functional molecular inks such as fluorescein isothiocyanate labelled bovine serum albumin (FITC-BSA) and polyethylene glycol (PEG)-silane for a biomolecule array, and 3-aminopropyltriethoxysilane (APTES) and PEG-silane pattern for a self-assembled colloid gold nanoparticle monolayer. With a certain composition of molecular inks for the patterning, bi-composite surface patterns could be produced by this µCP-DFGP approach without any supplementary process. This patterning approach can be used in microfabrication and highly applicable to biomolecules and nanoparticles that spread as a monolayer.


Assuntos
Dispositivos Lab-On-A-Chip , Impressão/instrumentação , Custos e Análise de Custo , Dimetilpolisiloxanos/química , Ouro/química , Nanopartículas Metálicas/química , Nylons/química , Impressão/economia
6.
Lab Chip ; 18(20): 3074-3078, 2018 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-30183051

RESUMO

We developed a highly efficient method for patterning cells by a novel and simple technique called lift-off cell lithography (LCL). Our approach borrows the key concept of lift-off lithography from microfabrication and utilizes a fully biocompatible process to achieve high-throughput, high-efficiency cell patterning with nearly zero background defects across a large surface area. Using LCL, we reproducibly achieved >70% patterning efficiency for both adherent and non-adherent cells with <1% defects in undesired areas.


Assuntos
Células/citologia , Microtecnologia/métodos , Impressão/métodos , Adesão Celular , Células HeLa , Humanos , Microtecnologia/instrumentação , Impressão/instrumentação
7.
PLoS One ; 13(8): e0202531, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30138342

RESUMO

Microcontact printing has become a versatile soft lithography technique used to produce molecular micro- and nano-patterns consisting of a large range of different biomolecules. Despite intensive research over the last decade and numerous applications in the fields of biosensors, microarrays and biomedical applications, the large-scale implementation of microcontact printing is still an issue. It is hindered by the stamp-inking step that is critical to ensure a reproducible and uniform transfer of inked molecules over large areas. This is particularly important when addressing application such as cell microarray manufacturing, which are currently used for a wide range of analytical and pharmaceutical applications. In this paper, we present a large-scale and multiplexed microcontact printing process of extracellular matrix proteins for the fabrication of cell microarrays. We have developed a microfluidic inking approach combined with a magnetic clamping technology that can be adapted to most standard substrates used in biology. We have demonstrated a significant improvement of homogeneity of printed protein patterns on surfaces larger than 1 cm2 through the control of both the flow rate and the wetting mechanism of the stamp surface during microfluidic inking. Thanks to the reproducibility and integration capabilities provided by microfluidics, we have achieved the printing of three different adhesion proteins in one-step transfer. Selective cell adhesion and cell shape adaptation on the produced patterns were observed, showing the suitability of this approach for producing on-demand large-scale cell microarrays.


Assuntos
Proteínas da Matriz Extracelular/isolamento & purificação , Técnicas Analíticas Microfluídicas/métodos , Impressão/instrumentação , Análise Serial de Tecidos/instrumentação , Técnicas Biossensoriais , Adesão Celular/genética , Forma Celular/genética , Proteínas da Matriz Extracelular/química
8.
Pharm Res ; 35(9): 181, 2018 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-30054741

RESUMO

PURPOSE: To use valvejet technology for printing a fixed dose combination of ramipril and glimepiride, and to investigate the stability profile of ramipril, which is susceptible to a range of processing and storage conditions. METHODS: Inks of ramipril and glimepiride were formulated and printed on to HPMC film and the films were evaluated for the chemical and solid-state integrity of the APIs using HPLC and XRPD. The stability of the APIs in the inks and in the printed samples was investigated using Raman and NMR techniques. RESULTS: The printed samples demonstrated excellent precision and accuracy in the doses of APIs deposited. Both drugs were chemically intact in the freshly printed samples and ramipril was found to be in its amorphous form. Ramipril in the printed samples has transformed into ramipril diketopiperazine when stored at 40°C with 75% RH, but remained stable when stored in a desiccator. Results from the stability study of ramipril ink show that the API has undergone degradation when stored both at room temperature and at 40°C but remained stable when stored in a refrigerator. CONCLUSION: An FDC of ramipril and glimepiride was successfully printed using valvejet technology. The significance of inkjet printing in producing amorphous dosage forms from solution based inks and personalised dosage forms of drugs susceptible to processing conditions was demonstrated using ramipril. This study illustrates the significance of examining the stability of the APIs in the inks and the importance of appropriate storing of both the inks and printed samples.


Assuntos
Anti-Hipertensivos/química , Composição de Medicamentos/instrumentação , Hipoglicemiantes/química , Impressão/instrumentação , Ramipril/química , Compostos de Sulfonilureia/química , Cristalização , Combinação de Medicamentos , Estabilidade de Medicamentos , Armazenamento de Medicamentos , Excipientes/química , Derivados da Hipromelose/química , Viscosidade
9.
PLoS One ; 13(7): e0200918, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30024925

RESUMO

Silver nanoparticles (Ag-NPs) are known for their efficient bactericidal activity and are widely used in industry. This study aims to produce printable antibacterial devices by drop-on-demand (DoD) inkjet technology, using Ag-NPs as the active part in complex printable fluids. The synthesis of this active part is described using two methods to obtain monodisperse NPs: chemical and microwave irradiation. The synthesized NPs were characterized by UV-VIS, STEM, TEM, DLS and XRD. Two printable fluids were produced based: one with Ag-NPs and a second one, a polymeric nanocomposite, using silver nanoparticles and polyvinyl butyral (Ag-NPs/PVB). Cellulose acetate was used as a flexible substrate. The ecotoxicity analysis of fluids and substrate was performed with Artemia franciscana nauplii. Optimized electric pulse waveforms for drop formation of the functional fluids were obtained for the piezoelectric-based DoD printing. Activity of printed antibacterial devices was evaluated using the Kirby-Bauer method with Staphylococcus aureus and Escherichia coli. The results show that the printed device with Ag-NP fluids evidenced a bacterial inhibition. An important advantage in using the DoD process is the possibility of printing, layer by layer or side by side, more than one active principle, allowing an interleaved or simultaneous release of silver NP and other molecules of interest as for example with a second functional fluid to ensure effectiveness of Ag activity.


Assuntos
Antibacterianos/farmacologia , Escherichia coli/efeitos dos fármacos , Nanopartículas Metálicas/química , Nanocompostos/química , Polímeros/química , Impressão/instrumentação , Prata/química , Staphylococcus aureus/efeitos dos fármacos , Animais , Antibacterianos/química , Golfinhos/crescimento & desenvolvimento , Golfinhos/metabolismo
10.
J Vis Exp ; (137)2018 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-30059021

RESUMO

Electrohydrodynamic (EHD) jet printing has drawn attention in various fields because it can be used as a high-resolution and low-cost direct patterning tool. EHD printing uses a fluidic supplier to maintain the extruded meniscus by pushing the ink out of the nozzle tip. The electric field is then used to pull the meniscus down to the substrate to produce high-resolution patterns. Two modes of EHD printing have been used for fine patterning: continuous near-field electrospinning (NFES) and dot-based drop-on-demand (DOD) EHD printing. According to the printing modes, the requirements for the printing equipment and ink viscosity will differ. Even though two different modes can be implemented with a single EHD printer, the realization methods significantly differ in terms of ink, fluidic system, and driving voltage. Consequently, without a proper understanding of the jetting requirements and limitations, it is difficult to obtain the desired results. The purpose of this paper is to present a guideline so that inexperienced researchers can reduce the trial and error efforts to use the EHD jet for their specific research and development purposes. To demonstrate the fine-patterning implementation, we use Ag nanoparticle ink for the conductive patterning in the protocol. In addition, we also present the generalized printing guidelines that can be used for other types of ink for various fine-patterning applications.


Assuntos
Terapia por Estimulação Elétrica/métodos , Nanopartículas/química , Impressão/instrumentação
11.
Anal Chem ; 90(12): 7761-7768, 2018 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-29851349

RESUMO

Early screening of clinically relevant pathogens in the environment is a highly desirable goal in clinical care, providing precious information that will improve patient-care outcomes. In this work, a glove-based electrochemical sensor has been designed for point-of-use screening of Pseudomonas aeruginosa's virulence factors. The methodology used for the elaboration of the fabric platform relied on printing the conductive inks on the index and middle fingers of the glove, with the goal of screening pyocyanin and pyoverdine targets. The analytical signatures of the analytes were recorded in about 4 min, via the rapid and selective square-wave-voltammetry technique. Finger-based sensors display good performance and discrimination between the targets and potential interferences, along with good reproducibility. The sensors featured linearity over the 0.01-0.1 µM range for pyocyanin and 5-50 µM range for pyoverdine, with sensitivities of 2.51 µA/µM for pyocyanin and 1.09 nA/µM for pyoverdine ( R2 = 0.990 and 0.995, respectively) and detection limits of 3.33 nM for pyocyanin and 1.66 µM for pyoverdine. Moreover, the sensors were tested in binary mixtures of analytes, with successful outcomes. In order to gain information from the surrounding environment, the active electronic areas of the printed fingers were coated with a conductive hydrogel matrix, and relevant target surfaces were "swiped for notification" of contaminants. The simple fabrication, low-cost, and reusability of the proposed glove are likely to underpin the progressive drive of wearable sensors toward decentralized environmental and healthcare applications.


Assuntos
Técnicas Eletroquímicas , Oligopeptídeos/análise , Impressão , Pseudomonas aeruginosa/química , Piocianina/análise , Fatores de Virulência/análise , Técnicas Eletroquímicas/instrumentação , Elétrons , Humanos , Impressão/instrumentação , Soluções
12.
Nanotechnology ; 29(33): 335301, 2018 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-29808832

RESUMO

Nanofabrication approaches to pattern proteins at the nanoscale are useful in applications ranging from organic bioelectronics to cellular engineering. Specifically, functional materials based on natural polymers offer sustainable and environment-friendly substitutes to synthetic polymers. Silk proteins (fibroin and sericin) have emerged as an important class of biomaterials for next generation applications owing to excellent optical and mechanical properties, inherent biocompatibility, and biodegradability. However, the ability to precisely control their spatial positioning at the nanoscale via high throughput tools continues to remain a challenge. In this study electron beam lithography (EBL) is used to provide nanoscale patterning using methacrylate conjugated silk proteins that are photoreactive 'photoresists' materials. Very low energy electron beam radiation can be used to pattern silk proteins at the nanoscale and over large areas, whereby such nanostructure fabrication can be performed without specialized EBL tools. Significantly, using conducting polymers in conjunction with these silk proteins, the formation of protein nanowires down to 100 nm is shown. These wires can be easily degraded using enzymatic degradation. Thus, proteins can be precisely and scalably patterned and doped with conducting polymers and enzymes to form degradable, organic bioelectronic devices.


Assuntos
Elétrons , Fibroínas/química , Nanofios/química , Poliestirenos/química , Impressão/métodos , Sericinas/química , Tiofenos/química , Animais , Biodegradação Ambiental , Bombyx/química , Condutividade Elétrica , Fibroínas/isolamento & purificação , Metacrilatos/química , Microscopia Eletrônica de Varredura/métodos , Nanofios/ultraestrutura , Impressão/instrumentação , Sericinas/isolamento & purificação , Silício/química
13.
Biosensors (Basel) ; 8(1)2018 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-29342960

RESUMO

Recently, inkjet-printing has gained increased popularity in applications such as flexible electronics and disposable sensors, as well as in wearable sensors because of its multifarious advantages. This work presents a novel, low-cost immobilization technique using inkjet-printing for the development of an aptamer-based biosensor for the detection of lysozyme, an important biomarker in various disease diagnosis. The strong affinity between the carbon nanotube (CNT) and the single-stranded DNA is exploited to immobilize the aptamers onto the working electrode by printing the ink containing the dispersion of CNT-aptamer complex. The inkjet-printing method enables aptamer density control, as well as high resolution patternability. Our developed sensor shows a detection limit of 90 ng/mL with high target selectivity against other proteins. The sensor also demonstrates a shelf-life for a reasonable period. This technology has potential for applications in developing low-cost point-of-care diagnostic testing kits for home healthcare.


Assuntos
Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Muramidase/análise , Impressão/instrumentação , Animais , Aptâmeros de Nucleotídeos/química , Galinhas , Eletrodos , Impressão/métodos
15.
J Appl Biomater Funct Mater ; 16(2): 76-82, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29147994

RESUMO

BACKGROUND: In our contemporary world, while part of the fibers used in the paper industry is obtained from primary fibers such as wood and agricultural plants, the rest is obtained from secondary fibers from waste papers. To manufacture paper with high optical quality from fibers of recycled waste papers, these papers require deinking and bleaching of fibers at desired levels. High efficiency in removal of ink from paper mass during recycling, and hence deinkability, are especially crucial for the optical and printability quality of the ultimate manufactured paper. METHODS: In the present study, deinkability and printability performance of digitally printed paper with toner or inkjet ink were compared for the postrecycling product. To that end, opaque 80 g/m2 office paper was digitally printed under standard printing conditions with laser toner or inkjet ink; then these sheets of paper were deinked by a deinking process based on the INGEDE method 11 p. After the deinking operation, the optical properties of the obtained recycled handsheets were compared with unprinted (reference) paper. Then the recycled paper was printed on once again under the same conditions as before with inkjet and laser printers, to monitor and measure printing color change before and after recycling, and differences in color universe. RESULTS: Recycling and printing performances of water-based inkjet and toner-based laser printed paper were obtained. The outcomes for laser-printed recycled paper were better than those for inkjet-printed recycled paper. CONCLUSIONS: Compared for luminosity Y, brightness, CIE a* and CIE b* values, paper recycled from laser-printed paper exhibited higher value than paper recycled from inkjet-printed paper.


Assuntos
Tinta , Papel , Impressão/métodos , Reciclagem/métodos , Impressão/instrumentação
16.
J Acquir Immune Defic Syndr ; 76(5): 522-526, 2017 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-28825941

RESUMO

BACKGROUND: Despite significant gains made toward improving access, early infant diagnosis (EID) testing programs suffer from long test turnaround times that result in substantial loss to follow-up and mortality associated with delays in antiretroviral therapy initiation. These delays in treatment initiation are particularly impactful because of significant HIV-related infant mortality observed by 2-3 months of age. Short message service (SMS) and general packet radio service (GPRS) printers allow test results to be transmitted immediately to health care facilities on completion of testing in the laboratory. METHODS: We conducted a systematic review and meta-analysis to assess the benefit of using SMS/GPRS printers to increase the efficiency of EID test result delivery compared with traditional courier paper-based results delivery methods. RESULTS: We identified 11 studies contributing data for over 16,000 patients from East and Southern Africa. The test turnaround time from specimen collection to result received at the health care facility with courier paper-based methods was 68.0 days (n = 6835), whereas the test turnaround time with SMS/GPRS printers was 51.1 days (n = 6711), resulting in a 2.5-week (25%) reduction in the turnaround time. CONCLUSIONS: Courier paper-based EID test result delivery methods are estimated to add 2.5 weeks to EID test turnaround times in low resource settings and increase the risk that infants receive test results during or after the early peak of infant mortality. SMS/GPRS result delivery to health care facility printers significantly reduced test turnaround time and may reduce this risk. SMS/GPRS printers should be considered for expedited delivery of EID and other centralized laboratory test results.


Assuntos
Comunicação , Infecções por HIV/diagnóstico , Acesso aos Serviços de Saúde , Impressão/instrumentação , África Oriental , África Austral , Humanos , Recém-Nascido , Fatores de Tempo
17.
Proc Natl Acad Sci U S A ; 114(8): E1306-E1315, 2017 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-28167769

RESUMO

Isolation and characterization of rare cells and molecules from a heterogeneous population is of critical importance in diagnosis of common lethal diseases such as malaria, tuberculosis, HIV, and cancer. For the developing world, point-of-care (POC) diagnostics design must account for limited funds, modest public health infrastructure, and low power availability. To address these challenges, here we integrate microfluidics, electronics, and inkjet printing to build an ultra-low-cost, rapid, and miniaturized lab-on-a-chip (LOC) platform. This platform can perform label-free and rapid single-cell capture, efficient cellular manipulation, rare-cell isolation, selective analytical separation of biological species, sorting, concentration, positioning, enumeration, and characterization. The miniaturized format allows for small sample and reagent volumes. By keeping the electronics separate from microfluidic chips, the former can be reused and device lifetime is extended. Perhaps most notably, the device manufacturing is significantly less expensive, time-consuming, and complex than traditional LOC platforms, requiring only an inkjet printer rather than skilled personnel and clean-room facilities. Production only takes 20 min (vs. up to weeks) and $0.01-an unprecedented cost in clinical diagnostics. The platform works based on intrinsic physical characteristics of biomolecules (e.g., size and polarizability). We demonstrate biomedical applications and verify cell viability in our platform, whose multiplexing and integration of numerous steps and external analyses enhance its application in the clinic, including by nonspecialists. Through its massive cost reduction and usability we anticipate that our platform will enable greater access to diagnostic facilities in developed countries as well as POC diagnostics in resource-poor and developing countries.


Assuntos
Nanopartículas/química , Impressão/instrumentação , Linhagem Celular , Separação Celular/instrumentação , Países em Desenvolvimento , Desenho de Equipamento/instrumentação , Humanos , Dispositivos Lab-On-A-Chip , Técnicas Analíticas Microfluídicas/instrumentação , Microfluídica/instrumentação , Sistemas Automatizados de Assistência Junto ao Leito
18.
Anal Biochem ; 523: 1-9, 2017 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-28161099

RESUMO

The widespread use of pesticides has immense effect on increased crop productions. However, they are also responsible for posing detrimental health hazards and/or for contaminating the environment with chemical residues. A routine and an on-field detection of pesticide residues in different food, water, and soil samples has become a need of the hour for which biosensors can offer a viable alternative. The present work reports a functionalized graphene quantum dot (GQD) based screen printed electrochemical immunosensor for the detection of parathion. The application of GQDs has permitted the realization of a sensitive, robust, and reproducible sensor unlike those carried out earlier for the similar purposes. This immunosensor exhibited a dynamic linear response for parathion within the range of 0.01-106 ng/L with a very low detection limit of 46 pg/L. According to the analysis of potential interferences, the proposed sensor was specifically detecting parathion even in the presence of its metabolite, paraoxon. The investigations of the proposed sensing approach with respect to stability, response reproducibility, and regeneration have fully supported its potential practical applicability.


Assuntos
Anticorpos Imobilizados/química , Técnicas Biossensoriais , Técnicas Eletroquímicas/métodos , Grafite/química , Inseticidas/análise , Paration/análise , Impressão/métodos , Pontos Quânticos , Humanos , Limite de Detecção , Impressão/instrumentação
19.
AAPS J ; 19(1): 234-243, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27739009

RESUMO

Peptides and proteins represent a promissory group of molecules used by the pharmaceutical industry for drug therapy with great potential for development. However, the administration of these molecules presents a series of difficulties, making necessary the exploration of new alternatives like the buccal route of administration to improve drug therapy compliance. Although drop-on demand printers have been explored for small molecule drugs with promising results, the development of delivery systems for peptides and proteins through inkjet printing has seen little development. Therefore, the aim of this study was to assess the feasibility of using a thermal inkjet printing system for dispensing lysozyme and ribonuclease-A as model proteins. To address the absorption limitations of a potential buccal use, a permeation enhancer (sodium deoxycholate) was also studied in formulations. We found that a conventional printer successfully printed both proteins, exhibiting very high printing efficiency. Furthermore, the protein structure was not affected and minor effects were observed in the enzymatic activity after the printing process. In conclusion, we provide evidence for the usage of an inexpensive, easy to use, reliable, and reproducible thermal inkjet printing system to dispense proteins solutions for potential buccal application. Our research significantly contributes to present an alternative for manufacturing biologics delivery systems, with emphasis in buccal applications. Next steps of developments will be aimed at the use of new materials for printing, controlled release, and protection strategies for proteins and peptides.


Assuntos
Sistemas de Liberação de Medicamentos , Muramidase/química , Preparações Farmacêuticas/química , Impressão/instrumentação , Ribonuclease Pancreático/química , Tecnologia Farmacêutica/instrumentação , Estudos de Viabilidade
20.
Indoor Air ; 27(2): 398-408, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27219830

RESUMO

The knowledge of exposure to the airborne particle emitted from three-dimensional (3D) printing activities is becoming a crucial issue due to the relevant spreading of such devices in recent years. To this end, a low-cost desktop 3D printer based on fused deposition modeling (FDM) principle was used. Particle number, alveolar-deposited surface area, and mass concentrations were measured continuously during printing processes to evaluate particle emission rates (ERs) and factors. Particle number distribution measurements were also performed to characterize the size of the emitted particles. Ten different materials and different extrusion temperatures were considered in the survey. Results showed that all the investigated materials emit particles in the ultrafine range (with a mode in the 10-30-nm range), whereas no emission of super-micron particles was detected for all the materials under investigation. The emission was affected strongly by the extrusion temperature. In fact, the ERs increase as the extrusion temperature increases. Emission rates up to 1×1012  particles min-1 were calculated. Such high ERs were estimated to cause large alveolar surface area dose in workers when 3D activities run. In fact, a 40-min-long 3D printing was found to cause doses up to 200 mm2 .


Assuntos
Poluição do Ar em Ambientes Fechados/análise , Material Particulado/análise , Impressão Tridimensional , Temperatura , Tamanho da Partícula , Impressão/instrumentação
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