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1.
Anal Chem ; 96(8): 3508-3516, 2024 02 27.
Artículo en Inglés | MEDLINE | ID: mdl-38364051

RESUMEN

Extracellular vesicles (EVs) are cell-derived particles that exhibit diverse sizes, molecular contents, and clinical implications for various diseases depending on their specific subpopulations. However, fractionation of EV subpopulations with high resolution, efficiency, purity, and yield remains an elusive goal due to their diminutive sizes. In this study, we introduce a novel strategy that effectively separates EV subpopulations in a gel-free and label-free manner, using two-dimensional (2D) electrophoresis in a microfluidic artificial sieve. The microfabricated artificial sieve consists of periodically arranged micro-slit-well structures in a 2D array and generates an anisotropic electric field pattern to size fractionate EVs into discrete streams and steer the subpopulations into designated outlets for collection within a minute. Along with fractionating EV subpopulations, contaminants such as free proteins and short nucleic acids can be simultaneously directed to waste outlets, thus accomplishing both size fractionation and purification of EVs with high performance. Our platform offers a simple, rapid, and versatile solution for EV subpopulation isolation, which can potentially facilitate the discovery of biomarkers for specific EV subtypes and the development of EV-based therapeutics.


Asunto(s)
Vesículas Extracelulares , Microfluídica , Vesículas Extracelulares/química , Proteínas/análisis , Electroforesis , Biomarcadores/análisis
2.
Anal Chem ; 95(45): 16453-16458, 2023 11 14.
Artículo en Inglés | MEDLINE | ID: mdl-37916921

RESUMEN

Synchronous coefficient of drag alteration refers to a multidimensional transport mechanism where a net drift of molecules is achieved under a zero-time-average alternating motive force by perturbing their drag coefficient synchronously with the applied force. An electrophoretic form of the method is often applied to focus and purify nucleic acids in a gel under rotating electric fields. However, this method requires lengthy operation due to the use of limited field strengths. Here, using DNA as target molecules, we demonstrate that the operation time can be reduced from hours to minutes by replacing polymer gel with a microfabricated artificial sieve. We also describe an electrophoretic protocol that facilitates the collection of purified DNA from the sieve, which is shown to yield amplifiable DNA from crude samples including the lysates of cultured cells and whole blood. The sieve can be further equipped with nucleic acid amplification and detection functions for a point-of-care diagnostic application.


Asunto(s)
ADN , Ácidos Nucleicos , Electroforesis/métodos , Polímeros , Técnicas de Amplificación de Ácido Nucleico
3.
J Nanobiotechnology ; 21(1): 307, 2023 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-37644442

RESUMEN

A disorder of cholesterol homeostasis is one of the main initiating factors in the progression of atherosclerosis (AS). Metabolism and removal of excess cholesterol facilitates the prevention of foam cell formation. However, the failure of treatment with drugs (e.g. methotrexate, MTX) to effectively regulate progression of disease may be related to the limited drug bioavailability and rapid clearance by immune system. Thus, based on the inflammatory lesion "recruitment" properties of macrophages, MTX nanoparticles (MTX NPs) camouflaged with macrophage membranes (MM@MTX NPs) were constructed for the target to AS plaques. MM@MTX NPs exhibited a uniform hydrodynamic size around ~ 360 nm and controlled drug release properties (~ 72% at 12 h). After the macrophage membranes (MM) functionalized "homing" target delivery to AS plaques, MM@MTX NPs improved the solubility of cholesterol by the functionalized ß-cyclodextrin (ß-CD) component and significantly elevate cholesterol efflux by the loaded MTX mediated the increased expression levels of ABCA1, SR-B1, CYP27A1, resulting in efficiently inhibiting the formation of foam cells. Furthermore, MM@MTX NPs could significantly reduce the area of plaque, aortic plaque and cholesterol crystals deposition in ApoE-/- mice and exhibited biocompatibility. It is suggested that MM@MTX NPs were a safe and efficient therapeutic platform for AS.


Asunto(s)
Aterosclerosis , Placa Aterosclerótica , Animales , Ratones , Células Espumosas , Biomimética , Aterosclerosis/tratamiento farmacológico , Transporte Biológico
4.
Environ Geochem Health ; 43(1): 235-245, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32852689

RESUMEN

This study aimed to measure and discuss the relationship of ambient air precipitations with respect to mercury wet depositions at suburban, agriculture and traffic three characteristic sampling sites during the year of 2019. In addition, the mercury volume weighted mean concentrations (VWM) at three characteristic sampling sites were also calculated. Finally, the ambient mercury wet depositions data obtained in this study to various world sampling sites were also compared and discussed in this study. The results indicated that the average mercury wet depositions for suburban, agriculture and traffic areas were 0.62, 0.55 and 2.32 ng/m2 min, respectively. And the average mercury VWM values were 0.9, 0.72 and 1.85 ng/m2 min for suburban, agriculture and traffic sites, respectively. In addition, the highest VWM and wet depositions for mercury both occurred in March at traffic and suburban areas. And the mercury wet depositions displayed a declined trend when the month was moved from March to July at both traffic and suburban sampling sites. In addition, the relationship between wet depositions and precipitations was low to moderate correlated in traffic area, while the relationship between wet depositions and precipitations was insignificant at both suburban and agriculture areas. Moreover, the average highest mercury wet deposition occurred in Nepal when compared to the other world sites. In addition, the average value of mercury wet depositions in Nepal was about 17.23 times to that of data obtained in this study during the period of 2007-2019. Finally, the average highest VWM (ng/L) occurred in the China. In addition, the average value mercury VWM in China was about 14.82 times to that of data obtained in this study during the period of 2007-2019.


Asunto(s)
Contaminantes Atmosféricos/análisis , Ambiente , Monitoreo del Ambiente , Mercurio/análisis , Estaciones del Año , Taiwán
5.
Trends Analyt Chem ; 130: 115984, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32834243

RESUMEN

Infectious diseases, such as the most recent case of coronavirus disease 2019, have brought the prospect of point-of-care (POC) diagnostic tests into the spotlight. A rapid, accurate, low-cost, and easy-to-use test in the field could stop epidemics before they develop into full-blown pandemics. Unfortunately, despite all the advances, it still does not exist. Here, we critically review the limited number of prototypes demonstrated to date that is based on a polymerase chain reaction (PCR) and has come close to fulfill this vision. We summarize the requirements for the POC-PCR tests and then go on to discuss the PCR product-detection methods, the integration of their functional components, the potential applications, and other practical issues related to the implementation of lab-on-a-chip technologies. We conclude our review with a discussion of the latest findings on nucleic acid-based diagnosis.

6.
Opt Express ; 27(4): 4629-4647, 2019 Feb 18.
Artículo en Inglés | MEDLINE | ID: mdl-30876077

RESUMEN

Mueller matrix imaging polarimeter (MMIP) can be used to measure the polarization aberration (PA) of a lithographic projector in the form of the Mueller pupil, while the Jones pupil is required for lithographic imaging simulations, projection lens design and PA evaluation. In this paper, a Jones pupil measurement method of lithographic projection lens is proposed. The measurement device of the method is the same as an MMIP, but a new polarimetric measurement equation is derived to solve the Jones pupil directly from the Kronecker product of the Jones matrix and the measured intensities. Two new polarimeter configurations with the minimum condition number are designed to further improve the accuracy in the presence of error sources. The performance of the method is evaluated by measurement errors of a typical Jones pupil in the presence of error sources. Comparisons between the proposed method and the conventional method, in which the Jones pupil is converted from the Mueller pupil measured by MMIP, are given. The results validate that the measurement accuracy of the Jones pupil is significantly improved without increasing the complexity of existing measurement systems.

7.
Tumour Biol ; 37(4): 4517-22, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26503210

RESUMEN

Interleukin-10 (IL-10) is a multifunctional cytokine that participates in the development and progression of various malignant tumors. However, data regarding the role of IL-10 polymorphisms in osteosarcoma development are not available. A case-control study was conducted in 260 patients with osteosarcoma and 260 healthy controls to investigate the possible association between IL-10 polymorphisms and the risk of osteosarcoma. Our results indicate the IL-10 -1082A/G (rs1800896) polymorphism is significantly associated with an increased risk of osteosarcoma in all genetic models (AG vs. AA, odds ratio (OR) = 1.56; 95 % confidence interval (CI) = 1.28-2.32, P = 0.017; GG vs. AA, OR = 1.62, 95 % CI 1.24-2.61, P = 0.013; AG + GG vs. CC, OR = 1.76, 95 % CI = 1.31-3.01, P = 0.019). However, the genotype and allele frequencies of IL-10 -819C/T (rs1800871) and -592A/C (rs1800872) polymorphisms in osteosarcoma patients did not significantly differ from controls. Further analyses revealed that the IL-10 -1082A/G (rs1800896) genotypes were associated with advanced tumor stages and metastasis in osteosarcoma patients. Additionally, a statistically significant association between the IL-10 -1082A/G (rs1800896) genotype and poor survival in osteosarcoma patients was observed. Our results demonstrate that the IL-10 -1082A/G (rs1800896) genotype is associated with an increased susceptibility and worse outcome for osteosarcoma patients in the Chinese Han population.


Asunto(s)
Neoplasias Óseas/genética , Interleucina-10/genética , Osteosarcoma/genética , Polimorfismo de Nucleótido Simple , Adolescente , Adulto , Neoplasias Óseas/mortalidad , Neoplasias Óseas/terapia , Estudios de Casos y Controles , China , Femenino , Frecuencia de los Genes , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Genotipo , Humanos , Desequilibrio de Ligamiento , Masculino , Osteosarcoma/mortalidad , Osteosarcoma/terapia , Análisis de Secuencia de ADN , Análisis de Supervivencia , Resultado del Tratamiento , Adulto Joven
8.
Biomarkers ; 21(2): 160-3, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26754027

RESUMEN

BACKGROUND: There are no data about the role of MMPs polymorphism in development of osteosarcoma. PATIENTS AND METHODS: Two-hundred fifty-one patients with osteosarcoma and 251 healthy controls were included to investigate the association between the MMP2, 3, 9 polymorphisms and the risk of osteosarcoma. RESULTS: Compared with the MMP2 SNP rs243865 homozygote CC, The heterozygous CT genotype was associated with significantly increased risk for osteosarcoma (OR = 1.86, 95% CI = 1.18-4.22, p = 0.014); the TT genotype was associated with increased risk for osteosarcoma (OR = 1.92, 95% CI = 1.21-3.52, p = 0.028). However, the genotype and allele frequencies of MMP3 rs3025058 and MMP9 rs3918242 polymorphisms were not significantly different. CONCLUSION: MMP2 rs243865 genotype was associated with increased risk for development of osteosarcoma in Chinese Han population.


Asunto(s)
Predisposición Genética a la Enfermedad/genética , Metaloproteinasa 2 de la Matriz/genética , Metaloproteinasa 3 de la Matriz/genética , Metaloproteinasa 9 de la Matriz/genética , Osteosarcoma/genética , Polimorfismo de Nucleótido Simple , Adolescente , Adulto , Pueblo Asiatico/genética , China , Femenino , Frecuencia de los Genes , Predisposición Genética a la Enfermedad/etnología , Genotipo , Humanos , Desequilibrio de Ligamiento , Masculino , Osteosarcoma/etnología , Reacción en Cadena de la Polimerasa , Polimorfismo de Longitud del Fragmento de Restricción , Factores de Riesgo , Adulto Joven
9.
Yi Chuan ; 38(12): 1081-1089, 2016 12 20.
Artículo en Inglés | MEDLINE | ID: mdl-28034840

RESUMEN

Somatic cell nuclear transfer technique has great applications in livestock breeding, production of genetically modified animals, rescue of endangered species and treatment of human diseases. However, the currently low efficiency in animals cloning, an average of less than 5%, greatly hindered the rapid development of this technique. Among many factors which affect the efficiency of cloning pigs, X chromosome inactivation is an important one. Moreover, Xist gene is closely related to X chromosome inactivation, suggesting that it may directly or indirectly affects cloning efficiency. In this study, multiple sgRNAs were designed based on the CRISPR/Cas system, and two sites (Target 3 and Target 4) whose mutation efficiency were 1% and 3% at the cellular level were selected. We successfully knocked out Xist with 100% efficiency by microinjecting sgRNAs for Target 3 and Target 4 in embryo. Finally, 6 cloning piglets were born including two Xist-fully-knockout piglets. The follow-up studies on increasing cloning efficiency can be carried out based on the Xist-knockout model.


Asunto(s)
ARN Largo no Codificante/metabolismo , Animales , Sistemas CRISPR-Cas/genética , Sistemas CRISPR-Cas/fisiología , Técnicas de Inactivación de Genes , ARN Guía de Kinetoplastida/genética , ARN Largo no Codificante/genética , Porcinos
10.
Knee Surg Sports Traumatol Arthrosc ; 23(11): 3354-61, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24928371

RESUMEN

PURPOSE: The effectiveness of cryotherapy on joint arthroplasty recovery remains controversial. This systematic review was conducted to assess the effectiveness of cryotherapy in patients after joint arthroplasty. METHODS: Comprehensive literature searches of several databases including Cochrane Library (2013), MEDLINE (1950-2013), and Embase (1980-2013) were performed. We sought randomised controlled trials that compared the experimental group received any form of cryotherapy with any control group after joint arthroplasty. The main outcomes were postoperative blood loss, adverse events, and pain. Analyses were performed with Revman 5.0. Results were shown as mean differences (MD) and standard deviations or as risk difference and 95 % confidence intervals (CIs). RESULTS: Ten trials comprised 660 total knee arthroplastys and three trials comprised 122 total hip arthroplastys (THAs) met the inclusion criteria. Blood loss was significantly decreased by cryotherapy (MD = -109.68; 95 % CI -210.92 to -8.44; P = 0.03). Cryotherapy did not increase the risk of adverse effect (n.s.). Cryotherapy decreased pain at the second day of postoperative (MD = -1.32; 95 % CI -2.37 to -0.27; P = 0.0003), but did not decreased pain at the first and third day of postoperative (n.s.). CONCLUSIONS: Cryotherapy appears effective in these selected patients after joint arthroplasty. The benefits of cryotherapy on blood loss after joint arthroplasty were obvious. However, the subgroup analysis indicated that cryotherapy did not decreased blood loss after THA. Cryotherapy did not increase the risk of adverse effect. Cryotherapy decreased pain at the second day of postoperative, but did not decreased pain at the first and third day of postoperative. LEVEL OF EVIDENCE: II.


Asunto(s)
Artroplastia de Reemplazo de Rodilla/rehabilitación , Crioterapia , Articulación de la Rodilla/cirugía , Pérdida de Sangre Quirúrgica/prevención & control , Humanos , Dolor Postoperatorio/prevención & control , Cuidados Posoperatorios , Ensayos Clínicos Controlados Aleatorios como Asunto
11.
Int Orthop ; 38(1): 7-12, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23982638

RESUMEN

PURPOSE: Cementless acetabular fixation for total hip arthroplasty (THA) is widely used. The question of using screws for a better primary and secondary acetabular fixation has been discussed in the literature in recent years. The aim of this meta-analysis was to compare fixation of acetabular cups with and without screws in total hip arthroplasty. METHODS: Electronic databases Embase, PubMed and Cochrane Library were used to search for randomised controlled trials reported through May 2013 of cementless acetabular fixation for THA with and without screws. Two independent reviewers assessed the trials for eligibility and quality. All related data matching our standards were abstracted for meta-analysis by RevMan 5.0. Evaluation criteria included revisions, migration and osteolysis. RESULTS: A total of 1,130 THAs enrolled into five trials were included in this meta-analysis. All studies compared fixation of acetabular cups with and without screws, and our pooled data showed no statistical significance between the two surgical methods in revision, migration and osteolysis. CONCLUSION: There is no significant difference between cementless acetabular fixation for THA with and without screws in revisions, migration or osteolysis.


Asunto(s)
Acetábulo/cirugía , Artroplastia de Reemplazo de Cadera/instrumentación , Artroplastia de Reemplazo de Cadera/métodos , Tornillos Óseos , Prótesis de Cadera , Humanos , Incidencia , Fijadores Internos , Osteólisis/epidemiología , Falla de Prótesis , Reoperación/estadística & datos numéricos , Resultado del Tratamiento
12.
Acta Crystallogr Sect E Struct Rep Online ; 70(Pt 7): o798, 2014 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-25161579

RESUMEN

In the crystal structure of the title compound, C22H13Br2N3, the two bromo-phenyl rings are rotated out of the plane of the central benzyl-idene ring by 68.7 (1) and 69.3 (1)°. Both cyano substituents are located nearly in the plane of the benzylidene ring, with the mean plane of the methylmalononitrile group being inclined to this ring by 5.8 (1)°. In the crystal, the mol-ecules are linked by weak C-H⋯N hydrogen bonds into layers parallel to the bc plane.

13.
Lab Chip ; 24(2): 383, 2024 Jan 17.
Artículo en Inglés | MEDLINE | ID: mdl-38179894

RESUMEN

Correction for 'Sub-nL thin-film differential scanning calorimetry chip for rapid thermal analysis of liquid samples' by Sheng Ni et al., Lab Chip, 2023, 23, 1926-1934, https://doi.org/10.1039/D2LC01094A.

14.
Int J Biol Macromol ; 273(Pt 1): 133062, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38862051

RESUMEN

Chronic bacterial infections, excessive inflammation, and oxidative stress significantly hinder diabetic wound healing by prolonging the inflammatory phase and complicating the healing process. In this study, phenylboronic acid functionalized dextran (PODP) was developed to encapsulate curcumin, referred to as PODP@Cur. Experimental results indicate that PODP significantly improves the water solubility of curcumin and exhibits synergistic biological activity both in vitro and in vivo. PODP@Cur is capable of accelerating drug release under the pathological microenvironment with ROS accumulation. Furthermore, phenylboronic acid (PBA) has demonstrated potential for targeted bacterial drug delivery, enhancing antibacterial efficacy and trapping free LPS/PGN from dead bacteria to reduce undesirable inflammation. In a diabetic mouse model, PODP@Cur exhibits an excellent antibacterial, anti-inflammatory and antioxidant activities to ultimately promote the efficient and safe wound healing. Due to the specific interaction between PBA and LPS, PODP@Cur could enhance antibacterial activity against bacteria, reduce toxic side effects on normal cells, and alleviate the LPS-mediated pro-inflammatory pathological microenvironment. Therefore, PODP@Cur is capable of being exploited as an efficient and safe candidate for promoting the bacteria-infected diabetic wound healing.


Asunto(s)
Antibacterianos , Ácidos Borónicos , Curcumina , Dextranos , Diabetes Mellitus Experimental , Cicatrización de Heridas , Curcumina/farmacología , Curcumina/química , Animales , Cicatrización de Heridas/efectos de los fármacos , Dextranos/química , Ratones , Ácidos Borónicos/química , Ácidos Borónicos/farmacología , Antibacterianos/farmacología , Antibacterianos/química , Diabetes Mellitus Experimental/tratamiento farmacológico , Nanopartículas/química , Liberación de Fármacos , Portadores de Fármacos/química , Células RAW 264.7 , Masculino , Antioxidantes/farmacología , Antioxidantes/química , Infecciones Bacterianas/tratamiento farmacológico
15.
RSC Adv ; 14(31): 22763-22768, 2024 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-39027035

RESUMEN

At present, mainstream room-temperature phosphorescence (RTP) emission relies on organic materials with long-range charge-transfer effects; therefore, exploring new forms of charge transfer to generate RTP is worth studying. In this work, indole-carbazole was used as the core to ensure the narrowband fluorescence emission of the material based on its characteristic short-range charge-transfer effect. In addition, halogenated carbazoles were introduced into the periphery to construct long-range charge transfer, resulting in VTCzNL-Cl and VTCzNL-Br. By encapsulating these phosphors into a robust host (TPP), two host-guest crystalline systems were further developed, achieving efficient RTP performance with phosphorescence quantum yields of 26% and phosphorescence lifetimes of 3.2 and 39.2 ms, respectively.

16.
Int J Biol Macromol ; 263(Pt 1): 130249, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38368994

RESUMEN

Persistent over-oxidation, inflammation and bacterial infection are the primary reasons for impaired wound repairing in diabetic patients. Therefore, crucial strategies to promote diabetic wound repairing involve suppressing the inflammatory response, inhibiting bacterial growth and decreasing reactive oxygen species (ROS) within the wound. In this work, we develop a multifunctional nanomedicine (HA@Cur/Cu) designed to facilitate the repairing process of diabetic wound. The findings demonstrated that the synthesized infinite coordination polymers (ICPs) was effective in enhancing the bioavailability of curcumin and improving the controlled drug release at the site of inflammation. Furthermore, in vitro and in vivo evaluation validate the capacity of HA@Cur/Cu to inhibit bacterial growth and remove excess ROS and inflammatory mediators, thereby significantly promoting the healing of diabetic wound in mice. These compelling findings strongly demonstrate the enormous promise of this multifunctional nanomedicine for the treatment of diabetic wound.


Asunto(s)
Curcumina , Diabetes Mellitus , Humanos , Ratones , Animales , Curcumina/farmacología , Curcumina/uso terapéutico , Cicatrización de Heridas , Ácido Hialurónico/farmacología , Nanomedicina , Especies Reactivas de Oxígeno/farmacología , Hidrogeles/farmacología , Inflamación , Antibacterianos/farmacología
17.
ACS Appl Mater Interfaces ; 16(25): 32027-32044, 2024 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-38867426

RESUMEN

Atherosclerotic plaques exhibit high cholesterol deposition and oxidative stress resulting from high reactive oxygen species (ROS). These are the major components in plaques and the main pro-inflammatory factor. Therefore, it is crucial to develop an effective therapeutic strategy that can simultaneously address the multiple pro-inflammatory factors via removing cholesterol and inhibiting the overaccumulated ROS. In this study, we constructed macrophage membrane-encapsulated biomimetic nanoparticles (MM@DA-pCD@MTX), which not only alleviate cholesterol deposition at the plaque lesion via reverse cholesterol transport but also scavenge the overaccumulated ROS. ß-Cyclodextrin (ß-CD) and the loaded methotrexate (MTX) act synergistically to induce cholesterol efflux for inhibiting the formation of foam cells. Among them, MTX up-regulated the expression of ABCA1, CYP27A1, and SR-B1. ß-CD increased the solubility of cholesterol crystals. In addition, the ROS scavenging property of dopamine (DA) was perfectly preserved in MM@DA-pCD@MTX, which could scavenge the overaccumulated ROS to alleviate the oxidative stress at the plaque lesion. Last but not least, MM-functionalized "homing" targeting of atherosclerotic plaques not only enables the targeted drug delivery but also prolongs in vivo circulation time and drug half-life. In summary, MM@DA-pCD@MTX emerges as a potent, multifunctional therapeutic platform for AS treatment, offering a high degree of biosafety and efficacy in addressing the complex pathophysiology of atherosclerosis.


Asunto(s)
Aterosclerosis , Materiales Biomiméticos , Colesterol , Dopamina , Macrófagos , Metotrexato , Nanopartículas , Dopamina/química , Dopamina/farmacología , Nanopartículas/química , Aterosclerosis/tratamiento farmacológico , Aterosclerosis/metabolismo , Aterosclerosis/patología , Ratones , Animales , Materiales Biomiméticos/química , Materiales Biomiméticos/farmacología , Metotrexato/química , Metotrexato/farmacología , Colesterol/química , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Humanos , Ciclodextrinas/química , Ciclodextrinas/farmacología , Células RAW 264.7 , Estrés Oxidativo/efectos de los fármacos , Portadores de Fármacos/química , beta-Ciclodextrinas
18.
Microsyst Nanoeng ; 10: 66, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38784376

RESUMEN

This study presents a rapid and versatile low-cost sample-to-answer system for SARS-CoV-2 diagnostics. The system integrates the extraction and purification of nucleic acids, followed by amplification via either reverse transcription-quantitative polymerase chain reaction (RT-qPCR) or reverse transcription loop-mediated isothermal amplification (RT-LAMP). By meeting diverse diagnostic and reagent needs, the platform yields testing results that closely align with those of commercial RT-LAMP and RT‒qPCR systems. Notable advantages of our system include its speed and cost-effectiveness. The assay is completed within 28 min, including sample loading (5 min), ribonucleic acid (RNA) extraction (3 min), and RT-LAMP (20 min). The cost of each assay is ≈ $9.5, and this pricing is competitive against that of Food and Drug Administration (FDA)-approved commercial alternatives. Although some RNA loss during on-chip extraction is observed, the platform maintains a potential limit of detection lower than 297 copies. Portability makes the system particularly useful in environments where centralized laboratories are either unavailable or inconveniently located. Another key feature is the platform's versatility, allowing users to choose between RT‒qPCR or RT‒LAMP tests based on specific requirements.

19.
Lab Chip ; 23(7): 1926-1934, 2023 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-36883529

RESUMEN

Differential scanning calorimetry (DSC) is a popular thermal analysis technique. The miniaturization of DSC on chip as thin-film DSC (tfDSC) has been pioneered for the analysis of ultrathin polymer films at temperature scan rates and sensitivities far superior to those attainable with DSC instruments. The adoption of tfDSC chips for the analysis of liquid samples is, however, confronted with various issues including sample evaporation due to the lack of sealed enclosures. Although the subsequent integration of enclosures has been demonstrated in various designs, rarely did those designs exceed the scan rates of DSC instruments mainly because of their bulky features and requirement for exterior heating. Here, we present a tfDSC chip featuring sub-nL thin-film enclosures integrated with resistance temperature detectors (RTDs) and heaters. The chip attains an unprecedented sensitivity of 11 V W-1 and a rapid time constant of 600 ms owing to its low-addenda design and residual heat conduction (∼6 µW K-1). We present results on the phase transition of common liquid crystals which we leverage to calibrate the RTDs and characterize the thermal lag with scan rates up to 900 °C min-1. We then present results on the heat denaturation of lysozyme at various pH values, concentrations, and scan rates. The chip can provide excess heat capacity peaks and enthalpy change steps without much alteration induced by the thermal lag at elevated scan rates up to 100 °C min-1, which is an order of magnitude faster than those of many chip counterparts.

20.
Lab Chip ; 23(10): 2421-2433, 2023 05 16.
Artículo en Inglés | MEDLINE | ID: mdl-36951129

RESUMEN

Extracellular vesicles (EVs) are cell-derived bioparticles that play significant roles in various biological processes including cell-to-cell communication and intercellular delivery. Additionally, they hold great potential as liquid biopsy biomarkers for pre-diagnostic applications. However, the isolation of EV subpopulations, especially exosomes from a biological fluid remains a challenge due to their submicron range. Here, we demonstrate continuous-flow label-free size fractionation of EVs for the first time through a synergistic combination of electrothermal fluid rolls and dielectrophoresis in a microfluidic device. The device features three dimensional microelectrodes with unique sidewall contours that give rise to effective electrothermal fluid rolls in cooperation with dielectrophoretic forces for the electrokinetic manipulation and size separation of submicron particles. We first validate the device functionality by separating submicron polystyrene particles from binary mixtures with a cut-off size of ∼200 nm and then isolate intact exosomes from cell culture medium or blood serum with a high recovery rate and purity (∼80%). The device operation in a high-conductivity medium renders the method ideal for the purification of target bioparticles directly from physiological fluids, and may offer a robust and versatile platform for EV related diagnostic applications.


Asunto(s)
Exosomas , Vesículas Extracelulares , Técnicas Analíticas Microfluídicas , Microelectrodos , Dispositivos Laboratorio en un Chip
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