Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
Mais filtros











Base de dados
Intervalo de ano de publicação
1.
ACS Nano ; 10(6): 6201-10, 2016 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-27299807

RESUMO

Isolation of single circulating tumor cells (CTCs) from patients is a very challenging technique that may promote the process of individualized antitumor therapies. However, there exist few systems capable of highly efficient capture and release of single CTCs with high viability for downstream analysis and culture. Herein, we designed a near-infrared (NIR) light-responsive substrate for highly efficient immunocapture and biocompatible site-release of CTCs by a combination of the photothermal effect of gold nanorods (GNRs) and a thermoresponsive hydrogel. The substrate was fabricated by imprinting target cancer cells on a GNR-pre-embedded gelatin hydrogel. Micro/nanostructures generated by cell imprinting produce artificial receptors for cancer cells to improve capture efficiency. Temperature-responsive gelatin dissolves rapidly at 37 °C; this allows bulk recovery of captured CTCs at physiological temperature or site-specific release of single CTCs by NIR-mediated photothermal activation of embedded GNRs. Furthermore, the system has been applied to capture, individually release, and genetically analyze CTCs from the whole blood of cancer patients. The multifunctional NIR-responsive platform demonstrates excellent performance in capture and site-release of CTCs with high viability, which provides a robust and versatile means toward individualized antitumor therapies and also shows promising potential for dynamically manipulating cell-substrate interactions in vitro.


Assuntos
Hidrogéis , Raios Infravermelhos , Nanotubos , Células Neoplásicas Circulantes , Linhagem Celular Tumoral , Ouro , Humanos
2.
Anal Chem ; 88(13): 6773-80, 2016 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-27291464

RESUMO

Effective isolation of circulating tumor cells (CTCs) has great significance for cancer research but is highly challenged. Here, we developed a microchip embedded with a three-dimensional (3D) PDMS scaffold by a quadratic-sacrificing template method for high-efficiency capture of CTCs. The microchip was gifted with a 3D interconnected macroporous structure, strong toughness, and excellent flexibility and transparency, enabling fast isolation and convenient observation of CTCs. Especially, 3D scaffold chip perfectly integrates the two main strategies currently used for enhancement of cell capture efficiency. Spatially distributed 3D scaffold compels cells undergoing chaotic or vortex migration in the channel, and the spatially distributed nanorough skeleton offers ample binding sites, which synergistically and significantly improve CTCs capture efficiency. Our results showed that 1-118 CTCs/mL were identified from 14 cancer patients' blood and 5 out of these cancer patients showed 1-14 CTC clusters/mL. This work demonstrates for the first time the development of microchip with transparent interconnected 3D scaffold for isolation of CTCs and CTC clusters, which may promote in-depth analysis of CTCs.


Assuntos
Dimetilpolisiloxanos/química , Técnicas Analíticas Microfluídicas/métodos , Células Neoplásicas Circulantes/metabolismo , Anticorpos Imobilizados/química , Anticorpos Imobilizados/imunologia , Molécula de Adesão da Célula Epitelial/imunologia , Molécula de Adesão da Célula Epitelial/metabolismo , Humanos , Células MCF-7 , Análise em Microsséries , Técnicas Analíticas Microfluídicas/instrumentação , Microscopia de Fluorescência , Neoplasias/sangue , Neoplasias/patologia , Células Neoplásicas Circulantes/patologia , Porosidade
4.
Anal Chem ; 88(2): 1378-84, 2016 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-26707930

RESUMO

DNA methylation (5-methylcytosine, 5-mC) is the best characterized epigenetic mark that has regulatory roles in diverse biological processes. Recent investigation of RNA modifications also raises the possible functions of RNA adenine and cytosine methylations on gene regulation in the form of "RNA epigenetics." Previous studies demonstrated global DNA hypomethylation in tumor tissues compared to healthy controls. However, DNA and RNA methylation in circulating tumor cells (CTCs) that are derived from tumors are still a mystery due to the lack of proper analytical methods. In this respect, here we established an effective CTCs capture system conjugated with a combined strategy of sample preparation for the captured CTCs lysis, nucleic acids digestion, and nucleosides extraction in one tube. The resulting nucleosides were then further analyzed by liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS). With the developed method, we are able to detect DNA and RNA methylation (5-methyl-2'-deoxycytidine, 5-methylcytidine, and N(6)-methyladenosine) in a single cell. We then further successfully determined DNA and RNA methylation in CTCs from lung cancer patients. Our results demonstrated, for the first time, a significant decrease of DNA methylation (5-methyl-2'-deoxycytidine) and increase of RNA adenine and cytosine methylations (N(6)-methyladenosine and 5-methylcytidine) in CTCs compared with whole blood cells. The discovery of DNA hypomethylation and RNA hypermethylation in CTCs in the current study together with previous reports of global DNA hypomethylation in tumor tissues suggest that nucleic acid modifications play important roles in the formation and development of cancer cells. This work constitutes the first step for the investigation of DNA and RNA methylation in CTCs, which may facilitate uncovering the metastasis mechanism of cancers in the future.


Assuntos
Metilação de DNA , DNA de Neoplasias/análise , DNA de Neoplasias/química , Neoplasias Pulmonares/química , Células Neoplásicas Circulantes/química , RNA Neoplásico/análise , RNA Neoplásico/química , Cromatografia Líquida de Alta Pressão , DNA de Neoplasias/sangue , Humanos , Neoplasias Pulmonares/sangue , Neoplasias Pulmonares/patologia , Células MCF-7 , Células Neoplásicas Circulantes/patologia , RNA Neoplásico/sangue , Espectrometria de Massas em Tandem
5.
ACS Appl Mater Interfaces ; 7(16): 8817-26, 2015 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-25853336

RESUMO

Isolation of rare, pure, and viable circulating tumor cells (CTCs) provides a significant insight in early cancer diagnosis, and release of captured CTCs without damage for ex vivo culture may offer an opportunity for personalized cancer therapy. In this work, we described a biotin-triggered decomposable immunomagnetic system, in which peptide-tagged antibody designed by chemical conjugation was specifically immobilized on engineered protein-coated magnetic beads. The interaction between peptide and engineered protein can be reversibly destroyed by biotin treatment, making capture and release of CTCs possible. Furthermore, the peptide could mediate multiple antibodies' coimmobilization on engineered protein-coated magnetic beads, by which capture efficiency for CTCs was obviously improved. Quantitative results showed that 70% of captured cells could be released by biotin addition, and 85% of released cells remained viable. In addition, 79% of cancer cells spiked in human whole blood were captured and could also be successfully released for culture. Finally, immunomagnetic beads simultaneously loaded with anti-EpCAM, anti-HER2, and anti-EGFR were successfully applied to isolate and detect CTCs in 17 cancer patients' peripheral blood samples, and 2-215 CTCs were identified with high purity. These results suggest that our method is reliable and has great potential in CTC detection for CTC-based molecular profiling, diagnosis, and therapy.


Assuntos
Biotina/química , Separação Imunomagnética/métodos , Microesferas , Células Neoplásicas Circulantes/patologia , Antígenos de Neoplasias/metabolismo , Moléculas de Adesão Celular/metabolismo , Linhagem Celular Tumoral , Separação Celular , Sobrevivência Celular , Molécula de Adesão da Célula Epitelial , Humanos , Imunoglobulina G/metabolismo , Estreptavidina/química
6.
Analyst ; 140(11): 3753-8, 2015 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-25630568

RESUMO

Here, we report a self-supported nanoporous gold microelectrode decorated with well-dispersed and tiny platinum nanoparticles as an electrochemical nonenzymatic hydrogen peroxide biosensor. Nanoporous gold was fabricated by electrochemical alloying/dealloying and then small-sized platinum nanoparticles were electrodeposited uniformly on them. This novel hybrid nanostructure endows the sensor with high sensitivity and selectivity towards the reduction of hydrogen peroxide with a low detection limit of 0.3 nM. The sensor has been successfully applied for the measurement of H2O2 release from a single isolated human breast cancer cell, demonstrating its great potential for further physiological and pathological applications.


Assuntos
Ouro/química , Peróxido de Hidrogênio/metabolismo , Nanopartículas Metálicas/química , Nanoporos , Platina/química , Análise de Célula Única/instrumentação , Ligas/química , Eletroquímica , Humanos , Células MCF-7 , Microeletrodos , Tamanho da Partícula , Fatores de Tempo
7.
Chem Sci ; 6(11): 6432-6438, 2015 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-28757959

RESUMO

Isolation, release and culture of rare circulating tumor cells (CTCs) may, if implemented, promote the progress of individualized anti-tumor therapies. To realize the release of CTCs without disruption of their viability for further culture and analysis, we designed an effective photocontrolled CTC capture/release system by combination of photochemistry and immunomagnetic separation. 7-Aminocoumarin was synthesized as the phototrigger to bridge the connection between the anti-EpCAM antibody and the magnetic beads. The coumarin moieties produced cleavage of a C-O bond under both ultraviolet (UV) and near-infrared (NIR) light illumination, breaking the bridge and releasing CTCs from the immunomagnetic beads. Compared with conventional immunomagnetic separation systems, the negative influence of absorbed immunomagnetic beads on further CTCs culture and analysis was effectively eliminated. The system can specifically recognize 102 MCF-7 cells in 1 mL of human whole blood samples with 90% efficiency and 85% purity. Under the irradiation of UV and NIR light, 73 ± 4% and 52 ± 6% of captured cells were released with a viability of 90% and 97%, respectively. Furthermore, this technique has been used to detect CTCs from whole blood of cancer patients with high purity. This study demonstrates that the photochemical-based immunomagnetic separation method for isolating, releasing and culturing CTCs from clinic patients may provide new opportunities for cancer diagnosis and personalized therapy.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA