摘要:

Insight, innovation, integrationUsing straightforward microfabrication processes, biomaterials surfaces can be topographically structured to comprise high-density arrays of micron-sized cavities, termed ‘microwell arrays’. These substrates are, for example, ideally suited to culture and probe the fate of large numbers of trapped single cells, such as rare and heterogeneous stem cells. Here we highlight the key applications of these platforms, hopefully inspiring biologists to apply these systems for their own studies.

ISSN:1757-9694    

DOI:10.1039/b918172p

出版商:RSC    

年代:2009

数据来源: RSC

摘要:

Insight, innovation, integrationCaspases have been recognized as emerging therapeutic targets in caspase-dependent diseases. The development of new methods to screen intracellular caspases as potential drug targets is difficult because the initiation of complex caspase cascade involves simultaneous activation of initiator and downstream caspases, leading to the distinct modes of cell death. We showed the application of high-content cellular imaging cytometry based on a new approach of uniform threshold intensity distribution that allows simultaneous quantitative monitoring of the caspase cascade in an intact cell. It facilitates rapid, quantitative, live cellular monitoring of drug-induced caspase cascades through multi-spectral and multicolor imaging cytometry. The present study provides important information for the design of new methodologies or the refinement of existing methodologies for efficient therapeutic drug target monitoring.

ISSN:1757-9694    

DOI:10.1039/b916481b

出版商:RSC    

年代:2009

数据来源: RSC

摘要:

Insight, innovation, integrationAptamers are reagents which can be developed to bind target ligands with a combination of high affinity and specificity. Given that aptamers are oligonucleotides, they are particularly suited to array based diagnostics, which can be used to directly quantify biological entities at both the proteomic and metabolomic level. The development of such devices, however, requires the coming together of technologies from the analytical, biological and computational fields. Detection and quantification of bound analytes is key to this task, particularly at the metabolomic level. We review some of the advances in this area and highlight some of the innovations which may facilitate the transfer of solution based aptamer applications to the array platform.

ISSN:1757-9694    

DOI:10.1039/b815539a

出版商:RSC    

年代:2008

数据来源: RSC

摘要:

Insight, innovation, integrationAdult stem cell microenvironments, termed niches, are crucial for stem cell function. They are complex, multifactorial regulatory entities that are difficult to study using conventional experimentalin vivoorvitroparadigms. We have combined biomaterials technology with microengineering to produce protein-functionalized hydrogel-microwell arrays. Analyses of single hematopoietic stem cells (HSCs) by time-lapse microscopy resolved kinetic differences obscured in bulk cultures and showed thatin vitrobehavior could predictin vivostem cell function. By demonstrating that single cells undergo self-renewal divisions in microwells in response to selected soluble proteins or immobilized proteins that mimic cell–cell interactions typical of HSC niches, we could deconstruct a complex niche and parse out the role of certain individual components using novel ‘artificial niches’.

ISSN:1757-9694    

DOI:10.1039/b815718a

出版商:RSC    

年代:2008

数据来源: RSC

摘要:

Insight, innovation, integrationStem cells in adult tissues reside within niches and maintain homeostasis within an organ for the life of an organism. To do so they must self-maintain and generate differentiated progeny; the decision to do one or the other is called a cell fate decision. How the microenvironment that surrounds stem cells influences cell fate decisions is poorly understood. This is because the compositions of microenvironments are complex and stem cells are extremely scarce. Dissecting a human stem cell niche, understandably, is even more difficult because of the inability to do experimentsin vivo. To begin to overcome these obstacles, we utilized a new technology that enables highly parallel functional analysis of combinatorial microenvironments, image analysis of 3D organotypic cultures and micropatterned culture substrata. Here we have identified combinations of components in the human mammary microenvironment that impose distinct cell fate decisions and could putatively direct mammary progenitor cell functionsin vivo.

ISSN:1757-9694    

DOI:10.1039/b816472j

出版商:RSC    

年代:2008

数据来源: RSC

摘要:

Insight, innovation, integrationWe have developed novel image analysis tools to characterize cell populations at multiple scales. We have applied these tools to cells that actively divide during mammary development and then remain quiescent for months (label-retaining cells, LRC). Morphometric analysis and Monte Carlo simulations demonstrated that LRC have characteristic nuclear features, form small, non-random, clusters in large mammary ducts, are undifferentiated and remain proliferation competent. Tissue-wide quantification showed that LRC are asymmetrically distributed in the tissue, suggesting patterning of the progenitor cell reservoir. We confirmed this hypothesis using fluorescence activated cell sorting of mammary stem cell markers. The high through-put image analysis of putative progenitor cells in the murine mammary gland revealed a previously unrecognized architecture of the mammary gland.

ISSN:1757-9694    

DOI:10.1039/b816933k

出版商:RSC    

年代:2008

数据来源: RSC

摘要:

Insight, innovation, integrationThere is a need for rapid testing of drug candidates obtained from various sources, such as herbal compounds. There is also an increasing demand for drug testing using the cell-based method. The direct testing of chemotherapeutic drugs on patient cancer cell samples before treatment may open a new avenue for personalized medicine. We invented a microfluidic chip for the real-time detection of cytotoxicity of drug candidates. This is based on the quantitative measurement of cytosolic calcium ([Ca2+]i) on single cancer cells. Such a single-cell method is rapid because it readily detects the early event of drug cytotoxicity based on the sustained increase in [Ca2+]i. This method is faster than the conventional MTT assays that usually take a few days to complete. Moreover, any color or chemical interference problems interfering conventional assays for herbal compounds could be resolved. The microfluidic single-cell method not only reduces reagent cost and demands less cells, but also reveals some phenomena due to cellular heterogeneity that cannot be observed in bulk analysis.

ISSN:1757-9694    

DOI:10.1039/b812987h

出版商:RSC    

年代:2008

数据来源: RSC

摘要:

Melissa MarianiMelissa Mariani obtained her BSc in Biology from Oxford Brookes University and her MSc in Immunology from the University of Manchester. She continued her education with an interdisciplinary PhD at the Technical University of Dortmund under the supervision of Dr Volker Deckert, where she used model biological systems with vibrational spectroscopic techniques to study fundamental cell interactions.

ISSN:1757-9694    

DOI:10.1039/b920572a

出版商:RSC    

年代:2009

数据来源: RSC

摘要:

Petra KorpisaloDr Petra Korpisalo, MD, PhD, has extensive experience in utilizing gene transfer techniques for the treatment of ischemic vascular diseases. She has also developed highly sensitive imaging techniques based on ultrasound and evaluation of metabolic functions in tissues with MRS techniques.

ISSN:1757-9694    

DOI:10.1039/b921869f

出版商:RSC    

年代:2009

数据来源: RSC

摘要:

Insight, innovation, integrationAptamers are ideal for diagnostic and pharmaceutical studies, but gaining knowledge into mechanism and key structural features is essential for novel and diverse future applications. DNA microarrays allow thousands of sequences to be interrogated simultaneously. We have therefore utilized a high density array format to screen key structural features for G quadruplex forming sequences, using the known protein thrombin. This format rapidly yields a vast amount of data allowing a detailed model to be built describing key loop–sequence–functionality relationships. The ability to survey the landscape systematically using aptamers of known sequence makes microarray formats highly suited for studying sequence specific protein binding profiles.

ISSN:1757-9694    

DOI:10.1039/b814892a

出版商:RSC    

年代:2008

数据来源: RSC