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发表于 2007-8-27 16:13:04
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nanoparticles used for molecular imaging of malignant lesions.Nanoparticles Nanoscale devices have the potential to radically change cancer therapy for the better and to dramatically increase the number of highly effective therapeutic agents.
In this example, nanoparticles are targeted to cancer cells for use in the molecular imaging of a malignant lesion. Large numbers of nanoparticles are safely injected into the body and preferentially bind to the cancer cell, defining the anatomical contour of the lesion and making it visible.
These nanoparticles give us the ability to see cells and molecules that we otherwise cannot detect through conventional imaging. The ability to pick up what happens in the cell - to monitor therapeutic intervention and to see when a cancer cell is mortally wounded or is actually activated - is critical to the successful diagnosis and treatment of the disease.
Nanoparticulate technology can prove to be very useful in cancer therapy allowing for effective and targeted drug delivery by overcoming the many biological, biophysical and biomedical barriers that the body stages against a standard intervention such as the administration of drugs or contrast agents. Reference Scientific Bibliography:http://nano.cancer.gov/resource_ ... ed-therapeutics.asp
Nanoshells kill tumor cells selectively.Nanoshells have a core of silica and a metallic outer layer. These nanoshells can be injected safely, as demonstrated in animal models.
Because of their size, nanoshells will preferentially concentrate in cancer lesion sites. This physical selectivity occurs through a phenomenon called enhanced permeation retention (EPR).
Scientists can further decorate the nanoshells to carry molecular conjugates to the antigens that are expressed on the cancer cells themselves or in the tumor microenvironment. This second degree of specificity preferentially links the nanoshells to the tumor and not to neighboring healthy cells.
As shown in this example, scientists can then externally supply energy to these cells. The specific properties associated with nanoshells allow for the absorption of this directed energy, creating an intense heat that selectively kills the tumor cells. The external energy can be mechanical, radio frequency, optical - the therapeutic action is the same. The result is greater efficacy of the therapeutic treatment and a significantly reduced set of side effects. Reference Scientific Bibliography:
http://nano.cancer.gov/resource_ ... ed-therapeutics.asp
Nanoscale cantilevers biosensors.a very interesting idea which has been achieved by many researchers, especially it is achieved by SPM. Here, how to make nanoscale cantilevers is a big problem. Ecthing process is very important.
microscopic, flexible beams resembling a row of diving boards - are built using semiconductor lithographic techniques. These can be coated with molecules capable of binding specific substrates-DNA complementary to a specific gene sequence, for example. Such micron-sized devices, comprising many nanometer-sized cantilevers, can detect single molecules of DNA or protein.
As a cancer cell secretes its molecular products, the antibodies coated on the cantilever fingers selectively bind to these secreted proteins. These antibodies have been designed to pick up one or more different, specific molecular expressions from a cancer cell. The physical properties of the cantilevers change as a result of the binding event. Researchers can read this change in real time and provide not only information about the presence and the absence but also the concentration of different molecular expressions.
Nanoscale cantilevers, constructed as part of a larger diagnostic device, can provide rapid and sensitive detection of cancer-related molecules.
nanowire sensors.which was first described by Charles M. Lieber.In this diagram, nano sized sensing wires are laid down across a microfluidic channel. These nanowires by nature have incredible properties of selectivity and specificity. As particles flow through the microfluidic channel, the nanowire sensors pick up the molecular signatures of these particles and can immediately relay this information through a connection of electrodes to the outside world.
These nanodevices are man-made constructs made with carbon, silicon and other materials that have the capability to monitor the complexity of biological phenomenon and relay the information, as it is monitored, to the medical care provider.
They can detect the presence of altered genes associated with cancer and may help researchers pinpoint the exact location of those changes.
纳米尺度的图片概念
Quantum DotsResearchers such as Xiaohu Gao of the University of Washington are finding ways to introduce quantum dots into the body. Rats are injected with the dots, which find their way to cancer cells. If such cells are present, the cancers can be pinpointed by medical imaging technology, as shown here. Source: Xiaohu Gao , University of Washington.
盐和胡椒
照片的作者大卫·麦卡锡是伦敦药剂学校的一位研究人员。他使用一台电子显微镜拍下了一个胡椒子和一粒海盐的特写照片，让人们清楚地看到了这两种生活中常见的物体的真实构造。
癌细胞运动
安妮是一名医学研究人员，她是利用一台电子显微镜拍摄到上面这张照片的。当癌细胞慢慢“爬进”一个试验室过滤器上的小孔时，安妮拍下了照片，以阐明癌细胞是如何运动的。
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发表于 2007-8-27 16:10:31
