Liquid biopsy technology has developed rapidly since its inception. For the separation, capture, enrichment and purification of CTC, ctDNA and exosomes, such as immunoassay, magnetic sorting, membrane filtration, ddPCR, differential centrifugation have been developed. Laws, etc., and many advanced technologies have emerged in their identification and analysis. It is the continuous emergence of these technologies that has pushed liquid biopsy into clinical practice step by step. Although liquid biopsy technology has made great progress, researchers have not stopped their continuous optimization. From the current trend of liquid biopsy technology research and development, people are increasingly inclined to develop automation, miniaturization and Qualcomm. Quantitative instruments, because traditional manual methods have many problems, such as long steps, long time, and large human error, which is not conducive to large-scale detection of clinical samples and difficult to establish stable enrichment efficiency and identification criteria. Therefore, based on the prior art, the other detection methods can be fully combined, and the multi-mode comprehensive detection can be realized without increasing the complexity of the whole detection process, so that the completion of efficient, accurate and inexpensive detection should be the focus of future development research. .
At present, the microfluidic technology, nanotechnology and single cell sequencing technology have appeared in the detection of CTC. The emergence of these technologies has accelerated the automation process of CTC detection to some extent. Especially represented by microfluidics and nanotechnology, its precise control performance, efficient detection efficiency and simple and convenient operation advantages have helped its glory in the biomedical field. At present, many automated detection platforms use this technology, and their respective characteristics and development status are introduced below.
Microfluidic technology
Microfluidics, in general, refers to the science and technology involved in systems that use microchannels to treat tiny fluids. It is an emerging interdisciplinary subject involving chemistry, fluid physics, microelectronics, new materials, biology, and biomedical engineering. Microfluidic devices are often referred to as microfluidic chips because of their miniaturization, integration, and the like. Microfluidic is considered to have great development potential and broad application prospects in biomedical research. The current CTC chip sorting principle can be roughly classified into two categories: passive sorting and active sorting. Different types of cells differ in physical and biological properties such as size, density, shape, deformability, and affinity. According to these different characteristics, passive sorting technology applies cells to cells through microstructures or microfluidics in the flow channel. The effect, in order to achieve separation, generally has the advantage of high flux and no additional application of force fields. These separation methods mainly include microstructure filtration, field flow and hydraulic sorting, deterministic lateral offset, inertial sorting, bionic sorting, and affinity sorting. The active sorting technique exerts a force on the cells in the sample stream through the external force field, thereby causing separation, and the sorting precision is often higher than the passive sorting technique. These sorting methods mainly include dielectrophoresis sorting, magnetic sorting, sound sorting, and light sorting. In view of the fact that microfluidic technology still has problems such as low purity and low flux, especially for the sorting of CTCs with extremely low content in peripheral blood, it is difficult to meet the high-throughput and high-purity sorting requirements at the same time. Therefore, researchers have adopted a multi-stage sorting chip that combines passive sorting technology and active sorting technology to achieve sorting requirements for rare cells.
The microfluidic CTC chip technology (CTC-Chip), known as the second generation CTC capture technology, demonstrates its great potential for separation and detection of CTCs. The CTC chip is a silicon wafer of the same size as a standard slide as a solid phase support with a plurality of etched specially arranged microcells arranged thereon. This method is very flexible and can be combined with different CTC sorting strategies. For example, various antibodies can be coated on the solid support, which greatly improves the sensitivity and the probability of capturing rare cells from whole blood. At the same time, the operation process is relatively simple and gentle, so that the separated CTC maintains a certain vitality. Although the current microfluidic CTC chip is more complicated in design and processing, its good sorting effect, light volume, low injection volume, high sensitivity and easy-to-use convenience are positive. Attracting more and more attention is a major direction for the future industrialization.
However, there are still some shortcomings in the application of microfluidic chip technology to rare cell sorting. For example, it has been found that there are 16 subtypes of CTC, and it is necessary to immobilize corresponding antibodies to achieve higher capture efficiency, and some antibodies have not yet been commercialized. Or CTC does not express the corresponding antigen, which will cause missed detection; at this stage, the microfluidic platform still relies on specific immune recognition, and it is impossible to capture CTC full subtype and CTM and CTC wrapped by white blood cells, from the periphery. It is still difficult to obtain very few CTCs in the blood, and it takes a certain period of time to ensure that a sufficient immune response can occur, even if the method based on antigen-antibody adsorption can not completely avoid the loss of CTC; The extrusion of the microstructure in the channel, the flow field of the high shear flow, and the applied electric field all cause a certain degree of damage to the activity of the cells, which causes trouble to the subsequent separation and culture.
nanotechnology
The rapid development of nanotechnology in recent years has been successfully applied in many fields, including medicine, pharmacy, and chemistry. Nanoparticles have unique optical, electrical, chemical, mechanical and physical properties that have greatly contributed to solving the problems of medical detection. Nanomaterials can be divided into various types according to materials and shapes, such as gold nanoparticles, magnetic nanoparticles, carbon nanotubes, nanopores and microcantilevers. With the development of nanotechnology, people can obtain different kinds of nanomaterials with controllable structure and surface functionalization. The small size effect and high specific surface area exhibited by nanomaterials are different from those of general materials, making a very small amount in blood. The capture of CTCs is possible. The high contact probability of nanomaterials and nanostructures with CTC can also greatly improve the enrichment efficiency of CTC and is widely used in the enrichment and detection of CTC. Based on the third generation of non-antibody-dependent capture technology, the Nextctc cycle tumor live cell capture instrument combines international leading nanotechnology and microfluidic technology to achieve non-antibody-dependent CTC activity in single cells. Non-destructive capture, the use of nanotechnology to capture isolated CTC cells preserves the original viability, can be used for subsequent susceptibility testing and whole-genome sequencing, but also maximizes capture of epithelial sources, interstitial sources, and stem cell sources. Type of circulating tumor cells minimizes missed detection due to EMT processes or the formation of CTM and entrapment by other cells. In view of the many advantages of nanomaterials, the application of nanoparticles to the detection of CTC has great potential.
Vpsa Oxygen Generator,Vpsa Oxygen,Vacuum Swing Adsorption Oxygen Generator,Adsorption Oxygen Generator
Hangzhou Zhongju air separation equipment manufacturing Co., Ltd , https://www.hzzjkfzz.com