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Research on the application of magnetic polymer microspheres in biology

2019-02-28 来源:亚科官网

As a new type of organic-inorganic composite functional material, magnetic polymer microspheres are attracting more and more attention of scholars at home and abroad due to their performance advantages and huge application potential. In recent years, it has been increasingly valued by scientists due to its excellent properties. Research on magnetic biopolymer microspheres has become a research hotspot in the field of new biomaterials. The following is a look at the application of magnetic polymer microspheres in the biological field.

Application in immunoassay

Immunoassay is an analytical method that utilizes the specificity between an antibody and an antigen, detects an antigen with an antibody, or detects an antibody with an antigen. Magnetic separation greatly accelerates and simplifies the separation process of immune substances. Since the specificity of the antigen-antibody is good, the loss is small and the separation purity is high. At present, immunoassay methods mainly include anti-radiation immunoassay, fluorescence immunoassay, electrochemical immunoassay and luminescence immunoassay. The introduction of magnetic particles in immunoassays is a new method that has been developed in recent years. The antigen or the antibody is immobilized on the magnetic microparticles, and after the immune reaction, a complex of the antigen and the antibody is formed in the solid phase magnetic microparticles, and the magnetic field sedimentation complex is applied, and then the excess antigen and the antibody are washed, or the complex and the unnecessary complex are not separated. Antibodies and antigens were assayed directly in free solutions. The magnetic particle separation technology uses a magnetic particle coupling agent as a biomolecule of a ligand to separate a substance specifically bound to the system, thereby greatly simplifying the separation of the antigen and the antibody.

Application in biological separation analysis

In the field of biological sciences, many trace components (such as proteins, peptides, enzymes, nucleic acids, etc.) that need to preserve physiological activity exist in complex biological samples and require separation analysis. Magnetic microspheres, due to their magnetic properties, can be quickly separated from the surrounding medium or oriented to specific locations under the action of a magnetic field. This shows a compelling application prospect in this field compared to the commonly used separation methods.

(1) Immobilized enzyme

Enzyme is a catalytically active protein that plays an important role in the metabolism of substances in living organisms. Since the structure and activity of enzymes are easily destroyed during the separation process, its catalytic effect is greatly affected. The immobilized enzyme refers to a technique of immobilizing a free enzyme to a carrier by physical adsorption or chemical demarcation to improve the operational stability of the enzyme and repeatedly recover the enzyme. At present, the methods of immobilizing enzymes can be roughly classified into four types: adsorption method, covalent method, cross-linking method, and embedding method. The selective adsorption of the carrier during the curing of the enzyme in the fermentation broth or its crude liquid can play a certain purification role, and the covalent cross-linking between the enzyme molecules ensures that the enzyme molecule is tightly bound to the carrier. As the carrier for immobilization of the enzyme, the magnetic polymer microsphere has the following advantages: 1. It is advantageous for the separation and recovery of the immobilized enzyme from the reaction system, and the operation is simple; 2 the immobilized enzyme can be reused to reduce the cost; 3 can improve the stability of the enzyme. 4; can improve the biocompatibility and immunological activity of the enzyme.

(2) Cell separation

The labeling and separation of cells is one of the earliest applications of magnetic polymer microspheres. Magnetic polymer microspheres can separate unwanted cells (negative selection) or enrich cells (positive selection) by immunological or non-immune logic reactions. For example, by combining a monoclonal antibody with a magnetic microsphere, the magnetic microsphere can be directly attached to the tumor cell, and the bound tumor cell can be separated from the unbound normal bone marrow cell by using an external magnetic field. The United States and the United Kingdom have applied this technology to the clinic.

Targeted drug

In order to improve the efficacy of drugs and reduce their toxic side effects, biological missile technology (targeted drugs) is becoming a hot topic today. The so-called biological missile technology is to use the characteristics of pH sensitivity, heat sensitivity and magnetic sensitivity of drug carriers in the external environment. Targeted administration of the diseased tissue is performed. By functionalizing the surface of the magnetic microspheres, as a drug carrier, the drug is carried to a predetermined area under the action of an external magnetic field to realize a targeted drug delivery technique. The targeted administration of magnetic microspheres began in the early 1970s. After taking this preparation, magnetic microspheres were guided to a specific target area in the body at a suitable site in vitro to achieve the desired concentration. Some scholars have used magnetic soluble polyelectrolytes and magnetic drug carriers containing neuromuscular anesthetics for liposome experiments, which have achieved good results. According to the mode of administration of the targeted drugs, it can be divided into active administration (Active Delivery of Drugs) and passive administration (Passivedilivery of Drugs). Passive administration relies on changing the hydrophilic, hydrophobic properties and particle size of the drug carrier surface to the target; active administration mainly relies on the orientation of external magnetic fields and the like and drug carrier coupling such as monoclonal antibodies, exogenous coagulation, hormones Orientation is achieved by a special affinity for the target of administration.

Related links: Carboxyl magnetic microspheres

Edited by Suzhou Yacoo Science Co., Ltd.