ADC Reviews

What is targeted drug delivery?

targeted drug delivery

There is a big difference between targeted drugs and ordinary drugs. They can neither be taken blindly by themselves, nor can they ignore their suitability. Although they have excellent results in the treatment of cancer, they cannot cure all diseases. After all, targeted drugs cannot be treated. Cancer has become miraculous. Cancer friends must be careful and careful on the road of treatment. They must not go into the misunderstanding of treatment. It will bring only disadvantages and absolutely no benefits. For cancer patients, this situation is the saddest. of.

What is targeted drug delivery?
Targeted drug delivery refers to the process in which target agents selectively bind to target cells to produce pharmacological effects.

Targeted drug delivery is a process in which a target agent selectively binds to target cells to produce a pharmacological effect. Due to different routes of administration, drug target preparations can enter different positions, resulting in different targeting and action characteristics. For example, liposome preparations can be injected intravenously, intraperitoneally, intramuscularly, subcutaneously or in lymph nodes, and can also be administered bronchially or intracerebrally and spinally. Intravenous administration! Liposomes are preferentially taken up by tissues rich in reticuloendothelial cells (liver and spleen) in the body, and are rapidly phagocytosed and degraded by mononuclear phagocytes. Two mainly include liposome delivery systems, receptor targeting and Magnetic drugs: liposome preparations encapsulate drugs in bimolecular lipid membranes. This phospholipid membrane is similar to biological membranes and becomes the carrier of drugs. It has a strong affinity with cell membranes, which increases the uptake of cancer cells, improves efficacy, and increases tolerance. sex. Receptor targeting is to use! The surface of liposome is combined with monoclonal antibody against tumor cell surface antigen by covalent bond, so that liposome is concentrated in tumor cells in a large amount, which improves the selectivity of anti-tumor cells. Two magnetic drugs are Refers to the drug binding to highly magnetic iron sulfate. after administration. A strong magnetic field is used in vitro to place the tumor site in one of such strong magnetic fields. The drugs are selected and concentrated in the tumor cells to improve the therapeutic index.

What does targeted drug mean?
Drug targets refer to the binding sites of drugs in the body, including biological macromolecules such as genetic loci, receptors, enzymes, ion channels, and nucleic acids. The key to modern new drug research and development is first to find, determine and prepare drug screening targets—molecular drug targets. Drug targets refer to the binding sites of drugs in the body, including biological macromolecules such as genetic loci, receptors, enzymes, ion channels, and nucleic acids. Selecting and determining novel and effective drug targets is the primary task of new drug development. The total number of therapeutic drug targets has been found to be about 500, of which receptors, especially G-protein coupled receptors (GPCR) targets account for the vast majority, and there are also enzymes, antibacterial, antiviral, antiparasitic targets. drug target. Rational drug design can be based on the potential drug targets, such as enzymes, receptors, ion channels, nucleic acids, etc. revealed in life science research, or the chemical structure characteristics of their endogenous ligands and natural substrates. to design drug molecules to discover new drugs that selectively act on their targets.

Molecularly targeted antitumor drug mechanism:
Common drugs currently used in tumor targeted therapy research include folic acid, various antibodies, and porphyrins. Among them, porphyrin is the most common. The following is an example of molecular targeted anti-tumor drug mechanism.
Porphyrins have special affinity and high selectivity for tumor tissues, but their distribution in tumor tissues and normal tissues is affected by many factors, such as the hydrophobicity of porphyrins, the configuration of complexes, and the cellularity of porphyrins. The selective binding of tumor tissue and the difference in the permeability of normal tissue.
So far, the aggregation mechanism of porphyrins in tumor tissues has not been concluded, and there are two more reasonable explanations:
(1) Theoretical pH value porphyrin enters into cells by passive diffusion, and its diffusion efficiency increases with the decrease of extracellular pH value. Usually, normal tissue and tumor tissue have different pH values ​​(7.0-8.0, 5.85-7.68, respectively); and tumor tissue’s extracellular pH value decreases with the acceleration of metabolism, and the pH value of large tumor cells is small, and tumor cells are low. Therefore, porphyrin can enter more tumor cells and complete the preferential aggregation in tumor tissue.
(2) Low-density lipoprotein receptor theory Monoclonal antibodies, liposomes, microspheres, growth factors, hormones and low-density lipoprotein receptors are considered to be anti-tumor drugs that can improve the selectivity of anti-tumor drugs to tumor cells Transportation System. A large number of in vivo and in vitro experiments have shown that the surface of rapidly proliferating tumor cells contains more LDL receptors with strong activity. Many lipophilic drug molecules bind to the LDL receptor center and enter cells through specific membrane receptors that interact with the LDL receptor apoprotein B.

In most cases, the large lipid vesicles that enter the LDL receptor can bind to the LDL receptor, and the various drug-LDL receptor complexes formed can effectively kill tumor cells. . According to the low-density lipoprotein receptor theory, a higher number of low-density lipoprotein receptors in tumor tissue contributes to more binding of porphyrin to tumor tissue. The mechanism was analyzed by flow cytometry, and it was found that porphyrin and low-density lipoprotein receptors have competitive receptors, and these receptors are not the same as low-density lipoprotein receptor receptors, so the binding of porphyrin to tumor cells Affected by the surrounding low-density lipoprotein receptor concentration. Seeking effective methods to control the concentration of LDL receptors in target tumor cells or increase the number of LDL receptors to improve the binding of porphyrins to tumor cells will become one of the new cancer treatment strategies.

The occurrence of cancer is not easy, and of course targeted drug therapy is not simple. The more patients are familiar with targeted therapy, the more spillover they will have on subsequent treatments. Some cancer friends can only stay in bed in the middle and late stages. Pass through, at this time, you should be more cautious about taking medicine, otherwise you will say goodbye to the world if you are not careful.