How To Achieve Lung Targeting By Nano Drug Carrier

Due to the increasing environmental pollution and the harm of smoking, lung diseases have become an important factor affecting human health. One of the more serious diseases is lung cancer. Lung cancer is a malignant lung tumor that results from the uncontrolled growth of lung tissue cells. If left untreated, the tumor cells will metastasize to nearby tissues or elsewhere in the body. The most common primary malignant tumor of the lung is epithelial cancer, which can be roughly divided into small cell carcinoma (SCLC) and non-small cell carcinoma (NSCLC). The most common symptoms of lung cancer are cough (including hemoptysis), weight loss, shortness of breath, and chest pain. The majority (85%) of patients with lung cancer develop long-term smoking, yet about 10-15% of patients never smoke. Lung cancer in these people is o ften caused by genetic factors and inhalation of radon, asbestos, secondhand smoke, or other air pollutants. The treatment of lung cancer depends on the type of cancer cells, the extent of their spread and the physical condition of the patient. Common treatments include palliative care, surgery, chemotherapy and radiation. But for advanced lung cancer, targeted therapy is the hope of cure.

Lung-targeting drug carriers are mainly liposomes, microparticles, nanoparticles, emulsions, and cyclodextrins. These tiny particle storage systems are called micro storage systems. They have the advantages of small amount of carrier, high drug loading, controllable particle size and permeability, controllable drug release rate, low toxicity, and few side effects.

Liposomes

Lung-targeting liposomes include immunoliposomes, gene liposomes, and bioadhesive liposomes. Immune liposomes can be targeted to cells in vitro.In order to reduce capture by the RES system in vivo, the method of modifying liposomes with antibodies and polymers (such as PEG) can obtain long-circulating immune liposomes. Among them, in order to improve the effect of the polymer on the targeting performance of the antibody, the antibody can be connected to the surface of the liposome to achieve the targeting of the polymer. Gene liposomes are generally the products of gene nucleotide anions and cationic liposomes through electrostatic interaction. Cationic liposomes are positively charged liposomes prepared with cationic lipids and phospholipids as the main membrane material. The basic principle of bioadhesive liposomes is to modify the surface of liposomes with bioadhesive substances (such as collagen) to increase their bioadhesion and controlled release properties.

Solid Lipid Nanoparticles (SLN)
Solid lipid nanoparticles (SLN) can replace traditional glial carriers, such as emulsions, liposomes, polymer emblems and nanoparticles. High-purity triglycerides, synthetic glycerides, wax mixtures, and p-acylcalixarene can be used as lipid raw materials for preparing SLN. Dehydrocorticosteroids, diazepam, and camptothecin have been encapsulated in solid lipid nanospheres to make a pulmonary drug delivery system.
High polymer particles
Microparticles Microparticles made of natural polymers or synthetic polymers are called polymer particles. Generally, when the particle size is less than 7 μm, it is taken up by macrophages in the liver and spleen. Particles larger than 7 to 10 μm are usually trapped by the smallest capillary bed of the lung by mechanical filtration, and then they are taken up by macrophages into human lung tissue or lung bubble. When inhaled, the porosity can reduce the attraction between the emblem particles, thus reducing the shear force and increasing the fluidity of the powder. The large porous particles have less polymerization between them and easily leave the inhaler, and the effective inhalation quantity is large. In addition, surfactant modification also has a great impact on the accumulation of emblem particles in the lungs.

Nanoparticle

Nanoparticles (NP) In addition to factors such as surface charge, particle size, and surface modification that affect the performance of nanoparticles, their surface adhesion properties are worth noting during pulmonary administration. Biohydrogel polymers can increase the residence time of nanoparticles, which is beneficial to the administration of nanoparticles by inhalation into the lungs. In addition, mucosal adhesion nanoparticles are polymerized with mucosal affinity, such as polyacrylic acid and chitosan modified nanoparticles. Experimental studies of animals administered through the respiratory tract show that the unmodified nanospheres are destroyed before release, and the chitosan mucosal affinity nanospheres are easy to adhere to lung tissue.

In recent years, great progress has been made in the study of lung targeting agents. Liposomes, microparticles, and nanoparticles have the advantages of high drug encapsulation efficiency, easy adjustment of particle size, controllable permeability and drug release rate, and more ways to achieve lung targeting. However, most lung-targeting preparations are still in the experimental research stage, and the relationship between carrier performance and lung-targeting effects is one of the key issues. The targeting effects of liposome targeting systems are not ideal, the stability is not good, and the sudden release of drugs from the microsphere targeted drug delivery system remains to be solved. However, with the deepening of research, nanocarrier lung targeting will open a new door for lung targeted therapy.