Advances in research of lung-targeted anticancer drug liposomes

Lung cancer is one of the major diseases that threaten human health. In recent years, clinical research on anti-lung cancer drugs has developed rapidly. However, anti-lung cancer drugs have weak targeting, and they also kill normal tissue cells while attacking tumor cells. The major toxic and side effects are the difficulty in studying anti-lung cancer drugs. The research and development of lung-targeted anticancer drugs has become an important way to overcome this problem.

Worldwide, approximately 1.5 million cancer cases are diagnosed with lung cancer each year, 85% of which are non-small cell lung cancer (NSCLC). Surgery or radiotherapy is usually used to treat NS CLC. But more often, in order to prevent tumor metastasis, recurrence and improve survival, chemotherapy is also needed. At present, the anticancer drugs, such as paclitaxel or DTX injection which are commonly used in clinical practice, have poor targeting ability, and at the same time they will also kill tumor cells and destroy normal tissue cells, thereby enhancing the adverse reactions of the drugs. Therefore, research and development of lung targeting antibiotics Cancer drugs have become an important way to solve this problem.

Liposome have the characteristics of strong targeting, good cell affinity, strong biodegradability, good sustained release, and low toxicity, and are the most drug-forming carriers. The development of anti-lung cancer targeting drug liposomes has become a research hotspot for medical workers.

Targeted preparation
Targeted preparations, also known as targeted delivery systems, refer to drug delivery systems that can localize and enrich drugs in target organs, target tissues and target cells through local or systemic blood circulation. The lung targeting carrier delivery system refers to a drug delivery system that selectively accumulates drugs in the lungs by using the carrier, ultimately achieving the goal of improving drug efficacy and reducing adverse reactions.

Numerous studies have shown that liposomes, as a common drug carrier, have the best drug-forming properties of targeted delivery systems. The main reason is that liposomes are made of lipid-like phospholipids, cholesterol and the like as membrane materials. They have the advantages of good biocompatibility, biodegradability, low toxicity, high safety and the like. The prepared liposomes have a cell membrane-like structure and can control drug release. In recent years, there have been many studies on liposome materials. Liposomes as drug carrier have shown good development prospects in pharmaceutics.

liposome route of administration
The drugs encapsulated by liposomes can increase the targeting of tissues, organs, cells and the like other than liver and spleen, especially to the lungs. A large number of studies have found that the lung targeting of liposomes is mainly achieved through two ways: the first route is to take local administration. The second route is to take intravenous administration.

Preparation and targeting of liposomes
At present, there are many methods for preparing liposomes. The selection of specific methods should be determined according to liposomes application purpose of and the properties of the encapsulated drugs. The common methods are : solid dispersion technology combined with hydration technology, film dispersion method, Solvent injection method, ultrasonic method, reverse evaporation method, etc. Different preparation methods and process groups can achieve the targeting of different organs, tissues and cells. However, some of the common liposomes prepared by the preparation method and the process group are not targeted, and are distributed to various tissues and organs throughout the body after administration.

Conclusion
As LTDs ,Liposomes are administered by whole body, and their targeting is closely related to the choice of membrane material, particle size and charge. Therefore, in order to prepare lung-targeting liposomes to improve the anti-lung cancer efficacy and reduce adverse reactions, the following aspects must be paid attention to in the preparation of such liposomes:
( 1 ) selection and composition of liposome membrane materials: attention should be paid to the selection of biodegradable phospholipids similar to those of pulmonary capillary cells as liposome membrane materials to facilitate lipid exchange;
( 2 ) Charge control: suggested modification to prepare negatively charged liposomes;
( 3 ) controlling the particle size: preparing and controlling the particle size of the liposome to be less than 2mum. These are conducive to the interaction between lung cancer cells and liposomes, and can be starting points for designing such targeted liposomes.