1、目的及意义

Cancer is one of the diseases that threaten human life and health. Chemotherapy is one of the most effective methods for the treatment of cancer, and it is also an indispensable and effective method for the treatment of cancer. However, most of the chemotherapeutic drugs in clinical use, there are many problems, such as water solubility and poor stability, poor selectivity, high toxicity, distribution of lack of target and short circulation time in vivo, only the curative effect is low, but also easy to damage to the human body immunity, damage to the normal body, cause serious side effects, bring the pain to the patient. The best way to reduce the side effects of drugs, reduce the dosage of drugs, and enhance the efficacy of drugs in the treatment of antitumor drugs. Therefore, the method of tumor target therapy has been widely studied in the field of cancer treatment, with its high selectivity and low toxicity.

Tumor targeting therapy technology is a method that utilizes specific drug carriers, directing cancer drugs or their active substances to cancer tissue, and does not affect the growth and development of normal tissue cells, so as to improve treatment effect and reduce toxic and side effects. Therefore, to find efficient and low toxic transport system to solve the above problems of chemotherapeutic drugs has become a hot topic in the related fields As an ideal drug carrying system, it must have four characteristics: positioning accumulation, controlling drug release, innocuous and biodegradable.

1. Drug carrying system

Drug delivery system, also known as drug delivery system, drug delivery systems DDS), in the past decades, in order to improve the therapeutic effect of drugs, the drug delivery system has been deeply researched and developed [7-10]. Drug delivery system can improve the routine drug administration problem by improving the solubility of drugs, prolonging the duration, reducing the side effects and maintaining the biological activity of drugs. [1,2] All kinds of carriers, such as particle carrier [3,4], polymer gel [5,6], lipid [7,8], are widely used in the drug loading system.

2. Double drug delivery system

In recent years, in the field of disease treatment and tissue regeneration, the combination of different therapeutic effects of different drugs is a very effective way of [12,13]. In order to optimize the effect of combined therapy, different drugs should be used at its best dose and at different times. One of the major challenges for combined treatment is to control the release of each drug alone. However, the single drug delivery system does not meet the needs of this treatment. Therefore, it is worth looking forward to developing a dual drug delivery system (dual-drug delivery system, DDDS) that controls the release behavior of each drug.

There are more than 30 chemotherapeutic drugs that are currently used in the treatment of cancer. Most of the drugs are designed according to the chemical structure characteristics of active ingredients in the drug, and designed a specific adapter that can respond to an environment, and connect the drug to the carrier to get the product.