Anti-cancer nanomaterials multi-stage drug delivery system enters deep tumor
The birth of anti-cancer nanomaterials
In a laboratory at the School of Translational Medicine, Zhejiang University, China, scientists irradiated breast cancer mice with a near-infrared laser. After 3 minutes, the "medicine box" waiting at the tumor site opened, and the anti-tumor drug quickly and evenly penetrated into the deep tissue of the tumor. After 4 hours, the tumor cells successively apoptosis.
This is a kind of "anti-cancer nanomaterial multi-level drug loading system" constructed by the team led by Professor Zhou Min of the Second Affiliated Hospital of Zhejiang University School of Medicine and the Institute of Translational Medicine. This multi-level drug loading system can make tumor drugs Deep delivery to tumor tissue, significantly inhibiting the metastasis of malignant tumors. The research results were published in the internationally renowned academic journal "Advanced Functional Materials".
The researchers said that some drugs that have been proven to have an effect on tumors are currently limited in clinical use. For example, drugs always "run too fast" and "not far". "In general, less than 24 hours, the drug will be metabolized out of the body, and the time for the drug effect to play is very short, resulting in very few drugs that actually go to the tumor, so I have to continue to use the drug." Zhou Min introduced The multi-level drug loading system newly designed by their team can reduce the metabolic rate of anticancer drugs and penetrate deep tissues of tumors that conventional anticancer drugs cannot enter.
There are abundant blood vessels around the tumor cells, but the growth of blood vessels often cannot keep up with the rate of tumor cell division, resulting in no blood vessel distribution deep in the tumor cells. Traditional anti-cancer drug molecules must pass through blood vessels to reach tumor cells. Without blood vessels, it means that drugs cannot reach. This is also one of the major challenges in the development of oncology drugs.
Zhou Min's team transformed a broad-spectrum anticancer drug doxorubicin to allow multiple small molecules of doxorubicin to form a polymerization ball. Through this design, the "size" of the drug becomes larger, and the time that the drug stays in the body is extended to a certain extent.
The use of anti-cancer nanomaterials
In addition, the drug delivery system is designed as a light-controlled "pillbox". Only when excited by light of a specific wavelength, the anti-cancer molecules carried on the polymeric sphere will be released and diffused. In the experiment, the research group selected near-infrared light with a wavelength of 800 nanometers, which can penetrate up to 5 cm of biological tissue. Under light, the nanospheres "disintegrate" into ultra-small-sized nanodots and anti-cancer molecules, which quickly penetrate inside the tumor tissue.
Further experiments show that the multi-stage drug loading system can not only effectively destroy tumor cells, but also significantly inhibit the growth of tumor stem cells, and can also inhibit the occurrence of tumor metastasis. Because of its good tumor aggregation ability, this system can significantly reduce the cardiac and systemic toxicity of anti-tumor drugs, and has a high prospect of clinical transformation. However, if this treatment method is to be used clinically, a large number of trials are still required.