New nanomaterials for radiotherapy "double sensitivity"

The team of Professor Chen Xiuxuan of Harbin Medical University's affiliated oncology hospital, in cooperation with experts such as Meng Xianwei of the Institute of Science and Technology of the Chinese Academy of Sciences, designed a multi-functional and biodegradable nanomaterial that effectively inhibited the expression of carbonate enzyme 9 in tumor cells, and achieved the effect of inhibiting hypoxia in tumor cells; The research paper was recently published in the journal Nano, sponsored by the American Chemical Society.According to the introduction, the principle of radiotherapy is to use the biological role of radiation, the largest number of killing tumor tissue, induce cancer cell necrosis and apoptosis, and ultimately achieve the goal of killing tumors. The sensitivity of tumor cells to radiation is a key factor in determining efficacy, and the amount of oxygen in tumor cells determines the sensitivity of the cell to radiotherapy. In other words, the effect of tumor radiotherapy is closely related to the hypoxia state in tumor.In view of the practical problems faced by the clinic, Professor Chen Xiuxuan's team members, Dr. Ma Tengjun, Dr. Liu Yunxuan and Meng Xianwei of the Institute of Science and Technology of the Chinese Academy of Sciences, jointly carried out the design and application of multi-functional nanomaterials in 2016, and explored the light heat and microwave treatment of tumors. On this basis, based on the presence of oxygen-deprived state in tumor micro-environment, in order to better enhance the sensitivity of radiotherapy, the team designed and synthesized metal organic frame material. The material is easy to surface modify and load with a variety of drugs, is biodegradable and biosysorptible.At the same time, Chen Xiuxuan's team innovatively introduced the medium-drug quercetin with radiation sensitivity. Quercetin and its derivatives are flavonoids with a variety of biological activities, widely found in the flowers and fruits of various plants in nature. It has been found that quercetin has a strong anti-tumor effect, and its mechanism is to inhibit tumor cell proliferation and induce its apoptosis through multiple ways. The team made an in-depth exploration of the radiosensitive effect of quercetin, and proved that quercetin not only kills tumor cells, but also has significant sensitivity effect on radiotherapy. Its sensitivity mechanism may be the mediated and involved in the γ-H2AX (marker of DNA double fracture) gene in capillary dilation disorder mutant protein kinase. Therefore, the team designed a multi-functional and biodegradable nanomaterial, using its porous properties, the Chinese medicine quercetin wrapped in, and then through joint radiotherapy to expand the radiation sensitivity of tumor cells.The results show that in tumor acidic environment, the new material can be degraded to 1-4 benzoic acid and ligation, 1-4 benzoic acid can effectively inhibit the expression of sterilization factor carbonate enzyme 9 on tumor cell membrane, change the obsessive-oxygen state of tumor microenvironment, thereby increasing the radiation sensitivity of tumor. This material reduces the release of quercetin can effectively enter the cell, increase the permeability of tumor cells to rays, further enhance the radiation sensitivity of tumor cells, to achieve the goal of double sensitivity.
(Health Journal)