Recently, Cheng Yu, Tongji University School of Medicine Task Force in biologically responsive self-assembled nano-gold targeting brain tumors made new progress, Related Research Posted in "Self-Assembly of Gold Nanoparticles Shows Microenvironment-Mediated Dynamic Switching and Enhanced Brain Tumor Targeting" in Internationally Prestigious Journals 《Theranostics》. Task Force research assistant Feng Qiahuai is the first author of this paper, Corresponding author Dongcheng Hospital Affiliated to Tongji University School of Medicine Chengyu, Eastern Hospital, director of neurology Li Gang and Northwestern University School of Medicine brain tumor director Maciej S.Lesnia.

Malignant tumors of brain tumors are more common, with rapid development, treatment difficulties, high mortality, the main reason is that the blood-brain barrier limits the drug into the brain tumor tissue, it is difficult to achieve good effect of chemotherapy. At present, researchers at home and abroad use nanometer drug delivery system to improve the intra-brain delivery efficiency of drugs. Nano gold clusters with biologically responsive self-assembly can not only effectively penetrate the blood-brain barrier to increase the drug enrichment in the brain tumor tissue area, but also accelerate the biodegradation of the brain tumor in response to changes in the micro-environment of the brain tumor, Reduce their own systemic toxicity.

Task Group used advantage of HS-PEG-SH build Non-assemblies，＜10 nm up Assemblies，~80 nm. The chemotherapeutic drug Doxorubicin, which has a pH-sensitive modification, is loaded therein. The results show that in the nude mouse brain tumor model, gold nanoclusters can penetrate the blood-brain barrier and then enrich in the brain tumor tissue, and its distribution in the normal brain tissue less. Among them, gold nanoclusters in the brain is about 3 times the size of the smaller gold nanoparticles, indicating that larger gold nanoclusters have better brain tumor targeting ability. Animal blood half-life data show that gold nanoclusters circulate longer in the blood than gold nanoparticles. After 24 hours of intravenous injection, the blood concentration of gold nanoclusters returned to the same level as that of gold nanoparticles, indicating that the gold nanoclusters can be rapidly cleared by the body after being kept at a high concentration for a period of time to avoid causing biological toxicity. In addition, in vitro data revealed that gold nanoclusters have good glutathione (GSH) response to high levels of tumor microenvironment and thus are more conducive to the release of loaded drugs and their own degradation and metabolism.

In summary, the biologically responsive self-assembled nanostructured gold nanoparticles have the advantages of simple preparation, high efficiency of targeting, good safety and the like, which can be used as a carrier platform for chemotherapeutic drugs to promote the enrichment of chemotherapeutic drugs in brain tumor tissues, Improve the low bioavailability of chemotherapy drugs defects, the future will help to improve the efficacy of targeted therapies for brain tumors.

The work won the support of the Ministry of Science and Technology,  the National Natural Science Foundation of China, the Shanghai Pujiang Talents Project, the Shanghai Cooperation Council International Cooperation Project and the National Institutes of Health.