ACS appl. Mater. Interfaces.: a new multifunctional nano drug delivery system developed by Suzhou Institute of medicine, Chinese Academy of Sciences

Photothermal therapy is a kind of physical therapy mode that uses photosensitizers to absorb near-infrared light, and converts light energy into heat energy, and then kills tumor cells It has a simple and controllable treatment mode and high biological safety, which is a hot issue in related research fields at present The photosensitizers include gold nanomaterials, copper sulfide, carbon point and some organic near-infrared light dyes Among them, indocyanine green (ICG) has great potential for clinical transformation because of its high efficiency of photothermal transformation, low cytotoxicity and excellent near-infrared imaging effect However, ICG is easy to be degraded in vivo, and lack of specificity for tumor tissue in the process of cancer treatment Therefore, its clinical application is limited In addition, although photothermal therapy is a safe and effective tumor treatment mode, a single photothermal therapy is not enough to completely eliminate tumor tissue Photothermal therapy should be combined with other treatment modes, through the synergistic effect of multiple treatment modes, to improve the killing of tumor tissue In recent years, scientists have found that the thermal effect of photothermal treatment can promote the release of silver ions from silver nanomaterials Silver ions can produce living oxygen free radicals in cells and induce apoptosis through mitochondrial apoptosis Therefore, silver nanomaterials combined with photothermal therapy will be an effective and safe tumor treatment strategy However, the related research is faced with difficulties and challenges First, how to transport photosensitizer ICG and silver nanomaterials to tumor tissue at the same time to increase the therapeutic effect of cancer; second, how to develop a switch to regulate the release of silver ions and the dose of ICG to increase the safety of treatment; third, how to improve the targeting of tumor tissue and enhance the stability of its environment in vivo Recently, Wang Zheng and other researchers of Dong Wenfei research group, researcher of Suzhou Institute of biomedical engineering technology, Chinese Academy of Sciences, developed a Janus type silver mesoporous silica nano platform modified by folate polymer And it is used in the cooperative treatment of liver cancer, which effectively solves the above three problems The nano platform is composed of two parts: silver nanospheres and mesoporous silica rods, and the two parts do not interfere with each other in function, which can greatly play the role of ion release of silver nanospheres and drug delivery of mesoporous silica In addition, Janus type silver mesoporous silica nano carriers show excellent ICG delivery capacity, which can continuously release ICG and generate excellent thermal effect under near-infrared stimulation Thermal effect can not only inhibit the growth of tumor tissue, but also further promote the release of silver ions from silver spheres, so as to improve the killing effect of the drug loading system on tumor cells In the nano platform, folate polymer is modified on the surface of nano carrier to improve its biological stability and targeting to tumor tissue In vivo evaluation of the antitumor effect of the drug loading system (source: ACS appl Mater Interfaces.) the researchers studied the therapeutic effect of the nano platform on liver cancer at the cellular and animal levels and evaluated its biological safety The results show that Janus type silver mesoporous silica nano carriers have uniform morphology and excellent stability The drug loaded nanoparticles not only show high drug loading capacity, but also show the characteristics of near-infrared light responsive ICG release In the cell experiment, the inhibition rate of Janus type silver mesoporous silica nano drug delivery system on human hepatocarcinoma cells is significantly higher than that of the same specification of mesoporous silica nano drug delivery system, which proves that silver ion plays a role in supplementing the photothermal treatment killing effect in the system At the animal level, the nano drug delivery system showed excellent antitumor effect Through HE staining and detection of serum biochemical indicators, researchers found that the nano drug delivery system has a high biological safety Therefore, the researchers believe that Janus silver mesoporous silica nano drug delivery system is an efficient and safe anti-tumor nano platform Paper link: http://pubs.acs.org/doi/abs/10.1021/acsami.7b06446 corresponding author: Dong Wenfei http://sourcedb.sibe.cas.cn/zw/yjdw/yjy/201306/t20130621_.html