Structure, preparation and applications of reduction responsive fluorescent probe

Abstract

The invention relates to a structure, a preparation and applications of a reduction responsive fluorescent probe, and belongs to the field of organic fluorescent probes. Based on the problem of generally not high signal-to-noise ratio of the imaging of the existing fluorescent probe, the invention discloses an efficient fluorescent nano-probe, wherein the outermost layer is albumin, the middle layer is a hydrophilic polymer block, and the inner layer is a hydrophobic polymer block core simultaneously coupled with a reduction-responsive chemical bond and a fluorescent dye. According to the invention, in a non-reducing environment, the fluorescent molecules in the nanometer core are subjected to fluorescence quenching, so that the nano-probe is in an extremely low fluorescence state; in a reducing environment, the fluorescence molecules are subjected to core / shell transition under the combined action of a reducing agent and nano-shell albumin, so that the nano-probe is converted to an extremely high fluorescence state so as to achieve high signal-to-noise ratio; and the nano-probe disclosed by the invention can be used for specific living body imaging of tumors, imaging-guided operations, tumor-related lymph node imaging, tumor pathological section imaging and the like.

Description

technical field [0001] The invention relates to the structure, preparation and application of a reduction-responsive fluorescent probe, belonging to the field of organic fluorescent probes. Background technique: [0002] Tumors seriously threaten human health. According to statistics, 8.8 million people died of tumors in the world in 2017. In addition to radiotherapy, chemotherapy, and immunotherapy, most patients with early-stage tumors currently receive surgical treatment. However, due to the complexity of the growth site of malignant tumors and the characteristics of invasive growth, it is often difficult for surgeons to accurately judge the boundary between tumor tissue and surrounding normal tissue, and it is also difficult to identify scattered tiny tumor lesions in normal tissue only by visual judgment. If the tumor cannot be completely removed, it will easily lead to postoperative tumor recurrence; if the normal tissue around the tumor is excessively removed, it may...

AI Technical Summary

Problems solved by technology

Although bioresponsive nanoprobes have the above advantages, their in vivo imaging signal-to-noise ratio is still not high enough, which limits their application in precise tumor imaging.

There are two main reasons for the low signal-to-noise ratio of this type of probes: First, the response efficiency of biologically responsive nanoprobes is generally low, which affects the imaging signal-to-noise ratio.

There are two main reasons for the low response efficiency: first, because the concentration of stimulating factors in the body is often low, the reaction efficiency of many bio-responsive nanomaterials under the action of low-concentration stimulating factors is not high for chemical bond breaking; second, some stimuli Sensitive chemical bonds take a long time to break, such as polycarbonate or some aliphatic polyesters often take hours or even days to degrade in vivo

The second is the question of whether the fluorescent dye molecules can be released quickly and effectively from the nanoparticle core.

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