Fluorescence specific nanometer iron oxide hybrid dispersion liquid for cancer metastatic lymph node tracing as well as preparation method and purpose of fluorescence specific nanometer iron oxide hybrid dispersion liquid

Abstract

The invention relates to the field of medical preparations, in particular to fluorescence specific nanometer iron oxide hybrid dispersion liquid for cancer metastatic lymph node tracing as well as a preparation method and a purpose of the fluorescence specific nanometer iron oxide hybrid dispersion liquid. The fluorescence specific nanometer iron oxide hybrid dispersion liquid for cancer metastatic lymph node tracing comprises a dextran derivative, iron oxide particles and water; the dextran derivative is combined with the iron oxide particles to form a nanometer iron oxide hybrid which is uniformly dispersed in the water and is prepared from the dextran derivative and ferric salt through a coprecipitation method; and the dextran derivative is prepared from 5-aminolevulinic acid and oxidized dextran through Schiff base reaction. The prepared fluorescence specific nanometer iron oxide hybrid dispersion liquid is hopeful to be applied to evaluation of gastrointestinal cancer metastatic lymph nodes and can be coupled to an anti-tumor drug through function derivatization of dextran so as to realize the purpose of diagnosis and treatment integration.

Description

technical field [0001] The invention relates to the field of medical tracer diagnostic reagents, in particular to a fluorescence-specific nano-iron oxide hybrid dispersion liquid for cancer metastasis lymph node tracer and its preparation method and application. Background technique [0002] Gastrointestinal cancer is one of the most lethal tumors worldwide. my country is a high-incidence area of ​​gastrointestinal cancer. Gastric cancer and colorectal cancer are the third and fourth leading causes of cancer death, with mortality rates of 17.96 / 100,000 and 12.59 / 100,000, respectively. Lymph node metastasis is the main way of metastasis of gastrointestinal cancer, and the evaluation of its metastasis is the most important basis for deciding the operation method, accurate pathological staging, and formulating adjuvant treatment plan. Doctors often use imaging methods to evaluate the metastatic lymph nodes before surgery. Such as B-ultrasound, CT and magnetic resonance method...

AI Technical Summary

Problems solved by technology

However, clinical experiments have shown that oral or intravenous ALA-induced porphyrin fluorescence is still limited to isolated specimens for the diagnosis of human gastrointestinal cancer metastatic lymph nodes. Although the specificity is high, the sensitivity is not satisfactory, and false positives and false positives are prone to occur. negative result

The inventors analyzed the reasons as follows: (1) Since ALA-induced autofluorescence does not have the effect of visual tracer under white light, the use of fluorescence detectors in intra-abdominal living tissues cannot be targeted. In order to avoid missing lymph nodes, we can only choose Fluorescent detection of isolated specimens

(2) Although oral or intravenous administration of exogenous ALA can cause the accumulation of protoporphyrin in the lymph nodes and produce autofluorescence with an intensity 10 times higher than that of normal cells, but at the same time, the fat or connective tissue around the lymph nodes will also be exposed to protoporphyrin due to the increased concentration of ALA. The relative lack of free iron ions necessary for the continued metabolism of phyllophyrin to form heme leads to the accumulation of protoporphyrin and autofluorescence, which affects the observation of porphyrin fluorescence in tumor metastatic lymph nodes, resulting in false positive or false negative results

(3) Due to the limitation of ALA concentration in the lymph nodes through the systemic blood circulation after oral and intravenous administration of exogenous ALA, it is almost impossible for metastatic lesions smaller than 200 μm in tiny lymph nodes to produce sufficient autologous porphyrin fluorescence to detect, resulting in false negative results

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