Near-Infrared Optical Probe And MMP-Responsive Drug Delivery System For Tumor Therapy

The traditional clinical diagnosis and treatment of cancer have a long interval and easy to miss the best opportunity for treatment.The chemotherapy requires repeated high-dose administration of drug to treat cancer and multi-drug resistance of tumor cells will be triggered in this course.So,integrate optical imaging probe and chemotherapeutics to visualize the pathological changes of malignant tumors during chemotherapy,tracing the release and distribution of drugs in vivo,which is an effective way to improve treatment effect.However,the poor selectivity of chemotherapeutic drug will inevitably damage normal cells while cancer cells apoptosis.Therefore,to establish tumor-responsive drug delivery system and achieve specific diagnosis and treatment of tumor have caused widespread concern.For this research trend,we established a near-infrared optical probe CyINC-GEM by coupling chemotherapy drug GEM with water-soluble near-infrared dye CyINC.We also introduced MMP-2 enzyme-responsive polypeptide to construct tumor-targeted drug delivery system GPLGIAGQ-GEM,further explore their application in tumor therapy:We took advantage of one-step method to synthesizing three single-carboxyl functionalized near-infrared cyanine dyes CyINC,CyBIC,and CyQUC.The structures of the dyes were identified using ¹H NMR,¹³C NMR and HRMS and the spectral characteristics were measured.The results showed that the maximum absorption peaks and fluorescence emission peaks of the three dyes were all located in the near-infrared region.Among them,CyBIC and CyQUC had higher fluorescence quantum yields in the culture medium.Subsequently,we performed fluorescence confocal and flow experiments,showing that the three dyes have small fluorescence background interference.Among them,CyBIC and CyQUC have good membrane permeability and can strongly label cells,while CyINC has poor membrane permeability and it is suitable for monitoring cell apoptosis.We utilized one-step method to designing and synthesizing a near-infrared optical probe CyINC-GEM,the structure of the probe was identified using HRMS and the spectral characteristics were also measured.The tumor treatment ability of CyINC-GEM was explored by fluorescence confocal imaging,cell flow assay,high-content toxicity analysis and in vivo experiment.The results showed that CyINC-GEM can induce and monitor cell apoptosis,diagnose and treat the disease,trace drug releases and distribution,regulate drug doses.We constructed the MMP-2 responsive peptide drug delivery system GPLGIAGQ-GEM and identified its structure and productivity using HRMS and HPLC.Western blot analysis showed that MMP-2 expression was relatively high in 4T1 cells and was hardly expressed in MCF7 cells.We performed CCK-8 cytotoxicity test and in vivo experiment proving that GPLGIAGQ-GEM can specifically inhibit 4T1 cell?high expression of MMP-2?proliferation and low tocxity.To trace the therapeutic process of GPLGIAGQ-GEM,the dye CyINC was coupled to the GPLGIAGQ-GEM through the condensation reaction between the aminocarboxyl groups to synthesize the near-infrared probe CyINC-GPLGIAGQ-GEM.The fluorescence confocal imaging of 4T1 and MCF7 breast cancer cells showed that CyINC-GPLGIAGQ-GEM could inhibit the proliferation of 4T1 cells,and bright fluorescence was detected at the same time,demonstrating that GPLGIAGQ-GEM have the capacity of response to MMP-2 by optical imaging.