Study On A Near-infrared Response Nano-drug Syst-targeted Anti-HCC Activity

The lack of cancer cell specificity and the occurrence of multidrug resistance(MDR)are two major obstacles in the treatment of hepatocellular carcinoma(HCC).To tackle these challenges,a novel nanoparticle(NP)-based drug delivery system(DDS)with a core/shell structure consisted of D-α-tocopheryl polyethylene glycol 1000 succinate(TPGS)-galactose(Gal)/polydopamine(PDA)is fabricated.The NP is loaded with doxorubicin(DOX)and a heat-sensitive nitric oxide(NO)donor BNN to afford NO-DOX@PDA-TPGS-Gal.The specific recognition of Gal by asialoglycoprotein receptor(ASGPR)and the p H-sensitive degradation of NP ensure the targeted delivery of NP into liver cells and the release of DOX in HCC cells.Near-infrared(NIR)light further facilitates DOX release and initiates NO generation from BNN due to the photothermal property of PDA.In addition to the cytotoxicity contributed by DOX,NO,and heat,TPGS and NO function as MDR reversal agents to inhibit P-glycoprotein(P-gp)mediated efflux of DOX by Hep G2/ADR cells.The main research contents are as follows:First,we prepared PDA-TPGS-Gal nanoparticles by chemical synthesis,and loaded the chemotherapeutic drugs DOX and BNN through hydrophobic-hydrophobic interaction to obtain NO-DOX@PDA-TPGS-Gal.Detected the particle size and electronegativity of nanomaterials,which were(189.9 ± 0.4)and(-18.5 ± 0.6),respectively.The drug loading rate and loading rate were determined.The drug loading rate of DOX was 14.2% and the loading rate was 68.0%;the drug loading rate of BNN was 6.4% and the loading rate was 36.0%.The seven-day stability test proved that NO-DOX@PDA-TPGS-Gal can stably exist in the normal physiological environment of drug-loaded nanoparticles.The powdered solid was observed under an electron microscope to show uniform spherical particles with a diameter of about120 nm.Because the nanomaterial has the characteristics of photothermal conversion performance and weak acid sensitivity,we conducted photothermal conversion experiments and drug release experiments,and obtained the conclusion that it has good photothermal conversion performance and accelerated drug release under weak acid conditions.Secondly,we measured the toxicity of the material to cells through the MTT test.The free drug-loaded material PDA-TPGS-Gal has no obvious toxicity to various cells,and the drug-loaded material has no obvious toxicity to non-liver cancer cells,but to HCC cells and drug-resistant HCC cells with a higher inhibitory effect,and with the aid of NIR irradiation,it has a higher inhibitory rate of HCC cells.The results of cellular uptake imaging of NO-DOX@PDA-TPGS-Gal observed by confocal laser scanning microscopy(CLSM)showed that NO-DOX@PDA-TPGS-Gal is endocytosis mediated by the binding of Gal and ASGPR receptor over-expressed on the membrane of HCC cells into the cell,and in non-HCC cells this phenomenon was not observed in the department.After assisted by NIR irradiation,drug uptake can be observed more clearly in HCC cell lines and drug-resistant HCC cell lines.Because TPGS and NO have the function of reversing drug resistance,we studied the drug resistance mechanism of NO-DOX@PDA-TPGS-Gal.Through the accumulation test of Rh123,cell ATP level change test,mitochondrial membrane potential test,and Western Blot test,it has been verified that TPGS and NO can reduce the P-gp activity,reduce the production of ATP,and increase the accumulation of Rh123 in drug-resistant cells.Change the mitochondrial membrane potential.In addition,NO can down-regulate the activities of MRP3,HIF-1α and p-NF-κB,and exert anti-drug resistance.Finally,we separately explored the distribution of NO-DOX@PDA-TPGS-Gal in mice and rats,and got the conclusion that it is targeted and prolongs the metabolic time.The tumor inhibition test showed that the tumor inhibition rates of Huh7 and Hep G2/ADR tumor-bearing mice reached 97.8% and 70.0%,respectively,which were significantly different from the other groups(p < 0.01).The survival time of tumor-bearing mice after a 21-d of treatment was significantly longer than that of untreated mice,and the difference was statistically significant(p < 0.01).The combined chemo-photothermal therapy(CT-PTT)by NO-DOX@PDA-TPGS-Gal thus shows potent anticancer activity against drug-resistant HCC cells in vitro and in vivo,and significantly prolongs the life span of tumor-bearing mice.The present work provides a useful strategy for highly targeted and MDR reversal treatment of HCC.