Folate-phytosterol-carboxymethyl Cellulose Self Assembled Nanoparticles Derived From Plant Material And Combined Inhibition Of Cancer Cells By Drug-loaded Nanoparticles And Hydroxychloroquine

Cancer is still one of the most difficult global medical problems.Although there are a lot of drugs that can be used to treat cancer,the problem of selectively kill all cancer cells while reducing the side effects on healthy cells remains unresolved.There are several biological barriers against effective drug delivery in cancer;such as,nonspecifically drug distribution,clearance of anticancer drug by renal,hepatic,or immune system.Drug loaded nanoparticles can be designed to overcome these biological barriers,improve treatment efficacy and reduce side effects.Nanomedicine ushers in a new era of cancer treatment by targeting drug delivery for improving the therapeutic index of nano-carrier-loaded drugs.The multidrug resistance(MDR)has also become a major obstacle to cancer chemotherapy,resulting treatment failure among 90% of patients with metastatic cancer.Recently,some studies have proved that drug combinations can selectively kill drug-resistant tumor cells while protecting normal cells.Antimalarial drugs chloroquine(CQ)and its derivative hydroxychloroquine(HCQ)as autophagy inhibitor are promising for cancer therapy.The combination formulation of CQ(or HCQ)with doxorubicin(DOX)shows distinct anticancer effects to human lung cancer cells and human breast cancer cells.In this paper,self-assembled folate-phytosterol-carboxymethyl cellulose nanoparticles(FPCMCNPs)derived from plant material were fabricated.Firstly,hydrophobic phytosterol was grafted onto the framework of water-soluble carboxymethyl cellulose.Then folate,as tumor-targeting ligand,was coupled to the phytosterol-carboxymethyl cellulose.The self-assembled FPCMC NPs were obtained by ultrasonic treatment.The structure of grafted FPCMC polymer was identified by nuclear magnetic resonance(NMR)and Fourier infrared spectroscopy(FT-IR).The average diameter of FPCMC NPs was about 107 nm with polydispersity index of 0.214 and zeta potential of –40.2 m V.The critical assembly concentration(CAC)value of FPCMC polymer was found to be 31μg/ml.DOX was selected as model anticancer drug that was entrapped in prepared FPCMC NPs with satisfactory loading content(7%)and loading efficiency(71.2%).The drug release test in vitro showed that the release amount of DOX from drug-loaded FPCMC NPs at p H 5.5was much higher than that at p H 6.5 or p H 7.5.The blank FPCMC NPs exhibit no cytotoxicity on A549 human lung cancer cells by MTT method.The alone HCQ,free DOX or DOX/FPCMC NPs,DOX+HCQ and DOX/FPCMCNPs+HCQ all showed obvious dose-dependent cytotoxicity against A549 cells.Their IC50 value(inhibitory concentration of half cells)to A549 cells was about 78.5 μmol/L,7.32 mg/L,5.57mg/L,3.73mg/L and 1.92mg/L respectively.In all formulations,the DOX/FPCMC NPs+HCQ showed the highest cytotoxicity to A549 cells because of the folate-receptor-mediated endocytosis and autophagy inhibition brought by HCQ.The free folate in culture medium competitively inhibited cytotoxicity of DOX/FPCMC NP on A549 cells.The wound healing assay verified that the A549 cells treated with DOX/FPCMC NPs+HCQ exhibited the lowest cell proliferation and migration capacity.The cellular uptake and internalization of free DOX and DOX/ FPCMC NP was studied by confocal laser scanning microscopy(CLSM)image.It was revealed that pattern of DOX enter into cells is passive diffusion,but DOX/ FPCMC NP entered into cells through folate receptor mediated endocytosis.The DOX/FPCMC NPs could elevate the drug concentration in target cells,enhance the anticancer effect of DOX,and reduce the toxic and side effect of drug.Once combined with HCQ,the DOX/FPCMC NPs might even reverse the MDR of tumor cells.