| Purpose:Natural product Ursolic acid(UA)and clinical drug sorafenib(SO)both show strong activity against liver cancer,but low water solubility,low bioavailability and low selectivity for the tumor tissues limite their clinical application.Thus,we used mesoporous silica to load these two drugs separately and conjugated the chitosan linking with lactobionic acid to establish one nanoparticle drug delivery system with the characteristics of targeting liver cancer and pH response.Method:Firstly,we synthesized mesoporous silica nanoparticles(MSN)using stober method with suitable particle diameters.Then UA and SO were loaded into the MSN nanoparticles with a physical method and the CS-LA was conjugated with the drug-loaded nanoparticles to form the(SO+UA)@MSN-CS-LA drug delivery system.The particle size,morphology,zeta potential and infrared spectra of nanoparticles were characterized by TEM,AFM,DLS and Infrared Spectroscopy(IR).The drug release properties under different pH were detected by UV.The selective effect on liver cancer cells of MSN-CS-LA was investigated by confocal microscopy and flow cytometry The cytotoxicity of free single drugs,combination of drugs and nano-drugs with different concentrations were detected by MTT assay.Furthermore,the tumor growth and metastasis inhibitory effects of(SO+UA)@MSN-CS-LA on Kunming mice were also investigated.Finally,we investigated the anti-tumor/anti-metastasis mechanism of(SO+UA)@MSN-CS-LA by Western Blotting and immunohistochemistry.Results:The particle sizes of nanomaterials and nanodrugs were all below 200 nm(which could be defined as uniform size)and those particles possessed good dispersity and redispersibility.The drug release rate of SO/UA@MSN-CS-LA under acidic condition(about 50%)in vitro was significantly higher than that under neutrality condition(about 20%).The results of confocal microscopy and flow cytometry showed that MSN-CS-LA could recognize Huh-7,SMMC-7721 and HepG2(asialoglycoprotein receptor over-expressing)cells more strongly than HeLa(asialoglycoprotein receptor negative expressing)cells;MTT assay determined that(SO+UA)@MSN-CS-LA could increase the cytotoxicity of each single drug(UA or SO)against liver cancer cell lines;The apoptosis rates of(SO+UA)@MSN-CS-LA(9.19,61.3%)are significantly higher than SO+UA group(7.65%,46.8%);Western Blotting showed that(SO+UA)@MSN-CS-LA could down-regulate the expression of EGFR and VEGFR2.The in vivo study on rat model showed that(SO+UA)@MSN-CS-LA could inhibit the growth of H22 tumor and metastasis of cancer cells to lung.Western Blotting and immunohistochemistry results demonstrated that(SO+UA)@MSN-CS-LA could result in down-regulation of EGFR and VEGFR2 in vitro and in vivo.Conclusion:In this study,we have successfully developed a dual-drug-loaded delivery system of(SO+UA)@MSN-CS-LA.This drug delivery system ensures both UA and SO to reach the tumor issue by improving the water solubility and tumor-targeting property of UA and SO.Therefore the drug delivery system reached a result of combined anti-tumor growth and metastasis effects.Our study provided a novel method to enhance the curative effect of anticancer drugs.This drug delivery system may provide a novel alternative for enhancing anti-cancer efficacy and reducing side effects of drugs. |
PDF Full Text Request