Preparation,Characterization And Anticancer Effect Of Reduction-Responsive Small Molecule Prodrug/Albumin Nanoparticle Drug Delivery System

In recent years,human serum albumin has attracted much attention because of its outstanding advantages such as good biocompatibility,high stability,strong drug delivery ability,outstanding targeting ability,long half-life and availability.Docetaxel（DTX）is a semisynthetic analogue of paclitaxel,which is often used to treat a variety of cancers.Because of its poor water solubility,DTX is commonly used in clinical applications with high concentrations of surfactants and ethanol solubilization,which is easy to cause hypersensitivity.Adriamycin is the most important chemotherapeutic drug in the treatment of breast cancer,but its clinical use is often affected by congestive heart failure,and its cardiotoxicity has cumulative effects.In order to overcome these problems,we developed two kind of DTX prodrug/HSA nanoparticles（DTX-SS-COOH/HSA NPs）and a kind of DOX prodrug/HSA nanoparticles（DOX-SS-COOH/HSA NPs）with the characteristics of redox reaction release.In partⅠ:A disulfide-bridged mercaptoundecanoic acid-modified DTX prodrug（DTX-SS-COOH）was synthesized in four steps.Then,the DTX-SS-COOH/HSA nanoparticles were prepared by desolvation method.Dynamic light scattering（DLS）,scanning electron microscopy（SEM）and transmission electron microscopy（TEM）observations show that the complex is spherical with a narrow distribution and a diameter of 180-200 nm.The drug-loading rate was 12.84%and the entrapment efficiency was 93.11%.The preparation had good long-term stability.Fluorescence quenching analysis confirmed the formation of the DTX-SS-COOH/HSA complex,attributing to electrostatic interactions and hydrophobic forces.In addition,the redox sensitivity test showed that DTX had reduction-triggered release behavior in the presence of glutathione（GSH）.The in vitro cytotoxicity test of breast cancer cell lines showed that DTX-SS-COOH/HSA NPs had obvious anti-tumor cell proliferation ability.Confocal laser scanning microscopy（CLSM）was used to observe the enhanced cellular uptake of DTX-SS-COOH/HSA NPs.The apoptosis of cancer cells induced by DTX-SS-COOH/HSA NPs at different incubation time was analyzed by flow cytometry.Throught in vivo pharmacokinetic study,NPs showed significantly longer circulation time(t_1/2,2.64-fold)and higher bioavailability(AUC_0-t,1.88-fold)compared with free DTX.Finally,the in vivo antitumor test in MDA-MB-231 tumor-bearing mice showed that the tumor volume,tumor inhibition rate and tumor weight of mice in the DTX-SS-COOH/HSA NPs group were superior to those in the free DTX group,respectively.In summary,DTX-SS-COOH/HSA nanoparticles with high drug loading,redox-responsive release and higher anticancer activity are promising DTX nanoformulations.In partⅡ:A disulfide-bridged thioundecanoic acid modified DOX prodrug（DOX-SS-COOH）was synthesized by the same reaction.Then,DOX-SS-COOH/HSA nanoparticles were prepared by desolvation method.Fluorescence quenching analysis confirmed the formation of the DOX-SS-COOH/HSA complex,attributing to electrostatic and hydrophobic forces.Dynamic light scattering（DLS）,scanning electron microscopy（SEM）and transmission electron microscopy（TEM）observations show that the complex has a spherical structure with a narrow size distribution of 200-250 nm.The drug loading and encapsulation efficiency of the composite nanoparticles were 9.19%and 69.58%,respectively.In addition,redox sensitivity test showed that DOX-SS-COOH/HAS NPs had reduction-triggered release behavior in the presence of glutathione（GSH）.The in vitro cytotoxicity test showed that DTX-SS-COoh/HSA NPs had obvious anti-tumor cell proliferation ability.Confocal laser scanning microscopy（CLSM）was used to observe the enhanced cellular uptake of DOX-SS-COOH/HSA NPs.Flow cytometry was used to analyze the apoptosis induced by DOX-SS-COoh/HSA NPs at different incubation time.Finally,throught in vivo antitumor test in MDA-MB-231 tumor-bearing mice,the tumor volume,tumor inhibition rate and tumor weight of mice in the DOX-SS-COOH/HSA NPs group were superior to those in the free DOX group,respectively.In summary,DOX-SS-COOH/HSA nanoparticles with high drug loading,redox-responsive release and higher anticancer activity are promising for DOX nanoformulation.