| Background:Oral squamous cell carcinoma,especially tongue squamous cell carcinoma,is usually diagnosed at late stage with strong invasiveness,and chemotherapy has been considered as an important adjuvant treatment.Paclitaxel（PTX）,as a kind of natural anticancer drug,is widely used in clinical chemotherapy,but it may lead to side effects with poor solubility.In recent years,nanomaterials have developed rapidly in the field of medicine.Due to the convenient synthesis process,adjustable pore size and structure,high drug loading and low cytotoxicity,mesoporous silica nanoparticles（MSN）as drug delivery carriers have promising application prospects in cancer treatment.However,problems such as slow biodegradability in organisms,premature and incomplete release of drugs,and complex steps of bottom-up targeted modification still need to be solved.Objective:Synthesize calcium carbonate-coated degradable disulfide-doped mesoporous silica nanoparticle（ssMSN）loaded with PTX（PTX/ssMSN@CaCO3）to construct a p H/redox dual-responsive controlled-release nanomaterial,which can avoid premature leakage and incomplete release of PTX.Coat Tca8113 cell membrane（TC）onto the surface of PTX/ssMSN@CaCO3 through the top-down approach in order to realize homologous targeted killing of tongue squamous cell carcinoma.Method:ssMSN was synthesized by a sol-gel method and characterized by transmission electron microscopy and nitrogen adsorption/desorption measurements.Then,the degradability of ssMSN in phosphate buffered saline solution containing glutathione（GSH）was tested.Synthesize carboxylated ssMSN（ssMSN-COOH）to load PTX by a vacuum-rotary evaporation method,and the drug loading rate was verified by ultra-high performance liquid chromatography.Then,PTX/ssMSN@CaCO3 was obtained by coating calcium carbonate on the surface of PTX/ssMSN-COOH,which was characterized by Fourier transform infrared spectrometer and zeta potential and particle size analysis.Besides,the effect of high reducing（10m M GSH）and acidic（p H 5）environment on the release of PTX was studied.In order to evaluate the biocompatibility of the materials,different concentrations of materials without drug loaded were co-cultured with L929 cells for 1or 3 days.The cell viability was measured quantitatively with CCK8 reagent to determine the concentration range of the materials.Combined with the killing effect of different concentrations of PTX on cells,the most appropriate concentration of PTX/ssMSN@CaCO3 was determined,followed by verifying the killing effect on Tca8113 tongue squamous cell carcinoma cells.After coated by Tca8113 cell membrane（TC）,PTX/ssMSN@CaCO3@TC was characterized by TEM,zeta potential and gel electrophoresis.The colloidal stability was measured by dynamic light scattering.After synthesizing ssMSN-FITC@TC,the uptake of cell and tumor was explored by confocal laser scanning microscope,flow cytometry and fluorescence imaging in vivo.According to the difference of fluorescence intensity among different groups,the homologous targeting performance was verified.Finally,the homologous targeted killing effect of PTX/ssMSN@CaCO3@TC was confirmed in vitro and in vivo.Besides,the biosafety in vivo was evaluated by the body weight change of mice and the H＆E stained slices of major organs.Results:The transmission electron microscope images showed the characteristic morphology of ssMSN,ssMSN@CaCO3 and PTX/ssMSN@CaCO3@TC,and confirmed that ssMSN could be degraded gradually.The nitrogen adsorption/desorption isotherms demonstrated IV-type curves,which was in accord with the characteristics of mesoporous structure.According to the ultra-high performance liquid chromatography,the drug loading rate of PTX/ssMSN-COOH was 9.68±0.21%.The results of Fourier transform infrared spectrometer and zeta potential and particle size analysis confirmed the successful synthesis of PTX/ssMSN@CaCO3.The zeta potential decreased after further coated with the cell membrane.Release curves of PTX from PTX/ssMSN@CaCO3 demonstrated p H/redox dual-responsive release performance.Ensuring the biosafety of materials without drug loaded as well as the killing effect of PTX,the optimal concentration of PTX/ssMSN@CaCO3 was finally determined to be7.8125μg·m L-1,which was confirmed to kill Tca8113 cells effectively.Results of dynamic light scattering showed the excellent colloidal stability of PTX/ssMSN@CaCO3@TC under mimic physiological condition.Gel electrophoresis showed that the protein compositions of PTX/ssMSN@CaCO3@TC were consistent with Tca8113 cell lysates and cell membrane vesicles.Confocal laser scanning microscope images,flow cytometry and fluorescence imaging in vivo demonstrated that the groups of ssMSN-FITC@TC uptaked by Tca8113 cell and tumor exhibited the strongest FITC fluorescence,which proved the homologous targeting ability of ssMSN-FITC@TC.The experiments in vitro and in vivo confirmed that PTX/ssMSN@CaCO3@TC can promote the killing of Tca8113 cell and tumor by homologous targeting.Besides,the normal performance of body weight change and H＆E stained slices preliminarily confirmed the biosafety in vivo.Conclusion:The Tca8113 cell membrane-coated and PTX-loaded degradable controlled-release nanomaterial（PTX/ssMSN@CaCO3@TC）was successfully synthesized in this study.This nanosystem can realize p H/redox dual-responsive release of PTX under the condition of acidity and high reducibility with the ability of homologous targeting.It can not only avoid the premature leakage of PTX in the process of blood circulation,but also target to the homologous tumor.Thus,the tumor can be killed efficiently and accurately with reduced side effects caused by PTX leakage or inaccurate targeting.This study provides a new idea to improve the therapeutic effect of PTX on tongue squamous cell carcinoma.In addition,other therapeutic agents can be co-loaded on the basis of PTX/ssMSN@CaCO3@TC,which has promise to further promote the killing of tongue squamous cell carcinoma in the way of synergistic treatment. |
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