| Lung cancer is one of most common malignant tumors in clinic,mainly including non-small cell lung cancer(NSCLC)and small cell lung cancer(SCLC).NSCLC accounts for about 80~85% of lung cancer with the about 15% 5-year survival rate.Currently,the clinical treatments of lung cancer mainly include surgery,radiotherapy,and chemotherapy.Chemotherapeutic agents are basically administered via oral or intravenous route,leading to whole body distribution of drugs and limited distribution in the lung cancer tissues.Photodynamic therapy(PDT)is an arising treatment characterized by the production of singlet oxygen after photosensitizers are excited by a certain wavelength of light,and the surrounding tumor cells are killed.The photosensitizer must maintain a certain amount in the tumor tissue and the light has to reach the site for effective PDT.Gefitinib is the first marketed epidermal growth factor tyrosine kinase inhibitor(EGFR-TKI),which is a molecular-targeting drug.Gefitinib tablet is currently the unique clinically applied dosage form.However,the drug distribution in the lung is limited after oral administration of gefinitib.Moreover,the wide distribution of gefinitib leads to side effects such as diarrhea,rash,dry skin and acne.In fact,the limited distribution of gefitinib in the lung cancer tissue further takes large costs of treatment due to itself high price.In this study,gefitinib liposomes and nanoparticles were prepared,which were further transformed to pulmonary drug delivery systems(PDDSs),i.e.,gefitinib nanoinhalers.The gefitinib nanoinhalers can directly transport gefitinib to the lungs.Compared with gefitinib tablets,gefitinib nanoinhalers show the advantagtes of high distribution in the lung,retention for a long time,and more importantly,high therapeutic efficacy.Furthermore,the combination of gefinitib nanoinhalers and PDT was explored for treatment of lung cancer.Curcumin is reported to have anti-tumor effect,although it is ready to oxidation,poor water solubility,and rapid in vivo metabolism.Therefore,its clinical application is always limited.In this study,a liposomal curcumin dry powder inhaler(LCD)was prepared,which was compared with the inhaled curcumin powders(CPs)and gemcitabine solution.LCDs showed stronger therapeutic efficacy than the others.The anticancer mechanisms were explored.1.Preparation and properties of gefitinib nano formulationsThe gefitinib liposomes were prepared by ethanol injection,freeze-dried and sieved to obtain liposomal gefitinib dry powder inhalers(LGDs).The optimal formulation was selected by orthogonal test.Soybean phospholipids: cholesterol: gefitinib = 15:3:5(mol/mol),accounting for 25%,and mannitol accounted for 75%;the resuspented liposomes had a particle size of 79.22 nm.The drug loading of gefitinib liposome was5.91% and the entrapment efficiency was 98.09% by UV spectrophotometry and gel column chromatography.The aerodynamic particle size of powder aerosol was 5.32 ?m,and the lung deposition rate was 35.23%.It was suitable for pulmonary inhalation.Gefitinib poly(lactide-co-glycolic acid)(PLGA)nanoparticles were prepared by emulsification method and the particle size was 222.53 nm.The drug content of gefitinib nanoparticles was determined by high performance liquid chromatography with centrifugation at 5 mg/m L,and the entrapment efficiency was 100%.2.Pharmacokinetics of gefitinibEstablishment of primary rat lung cancer model,gefitinib powders(GPs)and LGDs were administrated by pulmonary delivery drug system.Gefitinib tablets were administrated by oral.The plasma concentrations and tissue distribution were detected by high performance liquid chromatography(HPLC).At the same dose,the drug concentration of the three groups about plasma concentrations were comparable,but the gefitinib and liposomes in the lung tissue is 5 times more than oral group,oral group of liver drug concentration significantly higher than the lung administration group,the CPs group had a longer lung retention time.3.Gefitinib PharmacodynamicsPrimary lung cancer rats were treated with oral gefitinib,pulmonary GPs or LGPs.Compared with the oral group,the injury of the lung tissue of the GPs and LGPs group was alleviated,the inflammatory factor(TNF-?,total protein)in the bronchoalveolar lavage fluids was significantly reduced,and the lung tissue EGFR and Akt were significantly inhibited.In the LGPs group,the mitochondrial membrane potential of the lung cancer cells was decreased,the level of Caspase-3 was increased,and the apoptosis was enhanced.There was a significant difference compared with the oral and GPs groups.Pulmonary gefitinib nanoparticles(GNPs)were administered to primary lung cancer rats,alone or in combination with 5-aminolevulinic acid(5-ALA)PDT(660 nm,30 s).After 1 week of treatment,Gefitinib and PDT were administered.The efficacy is better than gefitinib alone or PDT alone.4.Preparation and properties of liposomal curcumin dry powder inhalersThe curcumin liposome was prepared by film dispersion method,and then liposomal curcumin dry powder inhalers(LCPs)were prepared by spray drying method.The optimal formulation was selected by orthogonal test,soybean phospholipid: curcumin =2:1(mol/mol),accounting for 17%,lactose accounted for 83%;resuspented liposome particle size is 20 ~ 30 nm.After centrifugation,the drug loading of curcumin liposomes was determined to be 3.5% by HPLC and the encapsulation efficiency was89.1%.The LCDs size was 5.81±0.06 ?m,and the lung deposition rate was 46.71%.It was suitable for pulmonary inhalation.5.Cytotoxicity of curcuminThe toxicity of curcumin powders and liposomes on human lung cancer A549 cells and human bronchial epithelial BEAS-2B cells was investigated.Curcumin liposomes had a higher uptake rate than A549 cells derived from curcumin,induced A549 cell apoptosis,and had strong cytotoxicity.But the selection index of curcumin liposomes on A549 is about 90 times that of curcumin at 100 ?mol/L.6.Pharmacodynamics of LCPsPrimary lung cancer rats were administered with gemcitabine solution,curcumin powders,and LCPs.Compared with the gemcitabine group and the raw material group,the lung tissue damage in the liposome group was reduced,and the inflammatory factors(TNF-?,MDA,Bcl-2)in the alveolar lavage fluid and the lung tissue were significantly reduced.In the liposome group,the mitochondrial membrane potential of lung cancer cells was decreased,the level of Caspase-3 was increased,and the apoptosis was increased.There was a significant difference compared with the gemcitabine group and the raw material group.Curcumin has a small side effect,and pulmonary administration overcomes its shortcomings and may become an effective drug and a new generation of lung inhaler for the treatment of lung cancer. |
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