Inhaled Curcumin Large Porous Microparticles In The Prevention And Treatment Of Pulmonary Fibrosis

The lung is an important organ of the human body,and it is vulnerable.There are many lung diseases such as lung cancer,tuberculosis,pneumonia,asthma,emphysema,pulmonary fibrosis and so on.Pulmonary fibrosis is characterized by the replacement alveolus with fibrous material,hardness and thickness of lung tissue,the loss of capacity for the exchange of oxygen into the blood,patients with hypoxia due to dyspnea.In recent years,with the development of industrialization,environmental pollution has become more and more serious,which has caused a lot of lung diseases,such as the incidence of pulmonary fibrosis is increasing,rapid development,high mortality.The traditional clinical treatment of pulmonary fibrosis is mainly glucocorticoid,but the the side effects are large.In this study,the large porous microparticles(LPMPs)were used to treat pulmonary fibrosis by lung inhaled drug delivery,which can reduce drug dosage and side effects.Curcumin was a model drugs to treat pulmonary fibrosis.However,its application is highly limited due to its poor water solubility,low bioavailability,unstable structure,easy metabolism in the body,the oral absorption was not easy.The curcumin-loaded LPMPs of inhalation was prepared by the emulsion solvent evaporation method,which overcame some disadvantages of curcumin,can avoid being swallowed by alveolar macrophages,and increased the concentration of drug to the lesion.And the properties and cytotoxicity of the LPMPs was investigated in vitro.The model of pulmonary fibrosis was establishedby the bleomycin induction,which was used to the pharmacodynamics evaluation of the prevention and treatment of pulmonary fibrosis.The curcumin LPMPs powder was directly injected into the lung of rats though tracheal cannula,which was to investigated to the prevention and treatment effect of pulmonary fibrosis in vivo and explored the preliminary mechanism.1.Preparation of curcumin LPMPs The main factors affecting the preparation process were determined by single factor investigation.The encapsulation efficiency and drug loading were as evaluation index,and the optimal preparation of the curcumin LPMP prescription was sieved by orthogonal design experiment.The optimal preparation was 15%PLGA,1% hole porogen ammonium bicarbonate and 2%PVA(w/v).The curcumin LPMPs were prepared according to the optimal prescription,it's encapsulation efficiency and drug loading were 95.8% ± 0.01% and 16.9% ± 0.2%,respectively.Under the scanning electron microscope,it was observed that the surface of the particles was porous and had a small pore distribution inside.The geometrical particle size of the curcumin LPMPs was De 11.58 ± 2.28?m,the tap density was 0.060 ± 0.018mg/ml,the angle of repose was 30.09 ± 1.71°,the aerodynamic particle size was 3.12 ± 0.62?m,the lung deposition rate was 28.9 %.These were suitable for the pulmonary inhalation.2.Curcumin content determination method HPLC method was established to calculate the quality of curcumin in the formulation.The chromatographic conditions were determined.The method was verified by the precision and recovery rate.3.Evaluation of curcumin LPMPs in vitro The artificial lung fluid was used as dissolution medium.The release experiment in vitro was performed by imitating internal environment,which showed that curcumin released from the LPMPs with approximately 75% for 24 hours.The curcumin LPMPs release mechanism was mainly due to the combination of diffusion and PLGA erosion.Curcumin can inhibit the proliferation of human lung fibroblasts(HLF)and the growth inhibition ratio was about 30%,which was demonstrated by the cytotoxicity of curcumin LPMPs to HLF.4.Establishment of pulmonary fibrosis model in rats The pulmonary fibrosis model was established in a short time by direct trachea injection of bleomycin solution.The pulmonary fibrosis model was established successfully by the appearance of lung tissue,HE and Masson staining.The content of total protein and tumor necrosis factor-?(TNF-?)in lung tissue of 7,28 days were detected by ELISA.It can prove the pathogenesis process of pulmonary fibrosis,and the process included the early inflammatory response and the late pulmonary fibrosis.5.Treating effect of curcumin LPMPs on the pulmonary fibrosis rat models and the study of mechanism The curcumin LPMPs could improve the prevention and treatment effect of pulmonary fibrosis in vivo.Compared with the curcumin powder group,the expression of NFkappa B was reduced in curcumin-loaded LPMPs.It proved that curcumin could inhibit the early inflammatory response of the pulmonary fibrosis,maybe becsuse curcumin inhibited the inflammatory NF-kappa B signaling pathway.The expression of TGF-?1 and Collagen I were decreased,indicating curcumin can inhibit the release of extracellular matrix Collagen I,which may further inhibited the activation of TGF-?1 channel,that lead to the release of collagen decreasing.The results of pathological sections,TGF-?1 immunohistochemistry and hydroxyproline content showed that curcumin-loaded LPMPs has the effect of the prevention and treatment pulmonary fibrosis.