Synthesis Of Low Molecular Weight Chitosan Glycyrrhizin Conjugate And Study Of Renal Fibrosis Research

Objective Synthesis of glycyrrhizic acid and low molecular chitosan conjugate(GL-LMWC),in order to improve the solubility of glycyrrhizic acid and intravenous drug delivery for the treatment of kidney,providing a stable and efficient new preparation.Target for the design,preparation research provides theoretical and important experimental reference.Methods Low molecular weight chitosan which gained by degradation and acetylation reaction used as carrier material.NHS and DMAP as catalyst,Glycyrrhizin-LMWC conjugate was synthesized by the reaction between the amino group of LMWC and the active ester group of GL.The structure of GL-LMWC conjugation can be proved by UV,1H-NMR,FT-IR and substitution degree of the amino group.In this study,the physicochemical and stability profiles of GL-LMWC conjugation was investigated drug release was studied in phosphate buffer containing papain.The uptake of the conjugates by HK-2 cells and their intracellular localization were studied with laser confocal microscopy.Level of pharmacodynamic experiments on animals,ICR mice as experimental animal,UUO model,glycyrrhizin and glycyrrhizin-LMWC conjugate and the effect of captopril tablets on ICR mice,and by HE and Masson staining,immunohistochemical staining and Western blot,damage degree evaluation of renal tubule interstitial fibrosis and kidney tissue α-smooth muscle actin(α-SMA)expression.Results The chemical structure of GL-LMWC conjugate was confirmed by FT-IR 1H-NMR,UV and substitution degree of the amino group.The GL grafting rate was determined to be 29,3%;Drug liberation from the conjugates was significantly accelerated in the presence of papain,which confirms the capability of the conjugate and degrade in the lysosome.While it is relatively stable in phosphate buffer.The conjugate could be quickly internalized by HK-2 cells.Kidney tissue morphological observation showed that UUO model group of renal tubular epithelial cell degeneration,necrosis,renal tubular expansion or contraction of the intervention group were eased.Masson staining of renal interstitial collagen fiber hyperplasia UUO model group and control group with significant difference,the intervention group decreased obviously.Immunohistochemical staining showed that UUO model group mice after the relative expression of renal interstitial α-SMA were significantly higher than control group,Glycyrrhizin and glycyrrhizin-LMWC conjugate renal interstitial fibrosis,α-SMA protein expression of UUO model group significantly reduced relatively.Conclusion In the study,we prepared,characterized and evaluated the GL-LMWC conjugation;the analysis methods in vitro was established successfully.The release behavior in vitro of GL-LMWC conjugation indicated that it was relatively stable before reaching the kidney,while it could released GL rapidly after arrived the kidney.The GL-LMWC conjugation with well-defined structure was found to exhibit higher cellular uptake efficiency.The results obtained imply that the conjugates have the potential to retaing GL in the kidney for a prolonged duration and to sustain its release locally for a better.Pharmacodynamics study indicated,glycyrrhizin and glycyrrhizin-LMWC conjugate can significantly inhibit the renal tubular epithelial cells and renal tubular interstitial cell phenotype transformation,which prompt it can effectively improve the renal interstitial fibrosis.