A Novel Stone Dissolution Drug-eluting Metal Stent For The Treatment Of Difficult Common Bile Duct Stone

Gallstone disease was a common biliary tract disease and brought great pain to the patient.Drug-eluting stents with choledocholithiasis are considered to be one of the best routes for Gallstone.And abrasion between stent and gallstone can increase the stone-dissolving effect.In addition,the stent was also able to drain bile and kept bile duct clear.In this study,two kinds of drug-eluting metal stents,electrospinning drug-loaded nanofiber-coated metal stents and applying-coated drug-eluting stents,were prepared by different methods.The electrospinning drug-loaded nanofiber-coated metal stent was prepared by coaxial electrospinning and the highest drug-containing rate was37.5%.The properties of the drug-loaded nanofibrous films were analyzed by scanning electron microscopy,transmission electron microscopy,Fourier transform attenuated total reflection infrared spectroscopy,thermogravimetric analysis and mechanical testing.In vitro experiments,drug release behavior and degradation of drug-loaded nanofibers were investigated,and gallstone dissolving effect of electrospinning drug-loaded nanofiber-coated stents were also evaluated.The results showed that the drug-loaded nanofibers had desireable morphology as well as shell-core structure,and sodium cholate(SC)and edetic acid disodium(EDTA)were successfully loaded into the nanofibers.The larger amount of EDTA & SC loaded in nanofibers was,the more amount of EDTA & SC was released,and the better the dissolving effect was.The drug-loaded nanofibers with EDTA & SC had no obvious cytotoxicity and were unable to inhibit the proliferation of cells.Applying-coated drug-eluting metal stent was prepared by applying method,anddrug rate in the film was 50%.Scanning electron microscopy,X-ray diffraction,thermogravimetric analysis and radial mechanical testing of the stent were used to analyze the drug-loaded form in the film and applying-coated drug-eluting metal stent mechanics.In vitro drug release test and in vitro dissolution test were used to evaluate the sustained release time and the dissolving effect to gallstone.The results showed that EDTA and SC were successfully loaded into the film of applying-coated drug-eluting metal stent,and EDTA existed with the form of crystal particles in the film,while SC was amorphous.The mechanical properties to radial compression of applying-coated drug-eluting metal stent was desirable.The release time of applying-coated drug-eluting metal stent enable to reach 28 days in vitro,and the effect of dissolving effect of stone was obvious and the final mass loss of gallstone was 33.3%.The results of comparing experiment showed that the applying-coated drug-eluting metal stent was better for dissolving gallstone than the electrospinning drug-loaded nanofiber-coated metal stent.