Biodegradable rapamycin-eluting ureteral stent inhibits scar formation after ureteral injuriy

Abstract

Objective To evaluate the effect of biodegradable rapamycin-eluting ureteral stent in inhibiting scar formation after ureteral injuries.Methods Smooth muscle cells were primary cultured.The inhibitory effect of rapamycin on the proliferation of smooth muscle cells was investigated by methyl thiazol tetrazolium (MTT) detection.And then,the optimal drug concentration was selected to construct drug-eluting stent.Biodegradable rapamycin-eluting ureteral stent and double-J stent were surgically implanted into the traumatic ureteral injury animal model,to evaluate the inhibitory effect in situ by histological tests.Results Smooth muscle cells were successfully cultured in vitro,and the results of MTT confirmed rapamycin could effectively inhibit the proliferation of smooth muscle cells depending on concentration.The IC50 was 23.3 mg/L.All stents were successfully implanted.At 18 weeks,masson trichrome and α-smooth muscle actin (α-SMA) immunohistochemical staining showed that biodegradable rapamycin-eluting ureteral stent,compared with double-J stent,can effectively inhibit the excessive proliferation of smooth muscle cells and collagen deposition.Conclusion Biodegradable rapamycin-eluting ureteral stent can effectively inhibit the excessive proliferation of smooth muscle cells and collagen deposition,thereby preventing ureteral scar stenosis. Key words: Rapamycin eluting stent; Ureteral injury; Scar formation