An example medical stent for treating a body lumen is disclosed. The example stent includes an expandable scaffold having a first end region, a second end region and an outer surface. The stent further includes a first fixation member coupled to the expandable scaffold and a biodegradable material disposed along the first fixation member at a first tissue engagement region. Further, the biodegradable material is designed to degrade from a first configuration in which the biodegradable material shields the first fixation member from a target tissue site to a second configuration in which the first fixation member is engaged with the target tissue site.