An example medical device for treating a body lumen is disclosed. The medical device includes an expandable scaffold including first and second regions, each of the first and second regions include a plurality of interstices located therein. The medical device also includes a covering spanning each of the plurality of interstices of the first region. The second region is free of the covering. A biodegradable gripping material is disposed on an outer surface of the covering. Further, the expandable scaffold is configured to shift from a collapsed state to an expanded state and the second region is configured to contact an inner surface of the body lumen in the expanded state. Additionally, the gripping material is designed to initially prevent migration of the expandable scaffold upon implantation in the body lumen until the second region is secured to the inner surface of the body lumen.