The present invention relates to an expansible hollow part, having at least one opening, which consists of an elastic biocompatible material and which comprises at least one biologically active substance and, optionally at least one matrix compound. The invention also provides a method of producing said expansible hollow part, a medical device covered at least partially with said hollow part, a kit-of-parts comprising said hollow part of the invention and the use of said hollow part as a therapeutic device and for protecting a medical device.