The present invention refers to medical devices comprising cross-linked modified polyamides especially to stent carrying balloon catheters, for use in angioplasty and other procedures of vessel repair. In a preferred embodiment, a balloon catherer is made of Nylon 12, cross linked using triallyl isocyanurate and electronic beam (E-beam), using but-2-enedioic acid and heating or 1,4-butylene diamine and UV-radiation.