The present invention relates to a surface-coated nanoparticle comprising biodegradable polymer chains and cyclopeptides, wherein the cyclopeptides are covalently attached to the biodegradable polymer chains forming the nanoparticle, thereby coating the surface of the nanoparticle. The present invention further relates to the use of said surface-coated nanoparticle as a capsule for an agent for improving the oral delivery thereof. In another aspect, the present invention relates to the surface-coated nanoparticle for use in the treatment or prevention of a disorder or disease in a patient, wherein the treatment or prevention is achieved by mucosal uptake of the surface-coated nanoparticle via the oral route.
