The present invention discloses a radiographic contrasting agent containing multiple aromatic groups, each of which is substituted with at least three halogen atoms. The radiographic contrasting agent can initiate a polymerization process. The present invention also discloses a radio-opaque polymeric material that comprises a biodegradable polymer having at least one radiographic contrasting moiety covalently attached thereto. The radio-opaque polymeric material provides enhanced contrasting intensity in radiographic imaging. The radio-opaque polymeric material can be applied on at least a portion of one surface of a medical device. The radio-opaque polymeric material can also be used to construct a medical device, a component thereof, or a portion of a component thereof.