A wire bolt comprising an elongated section of wire rope with a section of threaded stud attached to each end is disclosed for use in reinforcing concrete structures. The diamond-like carbon material of the present invention is highly tetrahedral, that is, it features a large number of the sp3 carbon-carbon bonds which are found within a diamond crystal lattice. The invention provides reactive thioester-terminated PEG polymers that have suitable reactivity with an N-terminal cysteine or histidine residue of a polypeptide to produce an amide bond between the PEG molecule and the polypeptide.