ABSTRACT
Pharmacologically active materials offer the advantage of providing sitespecific pharmacotherapy for prolonged periods of time. The use of biomaterials as drug delivery vehicles is a continuing area of research, due to the desire not only to provide localized drug therapy but to improve the body’s acceptance of the implanted materials or initiate desired cell responses at the implantation site. However, it is also possible to covalently modify materials such that the “drug” remains attached to the biomaterial, providing a truly localized therapy, and is pharmacologically active for indefinite periods of time. In this manner, not only do the materials retain their biological activity, but the activity of the incorporated biological molecule or drug is often better preserved when bound to a substrate than when free in solution. Many pharmacological agents have extremely short half-lives in vivo. Attachment to materials often helps to stabilize the active substance while allowing it to interact with its environment and perform its intended functions. A wide range of biologically active molecules can be covalently attached to synthetic biomaterials in a manner such that the substance retains its bioactivity, and is sometimes more effective than its soluble counterpart.
