Surface modifications and molecular imprinting of polymers in medical and pharmaceutical applications.

Recent developments in the field of biomaterials are based on molecular design of polymers with improved surface and bulk properties. Novel techniques of surface modification by addition of tethered chains can lead to materials with the ability to recognize biological and pharmaceutical compounds. Methods based on molecular imprinting can increase the recognition capabilities of such systems. Chain tethering can also can improve the mucoadhesive behavior of a delivery device and the effectiveness of a drug by allowing targeting and localization of a drug at a specific site. Acrylic-based hydrogels are well-suited for mucoadhesion due to their flexibility and nonabrasive characteristics which reduce damage-causing attrition to the tissues in contact. However, the adhesive and drug delivery capabilities of these devices can continue to be improved as presently known bioadhesive materials are modified and more bioadhesive materials are discovered. Tethering of long PEG chains on PAA hydrogels and their copolymers can be achieved by grafting reactions involving thionyl chloride, followed by PEG grafting. The ensuing materials exhibit mucoadhesive properties due to enhanced anchoring of the chains with the mucosa. Theoretical calculations can lead to optimization of the tethered structure.