(500a) Electrostatic Assembly as a Platform for Universal Multiagent Release
The ability to develop multifunctional release coatings, and to tune the release profiles of drugs on a near continuous level provides a disruptive technology that can create numerous pathways to new medical applications, ranging from stents and medical sutures to hip and bone implants. The electrostatic layer-by-layer assembly method allows very fine control of biomaterials interfaces by enabling the direct incorporation biological polymers at desired regions in the film. We have recently demonstrated the construction of multilayers for which one of the polyions is a degradable polycation; in such systems, once the film is constructed, it undergoes hydrolytic degradation at biological conditions to release the corresponding polyanionic species originally bound in the LBL film. On the other hand, hydrogen bonding can be used to design ultrathin films that fall apart at different rates depending on pH and the hydrogen bond donor-acceptor pair. We demonstrate the ability to incorporate a broad range of hydrophobic drugs including anti-inflammatory, antibacterial, and growth factors, while maintaining high activity and tunable drug loadings and release profiles. Recent work on the use of misting or spray layer-by-layer approaches of drug containing multilayers on solid and porous surfaces will also be discussed.