Dynamic manipulation of wetting behavior of a surface can be used to trigger attachment or detachment of biomolecules and cells, induce changes to affinity for tissue, and diffusion behavior. A biocompatible biomaterial, whose interface can be dynamically modulated, therefore can find potential application in bio-adhesives, bio-patches, biosensors, actuators, cell delivery and lab on chip. We have developed a family of biodegradable and biocompatible segmented thermoplastic polyester (STEP), which are capable of undergoing change in shape and wetting behavior upon exposure to an external stimulus, which is compatible with physiological environments. By surface engineering the aligned segregated hydrophobic segments, a system with an activatable surface wetting behavior has been realized. As an example, a 15 degree change in static contact angle was triggered in a mechanically programmed STEP device by illumination with infra-red light. By prescribing a shape during the mechanical programming shape-change devices possessing hydrophilic properties in a strained state and hydrophobic properties in a relaxed state have been achieved. In addition to practical applications the role of strain, chain relaxation, time, and temperature in STEP polymers with dynamically tunable interface will be presented.
Keywords: engineered biomaterials, dynamic bio-interface, programmable wettability
SM04: Understanding and Controlling the Structure and Function of Biomolecules at Material Interfaces.