Elastin: A Stimuli Responsive Biopolymer for Nano-, and Micro-Actuation

摘要

We developed hybrid materials comprising of silica and stimuli responsive polymers (SRPs) to demonstrate the feasibility of SRPs as actuation elements in functional nanostructured materials. We successfully demonstrated that the hybrid membranes comprising of silica and SRPs can function as molecular filters with reversible permeability and good stability. We dispersed these SRPs in a slilica matrix at a molecular level using sol-gel process. The encapsulated SRP molecules to act as nano- valves whose permeability can be controlled by cycling through the lower critical solution temperature (LCST) of the SRPs. Micropatterning studies on hybrid membranes suggest that a wide variety of water-soluble species can be patterned without need for a specific chemisorption or affinity label using localized heating with a UV laser. Developed porous silica nanocomposite materials and modified the surface with SRPs using atom transfer radical polymerization and demonstrated that the size and surface energy of the pores can be externally and reversibly controlled to dynamically modulate the adsorption and transport of molecular species. These have potential applications in the areas of separations, controlled drug delivery, environmental remediation, bioassays, biosensing, tissue engineering. Using a model system of silica and PNIPAAM we have demonstrated design principles and synthetic methods are applicable to a wide variety of porous structures and polymers (or small molecules) which are reversibly sensitive to different external stimuli such as temperature, light, electricity, pH, solutes, or enzymatic transformations.