Tunable growth factor release from nano-assembled starch multilayers

We report the preparation and characterization of polysaccharide-based nano-assembled surface coatings. Chitosan and fibroblast growth factor-2 (FGF-2) were assembled with starch through electrostatic layer-by-layer assembly. The chitosan/starch/FGF-2/starch nano-assembly surface coatings were formed via sequential adsorption of positively-charged chitosan and FGF-2 aqueous solutions and negatively-charged starch, with the process monitored by a profilometer. SEM was used to investigate the surface morphology and growth of multilayer coatings as a function of the number of bilayers. In addition, annealing of the multilayer structure induced physical reorganization of the starch granules. The FGF-2 release profile could be controlled by altering the microstructure of the starch. We expect that this demonstration of starch-based controlled release of growth factor will offer a new route to nano-assembly of truly biocompatible starch-based controlled-release surface coatings.