The development of crosslinked gelatin thin films as controlled release matrices

The aim of this thesis was to develop gelatin-based thin films that may be used as matrices for the controlled release of bioactive compounds. There were three objectives to this research: i) develop a method to generate the thin films ii) experimentally quantify the release of a fluorescent marker from these films, and iii) implement a mathematical model to characterize the release of the fluorescent marker. To achieve the first objective, a novel method of developing thin films was implemented where sub-micron thickness films affixed to standard glass slides were crosslinked with genipin, a naturally-occurring fixative. Gel thickness measured using atomic force microscopy (AFM) varied from 350 to 650 nm irrespective of the concentration of genifin added. AFM-based surface roughness decreased with increasing genipin concentration. Release behavior of a fluorescent marker from the thin films demonstrated a strong influence of genipin concentration on release kinetics, with greater genipin leading to slower release. A mathematical model for the water transport into, and fluorescent marker release from, the genipin-crosslinked gelatin films was developed and successfully implemented with both the water ingress (swelling) and marker release being effectively characterized by the model.