Discovery, isolation, characterization and biomedical application of the Acinetobacter Polyelectrolytic Exopolysaccharide (APE)

Bacterial polysaccharides are a class of biomaterials that have extensive industrial and biomedical applications. The primary advantages of these polymers are their ease of production, biodegradability and biocompatibility. Emulsan, an amphiphilic anionic, lipoheteropolysaccharide is an example of such a polysaccharide. While it has been traditionally used in industrial applications for its ability to stabilize oil-in-water emulsions, recent research has changed the focus to biomedical uses, making apparent the need to develop a more robust and effective purification process for emulsan. During the course of process development, it was discovered that emulsan was not a homogenous polysaccharide, but rather a complex of low molecular weight lipopolysaccharide and a high molecular weight polysaccharide now termed the Acinetobacter Polyelectrolytic Exopolysaccharide (APE).;Research demonstrated that APE was the emulsion stabilizing component of the emulsan complex. This discovery led to a complete physical and chemical characterization of the polysaccharide in order to develop a model describing its emulsion stabilization ability. Using the knowledge generated by the characterization studies, solid lipid nanoparticles to deliver the chemotherapeutic drug paclitaxel were developed using APE as one of the primary constituents. Based on the results described in this dissertation, APE was shown to be a potentially useful biomaterial for future biomedical and industrial applications.