Evaluating Pressurized Gas Expanded Liquid Processed Carbohydrates for Biomedical and Bioseparations Applications

Abstract

Significant challenges remain associated with forming scalable macroporous materials with high interconnectivity without requiring the use of substances that may cause negative effects in the end use of the material. In this light, pressurized gas expanded liquid (PGX) technology, a processing technique that uses ethanol and carbon dioxide to create high surface area morphologies in carbohydrate material, offers an attractive alternative. Through the chemical stabilization of these morphologies via crosslinking, the carbohydrate scaffolds can be used in multiple applications including the promotion of cell growth in tissue engineering applications, improvement in wound healing through moisture retention and delivery of biotherapeutics, and creation of interconnected internal morphologies in hard polymers for bioseparations and bone scaffolding applications by way of templating. This thesis investigates these potential applications of PGX-processed materials. First, the effects of the morphology of PGX-processed chitosan crosslinked with varying amounts of genipin (which affect both the gel mechanics and the adhesiveness of the gel) are investigated on the proliferation and morphology of muscle cells. Second, highly interconnected alginate networks created through PGX-processing were impregnated with ibuprofen, ionically crosslinked and evaluated for their use as a burn wound dressing in vivo, with the gels demonstrated to maintain moisture and deliver an anti-inflammatory drug to suppress scarring during wound healing. Finally, alginate networks were used as sacrificial scaffolds in the creation of an interconnected internal morphology within a hard polymer shell for applications requiring both high interconnectivity and high mechanical integrity, such as bone scaffolding and bioseparations. In conclusion, this work shows the promise of post-crosslinked PGX-processed carbohydrates in tissue engineering, wound healing and bioseparations.