Abstract

Biopolymers are able to address a wide variety of medical concerns from chronic wounds to stem cell cultivation to antibacterial and antifouling applications. They are non-toxic, biodegradable, and biocompatible, making them ideal candidates for creating green materials for biological applications. In this thesis, we cover the synthesis of two novel materials from the biopolymers, chitosan and pectin. Chitosan is a biocompatible antibacterial polycation and pectin is an anti-inflammatory polyanion with a strong propensity for hydrogen-bonding. The two chitosan:pectin materials, particles and hydrogels, explore some of the structures that can be created by tuning the electrostatic interactions between chitosan and pectin. Chitosan can spontaneously form polyelectrolyte complexes when mixed with a polyanion in appropriate aqueous conditions. In the first study, chitosan:pectin nanoparticles were synthesized using an aqueous spontaneous ionic gelation method. A number of parameters, polymer concentration, addition order, mass ratio, and solution pH, were then explored and their effect on nanoparticle formation was determined. The synthesis of chitosan:pectin hydrogels have previously been limited by harsh acidic synthesis conditions, which restricted their use in biomedical applications. In the second study, a zero-acid hydrogel has been synthesized from a mixture of chitosan and pectin at biologically compatible conditions. We demonstrated that salt could be used to suppress long-range electrostatic interactions to generate a thermoreversible biopolymer hydrogel that has temperature- sensitive gelation. We then characterized the hydrogel system’s suitability for use as a wound dressing.