Synthesis and application of biomaterials containing the 1,3,5-triazaadamantane moiety or functionalized alginate

This thesis describes the synthesis and study of novel biomaterials. This work can be broadly divided into two groups of projects based on the compounds and materials that were used. The first group involves a class of compounds called substituted 1,3,5-triazaadamantanes (TAAs). Formed from the condensation between tris(aminomethyl)methane and substituted benzaldehydes, these compounds possess tunable degradation rates that depend on the substituents on the aromatic aldehydes. TAAs possess a branched architecture that was utilized in a variety of projects. TAA monomers were synthesized that were used for the preparation of degradable dendrimers. Using an iterative, divergent strategy, dendrimers up to three generations were synthesized that contained 39 TAA monomer units, displayed 81 functional groups on its periphery, and had a molecular weight above 35 kDa. End group modification with propargyl alcohol initiated hyperbranched polyglycerol rendered the compounds water soluble creating nanomaterials capable of encapsulating and releasing small molecule guests. Water soluble TAA cross-linkers were used to make degradable hydrogels by performing photo initiated polymerization and in situ cross-linking with hydrophilic monomers. Hydrogel degradation rates depended on the cross-linker used with degradation times varying from less than one day to as long as several months. Gels discs were implanted in chicken embryos and shown to be nontoxic and were shown to release protein in a controlled fashion. Finally, TAA cross-linkers were also reacted with low molecular weight polyethyleneimine (PEI) to synthesize degradable gene delivery vehicles. Degradable PEIs had varying gene delivery efficiencies and cell toxicities based on the cross-linker used. A polymer was made that produced comparable gene delivery efficiency to high molecular weight PEI, a standard in polymeric gene delivery, but with significantly lower toxicity. The second group of projects involves the synthesis of hydrogels from polyethylene glycol and alginate. Both polymers can be synthetically functionalized to allow gel formation under physiological conditions, without the addition of reagents, and without the production of by-products. Photoresponsive gels have also been made that degrade upon exposure to light. This material can be patterned and post functionalized to display desired chemical cues