S-Nitrosothiol-Modified Hyperbranched Polyester and its In-situ Formation of NO-Releasing Foams (2014)
Undergraduates: Anand Shah, Yuan Lu
Faculty Advisor: Mark Schoenfisch
Department: Business Administration
Hyperbranched polyesters were synthesized and then functionalized to form S-nitrosothiol-modified organo-soluble polyester and porous polyester foams with large nitric oxide (NO) loadings. Functionalization of exterior hydroxyl groups with acryloyl chloride followed by a thiol-ene click reaction resulted in the synthesis of thiol-modified hyperbranched polyesters. S-nitrosothiol NO donors were formed on the resulting thiol-modified hyperbranched polyester. Organo-soluble hyperbranched polyesters exhibited NO storage of ~2.0 ¿mol/mg. Tunable NO release (maximum NO flux 450¿20,235 ppb/mg and half-life 0.12-1.80 h) was demonstrated by utilizing different triggers (thermal, light, and reducing agent) for the decomposition of S-nitrosothiols. Porous S-nitrosothiol-modified polyester foams were formed in-situ by utilizing the oxidative nature of nitrous acid for disulfide bonds crosslinking between thiol-modified hyperbranched polyesters with dinitrogen trioxide as the blowing agent. The NO-releasing foams showed longer NO release (half-life ~5.1 h). These results extend the range and scope of NO-releasing macromolecular scaffolds by designing biodegradable scaffolds with large NO loadings and porous structures for various biomedical applications; for example, tissues engineering and wound dressing.