Hydrogel scaffolds are used in biomedicine to study cell differentiation and tissue evolution, where it is critical to be able to deliver chemical cues (therapeutics and nutrients) in a spatially and temporally defined manner. Covalently tethering therapeutic agents into a hydrogel through a degradable linkage allows their predictable and controlled release. Hydrolyzable and enzymatically degradable linkages have been reported, but lack external control. In contrast, photodegradation is externally controlled, allowing user-dictated release.  We synthesized and characterized macromers with photodegradbale ortho-nitrobenzyl (o-NB) groups linked to activated disulfides.  These macromers were copolymerized into hydrogel depots.  The activated disulfide allows post-polymerization conjugation of thiol-containing molecules (such as peptides and proteins containing accessible cysteine residues) into the hydrogel depot via disulfide exchange. Using this approach, we fabricated hydrogels depots with photoreleasable peptide (glutathione) and protein (modified lysozyme), and quantified the release of the peptide/protein as a function of light exposure (365 nm, 10 mW/cm2).

Delivery of small and large molecules from a hydrogel via light

243rd National Meeting (2012)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.