Nuclear chemistry

Sodium

Catalysis

Engineering

Polymer chemistry

Biomedical engineering

Photodegradation

Biocompatible material

Biodegradation

Sodium alginate

Chemical engineering

Polysaccharide

Dissolution

Drug delivery

Organic chemistry

Self-healing hydrogels

Medicine

Chemistry

Glucuronic acid

Photocatalysis

Biomacromolecules

Biocompatible photoresponsive materials are of interest for targeted drug delivery, tissue engineering, 2D and 3D protein patterning, and other biomedical applications. We prepared light degradable hydrogels using a natural alginate polysaccharide cross-linked with iron(III) cations. The "hard" iron(III) cations used to cross-link the alginate hydrogel were found to undergo facile photoreduction to "soft" iron(II) cations in the presence of millimolar concentrations of sodium lactate. The "soft" iron(II) cations have a decreased ability to cross-link the alginate which results in dissolution of the hydrogel and the formation of a homogeneous solution. The photodegradation is done using long wave UV or visible light at neutral pH. The very mild conditions required for the photodegradation and the high rate at which it occurs suggest applications for iron(III) cross-linked alginate hydrogels as light-controlled biocompatible scaffolds.

Photodegradable Iron(III) Cross-Linked Alginate Gels