Degradation of partially oxidized alginate and its potential application for tissue engineering

Alginate has been widely used in a variety of biomedical applications inclu ding drug delivery and cell transplantation. However, alginate itself has a very slow degradation rate, and its gels degrade in an uncontrollable mann er, releasing high molecular weight strands that may have difficulty being cleared from the body. We hypothesized that the periodate oxidation of algi nate, which cleaves the carbon-carbon bond of the cis-diol group in the uro nate residue and alters the chain conformation, would result in promoting t he hydrolysis of alginate in aqueous solutions. Alginate, oxidized to a low extent (similar to5%), degraded with a rate depending on the pH and temper ature of the solution. This polymer was still capable of being ionically cr oss-linked with calcium ions to form gels, which degraded within 9 days in PBS solution. Finally, the use of these degradable alginate-derived hydroge ls greatly improved cartilage-like tissue formation in vivo, as compared to alginate hydrogels.