Gelation and release behavior of visible light-curable alginate

Visible light-curable alginate was prepared by coupling alginate with furfurylamine. The furan content of the alginate was investigated through Fourier transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy. The prepared furfuryl alginate (F-Alginate) underwent gelation in the presence of a photosensitizer, such as Rose Bengal or riboflavin, under visible light irradiation. The time course of this gelation was similar to that of conventional Ca2+-induced gelation. When the formed gel was assessed using a rheometer, it was found that F-Alginate has a high storage modulus G′ comparable with that of a Ca2+-cross-linked gel. It was possible to encapsulate substances in the gel through simple mixing. The release rate of encapsulated substances depended on their molecular weight. As the molecular weight of encapsulated dextran increased, slower release was observed. These release behaviors are comparable with those of a Ca2+-cross-linked gel. The release rate of a growth factor protein was the same as that of dextran with the same molecular weight. Cell growth was enhanced in response to a sustained release of insulin-like growth factor-1 from the F-Alginate hydrogel. Visible light-curable alginate was prepared by coupling alginate with furfurylamine. The prepared furfuryl alginate (F-Alginate) underwent gelation in the presence of a photosensitizer under visible light irradiation. The mechanical and release properties of the visible light-induced gel were similar to that of conventional Ca2+-induced cross-linked alginate. The release rate of encapsulated substances depended on their molecular weight. Cell growth was enhanced in response to a sustained release of insulin-like growth factor-1 from the F-Alginate hydrogel.