Microwave assisted methacrylation of Kappa carrageenan: A bioink for cartilage tissue engineering

In this study, we aimed to obtain stable Kappa carrageenan (kappa Car) hydrogel that could be used as a bioink for cartilage regeneration. For this purpose, we described an effective and considerably faster methacrylation process by using microwave energy. Thus, microwave-methacrylated kappa Car (Mw-kappa Car-MA) with >= 85% degree of methacrylation (DM) was synthesized despite the use of a low concentration of methacrylic anhydride (MA) at 1000 W in 5 min. Then, Mw-kappa Car-MA was photo-crosslinked by only using UV irradiation for 40 s. Characterization studies proved that Mw-kappa Car-MA hydrogels were stronger and have lower weight loss (similar to 20% at 30 days) than that of conventionally synthesized kappa Car-MA hydrogels. Viscosities of the Mw-kappa Car-MA hydrogels were found to be sufficient to use in 3D bioprinters. Furthermore, Mw-kappa Car-MA hydrogels enhanced the viability, proliferation, and GAG deposition of ATDC5 chondrogenic cells. Therefore, we proposed that Mw-kappa Car-MA can be considered as a suitable bioink for cartilage tissue engineering. (C) 2020 Published by Elsevier B.V.