It is important to focus on urgent needs in clinics and develop optimal materials. For successful augmentation of vocal folds, the ideal filler should be injectable through a syringe, and should stably maintain its volume for a long time without toxicity. To achieve these criteria, a click chemistry-based PEG (polyethylene glycol) hydrogel was developed and applied for vocal fold augmentation in vivo. The PEG hydrogel enables fast gelation in vivo after injection and provides long-term stability. Azide- and dibenzocyclooctyne (DBCO)-modified 4-arm PEG were cross-linked by chemical conjugation via click chemistry and yielded gelation within several minutes. After subcutaneous injection into mice and rats, the PEG hydrogel showed higher stability after 1 month compared to the traditionally used calcium hydroxyapatite-carboxymethyl cellulose (CaHA-CMC) filler. In rabbit models with vocal fold paralysis, the PEG hydrogel stably fixed the paralyzed vocal fold in 4 months and minimized the glottic gap. It was an improved therapeutic result compared to CaHA-CMC, demonstrating the potential of a click chemistry-based PEG hydrogel for vocal fold therapy.
C.-S. K. acknowledges the financial support of the Catholic Medical Center Research Foundation made in the program year of 2019. This work was supported by the Basic Research Program (2016R1C1B3013951 and 2020R1G1A1004280) through the National Research Foundation of Korea (NRF) funded by the Korean government (Ministry of Science, ICT, & Future Planning), a Clinical Research Institute Grant funded by The Catholic University of Korea Daejeon St. Mary\u2019s Hospital (CMCDJ-P-2019-003), and The E.N.T. Fund of the Catholic University of Korea made in the program year of 2018.
