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In Vivo Imaging of Composite Hydrogel Scaffold Degradation Using CEST MRI and Two‐Color NIR Imaging
Author(s) -
Zhu Wei,
Chu Chengyan,
Kuddannaya Shreyas,
Yuan Yue,
Walczak Piotr,
Singh Anirudha,
Song Xiaolei,
Bulte Jeff W. M.
Publication year - 2019
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201903753
Subject(s) - self healing hydrogels , materials science , gelatin , hyaluronic acid , biomedical engineering , magnetic resonance imaging , in vivo , scaffold , transplantation , chemistry , radiology , medicine , biochemistry , microbiology and biotechnology , biology , polymer chemistry , genetics , surgery
Hydrogel scaffolding of stem cells is a promising strategy to overcome initial cell loss and manipulate cell function post‐transplantation. Matrix degradation is a requirement for downstream cell differentiation and functional tissue integration, which determines therapeutic outcome. Therefore, monitoring of hydrogel degradation is essential for scaffolded cell replacement therapies. It is shown here that chemical exchange saturation transfer magnetic resonance imaging (CEST MRI) can be used as a label‐free imaging platform for monitoring the degradation of crosslinked hydrogels containing gelatin (Gel) and hyaluronic acid (HA), of which the stiffness can be fine‐tuned by varying the ratio of the Gel:HA. By labeling Gel and HA with two different near‐infrared (NIR) dyes having distinct emission frequencies, it is shown here that the HA signal remains stable for 42 days, while the Gel signal gradually decreases to <25% of its initial value at this time point. Both imaging modalities are in excellent agreement for both the time course and relative value of CEST MRI and NIR signals ( R 2 = 0.94). These findings support the further use of CEST MRI for monitoring biodegradation and optimizing of gelatin‐containing hydrogels in a label‐free manner.