Biocompatibility-on-a-chip: Characterization and evaluation of decellularized tendon extracellular matrix (tdECM) hydrogel for 3D stem cell culture in a microfluidic device.

Researchers have always tried expensive in vitro tests to show the 3D usability of dECM. The use of tissue-specific hydrogels in a microfluidic device is rarely studied. In this study, we have used ECM obtained from goat digital flexor tendons by decellularization technique. The tdECM was characterized for its structural properties using Scanning Electron Microscopy (SEM). Collagen, dsDNA, GAGs, and protein contents were quantified using spectrophotometric assays. The cell viability and proliferation of human umbilical cord-derived mesenchymal stem cells (hUMSCs) encapsulated in the tdECM hydrogel inside the microfluidic device were checked using Calcein-AM/PI. The FTIR data showed prominent peaks of the amide group, indicating the presence of collagen. The SEM data showed intact fiber morphology after the decellularization process. There was a 95 % reduction in double-stranded DNA (dsDNA) content, proving the effectiveness of the decellularization technique. There was no significant difference in the collagen content of tdECM and the GAGs were also in the acceptable range compared to the native tissue. Over 90 % cell viability in hUMSCs was observed qualitatively and quantitatively in vitro and inside a microfluidic device. In conclusion, we characterized the tdECM hydrogel and demonstrated its compatibility with the microfluidic device.