Preparation of deuterium-labeled κ-carrageenan and application in degradation evaluation for tissue engineering...

This study presents a novel stable isotope labeling strategy based on deuterium exchange for monitoring the degradation of κ-carrageenan tissue engineering scaffolds. This approach addresses the challenge of tracking scaffold fate under physiological conditions. Through optimized hydrogen‑deuterium exchange using 10% palladium‑carbon catalyst over 72 h, we achieved a deuterium incorporation efficiency of 65.01% as verified by nuclear magnetic resonance and mass spectrometry analysis. Deuterated and non-deuterated κ-carrageenan were blended at a 1:1 mass ratio to form composite scaffolds, enabling real-time degradation monitoring via fourier transform infrared spectroscopy through tracking of deuterium-related spectral shifts. Both scaffold types exhibited highly consistent degradation behavior, which was described by the Box-Lucas kinetic model, showing correlation coefficients of 0.984 and 0.982 and yielding degradation rate constants of 1.71 day^-1 and 1.83 day^-1 for the labeled and unlabeled scaffolds, respectively. The close agreement validates deuterium labeling as a reliable and sensitive monitoring method. This study establishes a methodological framework for monitoring the in vivo degradation of tissue engineering scaffolds, demonstrating significant potential for clinical translation.