Structural Characterization and Hydration Dynamics\nof Cross-Linked Collagen and Hyaluronic Acid Scaffolds by Nuclear\nMagnetic Resonance

Understanding\na biomaterial’s structural and hydration dynamics\nis essential for its development and applications in tissue regeneration.\nIn this study, collagen–hyaluronic acid (HA) scaffolds were\nanalyzed utilizing Nuclear Magnetic Resonance (NMR) techniques to\nelucidate how different cross-linking conditions influence the internal\narchitecture and interaction with solvents in these scaffolds. The\nscaffolds were fabricated using 3D printing and cross-linked with\n1,4-butanediol diglycidyl ether (BDDGE), a process known to impact\ntheir mechanical properties. We gained insights into the microstructural\norganization and hydration behavior within the scaffolds when exposed\nto water and ethanol by employing proton relaxation and diffusion\nmeasurements. To better understand the system’s performance,\nstatic and dynamic experiments were performed. Our results indicate\nthat the degree of cross-linking affects the scaffold’s ability\nto retain water, with higher cross-linking leading to more rigid structures.\nThis also altered the hydration dynamics mainly due to a difference\nin the diffusion of water within the scaffold. In addition, the anisotropy\nof the collagen fibers also decreases with the cross-linking. Ethanol,\na less polar solvent, provided a contrasting environment that further\nrevealed the structural dependencies on the cross-linking density.\nThe study’s findings contribute to a deeper understanding of\nhow the structure and morphology affect the functionality of collagen–HA\nscaffolds, offering critical information for optimizing their design\nfor specific biomedical applications, such as soft tissue regeneration.\nOur experiments show how NMR is a valuable tool to provide information\non dynamic processes not only in collagen–HA scaffolds but\nalso in many biocompatible polymeric samples. The outcomes of this\nresearch provide a foundation for future work aimed at tailoring scaffold\nproperties to enhance their performance in clinical settings, ultimately\nadvancing the field of tissue engineering.