Tough-engineered multifunctional alendronate anchoring of dysprosium impregnated luminescent polyvinyl...

Fabrication of multifunctional tissue engineered scaffolds with superior mechanical strength, and biocompatibility in combination with excellent contrast behaviour and luminescence is a daunting task. Herein, dysprosium integrated polyvinyl alcohol/chitosan hydrogel with the salient features of better mechanical strength, superior luminescence, T₂ contrast efficiency, alongside biocompatibility has been fabricated by the freeze-thawing technique. The swelling capacity ∼400 % has paved the way in anchoring the alendronate drug and demonstrated a sustained drug release ∼32 % for 10 h through Fickian diffusion. The synergy of crystalline domains, hydrogen bonds and ionic interactions of the hydrogel yielded high tensile strength, hardness and Young's modulus respectively of 13.7 MPa, 36.5 MPa and 668.21. Further, the integration of dysprosium in hydrogel provides the inherent luminescence in the visible region (450-650 nm), excellent T₂ contrast efficiency with the relaxivity value of 12.9 mM^-1 s^-1 and X-ray attenuation capabilities of 177 HU. The biocompatibility tests revealed ∼90 % cell viability and improved osteogenic differentiation such as ALP and calcium nodules. Moreover, the CAM assay revealed the ability of hydrogel to accelerate the vessel formation through their integration with the branching points.