Fecha de publicación: -- Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE Dynamic mechanics-assisted mineralization promotes ion transport, homogeneous calcium phosphate deposition, and strong organic–inorganic interfacial coupling within anisotropic PVA hydrogels. The resulting biomimetic scaffold exhibits enhanced structural organization and mechanical performance, providing an effective strategy for engineering bone-mimetic hydrogels.


ABSTRACT
Developing bone-mimetic hydrogels with both adequate mechanical performance and uniform internal mineralization remains challenging, as conventional static mineralization is diffusion-limited and often results in heterogeneous deposition and insufficient structural organization. Here, we developed a dynamic mechanics-assisted, matrix-directed mineralization strategy to fabricate anisotropic poly (vinyl alcohol) (PVA)-based composite hydrogels with bone-mimetic hierarchical features. Anisotropic poly (vinyl alcohol)-phytic acid (PVA–PA) scaffolds with unidirectional channels were prepared by directional freeze-casting and freeze–thaw crosslinking. These scaffolds then underwent cyclic stretching-assisted mineralization (involving periodic mechanical loading, hereafter abbreviated as dynamic mineralization) in simulated body fluid. Compared with static mineralization, dynamic mineralization promoted deeper ion infiltration, more homogeneous inorganic deposition, and greater mineral accumulation. The high-temperature residual mass increased from 4.01 wt.% in the statically mineralized hydrogel after 3 cycles (S-3) to 10.02 wt.% in the dynamically mineralized hydrogel after 3 cycles (D-3), while the Hermans orientation factor increased from 0.114 to 0.363. These structural changes were accompanied by improved mechanical performance: D-3 exhibited a tensile modulus of 0.230 MPa and an ultimate stress of 0.639 MPa, compared with 0.199 MPa and 0.361 MPa for S-3, respectively. Overall, dynamic mineralization offers an effective strategy for improving mineralization uniformity, structural anisotropy, and mechanical performance in bone-mimetic hydrogels.