Work

Ultrasound-responsive CPS piezoelectric hydrogel synergistically repairs annulus fibrosus defects through immune reprogramming and cell recruitment

Year: 2026

Type: article

Abstract: As a globally prevalent cause of disability, lumbar disc herniation has structural disruption of the annulus fibrosus (AF) as its pathological core. To address three critical bottlenecks in AF repair—microenvironmental imbalance (excessive inflammation/oxidative stress), inadequate cellular regeneration (low cell density), and mechanical instability—this study developed an ultrasound-responsive piezoelectric hydrogel scaffold (CPS gel) composed of cerium dioxide, poly-L-lactic acid fibers, and sodium alginate. The core mechanisms include: 1) Immune Reprogramming: Ceria nanoparticles exert dual superoxide dismutase/catalase-mimetic catalytic activity to scavenge reactive oxygen species, inhibit the NF-κB signaling pathway, downregulate IKKα/IκBα phosphorylation, and thereby drive macrophage polarization toward the M2 phenotype; 2) Directed Cellular Regeneration: Ultrasound-activated piezoelectric effects from PLLA fibers facilitate cell migration and proliferation via the ITGβ1/PI3K/AKT/ERK pathway, promoting collagen secretion; 3) Mechanical Reconstruction: The sodium alginate "egg-box" network provides physiologically matched compressive modulus, and in vivo experiments confirm the restoration of intervertebral disc compressive stiffness. Employing a triple synergistic strategy—immunomodulation, cell recruitment, and mechanical restoration—this study proposes a promising solution for structural regeneration of the annulus fibrosus.

Source: Materials Today Bio

DOI: 10.1016/j.mtbio.2026.102825