Hyperbranched poly-L-lysine surface-engineered bioprosthetic heart valves with anti-calcification, anti-infection, and durability

Bioprosthetic heart valves (BHV) remain limited by progressive calcification, infection, and structural degeneration, leading to premature failure despite decades of clinical use. Herein, a rapid and efficient surface grafting strategy based on hyperbranched poly-L-lysine (HBPL) was developed to re-engineer the pericardial interface toward improved functional performance and translational potential. The HBPL-surface engineering enhanced the structural stability, resistance to enzymatic degradation, and anti-calcification performance of bovine pericardium (BP). Mechanistic investigations revealed that the hyperbranched topology and dense amino functionality of HBPL regulate calcium binding behavior and inhibit the nucleation and phase transformation of amorphous calcium phosphate. In addition, HBPL modification significantly reduced bacterial adhesion while maintaining favorable cytocompatibility and hemocompatibility. Arteriovenous shunt (AV-shunt) assays ex vivo demonstrated improved blood compatibility under flow conditions, and subcutaneous implantation in rats showed attenuated inflammatory responses and reduced calcification. Furthermore, balloon-expandable valves fabricated from HB-BP exhibited satisfactory hydrodynamic performance and durability exceeding 200 million fatigue cycles. Collectively, these results identify the HBPL-based surface engineering as a simple and versatile platform for developing BHVs with enhanced resistance to calcification and infection, improved durability, and promising translational potential.