A multiscale biohybrid strategy using biostable and biodegradable polymers to develop a growth-accommodating heart valved conduit for children

Background Congenital heart diseases affect nearly 1% of births and often require valve replacement. Current prostheses lack growth potential and regenerative capacity, necessitating repeated surgeries. Tissue-engineered valve replacements offer promising alternatives; however, achieving long-term mechanical durability alongside tissue remodeling remains a key challenge. Technology Here, we developed a biohybrid valved conduit capable of supporting long-term valve function, promoting neo-tissue formation, and accommodating somatic growth without structural failure. A two-part biohybrid valved conduit consists of dip-molded biostable valve leaflets and a bilayer conduit which were fabricated by electrospinning a blend of biodegradable and biostable polymers. The continuous structure of the valve conduit aims to maintain mechanical integrity at the valve-conduit junction while accommodating tissue remodeling within the conduit. Results The bilayer conduits had inner layer pores of 3.71 ± 0.78 μm and varying outer layer pore sizes of 9.23 ± 1.23 μm-14.59 ± 1.07 μm supporting cellular infiltration and matrix deposition. Mechanical testing demonstrated that Young's modulus ranged from 1.98 ± 0.12-4.03 ± 0.62 MPa. Hydrodynamic performance of valved conduits met ISO5840:2019 standards, with regurgitation fraction between 0.6 and 4.7%, effective orifice area between 0.93 and 1.95 cm 2 , pressure gradient between 8.1 and 10.8 mmHg. They maintained functionality and structural integrity after 200 million cycles of accelerated wear test and adhesive strength between conduit wall and valve remained stable. In vitro and i n vivo studies confirmed biocompatibility, sustained cell migration, ECM deposition, and native tissue integration.These findings demonstrate the early feasibility of the biohybrid valved conduit technology as a growth-accommodating platform for heart valve replacements. Further long-term evaluation in large-animal models will be essential to validate durability, growth potential, and clinical translation.