3D-Printed Scaffolds for Ear Reconstruction Using Decellularized Human Cartilage-Derived Bioink and Polycaprolactone

Reconstructing auricular tissue is challenging because ear cartilage has few blood vessels and limited regenerative capacity. Traditional methods that utilize autologous costal cartilage or synthetic polymers often lead to donor site morbidity and suboptimal biocompatibility. In this study, we introduce 3D-printed scaffolds composed of decellularized human cartilage-derived bioink combined with polycaprolactone (PCL), designed to enhance both tissue regeneration and mechanical stability. The decellularization process effectively removed cellular components while preserving glycosaminoglycan and total collagen, comparable to those in native cartilage. We formulated the bioink by incorporating decellularized human cartilage particles into hyaluronic acid and carboxymethyl cellulose gels, optimizing the rheological properties for 3D printing. <i>In vitro</i> tests demonstrated that the decellularized human cartilage-derived bioink exhibited no cytotoxicity and facilitated the migration and chondrogenic differentiation of human adipose-derived stem cells. We fabricated 3D-printed scaffolds using this bioink combined with PCL and evaluated their performance in rabbits over a one-year implantation period. Our results indicated that the scaffolds maintained structural integrity throughout the year and exhibited significant neovascularization and chondrogenesis. Histological analysis revealed increased blood vessel formation in scaffolds with higher ratios and greater decellularized cartilage content with notable differences observed across varying porosities. These findings suggest that 3D-printed scaffolds with decellularized human cartilage-derived bioink and PCL offer a promising approach for auricular reconstruction, potentially improving outcomes for patients with microtia.