Digital Light Processing 3D Bioprinting of Biomimetic Corneal Stroma Equivalent Using Gelatin Methacryloyl and Oxidized Carboxymethylcellulose Interpenetrating Network Hydrogel

This study developed a dual-crosslinkable interpenetrating network (IPN) hydrogel composed of gelatin methacryloyl (GelMA) and oxidized carboxymethylcellulose (OxiCMC) for digital light processing (DLP) 3D bioprinting of a biomimetic corneal stroma equivalent. The hydrogel achieved high transparency (>90% above 500 nm), an improved compressive modulus of 106 ± 8 kPa—closely matching native corneal tissue—and supported >93% human corneal keratocyte viability and proliferation. Using tartrazine as a photoabsorber enhanced print resolution and shape fidelity. The printed constructs reproduced the native corneal curvature (central thickness ≈ 479 µm, peripheral ≈ 864 µm) with optical clarity and mechanical strength suitable for transplantable corneal equivalents.