Progressive Insights into 3D Bioprinting for Corneal Tissue Restoration

The complex architecture of the cornea, characterized by specifically organized collagen fibrils and distinct cellular layers, poses significant challenges for traditional tissue engineering strategies to replicate its native function. 3D Bioprinting offers a promising solution by enabling the precise, layer-by-layer fabrication of corneal tissues, closely mimicking the essential characteristics needed for vision restoration and long-term graft success. This Review critically examines the key biomechanical, optical, and structural attributes of the cornea necessary for its effective engineering and accurate 3D bioprinting. It provides a comprehensive overview of different 3D bioprinting modalities utilized for corneal tissue engineering and offers insights into potential improvements. Additionally, it details the requirements for a corneal bioink suitable for 3D bioprinting, ensuring it meets the necessary corneal functions. The Review also delves into the current challenges in 3D bioprinting of corneal tissue and proposes potential solutions to successfully replicate the complex architecture and function of the cornea. Furthermore, it explores innovative approaches such as the use of induced pluripotent stem cells, gene therapy, and cornea-on-a-chip technologies, which hold promise for advancing corneal regeneration. The Review aims to visualize the future of corneal 3D bioprinting and the potential of integrating it with other techniques. Lastly, the review discusses clinical implications, emphasizing the potential of bioprinted corneal implants to address the global donor cornea shortage and significantly improve patient outcomes.