Visible-Light-Induced Silk Fibroin Hydrogels with Carbon Quantum Dots as Initiators for 3D Bioprinting Applications

Digital light processing (DLP) 3D bioprinting technology has attracted increasing attention in tissue engineering in recent years. However, it still faces significant technical and operational challenges such as cell carcinogenesis caused by prolonged exposure to ultraviolet light and the presence of heavy metal ions in complex photoinitiator systems. In this study, a novel strategy is designed to introduce carbon quantum dots into visible-light-induced silk fibroin bioink as initiators (CDs/SilMA) applied for DLP 3D bioprinting technology. The incorporation of carbon quantum dots facilitates the formation of precise hydrogel structures at 415 nm visible wavelength, enabling the creation of brain, bronchus, spine, and ear models. Replacing heavy metal photoinitiators with carbon quantum dots imparts fluorescence properties to the bioink and enhances its mechanical properties. Meanwhile, the fibroin protein-based hydrogel exhibits favorable properties, such as drug loading, slow release, degradability, and biocompatibility. This is the first study to propose the application of carbon quantum dots in silk fibroin-based bioink. Moreover, the resulting product demonstrates excellent compatibility with the DLP printing process, making it promising for practical applications in various tissue engineering scenarios with specific requirements.