One-pot synthesis of hydroxyapatite hybrid bioinks for digital light processing 3D printing in bone regeneration

Three-dimensional (3D) bioprinting has revolutionized tissue engineering by enabling precise fabrication with bioinks. Among these techniques, digital light processing (DLP) stands out due to its exceptional resolution, speed, and biocompatibility. However, the progress of DLP is hindered by the limited availability of suitable bioinks. Currently, some studies involve simple mixing of different materials, resulting in bioinks that lack uniformity and photopolymerization characteristics. To address this challenge, we present an innovative one-pot synthesis method for bioinks based on methacrylated gelatin/alginate with hydroxyapatite (HAP). This approach offers significant advantages in terms of efficiency and uniformity. The synthesized bioinks demonstrate excellent printability, stability, and notably enhanced mechanical properties, facilitating optimal in vitro compatibility. Additionally, the HAP-hybrid bioinks printed scaffolds demonstrated impressive bone repair capabilities in vivo compared with pure organic bioinks. In conclusion, the Gel/Alg/HAP bioinks presented herein offer an innovative solution for DLP bioprinting within the field of bone tissue engineering. Their multifaceted advantages help overcome the limitations of restricted bioink choices, pushing forward the boundaries of bioprinting technology and contributing to the progress of regenerative medicine and tissue engineering.