The Application of Three-Dimensional-Printed Hydrogels in Bone Tissue Engineering.

Bone defects are a prevalent clinical issue that presents a serious medical challenge. Bone tissue engineering (BTE) has emerged as an effective approach for treating large bone defects. Hydrogels, as hydrophilic three-dimensional polymers, are recognized as suitable material for BTE due to their excellent biocompatibility and degradability. However, the submicron and nanoporous structure of hydrogels limits the survival of osteoblasts, hindering bone tissue regeneration. In recent years, 3D printing technology has attracted appreciable attention. The use of hydrogels as 3D-printed ink facilitates the printing of hydrogels in any desired shape, enabling personalized or more complex requirements. This article provides a systematic review of the latest applications of 3D-printed hydrogels in BTE. These hydrogels serve as a multifunctional platform for the next generation technology in treating bone defects. The advantages and limitations of 3D-printed hydrogels in BTE are discussed, and future research directions are explored. This review can form the basis for future hydrogel design.