3D printing of acellular scaffolds for bone defect regeneration: A review

Abstract

Bone injuries can be treated using tissue engineering scaffolds, but the conventional constructs have a big challenge in supplying requirements of native tissue, i.e., bioactivity potential, mechanical stability, controllable biodegradability, and proper cellular interaction. In this regard, 3D printing technology with the possibility of controlling the internal microstructure and geometry of synthesized matrixes was introduced as a promising approach for bone defect regeneration. Although a variety of novel materials, which have shown initial potential for bone repair, can be used for preparing the biocompatible matrixes, the 3D printer type and selecting an innovated technology depend on the properties of applied biomaterials. In all the used methods, tunable, controllable, and interconnected porous microstructure can be fabricated even though identification of suitable porosity and microstructure, which can supply required mechanical properties of natural bone and support cellular adhesion, proliferation, and differentiation, need to evaluate. Therefore, this mini-review explains current advances in acellular 3D printed scaffolds, proper microporous structure and geometry for bone repair, and suitable materials for 3D printing the regenerative bone substitutes. Herein, the novel and recent studies were focused and probable limitations, and existing strategies were discussed.