Critical-sized bone defect repair remains a substantial challenge in clinical settings
and requires bone grafts or bone substitute materials. However, existing biomaterials
often do not meet the clinical requirements of structural support, osteoinductive
property, and controllable biodegradability. To treat large-scale bone defects, the
development of three-dimensional (3D) porous scaffolds has received considerable focus
within bone engineering. A variety of biomaterials and manufacturing methods, including
3D printing, have emerged to fabricate patient-specific bioactive scaffolds that possess
controlled micro-architectures for bridging bone defects in complex configurations.
During the last decade, with the development of the 3D printing industry, a large
number of tissue-engineered scaffolds have been created for preclinical and clinical
applications using novel materials and innovative technologies. Thus, this review
provides a brief overview of current progress in existing biomaterials and tissue
engineering scaffolds prepared by 3D printing technologies, with an emphasis on the
material selection, scaffold design optimization, and their preclinical and clinical
applications in the repair of critical-sized bone defects. Furthermore, it will elaborate
on the current limitations and potential future prospects of 3D printing technology.
STATEMENT OF SIGNIFICANCE: 3D printing has emerged as a critical fabrication process
for bone engineering due to its ability to control bulk geometry and internal structure
of tissue scaffolds. The advancement of bioprinting methods and compatible ink materials
for bone engineering have been a major focus to develop optimal 3D scaffolds for bone
defect repair. Achieving a successful balance of cellular function, cellular viability,
and mechanical integrity under load-bearing conditions is critical. Hybridization
of natural and synthetic polymer-based materials is a promising approach to create
novel tissue engineered scaffolds that combines the advantages of both materials and
meets various requirements, including biological activity, mechanical strength, easy
fabrication and controllable degradation. 3D printing is linked to the future of bone
grafts to create on-demand patient-specific scaffolds.