Osteochondral Regeneration With Anatomical Scaffold 3D-Printing-Design Considerations for Interface Integration

Area of Science:

• Biomaterials Engineering
• Regenerative Medicine
• Orthopedic Surgery

Background:

• Clinical need exists for osteochondral scaffolds with complex geometries to restore articulating joint surfaces.
• 3D-printing enables anatomically shaped scaffolds with interconnected architectures, surpassing limitations of simple plug-shaped designs for focal defects.
• Mechanical loading and interface strength are critical challenges for 3D-printed osteochondral constructs, yet interface strength testing is often overlooked and lacks standardization.

Purpose of the Study:

• To review 3D-printed scaffolds for osteochondral applications, focusing on interface integration and biomechanical evaluation.
• To assess different 3D-printing methods and scaffold designs for creating multiphasic osteochondral constructs.
• To recommend standardized methods for evaluating interface strength and integration in stratified scaffolds.

Main Methods:

• Review of literature on 3D-printed scaffolds for osteochondral regeneration, including multiphasic cylindrical and anatomically shaped designs.
• Analysis of various 3D-printing techniques such as fused deposition modeling, stereolithography, and bioprinting.
• Evaluation of interface integration strategies, including interdigitating and mechanical interlocking designs.
• Assessment of biomechanical evaluation methods, particularly interface shear testing.

Main Results:

• 3D-printing allows for complex geometries and interconnected architectures in osteochondral scaffolds.
• Multiphase scaffolds commonly use interdigitating or mechanical interlocking designs to enhance interface strength and prevent delamination.
• Combining a robust 3D-printed osteal polymer with an interlocking chondral hydrogel phase shows promise for phase integration.
• Interface shear testing is recommended for reliable evaluation of layer integration in stratified scaffolds.

Conclusions:

• Mechanical interlocking is a promising strategy for scaling up multiphasic scaffold applications for large, anatomically shaped joint surface regeneration.
• Standardized interface strength testing, specifically the interface shear test, is crucial for advancing the field and enabling direct comparisons.
• The current body of research on 3D-printed interfacial scaffolds provides a strong foundation for future development in regenerating osteochondral tissues in load-bearing joints.