Nedrelow David S, Townsend Jakob M, Detamore Michael S
Stephenson School of Biomedical Engineering, University of Oklahoma, Norman, Oklahoma, USA.
College of Dentistry, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA.
J Biomed Mater Res A. 2025 Jan;113(1):e37804. doi: 10.1002/jbm.a.37804. Epub 2024 Oct 10.
There is a clinical need for osteochondral scaffolds with complex geometries for restoring articulating joint surfaces. To address that need, 3D-printing has enabled scaffolds to be created with anatomically shaped geometries and interconnected internal architectures, going beyond simple plug-shaped scaffolds that are limited to small, cylindrical, focal defects. A key challenge for restoring articulating joint surfaces with 3D-printed constructs is the mechanical loading environment, particularly to withstand delamination or mechanical failure. Although the mechanical performance of interfacial scaffolds is essential, interface strength testing has rarely been emphasized in prior studies with stratified scaffolds. In the pioneering studies where interface strength was assessed, varying methods were employed, which has made direct comparisons difficult. Therefore, the current review focused on 3D-printed scaffolds for osteochondral applications with an emphasis on interface integration and biomechanical evaluation. This 3D-printing focus included both multiphasic cylindrical scaffolds and anatomically shaped scaffolds. Combinations of different 3D-printing methods (e.g., fused deposition modeling, stereolithography, bioprinting with pneumatic extrusion of cell-laden hydrogels) have been employed in a handful of studies to integrate osteoinductive and chondroinductive regions into a single scaffold. Most 3D-printed multiphasic structures utilized either an interdigitating or a mechanical interlocking design to strengthen the construct interface and to prevent delamination during function. The most effective approach to combine phases may be to infill a robust 3D-printed osteal polymer with an interlocking chondral phase hydrogel. Mechanical interlocking is therefore recommended for scaling up multiphasic scaffold applications to larger anatomically shaped joint surface regeneration. For the evaluation of layer integration, the interface shear test is recommended to avoid artifacts or variability that may be associated with alternative approaches that require adhesives or mechanical grips. The 3D-printing literature with interfacial scaffolds provides a compelling foundation for continued work toward successful regeneration of injured or diseased osteochondral tissues in load-bearing joints such as the knee, hip, or temporomandibular joint.
临床上需要具有复杂几何形状的骨软骨支架来修复关节表面。为满足这一需求，3D打印技术使得能够创建具有解剖形状几何结构和相互连接内部架构的支架，突破了仅限于小的圆柱形局灶性缺损的简单塞状支架的限制。用3D打印构建体修复关节表面的一个关键挑战是机械加载环境，特别是要承受分层或机械故障。尽管界面支架的机械性能至关重要，但在先前关于分层支架的研究中，界面强度测试很少受到重视。在评估界面强度的开创性研究中，采用了各种不同的方法，这使得直接比较变得困难。因此，本综述聚焦于用于骨软骨应用的3D打印支架，重点是界面整合和生物力学评估。这种对3D打印的关注包括多相圆柱形支架和解剖形状的支架。在少数研究中，已经采用了不同3D打印方法的组合（例如，熔融沉积建模、立体光刻、用气动挤压载细胞水凝胶进行生物打印），以将骨诱导和软骨诱导区域整合到单个支架中。大多数3D打印的多相结构采用相互交错或机械互锁设计来加强构建体界面，并防止在功能过程中分层。组合各相的最有效方法可能是用互锁的软骨相水凝胶填充坚固的3D打印骨聚合物。因此，建议采用机械互锁来扩大多相支架在更大解剖形状关节表面再生中的应用。对于层整合的评估，建议采用界面剪切试验，以避免可能与需要粘合剂或机械夹具的替代方法相关的假象或变异性。有关界面支架的3D打印文献为继续致力于成功再生膝关节、髋关节或颞下颌关节等承重关节中受伤或患病的骨软骨组织的工作提供了令人信服的基础。
