Additively Manufactured Multiphasic Bone–Ligament–Bone Scaffold for Scapholunate Interosseous Ligament Reconstruction

Abstract

The scapholunate interosseous ligament (SLIL) is a frequently torn wrist ligament, and current surgical options for SLIL tears are suboptimal. This research aims to develop a novel multiphasic bone–ligament–bone scaffold (BLB) with a porous interface using 3D‐printing and cell sheet technology for the reconstruction of the dorsal scapholunate interosseous ligament. The BLB comprises two bone compartments bridged by aligned polycaprolactone fibers mimicking the architecture of the native tissue. Mechanical testing of the BLBs shows their ability to withstand physiological forces. Combination of the BLB with human bone marrow mesenchymal stem cell sheet demonstrates that the harvesting did not compromise cell viability, while allowing homogeneous distribution in the ligament compartment. The BLBs are loaded with cell sheets and bone morphogenetic protein‐2 in the ligament and bone compartment respectively prior to ectopic implantation into athymic rats. The histology demonstrates rapid tissue infiltration, high vascularization, and more importantly the maintenance of the compartmentalization as bone formation remains localized to the bone compartment despite the porous interface. The cells in the ligament compartment become preferentially aligned, and this proof‐of‐concept study demonstrates that the BLB can provide sufficient compartmentalization and fiber guiding properties necessary for the regeneration of the dorsal SLIL.

Biomaterial-Based Approaches for Regeneration of Periodontal Ligament and Cementum Using 3D Platforms

“…Although multilayered scaffolds [32,39,40] and PDL cell sheet technology [2,41,42] have facilitated spatially compartmentalized hierarchical tooth-supportive structures with specific dimensions for individual periodontal tissues, it is challenging for fibrous tissues to be directionally controlled using micron-scaled, engineered architecture. In particular, topological strategies on 2D substrates have been actively developed to control the angular organizations of PDL cells [43,44,45] as well as other fibrous connective tissue cells [46,47].…”

Finite element analysis of the performance of additively manufactured scaffolds for scapholunate ligament reconstruction

“…We studied the 3D-printed PCL multiphasic scaffold design previously developed by our colleagues for animal models (Fig 2, [21]). The goal of reconstruction with a printed multiphasic scaffold is to implant the bone plugs into drilled holes in the scaphoid and lunate with the longitudinal fibers aligned on the dorsal surface of the scapholunate articulation.…”

“…The BLB scaffold used in this study was a modification of that developed by Lui and co-workers [21] and is made by 3D-printing of medical grade PCL (PC12). The BLB scaffold design is depicted in Fig 2a and b in 2D and 3D views, respectively.…”

“…Henceforth, the ligament portion will be referred to as the "ligament-scaffold". In-vivo testing on small-and medium-sized animals demonstrated biocompatibility of the BLB, as evidenced by vascularisation and incorporation into the rabbit knee, as well as collagen deposition in the ligament-scaffold and bone formation within bone plugs [21,22]. Despite these promising results from animal studies, use of BLB scaffold in the human wrist remains a non-trivial challenge due to the limited understanding of the physiological conditions of the human wrist, and the interaction between scaffold design and surgical installation.…”

“…Tissue engineering is a promising avenue for replacing injured anatomical structures of the hand [19,20], especially given the limited availability of donor tissue. Recently, a multiphasic bone-ligament-bone (BLB) scaffold [21] has been proposed to reconstruct the dorsal SLIL, and which can be 3D-printed using medical grade polycaprolactone (PCL). In this BLB scaffold, the ligament portion was represented by approximately parallel fibers terminating onto orthogonal plugs that interface with bone (Fig 2).…”