Cartilage Repair and Subchondral Bone Migration Using 3D Printing Osteochondral Composites: A One-Year-Period Study in Rabbit Trochlea

Abstract

Increasing evidences show that subchondral bone may play a significant role in the repair or progression of cartilage damage in situ. However, the exact change of subchondral bone during osteochondral repair is still poorly understood. In this paper, biphasic osteochondral composite scaffolds were fabricated by 3D printing technology using PEG hydrogel and β-TCP ceramic and then implanted in rabbit trochlea within a critical size defect model. Animals were euthanized at 1, 2, 4, 8, 16, 24, and 52 weeks after implantation. Histological results showed that hyaline-like cartilage formed along with white smooth surface and invisible margin at 24 weeks postoperatively, typical tidemark formation at 52 weeks. The repaired subchondral bone formed from 16 to 52 weeks in a “flow like” manner from surrounding bone to the defect center gradually. Statistical analysis illustrated that both subchondral bone volume and migration area percentage were highly correlated with the gross appearance Wayne score of repaired cartilage. Therefore, subchondral bone migration is related to cartilage repair for critical size osteochondral defects. Furthermore, the subchondral bone remodeling proceeds in a “flow like” manner and repaired cartilage with tidemark implies that the biphasic PEG/β-TCP composites fabricated by 3D printing provides a feasible strategy for osteochondral tissue engineering application.

Integrating three-dimensional printing and nanotechnology for musculoskeletal regeneration

“…A schematic of this process is shown in figure 4. Findings of this study revealed increased levels of collagen type I and type II formation as well as increased glycosaminoglycan and DNA production when compared to samples without printed chondrocytes [67]. In vitro results show promise as a hybrid approach for repairing articular cartilage.…”

“…Researchers continue to struggle with the balance of biocompatibility, bioactivity, and acceptable mechanical properties of 3D printed implants. Currently, no effective scaffold has been fabricated to recapitulate the zonal organization, extracellular matrix composition, and mechanical properties of native load bearing cartilage, like that found within articulating joints [67]. Conversely, recent successes in non-load-bearing regions provide insight and promise of progress for this challenging tissue moving forward.…”

“…Images labeled with E represent a defect with scaffold after respective number of days. Image with C24 represents the control defect, without scaffold, after 24 d. Reproduced from [67]. CC BY 3.0.…”

Current advances in solid free-form techniques for osteochondral tissue engineering

“…In another study, Zhang et al [18] fabricated PEG/β-TCP OC scaffolds using, as in previous work, SL and gel casting. However, unlike the previous approach, the authors produced a β-TCP ceramic scaffold using the gel casting process, while for the chondral zone it was used SL.…”

Bioprinting of osteochondral tissues: A perspective on current gaps and future trends

“…For example, hydroxyapatite has been printed with a porous polylactide (PLA) scaffold to mimic the osteochondral tissue composition and in vivo results exhibited osteogenic and chondrogenic markers in both respective layers [45] . Similarly, stereolithography process has been used to fabricate osteochondral constructs with polyethylene glycol and beta (β)-tricalcium phosphate, which showed encouraging results in a year-long follow-up study in a rabbit critical-size defect model [46] . Using fused deposition modeling, Cao et al fabricated a honey-comb-like PCL scaffold with 0°/60°/120° lay-down pattern to create anisotropic structures [47] .…”