Autologous temporomandibular joint reconstruction independent of exogenous additives: a proof-of-concept study for guided self-generation

Abstract

Joint defects are complex and difficult to reconstruct. By exploiting the body’s own regenerative capacity, we aimed to individually generate anatomically precise neo-tissue constructs for autologous joint reconstruction without using any exogenous additives. In a goat model, CT scans of the mandibular condyle including articular surface and a large portion of the ascending ramus were processed using computer-aided design and manufacturing. A corresponding hydroxylapatite negative mold was printed in 3D and temporarily embedded into the transition zone of costal periosteum and perichondrium. A demineralized bone matrix scaffold implanted on the contralateral side served as control. Neo-tissue constructs obtained by guided self-generation exhibited accurate configuration, robust vascularization, biomechanical stability, and function. After autologous replacement surgery, the constructs showed stable results with similar anatomical, histological, and functional findings compared to native controls. Further studies are required to assess long-term outcome and possible extensions to other further applications. The absence of exogenous cells, growth factors, and scaffolds may facilitate clinical translation of this approach.

Prefabrication of a functional bone graft with a pedicled periosteal flap as an in vivo bioreactor

“…The DBM scaffolds were derived from eleven donated, human femoral head bones (n = 11 donors) during artificial femoral head replacement, and informed consent was obtained in accordance with the Declaration of Helsinki. DBM scaffolds were prepared as previously reported 39 . All methods regarding human tissue samples in this study were approved and conducted in accordance with the Laboratory Animal Research Committee of Shanghai Jiao Tong University School of Medicine.…”

“…Briefly, after removal of residual soft tissues, the cancellous bones of the femoral heads were trimmed to cylinders with a diameter of 4 mm and length of 10 mm using a trephine. After repeated washing and processes were performed, including degreasing, decalcification, and removal of non-collagen protein were performed, SEM (PhilipsXL-30, Amsterdam) scanning was performed to determine DBM microstructure and porosity as previously described 39 . Finally, the prepared scaffolds were sterilized by gamma-radiation (Zhejiang YinDu Ltd, China) before use.…”

“…Then, the specimens were decalcified in 20% ethylenediaminetetraacetic acid for 30 days and dehydrated, embedded in paraffin, and sectioned. Sections were stained with HE and AM for the evaluation of bone structures and blood vessels as previously described 39 . Meanwhile, the other half of the specimens was dehydrated in a graded alcohol series and then embedded in polymethylmethacrylate.…”

“…Then, the cross-sectional area and height of the test samples were measured using Image-Pro 5.0 software (Media Cybernetics). The samples were tested under uniaxial compression using a biomechanical analyzer (Instron-8874, Canton, MA) according to a previously described protocol 39 .…”

Large Animal Models of an In Vivo Bioreactor for Engineering Vascularized Bone

“…explored in generating tissues appropriate for temporomandibular joint (TMJ) repair in a caprine model. 30 Rather than implant scaffolds against the periosteum of the rib, scaffold was implanted against the transition region between the rib costal cartilage and bony periosteum. Thus, tissue generated had a cartilaginous end and bony end similar to the native TMJ.…”