Engineering a Joint: A Chimeric Construct with Bovine Chondrocytes in a Devitalized Chick Knee

Abstract

This study assessed the feasibility of a devitalized knee as a scaffold for an engineered chimeric joint. Embryonic chick knees (19 days old), devitalized by lyophilization or multiple freeze-thaw cycles, were tested as scaffolds for repopulation with bovine articular chondrocytes (bACs). bACs were seeded into porous three-dimensional collagen sponges and were cultured for 1 day before fabrication of chimeric constructs. A pair of cell-seeded sponges was inserted into the joint space to contact preshaved articular surfaces. In some constructs, a sterile membrane of expanded polytetrafluoroethylene (ePTFE) was inserted between the collagen sponges. Histologic analysis showed that at 1 week, sponges with bACs were adherent to the shaved articular surfaces of the joint with accumulation of metachromatic extracellular matrix. Penetration of bACs and neomatrix into the devitalized matrix appeared to begin in preexistent epiphyseal canals and was observed to some extent in all specimens. Membranes of ePTFE maintained a joint space at 2 and 3 weeks, whereas there was fusion across the two sponges in many specimens lacking the membrane. Gene expression analysis demonstrated that lyophilization, but not multiple freeze-thaw cycles, completely devitalized the chick knees. These studies identified several design parameters crucial for successful engineering of a chimeric joint.

Collagen scaffolds for tissue engineering

“…As a model for bioengineered joint, we used porous collagen sponges as a scaffold for bovine articular chondrocytes to generate articular cartilage in a chimeric construct with a devitalized chick knee. 38 Two sponges were used to resurface the femoral and tibial joint surfaces ( Figure 3). First, the construct was maintained in vitro and evaluated at intervals.…”

Phenotypic analysis of bovine chondrocytes cultured in 3D collagen sponges: effect of serum substitutes

“…This structure differs from that of woven polymer lattices (Li et al 2003;Woodfield et al 2004) or collagen hydrogels. Our previous work demonstrated that these constructs meet several criteria that are desirable for tissue engineering of cartilage: they are biologically compatible (demonstrated in mice, with osteoblasts) (Gerstenfeld et al 1996); they are adherent to cartilage (Zaleske et al 2003); and they support chondrogenesis in vitro and in vivo (Warden et al 2004). …”

Shape, loading, and motion in the bioengineering design, fabrication, and testing of personalized synovial joints

“…These include phalanges formed with solvent-cast synthetic polymer scaffolds in combination with periosteum and isolated chondrocytes (Isogai, et al, 1999, Landis, et al, 2005, Sedrakyan, et al, 2006), patella formed from a milled trabecular bone substrate with a molded chondrocyte-agarose layer (Hung, et al, 2003), and mandibular condyle formed from molded PEG hydrogel with stratified layers of encapsulated stem cells (Alhadlaq, et al, 2004). Whole-joint bioengineering has been attempted by apposition of engineered distal and middle phalanges with a joint capsule formed by a tenocyte-seeded PGA mesh (Isogai, et al, 1999, Landis, et al, 2005), and resurfacing devitalized chick knees with chondrocyte-seeded collagen sponges (Warden, et al, 2004, Zaleske, et al, 2003). In these whole-joint studies, anti-adhesion sheets of silicone or ePTFE were used to prevent fusion of opposing articular surfaces during in vitro or subcutaneous in vivo culture.…”