Composite Articular Cartilage Engineered on a Chondrocyte-Seeded Aliphatic Polyurethane Sponge

Abstract

To circumvent the reconstructive disadvantages inherent in resorbable polyglycolic acid (PGA)/polylactic acid (PLA) used in cartilage engineering, a nonresorbable, and nonreactive polyurethane sponge (Tecoflex sponge, TS) was studied as both a cell delivery device and as an internal support scaffolding. The in vitro viability and proliferation of porcine articular chondrocytes (PACs) in TS, and the in vivo generation of new articular cartilage and long-term resorption, were examined. The initial cell attachment rate was 40%, and cell density increased more than 5-fold after 12 days of culture in vitro. PAC-loaded TS blocks were implanted into nude mice, became opalescent, and resembled native cartilage at weeks 12 and 24 postimplantation. The mass and volume of newly formed cartilage were not significantly different at week 24 from samples harvested at week 6 or week 12. Safranin O-fast green staining revealed that the specimens from cell-loaded TS groups at week 12 and week 24 consisted of mature cartilage. Collagen typing revealed that type II collagen was present in all groups of tissue-engineered cartilage. In conclusion, the implantation of PAC-TS resulted in composite tissue-engineered articular cartilage with TS as an internal support. Long-term observation (24 weeks) of mass and volume showed no evidence of resorption.

Cell-seeded polyurethane-fibrin structures – A possible system for intervertebral disc regeneration

“…The PU we used provides a macroporous, biocompatible and biodegradable system with sufficient elasticity, and stiffness to resist compressive loading while maintaining structural integrity (Eyrich et al, 2007b). Indeed, PU has been used as a cancellous bone graft substitute in animals and as a scaffold in cartilage tissue engineering Gogolewski et al, 2006;Gogolewski et al, 2007;Liu et al, 2004;Grad et al, 2006;Guelcher et al, 2006). Yang et al (2009) selected PU material as a scaffold to regenerate the annulus fibrosus, demonstrating that the modulation of the PU surface chemistry can influence cell adhesion and early tissue formation.…”

Synthesis and Characterization of Elastin−Mimetic Hybrid Polymers with Multiblock, Alternating Molecular Architecture and Elastomeric Properties

“…Dry xEMHP was soaked in water for 24 h, and the excess water was gently removed prior to the tests. Parallel measurements were carried out on Tecoflex SG80A, a soft, aliphatic polyurethane widely used as an elastomeric material for tissue engineering. − The maximum strain applied to different samples (ε max ; Tecoflex SG 80A, 35%; hydrated xEMHP, 30%; dehydrated xEMHP, 19%) was arbitrarily chosen to avoid reaching the upper transducer limit (2000 g applied force) of the instrument. At least five consecutive loading−unloading cycles (Figure ; only three runs are shown for more facile interpretation) were carried out in order to assess the energy dissipation during cyclic compression, with 1 min recovery time before the next cycle was initiated.…”