Autogenous tissue-engineered cartilage: evaluation as an implant material.
OBJECTIVE
To determine whether autogenous tissue-engineered cartilage grafts can be synthesized in predetermined shapes, to compare tissue-engineered cartilage with native cartilage with respect to histological characteristics and biomechanical properties, and to demonstrate how multiple transplantations affect tissue-engineered cartilage.


METHODS
Controlled, prospective animal study.


METHODS
Twenty New Zealand white rabbits, 3 weeks old.


METHODS
Autogenous chondrocytes were seeded onto biodegradable polyglycolic acid-poly-L-lactic acid copolymer templates in 1 of 3 shapes (cross, nasal tip graft, or auricle). Grafts and controls of sculpted cartilage were divided among 3 groups: short-term implantation (4 or 8 weeks), long-term implantation (6 or 12 months), and a reimplantation group. The gross morphological features, histological findings, and tensile strength of grafts were assessed.


RESULTS
Production of tissue-engineered cartilage was confirmed in 30 of 31 implants. Histological evaluation demonstrated characteristic cartilaginous matrix, but with prominent vascular and fibrous tissue ingrowth. In long-term implantation grafts (n=4), foci of osteoid were evident by 6 months. In the subset of transplanted grafts (n=7), 5 of 7 demonstrated significant loss of cartilage viability. Tensile strength measurements demonstrated values 24% and 41% of those of controls at 4 and 8 weeks, respectively.


CONCLUSIONS
Tissue-engineered autogenous cartilage can be reliably produced, and predetermination of graft shape is possible. Histologically, grafts represent composites of mature cartilage infiltrated by vasculature and fibrous tissue, with delayed osteoid formation. Graft viability is compromised by early transplantation, and tensile strength is less than that of native cartilage. These results demonstrate the feasibility of tissue-engineered cartilage as a future graft material.
Britt
J C
JC
Department of Otolaryngology-Head and Neck Surgery, University of Virginia Medical Center, Charlottesville 22906-0008, USA.
Park
S S
SS
D000818:Animals; D001673:Biodegradation, Environmental; D002356:Cartilage / Q000637:transplantation*; D002478:Cells, Cultured; D019902:Chondrocytes / Q000166:cytology*; D006085:Graft Survival; D020007:Implants, Experimental; D019344:Lactic Acid; D008722:Methods; D011091:Polyesters; D011100:Polyglycolic Acid; D011108:Polymers; D011446:Prospective Studies; D011817:Rabbits; D013718:Tensile Strength; D014182:Transplantation, Autologous
D011091:Polyesters; D011108:Polymers; D011100:Polyglycolic Acid; D019344:Lactic Acid; C033616:poly(lactide)