ABSTRACT
OBJECTIVE: To investigate the histologic and biomechanical properties of rabbit tissue-engineered cartilage exposed to insulinlike growth factor 1 and transforming growth factor beta. DESIGN: Controlled study. SUBJECTS: New Zealand white rabbits aged 3 to 4 weeks. INTERVENTION: A mean of 3.42 million rabbit chondrocytes were placed onto 2 x 1-cm polyglycolic/poly-L-lactic acid mesh templates. One group (n = 21) was placed in complete medium for 4 days. The experimental group (n = 19) was placed into complete medium with insulinlike growth factor 1 (50 ng/mL) and transforming growth factor beta (1 ng/mL). After 96 hours the templates were removed and implanted into the dorsum of the donor rabbit. The templates were harvested after 8 weeks and subjected to gross, histologic, and biomechanical testing. RESULTS: All samples showed histologic characteristics consistent with normal cartilage. No statistically significant differences were found with biomechanical testing between the control and experimental groups. CONCLUSION: In spite of more promising results from earlier studies, these results do not support improved histologic features or mechanical performance with the addition of insulinlike growth factor 1 and transforming growth factor beta to the chondrocyte/template complex.
Subject(s)
Chondrocytes/drug effects , Ear Cartilage/drug effects , Insulin-Like Growth Factor I/pharmacology , Tissue Engineering/methods , Transforming Growth Factor beta/pharmacology , Animals , Biomechanical Phenomena , Chondrocytes/pathology , Chondrocytes/physiology , Ear Cartilage/pathology , Ear Cartilage/physiology , Models, Animal , RabbitsABSTRACT
OBJECTIVE: To describe tissue-engineered cartilage from rabbit and human chondrocytes. STUDY DESIGN AND SETTING: Chondrocytes from rabbit and human ears were seeded onto a template and implanted for 8 or 16 weeks of in vivo incubation. RESULTS: For the 8-week and 16-week groups, the UTS for cartilage was 3.8 MPa and 3.7 MPa, stiffness was 62.4 MPa and 51.8 MPa, and resilience was 181.8 J/m(3) and 109.1 J/m(3), respectively. Experimental cartilage was significantly different from controls. From 5 human specimens, the UTS was 5.4 MPa, stiffness was 6.6 MPa, and resilience was 2.0 J/m(3). The control had UTS of 8.8 MPa, stiffness of 12.2 MPa, and resilience of 2.9 J/m(3). Histology showed mature cartilage but with a fibrovascular infiltrate and increased cellularity. CONCLUSIONS: Mechanical properties of tissue-engineered cartilage can be quantified and are less than that of controls.