Background/purpose: This study was aimed at characterizing the structure and function of engineered fetal cartilage in vitro.

Methods: Chondrocytes from ovine specimens of fetal elastic, fetal hyaline, and adult elastic cartilage were expanded in culture and their growth rates determined. Cells were seeded onto synthetic scaffolds, which were then maintained in a bioreactor. Matrix deposition was determined by specific staining and quantitative assays for glycosaminoglycans (GAG), type II collagen (CII), and elastin, as well as compared with native tissue. Statistical analysis was by analysis of variance (ANOVA) and Students' t test, with significance set at P less than.01.

Results: Fetal elastic chondrocytes grew significantly faster than all other cell types. All fetal constructs resembled hyaline cartilage, regardless of the cell source. There were significantly higher levels of GAG and CII in fetal versus adult constructs, but no significant difference between fetal constructs from different sources. Unlike their adult counterparts, fetal constructs had GAG and CII levels similar to native tissues.

Conclusions: Fetal chondrocytes can be rapidly expanded in culture. Compared with adult constructs, matrix deposition is enhanced in engineered fetal cartilage, which closely resembles native tissue, regardless of the cell source. Engineered fetal cartilage may be a preferable option during surgical reconstruction of select congenital anomalies.