Tissue Engineering of Elastic Cartilage by Using Scaffold/Cell Constructs With Different Physical and Chemical Properties

In this study, we compared three scaffold/cell constructs with different physical and chemical properties, in their potential for tissue engineering elastic cartilage. Group I consisted of PCL scaffolds Group II custom-made non-woven made of PGA fibers in combination with agarose beads; collagen sponges were used in-group III. Chondrocytes were isolated via enzyme digestion from an ear cartilage biopsy of 2 year old male piglets. 250,000 cells in 30 μl were seeded into three different scaffold types. The specimens were then cultured for 1 week. The scaffold/cell constructs and controls were placed subcutaneously on the paravertebral fascia for 4 1/2 month. Explanted scaffolds were cut in cubical blocks and mechanically tested in phosphate buffered saline solution at 37°C in accordance with ASTM F451-99a Standard Specification for Acrylic Bone Cement. After explantation the non-seeded PCL specimens (control) had compressive stiffness and 1 % offset yield strength in plane of 5.6 ± 0.4 MPa and out of plane 4.9 ± 0.5 MPa, respectively. In comparison, the scaffolds with a seeded specimens had compressive stiffness of 4.9 ± 0.5 MPa and 3.9± 0.3 MPa, respectively. The polymer molecular weight distribution was determined by gel permeation chromatography to study the in vivo degradation of the polymer matrix. Sections of expiants were prepared using standard cryohistochemical techniques and stained with anti-type II III, DC collagen antibodies, Factin and anti-integrin beta, and I. There was considerably more organized extracellular matrix formation in group I, whereas group II and III exhibiting a loosely scattered patterns. Results of the toluidine blue, trichrome Goldner’s staining and collagen II expression showed cartilage-like tissue formation in the PCL scaffolds whereas all the other matrices showed fibrous tissue in combination with calcification.