The growth of chondrocytes into a fibronectin-coated biodegradable scaffold.

Porous scaffolds made from a biodegradable copolymer of trimethylene carbonate and glycolide were evaluated for tissue-engineered medical products. We examined the scaffold coated with cell adhesion protein and fibronectin and cultured under a dynamic mixing condition to enhance the growth of chondrocytes. Our hypothesis was that the combination of coating and dynamic mixing would be beneficial to the viability of the chondrocytic cells. Fibronectin was selected as the model protein because of its availability and routine assaying methods. Sterile samples of scaffolds of about 1 mm in thickness were coated with fibronectin at 37 degrees C for 1.5 h. Four groups of scaffolds were used: uncoated static or dynamic, and coated static or dynamic. Scaffold samples were placed in either a Petri dish or a spinner flask (static vs. dynamic groups) after inoculation with rat chondrocytes of an initial cell density of 1.29 x 10(5) cell/mL. After 7, 14, 21, and 28 days, each sample was fixed, embedded, and sectioned at 5 micro thickness. The sections were double-label immunostained using antibodies against cellular fibronectin synthesized by adherent cells as a measure of cell viability. A Hoechst 33258 nuclear stain was used to measure the number of cells attached to the scaffold at each time interval. The slides were examined using a fluorescence microscope to determine the cell ingrowth. At least 25 fields/treatment group (except the 7 day group) were measured. The data showed that cell in-growths into the porous scaffolds were higher at all time periods for the coated dynamic group than those for the other three groups.