213 POROUS POLYBUTYLENE TEREPHTHALATE IMPLANTS ALLOW FOR BONE INGROWTH AND PROVIDE A WELL-ANCHORED SCAFFOLD THAT CAN BE USED TO DELIVER TISSUE-ENGINEERED CARTILAGE

• Published in: Journal of investigative medicine Vol. 54; no. 1; p. S116
• Main Authors: Szivek, J. A., Bliss, C. L., Geffre, C., Margolis, D. S., DeYoung, D. W., Ruth, J. T., Schnepp, A. B., Tellis, B., Vaidyanathan, R. K.
• Format: Journal Article
• Language: English
• Published: London Sage Publications Ltd 01-01-2006
• ISSN: 1081-5589; 1708-8267
• DOI: 10.2310/6650.2005.X0004.212

While joint pain and loss of mobility are common causes of impairment, there are few procedures that can consistently restore the long-term function of damaged articular cartilage. One approach that offers a potential solution for articular cartilage repair is replacement of the damaged cartilage using a tissue-engineered scaffold. The goal of this study was to measure loading and bone attachment in sensate, porous, calcium phosphate ceramic (CPC) coated polybutylene terephthalate (PBT) scaffolds that have been implanted in the medial compartment of the knees of 6 canines. In addition histology, histomorphometry, and scanning electron microscopy (SEM) were used to characterize bone growth into and around the PBT scaffold. In vivo measurements from the calibrated scaffolds indicated that peak loads in the dog knees ranged from 80-120N. Post-sacrifice biomechanical testing indicated that these loads correlated to pressures of 11 ± 1.54 MPa in the medial compartment of the knees. Histology demonstrated a bone volume of 6.8 ± 8.8% within the scaffold pores and an osteoid volume of 64.9 ± 17.2%. Histomorphometry indicated an increased bone formation rate within the scaffold pores, 8.2E-5 ± 5.9E-5 μm3 /μm2 /day, compared to 1.3E-5 ± 0.8E-5 mm3 /μm2 /day in control knees. SEM demonstrated less bone within the scaffold pores compared to the extensive amount of bone surrounding the scaffold and in intimate contact with the CPC particles. These results demonstrate that the scaffold is mechanically coupled to the bone. In addition, the increased bone formation rate and osteoid within the PBT pores demonstrate that bone formation is still occurring 6 months post-op. Currently studies are focused on the integration of PBT scaffolds containing a tissue-engineered cartilage covering into damaged articular cartilage.