Meniscal tissue regeneration in porous 50/50 copoly(l-lactide/ε-caprolactone) implants

• Published in: Biomaterials 1997-04, Vol.18 (8), p.613-622
• Main Authors: de Groot, J.H., Zijlstra, F.M., Kuipers, H.W., Pennings, A.J., Klompmaker, J., Veth, R.P.H., Jansen, H.W.B.
• Format: Article
• Language: English
• Subjects: Animals; Biocompatible Materials; Biological and medical sciences; Calorimetry, Differential Scanning; Chromatography, Gel - methods; degradation; Dogs; Magnetic Resonance Spectroscopy; Medical sciences; Meniscal repair; Menisci, Tibial - physiology; Menisci, Tibial - surgery; Microscopy, Electron, Scanning; Orthopedic surgery; polyester; Polyesters; porous materials; Prostheses and Implants; Rats; Rats, Wistar; Regeneration - physiology; Spectroscopy, Fourier Transform Infrared; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases
• ISSN: 0142-9612; 1878-5905
• DOI: 10.1016/S0142-9612(96)00169-X

Porous materials of a high-molecular-weight 50/50 copolymer ofl-lactide and ɛ-caprolactone with different compression moduli were used for meniscal repair. In contrast to the previously used 4,4′-diphenylmethane and 1,4-trans-cyclohexane diisocyanates containing polyurethanes, degradation products of the copolymer are non-toxic. Two series of porous materials with compression moduli of 40 and 100 kPa respectively were implanted in the knees of dogs using a new, less traumatizing suturing technique. A porous aliphatic polyurethane series with compression modulus of 150 kPa was implanted for comparison. Adhesion of the implant to meniscal tissue was found to be essential for healing of the longitudinal lesion. Copolymer implants showed better adhesion, probably due to the higher degradation rate of the copolymer. Fibrocartilage formation was found to be affected by the compression modulus of the implant. Implants with a modulus of 40 kPa did not show ingrowth of fibrocartilage, whereas implants with compression moduli of 100 and 150 kPa yielded 50–70 and 80–100% fibrocartilage respectively. During degradation the copolymer phase separated into a crystalline phase containing mainlyl-lactide and an amorphous phase containing mainly ɛ-caprolactone. The copolymer degraded through bulk degradation.