Biodegradable poly(D,L-lactide) coating of implants for continuous release of growth factors

✍ Scribed by Schmidmaier, G. ;Wildemann, B. ;Stemberger, A. ;Haas, N. P. ;Raschke, M.

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: English
• Weight: 96 KB
• Volume: 58
• Category: Article
• ISSN: 0021-9304
• DOI: 10.1002/jbm.1040

✦ Synopsis

Abstract

Local application of growth factors like insulin like growth factor‐I (IGF‐I) and transforming growth factor‐beta 1 (TGF‐β1) from a biodegradable thin layer of poly(D,L‐lactide) (PDLLA) coated implants could stimulate fracture healing. A new “cold coating technique” for metallic implants was established to produce a biodegradable coating with a high mechanical stability that provides a continuous release of incorporated growth factors. The properties of this bioactive coating were investigated in vitro and in vivo. Scanning electron microscope analysis revealed a coating thickness of in average 14.8 μm on titanium and 10.7 μm on steel wires. Intramedullary implantation and extraction experiments depicted a loss of PDLLA coating from titanium and steel implants of less than 5%. After explantation of the implants, the coating displayed a complete and regular layer without any defects of PDLLA uncovering the metallic surface. Smear tests demonstrate that the coating can be performed under sterile conditions. The PDLLA depicted a reduction of about 8% within 6 weeks in vitro and in vivo. The growth factors were incorporated in a stable form and demonstrated a loss of stability of less than 3% within 42 days and less than 5% within one year. In an elution experiment, 54% IGF‐I and 48% TGF‐β1 were released within the first 48 h. After 42 days, 76% of IGF‐I and 71% of TGF‐β1 were detected in the elution fluid by ELISA. Comparable results were obtained in the in vivo experiments after 42 days. © 2001 John Wiley & Sons, Inc. J Biomed Mater Res (Appl Biomater) 58: 449–455, 2001