A biodegradable electrical bioconductor made of polypyrrole nanoparticle/poly(D,L-lactide) composite: A preliminaryin vitro biostability study

✍ Scribed by Wang, Zhaoxu ;Roberge, Christophe ;Wan, Ying ;Dao, L� H. ;Guidoin, Robert ;Zhang, Ze

• Publisher: John Wiley and Sons
• Year: 2003
• Tongue: English
• Weight: 268 KB
• Volume: 66A
• Category: Article
• ISSN: 0021-9304
• DOI: 10.1002/jbm.a.10037

✦ Synopsis

Abstract

The electrical stability of a novel polypyrrole (PPy)/poly(D,L‐lactide) (PDLLA) composite was studied in vitro and compared with that of PPy‐coated polyester fabrics. Specimens were incubated in Ringer's solution at 37°C for up to 8 weeks with or without the circulation of DC current under a constant 100 mV voltage. In situ current variation with incubation time was recorded. The AC volume electrical conductivity of the specimens before and after incubation in phosphate‐buffered saline was recorded using a frequency analyzer. Water absorption and weight loss were monitored metrologically. Changes in the oxidation state of incubated PPy were analyzed with X‐ray photoelectron spectroscopy. The morphological changes were observed with scanning electron microscopy, and the glass transition temperature of the PDLLA was investigated using differential scanning calorimetry. The PPy/PDLLA composite in Ringer's solution sustained a relatively stable conductivity up to 8 weeks after an initial period of “conditioning.” The PPy‐coated fabrics experienced a rapid loss of conductivity when subjected to electrical circulation and regained part of it when disconnected. The volume conductivity of the nonincubated PPy/PDLLA membrane behaved as a typical conductor in the low‐frequency range. The mechanisms involved in the various electrical behaviours of the PPy/PDLLA composite and PPy‐coated fabrics are discussed. In conclusion, the PPy/PDLLA composite was able to deliver a biologically significant electrical current in a simulated biological solution for up to 8 weeks and therefore may be considered as a first‐generation synthetic biodegradable bioconductor. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 66A: 738–746, 2003