Preparation of poly(lactic acid)/siloxane/calcium carbonate composite membranes with antibacterial activity

✍ Scribed by Shingo Tokuda; Akiko Obata; Toshihiro Kasuga

• Publisher: Elsevier Science
• Year: 2009
• Tongue: English
• Weight: 248 KB
• Volume: 5
• Category: Article
• ISSN: 1742-7061
• DOI: 10.1016/j.actbio.2008.10.005

✦ Synopsis

A poly(lactic acid) (PLA)/siloxane/calcium carbonate composite membrane containing mercapto groups (PSC-SH) with antibacterial ability and excellent bone-forming ability was prepared using 3-mercaptopropyltrimethoxysilane for application in guided bone regeneration. Mercapto groups were reported to adsorb silver ions, which are well known to show antibacterial activity. Ionic silicon species were reported to stimulate the proliferation of osteoblasts. A PSC-SH membrane with a thickness of about 10 lm shows high flexibility. The PLA in PSC-SH was converted from the crystalline phase to the amorphous phase due to dispersion of condensed siloxane clusters. The amount of mercapto group on PSC-SH surface was estimated to be about 55 nmol mm À2 by quantitative analysis using the thioldisulfide exchange reaction. PSC-SH adsorbed silver ions on its surface after being soaked in 6 lM silver acetate aqueous solution for 1 min. The adsorbed silver ions were seen by X-ray photoelectron spectroscopy to form SAg and SO 3 Ag bonds. A trace amount of ionic silicon species was released from the membrane after soaking in culture medium. PSC-SH with adsorbed silver ions showed good antibacterial activity and cellular compatibility in tests conducted with Staphylococcus aureus and mouse osteoblast-like cells, respectively. Antibacterial activity is expected to occur during the implantation operation by the silver ions but not to remain in the body for a long period, as the ions were present on the surface of the membrane but not inside the structure. The membrane should be useful as a biodegradable material with antibacterial activity and bone-forming ability.