(67a) Antibacterial Plga/silver Doped Amorphous-Tcp Nanocomposite Prepared By Electrospinning

In reconstructive surgery bioresorbable implant materials are in great demand for the repair of bone defects. Many investigated biomaterials consist of calcium phosphates which excel in their biocompatibility, bioactivity and osteoconductivity. However many commercially available products are limited for clinical applications because of their brittleness, incompressibility and difficulty to shape.

To overcome these limitations we combined flame sprayed amorphous calcium phosphate nanoparticles (ATCP) [1] with biodegradable poly(lactide-co-glycolide) (PLGA) by electrospinning resulting in an open structured and highly porous network of fibers [2]. In addition we enhanced the biomaterial by preparing silver containing scaffolds to satisfy the need for antibacterial implants. In vitro bioactivity tests in simulated body fluid (SBF) at 37 °C showed the deposition of a nano-featured hydroxyapatite layer on the fibers (Figure 1). Antibacterial properties were investigated by incubating the scaffolds with E.coli.

This compressible and highly bioactive biomaterial with antibacterial properties suggests application for complex shaped and non-load bearing bone defects as they exist for example in dental surgery.

Figure 1: Scanning electron microscopy images of PLGA/ATCP 80:20 containing 0.5wt% Ag. Overview (a) and close-up (b) of an as-electrospun scaffold. Small holes appear on the surface of the fibers after 8h incubating in E.coli/SBF (c). The deposition of a nano-structured hydroxyapatite layer on the fibers is shown after 52h immersion in SBF.

References

[1] S. Loher, W.J. Stark, M. Maciejewski et al., Chem Mater 2005;17(1):36-42.

[2] O.D. Schneider, S. Loher, T.J. Brunner, L. Uebersax, M. Simonet, R.N. Grass, H.P. Merkle, W.J. Stark, J. Biomed Mater Res B, accepted 2007.