166a Nano-Sized Bioactive Glass In a Biodegradable Polymer: How Advantageous Is Nano-Size?

Dirk Mohn¹, Tobias J. Brunner¹, Superb K. Misra², Aldo R. Boccaccini², and Wendelin J. Stark³. (1) Department of Chemistry and Applied Biosciences, ETH Zurich, Wolfgang-Pauli-Strasse 10, Zurich, 8093, Switzerland, (2) Department of Materials, Imperial College London, London, SW7 2BP, United Kingdom, (3) Chemistry and Applied Biosciences, ETH Zurich, Wolfgang-Pauli-Str. 10, ETH Hönggerberg, Zurich, 8093, Switzerland

Composites of biodegradable polymers and bioactive ceramics in the form of biocompatible scaffolds are widely used in the field of tissue engineering with emphasis towards hard tissue regeneration [1, 2]. Bioactive glasses can add bioactive properties to a polymer matrix. In order to investigate the effect of particle size of the fillers we have introduced micron- or nano-sized bioactive glass (NBG) particles [3] in different concentrations within a poly(3-hydroxybutyrate) (P(3HB)) matrix. Mechanical and thermal properties, topography, protein adsorption, in vitro degradation behaviour, and cell proliferation [4] were compared.

The addition of NBG particles induced a nano-structured topography (Figure) on the surface of the composites not visible on micron-sized particles containing composites. This surface effect observed for NBG composites considerably increased the protein adsorption and had a reinforcement effect on the composite (Figure). Immersion in SBF revealed a high level of in vitro bioactivity for P(3HB)/NBG composites. Proliferation of MG-63 osteoblast-like cells on the various composites demonstrated a good cytocompatibility of all composite materials.

This study revealed that such nanoparticles are a most interesting bioactive filler material for biodegradable polymers in order to prepare advanced composites for tissue engineering.

Figure: Scanning electron microscopy images of a planar section of P(3HB) with 30 wt% nano-sized bioactive glass particles (left). Modulus comparison for various concentrations of micron- and nano-sized bioactive glass particles in P(3HB) composites. **p < 0.01

References

[1] K. Rezwan, Q.Z. Chen, J.J. Blaker and A.R. Boccaccini, Biomaterials, 2006, 27, 3413-31.

[2] S. Loher, V. Reboul, T.J. Brunner, M. Simonet, C. Dora, P. Neuenschwander and W.J. Stark, Nanotechnology, 2006, 17, 2054-61.

[3] T.J. Brunner, R.N. Grass and W.J. Stark, Chem. Commun., 2006, 13, 1384-6.

[4] S.K. Misra, D. Mohn, T.J. Brunner, W.J. Stark, S.E. Philip, I. Roy, V. Salih, J.C. Knowles and A.R. Boccaccini, Biomaterials, 2008, 29, 1750-61.