Multifunctional Nano- and Macroporous Bioglass-Composites for Bone ReplacementTuesday (09.05.2017) 12:40 - 13:00 Part of:
Bone replacement after infection or cancer debridement are a critical problem in bone surgery. Therefore, the aim of the presented work is the development of a biodegradable implant material which can combat bacterial infection and support the formation of new bone at the same time.
In a first step nano- and macroporous bioglass scaffold are produced as a replica of porous PU sponge. The PU sponge is soaked with a precursor solution containing TEOS, as a silica source, ethanol, water, hydrochloric acid and F127 as structure directing agent. Additionally, it is possible to add a calcium or phosphate source. After coating and drying the initial sponge is removed together with the SDA by calcination at 600 °C . For improved mechanical stability of the scaffolds and possible drug carrier matrix for proteins these are coated with biodegradable polymers, namely chitosan or a mixture of chitosan and gelatine. In both cases the polymers are cross-linked by (3-glycydyloxypropyl)-trimethoxysilane. For a further functionalization nanoporous silica nanoparticles can be incorporated into the polymer matrix . These nanoporous nanoparticles can be applied as further drug delivery system, for example by loading with antibacterial metals like silver. The materials are characterized via scanning and transmission electron microscopy, X-ray diffraction, sorption experiments and infrared spectroscopy.
The sponge replicas show nanopores of about 6 nm and macropores in the range from micrometre to about 2 millime-tres. The surface area was determined to about 150 to 200 cm2 g-1.The polymer coatings lead to increased mechanical stability and were applied to deliver the bone growth factor BMP2 (bone morphogenetic protein 2). Furthermore, na-noporous silica nanoparticles (40-60 nm, surface area about 1100 m2 g-1) could be loaded with silver nanoparticles and incorporated into the polymer matrix. First in-vitro investigations of the unloaded base materials with human osteo-blasts showed a good general biocompatibility.
 Shih C., Lu P., Chen W., Chang, Y., Chien C., Ceram. Int. 40 (2014) 15019.
 Qiao Z.A., Zhang L., Guo M., Liu Y., Huo Q., Chem Mater 21 (2009) 3823.