Improved osteoblast viability in the presence of smaller nanometre dimensioned carbon fibres

摘要

Carbon nanofibres have been proposed as a possible new orthopaedic/dental implant material due to their unique mechanical, electrical, and cytocompatibility properties. Specifically, these fibres have dimensions (diameters ranging between 60 and 200 nm and aspect ratios of about 500) similar to hydroxyapatite crystals and collagen fibres found in bone. More importantly, previous in vitro studies have provided evidence that nanophase( < = 100 nm diameter) carbon fibres enhance osteoblast (the bone-producing cell) function over conventional (> 100 nm diameter) carbon fibres and current orthopaedic implant materials such as titanium, Ti6A14V, and CoCrMo. However, articulating components of orthopaedic implant materials may generate harmful wear debris. To determine, for the first time, the influence of carbon nanofibre wear debris on osteoblast viability, direct contact toxicity studies were performed in the present in vitro study. Not surprisingly, the results from direct-contact toxicity studies over a 24 h time period provided evidence of time- and concentration-dependent cell viability decreases when exposed to carbon nanofibres. Most importantly, the results from this study provided the first evidence that nanophase carbon fibres were less detrimental to osteoblast viability compared to larger diameter conventional carbon fibres. For this reason, this in vitro study provided continuing evidence of the promise of nanophase materials (particularly, carbon nanofibres) in improving orthopaedic implant efficiency.