Helical rosette nanotubes: a more effective orthopaedic implant material

Due to the nanometric properties of some physiological components of bone, nanomaterials have been proposed as the next generation of improved orthopaedic implant materials. Yet current efforts in the design of orthopaedic materials such as titanium (Ti) are not aimed at tailoring their nanoscale features, which is now believed to be one reason why Ti sometimes fails clinically as a bone implant material. Much effort is thus being dedicated to developing improved bioactive nanometric surfaces and nanomaterials for biospecificity. Helical rosette nanotubes (HRN) are a new class of self-assembled organic nanotubes possessing biologically-inspired nanoscale dimensions. Because of their chemical and structural similarity with naturally-occurring nanostructured constituent components in bone such as collagen and hydroxyapatite, we anticipated that an HRN-coated surface may simulate an environment that bone cells are accustomed to interacting with. The objective of the present in vitro study is therefore to determine the efficacy of HRN as a bone prosthetic material. Results of this study clearly show that both HRN-K1 and HRN-Arg coated Ti displayed enhanced cell adhesion when compared to uncoated Ti. Enhanced cell adhesion was observed even at concentrations as low as 0.005 mg ml−1. These results point towards new possibilities in bone tissue engineering as they serve as a starting point for further mechanistic studies as well as future manipulation of the outer chemistries of HRN to improve the results beyond those presented here. One such effort is the incorporation of peptide sequences on the outer surface of HRN and/or growth factors known to enhance bone functions.