Helical Rosette Nanotubes: Topographical and Chemical Roles in Osteoblast Attachment

Success in surgical joint replacements has resulted in a huge demand amongst patients. Coupled with the lowered average age of patients requiring hip replacements, younger patients are demanding longer life expectancy from such devices. The increasing need and demand for more durable implants have led to new formulations of high performance nanomaterials (materials with basic structural units of 1-100 nm). Nanotubes in particular have shown great promise because they: 1) have sizes that approach biological structures and 2) possess efficient channels for displaying chemistries relevant to living systems at high densities and well-controlled spatial distribution. Helical rosette nanotubes (HRN) are a new class of soft organic nanomaterials composed of a guanine-cytosine building block that self-assembles in aqueous environments into stable nanotubular structures with an inner diameter of ~1.1 nm. HRN can be decorated with biologically active chemical functionalities such as cell attracting peptide fragments. Previously, we have showed that HRN coated Ti can enhance OB attachment. In addition, proteins were seen to interact favorably with HRN networks in a manner favorable toward OB attachment. Furthermore, in the absence of proteins, HRN were seen to play the role of proteins in promoting OB attachment. The studies herein, attempt to understand the role of the lysine clusters on HRN toward OB attachment. Results show that OB do respond to lysine and molecular orientation considerations were shown to be important. Detailed structural considerations from molecular modeling further present the possibility of topographical influences (nanotube network architecture) towards OB attachment.