Abstract | It is widely known that mimicking the nanometric features of natural tissues in biomaterials is very useful for improving cell adhesion, proliferation and differentiation. Helical rosette nanotubes (HRN) are one type of such organic nanomaterials which self-assemble when added to water. Through non-covalent interactions such as H-bonding, base stacking interactions and hydrophobic interactions, the building blocks of HRN when self-assembled form a stable nanotube with a hollow core 11 Å across. Since the chemical properties and nanometric structures of HRN are very similar to those of collagen and hydroxyapatite (the nanostructured constituent components in bone), it is anticipated that HRN would be more well-suited for orthopaedic applications compared to conventional implant materials such as titanium which do not mimic the nanometer features of bone. For this reason, the current study is focused on investigating HRN as a potential orthopaedic tissue engineering scaffold. Compared to uncoated titanium, in vitro studies clearly showed that osteoblasts (bone-forming cells) adhered more on specialized versions of HRN, specifically HRN functionalized with lysine (K) and arginine (Arg) when coated on titanium surfaces. This phenomenon may be attributed to the presence of amino acids side chains (such as arginine and lysine) as well as the biologically-inspired nanometric features that HRN form when coated on titanium. Moreover, HRN can undergo a phase transition from liquid to a viscous gel when heated to 60 °C or when added directly to serum-free media at body temperatures. Transmission electron microscopy (TEM) showed that a densely-packed nanotube network is formed in the viscous gel. Further in vitro studies including measuring osteoblast adhesion and subsequent functions when cultured in the viscous HRN tissue engineering scaffold will be presented. In this manner, this study introduces a new self-assembled nanomaterial, HRN, that is showing promising in various orthopaedic tissue engineering applications. |
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