Design a Biologically Inspired Nanostructured Coating for Better Osseointegration

Abstract

To date, there are a strikingly growing number of patients who need various orthopedic implants. However, traditional orthopedic implants face many complications such as infection and implant loosening which may lead to implant failures. Conventional metal implants such as titanium were chosen for orthopedic applications mainly based on their excellent mechanical properties and biological inertness. Since natural bone matrix is nanometer in dimension, it is desirable to design a biologically inspired nanostructured coating that can turn conventional inert titanium surfaces into biomimetic active interfaces, thus enhance bone cell adhesion and osseointegration. For this purpose, we designed a biomimetic nanostructured coating based on nanocrystalline hydroxyapatites (nHA) and single wall carbon nanotubes (SWCNTs). Specifically, nHA with good crystallinity and biomimetic dimensions were prepared via a wet chemistry method and hydrothermal treatment; and the SWCNTs were synthesized via an arc plasma method with or without magnetic fields. TEM images showed that the hydrothermally treated nHA possessed regular rod-like nanocrystals and biomimetic nanostructure. In addition, the length of SWCNTs can be significantly increased under external magnetic fields when compared to nanotubes produced without magnetic fields. More importantly, our results showed that the above nHA and SWCNTs nanomaterials can greatly promote osteoblast (bone-forming cell) adhesion on titanium in vitro, thus holding great promise to improve osseointegration and lengthen the lifetime of current orthopedic implants.