Local and Systemic In Vivo Responses to Osseointegrative Titanium Nanotube Surfaces

M. N. Mydin RB, Widera D, Noordin SS, Harun NH, Wan Eddis Effendy WN, Hazan R, Sreekantan S. Double-edged sword of biofouling potentials associated with haemocompatibility behaviour: titania nanotube arrays for medical implant surface technology

Background

Medical implant failures are frequently associated with limitations of the surface technology that lead to biofouling and haemocompatibility issues. Titania nanotube array technology could provide a solution for this existing limitation. The present study describes the biofouling potential using the simulated body fluid model according to ISO 23317-2007 and haemocompatibility profiles according to ISO 10993-4 guidelines. Further haemocompatibility profiles were also assessed by evaluating full blood count, coagulation assays, haemolytic rate, whole blood clotting factor, platelet profiles, and FESEM characterization.

Result

Titania nanotube array nanosurface was found to present with better apatite biofouling and hydrophilic potential compared to bare titanium foil. Furthermore, good compatibility behaviour was observed based on the haemocompatibility profiles where no signs of thrombogenesis and haemolysis risks were observed. Titania nanotube array reduced fibrinogen adsorption, red blood cell and platelet adhesion and activation, which could be associated with detrimental biofouling properties.

Conclusion

Titania nanotube array could possess a double-edged sword of biofouling potentials that resist detrimental biofouling properties associated with thrombogenesis and haemolysis risk. It also provides better apatite biofouling potential for improved tissue and osseointegration activities. Knowledge from this study provides a better understanding of medical implant surface technology.

Graphical Abstract

Nanomaterials in Bone Regeneration

Nanomaterials are promising in the development of innovative therapeutic options that include tissue and organ replacement, as well as bone repair and regeneration. The expansion of new nanoscaled biomaterials is based on progress in the field of nanotechnologies, material sciences, and biomedicine. In recent decades, nanomaterial systems have bridged the line between the synthetic and natural worlds, leading to the emergence of a new science called nanomaterial design for biological applications. Nanomaterials replicating bone properties and providing unique functions help in bone tissue engineering. This review article is focused on nanomaterials utilized in or being explored for the purpose of bone repair and regeneration. After a brief overview of bone biology, including a description of bone cells, matrix, and development, nanostructured materials and different types of nanoparticles are discussed in detail.

Resveratrol-loaded titania nanotube coatings promote osteogenesis and inhibit inflammation through reducing the reactive oxygen species production via regulation of NF-κB signaling pathway

Although titanium and its alloys are widely used in bone surgeries, the implantation failures caused by sterile inflammation still occur. The excessive reactive oxygen species (ROS) in the peri-implant region are considered to cause inflammation and impede the osseointegration of titanium implants. In this study, a coating of resveratrol-loaded titania nanotube (TNT-Res) for eliminating ROS was fabricated on titanium surface through electrochemical anodization and following surface adsorption of resveratrol. The resveratrol concentration of released from TNT-Res coating was controlled by modulating the loading amount. The ROS production in macrophage cell lineage RAW 264.7 and bone mesenchymal stem cells (BMSCs) were significantly decreased when cultured on TNT-Res coatings. The pro-inflammatory factors, including tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β), and NO produced by RAW 264.7 cells were reduced when cells were cultured on TNT-Res coatings. These results proved that the TNT-Res coating can effectively eliminate ROS and inhibit inflammation. Moreover, the osteogenic indicators, including alkaline phosphatase (ALP) production, extracellular calcium deposition, and osteogenesis-related gene expression, including collagen І (Col-І), osteocalcin (OCN), osteopontin (OPN), and runt-related transcription factor 2 (Runx2), were significantly promoted for TNT-Res groups, which demonstrated that the TNT-Res coating can enhance the osteogenic differentiation of BMSCs. Additionally, the phosphorylation of nuclear factor κ-B (NF-κB) were down-regulated both in RAW 264.7 cells and BMSCs, which indicated that the TNT-Res coating could inhibit inflammation and promote osteogenesis by inhibiting the activation of NF-κB signaling pathway. The TNT-Res coating could be an effective implant surface for improving osseointegration ability of titanium implants.