Protein-mediated hydroxyapatite composite layer formation on nanotubular titania

Abstract

Realising controllable interactions at the bio-nanomaterial interfaces are vital in developing next-generation engineered implant materials. Titanium-based implants are key materials in biomedical engineering due to excellent bulk mechanical properties and biocompatibilities. Advanced bio-interfaces resolving nanostructured modulated surfaces that allow manipulation with the biological molecules is one of the keys to enhance favourable interactions with the surrounding biological species. Here, we developed a protein-mediated hydroxyapatite composite layer on nanotubular titania surface. Green fluorescence protein, engineered to contain hydroxyapatite binding peptides (GFPuv-HABP), was co-deposited with the hydroxyapatite precursors onto the titania nanotubes that are formed by anodisation. Ordered titanium dioxide nanotubular surfaces were coated with hydroxyapatite at physiological pH and temperature using simulated body fluid and pulsed electrochemical cathodisation. The hydroxyapatite deposit interdigitated into the nanotubes, producing a metal oxide-mineral composite. The engineered GFPuv-HABP protein was then self-assembled on the hydroxyapatite, forming a bio-modulated interface. Additionally, the engineered proteins were co-deposited with the precursor ions of hydroxyapatite mineral on the nanotubular titania plate. Bio-mediated assembly resulted in formation of a hybrid composite as an integrated interface on the nanotubular surface. Biomolecular assisted fabrication of hybrid composite interface on metal oxide substrate offers wide range of opportunities to design novel interfaces.Protein-mediated hydroxyapatite composite layer formation Utku, Yuca, Seckin et al.

Engineered Peptide Repairs Defective Adhesive–Dentin Interface

“…The HABP peptide was selected biocombinatorially using a phage display library and the peptide demonstrated distinctive ability to induce mineralization with morphological control . In previous studies, we demonstrated that the HABP peptides genetically engineered to couple with GFPuv eased the monitoring of the selective binding abilities of peptide on different biomineral and calcium phosphate coated implant materials . Here the peptides coupled with GFP were anchored at the a/d interface by simply dipping the prepared specimens into the protein solution.…”

Electrochemically designed interfaces: Hydroxyapatite coated macro-mesoporous titania surfaces

“…spreading and proliferation, differentiation, and protein synthesis [53]. While surface roughness of mm to 10 m scale contributes to primary long-term mechanical stability [54], roughness of 10-1 m contributes to biological fixation of the implant surface to the bone [54] and roughness of 1-100 nm scale enables adsorption of proteins and adhesion of osteoblastic cells [55] with various molecular processes taking place at the implant-tissue interface [56][57][58][59][60] Cellular adhesion to titania has been demonstrated to be a function of surface roughness, where the cells adhere to the surface through integrin receptors, causing changes in the cytoskeleton and thus leading to new gene expression [61]. Studies on this matter suggest that the substrate based conformational changes in cell shape affect membrane fluidity and calcium ion channels, altering gene expression and leading to attainment of a more advanced cellular development [22,56,61].…”

Editorial

“…After independent peer Editorial Chen review and revision process, we are proud to present five highquality original research papers in Bioinspired, Biomimetic and Nanobiomaterials, covering biomineralisation, biomechanics, bioinspired synthesis and biomedical applications. [1][2][3][4][5] We hope this special issue inspires both new research and lively participation in the Biological Materials Science Symposium at the TMS Meeting in future years.…”