Surface hydroxyl groups regulate the osteogenic differentiation of mesenchymal stem cells on titanium and tantalum metals.

Titanium (Ti) and tantalum (Ta) metals have been widely used as implants for their favorable mechanical features and good biocompatibility. However, the results on their osteogenic capacity have been conflicting due to the synergistic effects of complex and multiple material surface features (such as topography, surface chemistries etc.) on cellular behaviors. Here, we directly compare the osteogenic response of mesenchymal stem cells (MSCs) to Ti and Ta metal surfaces with alterable surface hydroxyl groups. Although no difference was found on both surface topographies, cellular adhesion, proliferation, and the expression of osteogenic-related markers were upregulated with the increasing amount of surface hydroxyl groups (-OH) after ultraviolet (UV) light treatment. Moreover, Ti showed better effects in promoting osteogenic differentiation of MSCs than Ta before UV light treatment, but demonstrated the opposite after UV light treatment. These results might be attributed to the comparative quantity of the distinct type of surface hydroxyl groups (bridging-OH and terminal-OH), which regulated the conformation of the initial protein adsorption and subsequent cellular behaviors. Our results demonstrate the central role of the surface hydroxyl groups in mediating cell-material interactions and implicate this interface as helping in optimizing osteointegration of Ti and Ta based orthopaedic and dental implants.

[1]  D G Lewallen,et al.  Clinical validation of a structural porous tantalum biomaterial for adult reconstruction. , 2004, The Journal of bone and joint surgery. American volume.

[2]  Vamsi Krishna Balla,et al.  Porous tantalum structures for bone implants: fabrication, mechanical and in vitro biological properties. , 2010, Acta biomaterialia.

[3]  Xinquan Jiang,et al.  Strontium delivery on topographical titanium to enhance bioactivity and osseointegration in osteoporotic rats. , 2015, Journal of materials chemistry. B.

[4]  P. Chu,et al.  Enhanced osteointegration on tantalum-implanted polyetheretherketone surface with bone-like elastic modulus. , 2015, Biomaterials.

[5]  P. Chu,et al.  UV-irradiation-induced bioactivity on TiO2 coatings with nanostructural surface. , 2008, Acta biomaterialia.

[6]  M. Kozak,et al.  Interaction of bovine serum albumin (BSA) with novel gemini surfactants studied by synchrotron radiation scattering (SR-SAXS), circular dichroism (CD), and nuclear magnetic resonance (NMR). , 2014, The journal of physical chemistry. B.

[7]  S. Sen,et al.  Matrix Elasticity Directs Stem Cell Lineage Specification , 2006, Cell.

[8]  Wenjie Zhang,et al.  A strontium-incorporated nanoporous titanium implant surface for rapid osseointegration. , 2016, Nanoscale.

[9]  D. Rodriguez,et al.  Biofunctionalization strategies on tantalum-based materials for osseointegrative applications , 2015, Journal of Materials Science: Materials in Medicine.

[10]  M. Niinomi,et al.  Development of new metallic alloys for biomedical applications. , 2012, Acta biomaterialia.

[11]  Vamsi Krishna Balla,et al.  Direct laser processing of a tantalum coating on titanium for bone replacement structures. , 2010, Acta biomaterialia.

[12]  Kiyotaka Shiba,et al.  A hexapeptide motif that electrostatically binds to the surface of titanium. , 2003, Journal of the American Chemical Society.

[13]  David Farrar,et al.  Interpretation of protein adsorption: surface-induced conformational changes. , 2005, Journal of the American Chemical Society.

[14]  F. Guilak,et al.  Control of stem cell fate by physical interactions with the extracellular matrix. , 2009, Cell stem cell.

[15]  G. Gronowicz,et al.  The in vitro response of human osteoblasts to polyetheretherketone (PEEK) substrates compared to commercially pure titanium. , 2008, Biomaterials.

[16]  W. Att,et al.  Ultraviolet light-mediated photofunctionalization of titanium to promote human mesenchymal stem cell migration, attachment, proliferation and differentiation. , 2009, Acta biomaterialia.

[17]  Matthias P. Lutolf,et al.  Designing materials to direct stem-cell fate , 2009, Nature.

[18]  Lee Whitmore,et al.  DICHROWEB, an online server for protein secondary structure analyses from circular dichroism spectroscopic data , 2004, Nucleic Acids Res..

[19]  Yaoquan Tu,et al.  On the Mechanism of Protein Adsorption onto Hydroxylated and Nonhydroxylated TiO2 Surfaces , 2010 .

[20]  Michael Tanzer,et al.  Characteristics of bone ingrowth and interface mechanics of a new porous tantalum biomaterial. , 1999, The Journal of bone and joint surgery. British volume.

[21]  D. G. T. Strange,et al.  Extracellular-matrix tethering regulates stem-cell fate. , 2012, Nature materials.

[22]  M. Anpo,et al.  The effect of ultraviolet functionalization of titanium on integration with bone. , 2009, Biomaterials.

[23]  T. Sen,et al.  Au Nanoparticle-Based Surface Energy Transfer Probe for Conformational Changes of BSA Protein , 2008 .

[24]  Tao Wu,et al.  Molecular simulation of protein adsorption and desorption on hydroxyapatite surfaces. , 2008, Biomaterials.

[25]  Kimiko Yamamoto,et al.  Proliferation, differentiation, and tube formation by endothelial progenitor cells in response to shear stress. , 2003, Journal of applied physiology.

[26]  B. Wallace,et al.  Protein secondary structure analyses from circular dichroism spectroscopy: methods and reference databases. , 2008, Biopolymers.

[27]  Kisuk Yang,et al.  Multiscale, hierarchically patterned topography for directing human neural stem cells into functional neurons. , 2014, ACS nano.

[28]  R. Das,et al.  A review of the effects of the cell environment physicochemical nanoarchitecture on stem cell commitment. , 2014, Biomaterials.

[29]  M. Foss,et al.  Morphology, proliferation, and osteogenic differentiation of mesenchymal stem cells cultured on titanium, tantalum, and chromium surfaces. , 2008, Journal of biomedical materials research. Part A.

[30]  Haipeng Li,et al.  Improvement of biological properties of titanium by anodic oxidation and ultraviolet irradiation , 2014 .

[31]  Huiming Wang,et al.  Surface hydroxyl groups direct cellular response on amorphous and anatase TiO2 nanodots. , 2014, Colloids and surfaces. B, Biointerfaces.

[32]  B Vamsi Krishna,et al.  Low stiffness porous Ti structures for load-bearing implants. , 2007, Acta biomaterialia.

[33]  M. S. Yong,et al.  Synthesis and bioactivity of porous Ti alloy prepared by foaming with TiH2 , 2009 .

[34]  C. Wen,et al.  Mechanical properties and bioactive surface modification via alkali-heat treatment of a porous Ti-18Nb-4Sn alloy for biomedical applications. , 2008, Acta biomaterialia.