Polymerized nanoporous titania surfaces: modification of cell adhesion by acrylic acid functionalization

Abstract

Nanoporous titania (nPTI) has been prepared by electrochemical processes and functionalized by photochemical activation of condensed acrylic acid vapors (AcAc). The nPTI surfaces obtained after electrochemical etching in HF electrolytes at constant potential consisted of nanotube disordered arrays. Elastic recoil detection and Rutherford backscattering spectroscopy studies confirm the presence of an in-depth carbon based layer, previous to the AcAc polymerization. The subsequent AcAc functionalization affected only a few molecular monolayers since the process did not modify the nPTI structure observed by scanning electron microscopy. In fact, X-ray photoelectron spectroscopy confirms the presence of a carboxylic group contribution in the C 1s core-level spectrum only after AcAc polymerization of nPTI. Such results are of relevance for cellular attachment of human mesenchymal stem cells, whose adhesion onto nPTI is drastically enhanced after AcAc biofunctionalization.

Keywords:

• nanoporous titania
• XPS
• acrylic acid
• biofunctionalization
• cell adhesion

Acknowledgements

We are especially thankful to L. García Pelayo for his assistance during materials processing and characterization. Grant from the Fundación Domingo Martínez is greatly acknowledged.