The Cytocompatibility of Nano-TiO₂ Thin Film Fabricated by Layer-by-Layer Assembly Technique

Abstract

Nanosized TiO₂ with suitable dimensions has been observed to enhance the functions of bone cells; however, the most effective type of nano-TiO₂ remains unknown. The Layer-by-Layer (LBL) self-assembly technique has been wildly used to fabricate multilayer thin films of controlled composition, thickness, and architecture. Therefore, to find an appropriate material for orthopedic surgical usage, this study investigates the cytocompatibility and cell activity (using MC-3T3-E1 cells) of nano-TiO₂ thin films fabricated by LBL. Four types of nano-TiO₂ thin films were synthesized. Surface roughness w measured by field emission scanning electron microscopy (SEM). Hydrophilicity was measured using the contact angle meter. Cell attachment to the materials was observed using SEM. Fluorescent dyes were used to observe the generation of reactive oxygen species and DNA damage. Apoptosis was measured through lactate dehydrogenase leakage assay. The 2-(4,5-dimethyl-2-thiazol-2-yl)-3,5-diphenyl-2H-tetrazolium (MTT) assay was used to determine the viability of the cells attached to the materials. This new film was found to produce better cell proliferation and function; it is comparatively cytocompatible, and therefore may be a better material for orthopedic surgery.

Keywords:

• Nanoscale TiO₂
• layer-by-layer
• scanning electron microscopy
• layered double hydroxide
• MTT assay
• bioactivity
• cytocompatibility

Acknowledgment

This work was financially supported by a grant from the China National Natural Science Foundation, Project No. 50802032. We gratefully acknowledge Edanz Editing China for revising the language.

**These authors contributed equally to this work.