In situ modification of cell-culture scaffolds by photocatalysis of visible-light-responsive TiO₂film

Abstract

We propose a novel process to modify the cell affinity of scaffolds in a cell-culture environment using the photocatalytic activity of visible-light (VL)responsive TiO 2 . The proposed process is the improved version of our previous demonstration in which ultraviolet (UV)-responsive TiO 2 was utilized. In that demonstration, we showed that cell-repellent molecules on TiO 2 were decomposed and replaced with cell-permissive molecules upon UV exposure in the medium where cells are being cultured. However, UV irradiation involves taking the risk of inducing damage to the cells. In this work, a TiO 2 film was sputter-deposited on a quartz coverslip at 640 °C without O 2 gas injection to create a rutile structure containing oxygen defects, which is known to exhibit photocatalytic activity upon VL exposure. We show that the cell adhesion site and migration area can be controlled with the photocatalytic activity of the VL-responsive TiO 2 film, while the cellular oxidative stress is reduced markedly by the substitution of VL for UV.

Selective Stimulation of a Target Neuron in Micropatterned Neuronal Circuits Using a Pair of Needle Electrodes

“…Micropatterning techniques are useful to predefine the position of neurons in primary culture systems. [25][26][27][28][29][30][31] For example, arranging two neurons on a glass substrate at an intercellular distance with or without intercellular connection is made possible by micropatterning techniques. For investigating intercellular signaling, applying electrical…”