Titanium oxide as substrate for neural cell growth

Abstract

Titanium oxide has antiinflammatory activity and tunable electrochemical behavior that make it an attractive material for the fabrication of implantable devices. The most stable composition is TiO2 and occurs mainly in three polymorphs, namely, anatase, rutile, and brookite, which differ in its crystallochemical properties. Here, we report the preparation of rutile surfaces that permit good adherence and axonal growth of cultured rat cerebral cortex neurons. Rutile disks were obtained by sinterization of TiO2 powders of commercial origin or precipitated from hydrolysis of Ti(IV)-isopropoxide. Commercial powders sintered at 1300-1600 degrees C produced rutile surfaces with abnormal grain growth, probably because of impurities of the powders. Neurons cultured on those surfaces survived in variable numbers and showed fewer neurites than on control materials. On the other hand, rutile sintered from precipitated powders had less contaminants and more homogenous grain growth. By adjusting the thermal treatment it was possible to obtain surfaces performing well as substrate for neuron survival for at least 10 days. Some surfaces permitted normal axonal elongation, whereas dendrite growth was generally impaired. These findings support the potential use of titanium oxide in neuroprostheses and other devices demanding materials with enhanced properties in terms of biocompatibility and axon growth promotion.

The Effects of Uniquely-Processed Titanium on Biological Systems: Implications for Human Health and Performance

“…Proximal location of materials coated with picometer to micrometer titanium particles reduced the resting membrane potential and action potential firing rate of pyramidal neurons [3] and increased alkaline phosphatase activity, mineral deposition, and bone-related gene expression in osteoblast cells [4]. These in vitro outcomes were consistent with other work showing titanium or titanium-coated materials to have anti-inflammatory and antioxidant effects, and promote nerve cell growth [5,6,7,8]. In humans, garments and tape permeated with Aqua Titan particles restored Achilles tendon stiffness and enhanced the short latency reflex response [9] with subsequent improvement in running economy [10] during recovery from strenuous hill running exercise in male athletes.…”

“…Aqua Titan, when integrated into a tape applied to the skin, also proved to be non-toxic to neuronal tissue [3]. TiO 2 -rutile cultures showed good survival of CNS neurons, with typical development of axons [5]. Together, these data suggest a potential use for titanium in CNS implants.…”

Materials directed to implants for repairing Central Nervous System

“…First cell cultures were carried out over TiO 2 -rutile dense samples covered with a solution of poly-l-lysine (PLL). Results showed that TiO 2 as rutile phase permits good survival of mammalian CNS neurons for at least 10 days in culture (39). Neurons generally extended axons with normal appearance but they had few and short dendrites with some differences being observed in relation with the temperature of annealing of the surfaces.…”

Nano-biointerfaces for Detection and Control of Biological Information

“…Ti has superior biocompatibility and its oxide is used in medical care for example as implants. 36 Thus, the evaluation of the neuronal affinity to different materials can lead to the optimization of neuronal growth scaffolds using nano-structures. Figure 6 shows SEM (A, C) and fluorescent (B, D) images of neurons cultivated on Au (A, B) and Ti (C, D), respectively.…”