Recent studies have revealed that vascular cells can produce reactive oxygen species (ROS) through NAD(P)H oxidase, which may be involved in vascular injury. However, the pathological role of vascular NAD(P)H oxidase in diabetes or in the insulin-resistant state remains unknown. In this study, we examined the effect of high glucose level and free fatty acid (FFA) (palmitate) on ROS production in cultured aortic smooth muscle cells (SMCs) and endothelial cells (ECs) using electron spin resonance spectroscopy. Exposure of cultured SMCs or ECs to a high glucose level (400 mg/dl) for 72 h significantly increased the free radical production compared with low glucose level exposure (100 mg/dl). Treatment of the cells for 3 h with phorbol myristic acid (PMA), a protein kinase C (PKC) activator, also increased free radical production. This increase was restored to the control value by diphenylene iodonium, a NAD(P)H oxidase inhibitor, suggesting ROS production through PKC-dependent activation of NAD(P)H oxidase. The increase in free radical production by high glucose level exposure was completely restored by both diphenylene iodonium and GF109203X, a PKC-specific inhibitor. Exposure to palmitate (200 µmol/l) also increased free radical production, which was concomitant with increases in diacylglycerol level and PKC activity. Again, this increase was restored to the control value by both diphenylene iodonium and GF109203X. The present results suggest that both high glucose level and palmitate may stimulate ROS production through PKC-dependent activation of NAD(P)H oxidase in both vascular SMCs and ECs. This finding may be involved in the excessive acceleration of atherosclerosis in patients with diabetes and insulin resistance syndrome.

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Here we report a novel approach to fabricating patterned three-dimensional (3D) mesoporous thin films by spin coating a surfactant-templated SiO2 or TiO2 precursor solution onto electron-beam (EB) lithographically prepared resist moulds. Subsequent mechanical polishing and calcination led to patterned SiO2 or TiO2 thin films with uniform mesopores and an amorphous or nanocrystalline framework. This approach provides a novel route for patterning mesoporous non-siliceous thin films as well as silica with feature sizes from hundreds of nanometres to sub-millimetres over areas of several square centimetres. This is of much interest for the miniaturization of devices and for potential applications from low-k materials to optoelectronic devices and biochemical sensors.