oa Editorial [Hot Topic: Architecture and Design of Non-Drug Therapy for Reactive Oxygen Spcecies (ROS)-Induced Diseases (Executive Guest Editors: Tohru Yoshioka and Mami Noda)]

It is generally accepted that ROS is major cause of life style-dependent diseases such as cancer, stroke and many other serious diseases. So far they were treated individually by various kinds of drugs specially designed for each symptom, but these approaches must be changed innovatively. Generally, ROS is generated intracellularly when mitochondria is producing ATP, while it is also generated extracellularly by the stimulation of ultraviolet light, electro-magnetic waves (heat), ultra-sound and radiations. Consequently, ageing may be one of the consequences of these ROS-induced oxidative stresses. Though there are many antioxidants, one of the most direct approach to remove ROS from animal body is to apply reducing gas such as H2, H2S and CO, now regarded as medical gases. Especially H2 gas dissolving in water (H2 water) could be widely used as a reducing reagent [1], which was found to be very effective for a number of diseases. Not only as a reducing reagent, but molecular mechanisms for ROSresistance of medical gases are also proposed [2]. Lithium (Li) is involved in glucose metabolism via cyclic AMP (cAMP)-dependent kinase (PKA). Although it was already known that Li inhibited phosphoinositide (PI) turn-over, but recently Li was found to be incorporated with the central nervous system (CNS) disorder and diabetes via glycogen synthase kinase 3. It is, therefore, reasonable to study relationships between Li and ROS-induced CNS diseases [3]. It is our dream to find out key protein controlling senescense. So many attempts were carried out to find out the most effective molecules for longevity such as hydrophilic scavengers, enzymatic antioxidants, lipophilic scavengers, repair mechanism. A new approach is proposed here that chromatin-remodeling factors may be important players in the senescence program [4]. The most orthodox approach, however, for the molecular mechanism for senescence is to analyze ROS signaling network using ultra-long-lived animals. Naked mole rat (NMR) may be an excellent model animal, because they survive for 30 years without cancer. It has no pain sensing system, presumably reducing stresses to a great extent. If cancer and stress are representative symbols for aging-associated phenomena, study with NMR in detail will give us quite a new aspect for aging mechanism [5]. It has been established that formation of ROS may occur during the interaction of animal cells with nanoparticles. Furthermore, some types of nanoparticles are sensitive to light and produce singlet oxygen and super oxide as well. Although there is no direct evidence so far, interaction between mitochondria and nanoparticle was expected to affect electron flow which may cause dysfunction of intracellular Ca2+ concentration. In this issue, two reviews describe about nanoparticle as drug carrier. Above all the metallodendrimer is the most attractive, because it has highly branched structure and functionally tunable peripheral effects. Therefore this type of nanoparticle is highly applicable to many fields, such as biomimetic catalysis, imaging contrast agents and biomedical sensors [6]. The magnetic sensitive nanoparticle (MNPs) is another attractive characteristic of nanoparticles, which will be applicable for magnetic resonance imaging diagnosis, drug/gene carriers for different kind of therapeutic agents, tissue repair, hyperthermia, immunoassay and cell separation and/or sensing. In this issue attention was focused on how to synthesize better MNPs for ferrying them to interested areas. Especially DNA-targeting delivery was extensively reviewed [7].....