Weniger schädliche Nano-Zigaretten
Der 31. Mai ist Welt-Nichtrauchertag und wurde 1987 von der WHO ins Leben gerufen. Denn jedes Jahr sterben 6 Millionen Menschen an den Folgen des Tabakkonsums. Tabakrauch enthält rund 12000 schädliche Substanzen. Darunter eine ganze Reihe kanzerogener Stoffe, wie z.B. die reaktiven Sauerstoffradikale. Eine Gruppe von Wissenschaftern hat jetzt einen Weg gefunden, um mit Hilfe von Nanopartikeln diese Radikale aus dem Zigarettenrauch zu entfernen und damit das Rauchen etwas weniger schädlich zu machen.
Researchers took the underlying idea behind the concept from natural enzymes. In the presence of an enhanced concentration of reactive oxygen species as a result of, for instance, enzymatic dysfunction, UV radiation or the inhalation of tobacco smoke, uncontrolled cell division and oxidative cell damage can occur.
Nature regulates the concentration of radicals by means of antioxidant enzymes such as superoxide dismutase (SOD), which plays a central role in the prevention of pathological processes, including tumor and cancer growth, inflammatory diseases, and stroke.
The naturally occurring enzyme utilizes metals such as copper-zinc, nickel, iron, and manganese as reactive centers that cause oxygen radicals to decompose so that the organism is protected from their aggressive reactive behavior.
Today it is possible to produce or isolate enzymes like SOD, but the process is accompanied by high costs. However, their poor stability on exposure to high temperatures and non-physiological pH values complicates matters. With natural enzymes in mind, researchers in the field of biomimetics are seeking ways to imitate natural biological reactions with the help of synthetic compounds. Chemist Karsten Korschelt and food chemist Dr. Carmen Metzger investigated amino acid-functionalized copper hydroxide nanoparticles as potential synthetic analogues of cupriferous SOD. They found that the particles were associated with a higher rate of catalytic activity in terms of the decomposition of oxygen radicals than the enzyme itself. "This is in principle not such a surprise as all copper atoms on the particle surface can have a catalytic effect, yet the enzyme has only one active center," said Professor Wolfgang Tremel. In contrast to natural enzymes, functionalized copper hydroxide nanoparticles are very stable and inexpensive to produce.
From laboratory to everyday life
Although natural enzymatic reactions can be mimicked with the help of nanoparticles, there are as yet only a few applications based on the principle. Nanoparticles themselves are used in cosmetics, for instance, and as nano sealants in paints and textiles. We are so extensively exposed to free radicals on a day-to-day basis that their presence is frequently ignored altogether. But in exhaust fumes and cigarette smoke they represent a major threat to health.
The team of chemists in Mainz is thus collaborating with the group headed by Professor Jürgen Brieger of the Mainz University Medical Center in order to determine whether it is possible to integrate functionalized copper hydroxide nanoparticles in cigarette filters and thus reduce levels of free radicals in smoke, hence providing smokers with greater protection against their toxic potential.
Cytotoxicity tests have shown that the cigarette smoke extracts in the examined concentrations no longer have a toxic effect on human cells after passing through cigarette filters containing nanoparticles, while there was increased toxicity in the case of controls in which untreated filters were employed.
"This demonstrates the positive effect of the particles when used in cigarette filters and their stability during the smoking process," emphasized Karsten Korschelt.
The researchers in Mainz have thus been able to demonstrate that imitating natural defense mechanisms with the help of nanoparticles is possible and that a reduction in the toxic effects of various types of smoke can be achieved.
Quelle: nanowerk news
Quelle Bild: pixabay