Studies on heart patients have shown for decades that particulate matter has a negative effect on the cardiovascular system. Yet, it remained unclear whether the nanoparticles do their damage directly or indirectly, for example through metabolic processes or inflammatory reactions. The reactions of the body are simply too complex.
Using a so-called Langendorff heart – an isolated rodent heart flushed with a nutrient solution in place of blood – scientists were able to show that nanoparticles have a clearly measurable effect on the heart. When exposed to a series of commonly used artificial nanoparticles, the heart reacted to certain types of particles with an increased heart rate, cardiac arrhythmia and modified ECG values that are typical for heart disease. “We use the heart as a detector,” explains Professor Reinhard Nießner, Professor at the TU Muenchen. “In this way we can test whether specific nanoparticles have an effect on the heart function. Such an option did not exist hitherto.”
Scientists can also use this new model heart to shed light on the mechanism by which the nanoparticles influence the heart rate. In order to do this, they enhanced Langendorff’s experimental setup to allow the nutrient solution to be fed back into the loop once it has flown through the heart. This allows the scientists to enrich substances released by the heart and understand the heart’s reaction to the nanoparticles.
This new heart model may prove to be particularly useful in medical research. Here, artificial nanoparticles are increasingly being deployed as transportation vehicles. Their intrinsically large surfaces provide ideal docking grounds for active agents. The nanoparticles then transport the active agents to their destination in the human body, for example a tumor. Most of the initial prototypes of such “nano containers” are carbon or silicate based. So far, the effect of these substances on the human body is largely unknown. The new heart model could thus serve as a test organ to help select those particles types that do not affect the heart in a negative way.
“We now have a model for a superior organ that can be used to test the influence of artificial nanoparticles,” Nießner explains further. “The next thing we want to do is to find out why some nanoparticles influence the heart function, while others do not influence the heart at all.” Both manufacturing process and shape may play an important role. Hence, the scientists plan further studies to examine the surfaces of different types of nanoparticles and their interactions with the cells of the cardiac wall.
COMPAMED.de; Source: Helmholtz Zentrum Muenchen - German Research Centre for Environmental Health