NEWS
NEWS
‘ LUNG-IN-THE-LAB ’
This exposure chamber can be used to assess the impact of different aerosols on the health of human lung cells . It is necessary to demonstrate that aerosol is effectively delivered to the lung cells in the first place in order to be confident in the results of cellular tests .
aerosol in
Human lung cells are supported by a permeable membrane in a test well . The cells are exposed to air / aerosol on one side and fed by nutrient media on the other , much like they are in the human body .
The wells containing the lung cells can be removed and replaced with tiny weighing scales . These scales are so sensitive they can weigh the aerosol being delivered to the wells . Research results show that e-cigarette aerosol droplets are effectively delivered to the wells and deposit onto the cell surfaces during lab-based biological tests . a distributor plate ensures uniform distribution of aerosols contained in the chamber
air-tight seal aerosol out
GETTING BACK TO BASICS
In order to be confident in the results of our own testing , we needed to get back to basics and prove that e-cigarette aerosol droplets are effectively delivered to cell surfaces in lab-based biological tests . We used smoking and vaping robots to produce aerosols ( from a scientific reference cigarette and Vype ePen ) in the lab and then used micro balances ( tiny scales that can measure microgram levels of aerosol ), to determine whether we could measure the aerosol in an exposure chamber . Basically , we were measuring amounts so small that they were the equivalent of a breath . The exposure chamber is a device we designed to expose lung cells to aerosols in a laboratory setting . A range of different types of cells can be grown in the lab , which are then placed into the exposure chamber to assess the impact of aerosols on the health of the cells . We place the cells in small dishes ( the size of a thimble ), which we place on the micro-balances , and can weigh the amount of aerosol that is delivered to the cells . This is the deposited particle mass in the exposure chambers which is measured , in addition to the amount of deposited nicotine . The results show that ( on a puff by puff basis and at a common dilution ) the
e-cigarette aerosol deposited greater mass than cigarette smoke in both systems . Nicotine delivery was much greater from the cigarette than from the e-cigarette . ‘ It may seem counter intuitive that the aerosol that delivered the most mass had the least impact , but it ’ s about what that mass represents ,’ explains Murphy . Smoke droplets carry the products of combustion : thousands of chemicals and hundreds of toxicants . Whereas e-cigarette aerosol droplets contain the aerosolised form of the main ingredients that make up e-liquids : humectants , water , nicotine and flavouring . ‘ This means the mass deposited on the cells by the e-cigarette vapour is compositionally very different to that deposited by cigarette smoke ,’ says Murphy . We published the results in Chemistry Central Journal ( DOI : 10.1186 / s13065-016-0221-9 ). We have done a series of tests that compare the impact of smoke with that of vapour . These tests mimic key events in the development of tobacco-related diseases like cardiovascular disease or chronic obstructive pulmonary disease . We have , for example , shown that that in contrast to smoke , e-cigarette vapour has substantially reduced responses in lab based tests representative of oxidative damage , cellular stress , and DNA damage .
‘ We are very excited about these latest results ,’ says Murphy , ‘ because it means that we can be confident that we are effectively delivering e-cig aerosol to cells in biological tests and that we can be confident , therefore , in the results of our biological tests . These are important findings as we have shown in our lab based chemical and biological tests that e-cigarettes have the potential to reduce risk in comparison to cigarettes . The next steps are to evaluate these products in clinical and population based studies to ensure that lab based reductions translate to disease relevant reductions in man , both at an individual and a population basis .’ Our Vype ePen test results to date are in line with current available evidence that e-cigarettes are of the order of 95 % less risk than conventional cigarettes . Public Health England , an executive body of the UK Department of Health , recently published a report saying that the current expert estimate is that using e-cigarettes is around 95 % safer than smoking cigarettes , although more research is needed . The Royal College of Physicians have said that the public can be reassured that e-cigarettes are much safer then smoking and that they should be widely promoted as an alternative to cigarettes .
VAPOUROUND MAGAZINE ISSUE 09 29