Effects of Engineered Nanomaterials in Human Immune System

Engineered nanomaterials, such as carbon nanotubes, nanofibrillated celluloses and metal oxides, may have beneficial but also adverse effects on our health. The exposure to these nanomaterials happens mostly via the respiratory tract and skin. A recent study at the University of Helsinki reveals that engineered nanomaterials have an ability to influence the reactions of our immune system in various ways.

The most probable occupational and consumer routes of exposure to engineered nanomaterials are via the respiratory tract and skin. Due to their small size, engineered nanomaterials are able to bypass physical and chemical barriers in the human body and come into contact with the immune system which is capable of recognizing foreign structures including engineered nanomaterials. Marit Ilves’s research provides knowledge of pulmonary and dermal effects of these materials; the results demonstrate that engineered nanomaterials with different physicochemical characteristics possess an ability to modulate our immune system by eliciting, aggravating or suppressing its reactions.

– These observations emphasize the diversity and complexity of the materials as well as highlight their impacts on the immune system and the resulting consequences on health. These data contribute to the safety assessment of engineered nanomaterials as well as information that can be useful in nanomedicine, says Marit Ilves, from the Faculty of Biological and Environmental Sciences, University of Helsinki. 

The downscaling of the materials increases their chemical reactivity, which in combination with the small size and other physicochemical properties, means that engineered nanomaterials could influence our immune system exerting possibly beneficial but also adverse effects on our health. Ilves investigated modulatory effects and physiological outcomes of engineered nanomaterials on a healthy and a compromised immune system in the lungs and skin. 

Ilves found out that in a healthy respiratory tract, rigid, rod-like but not long and tangled carbon nanotubes were able to induce a condition similar to allergic airway inflammation via activation of innate immunity. Nanofibrillated celluloses triggered an acute pulmonary inflammation which subsided within one month regardless of the material’s presence in the lungs. These findings showed that the health outcomes of these nanocellulose materials differed significantly from the long-term pathologies of the rigid, rod-like carbon nanotubes. 

In an impaired immune system, uncoated and functionalized copper oxide nanomaterials demonstrated an ability to worsen allergic airway inflammation by eliciting pulmonary neutrophilia, however Ilves established that when polyethylene-glycol molecules were added onto the surface of the uncoated copper oxide particles, the inflammatory potential of the core material was significantly suppressed. Dermal exposure to nano-sized zinc oxide in a murine model of atopic dermatitis revealed that the particles were able to pass through mechanically injured allergic skin. This penetration of the material resulted in a local inhibition of pro-inflammatory and allergic reactions and a systemic exacerbation of IgE antibody production. 

Dissertation

M.Sc. Marit Ilves is defending her doctoral dissertation on 14 December 2018 at 12:00 at the Faculty of Biological and Environmental Scineces in the University of Helsinki.  The title of the thesis is "Immunomodulatory Effects of Engineered Nanomaterials in Healthy and Diseased Lungs and Skin". The event will take place at Physicum, auditorium E204, Gustaf Hällströmin katu 2, Helsinki.

The Opponent is  Professor Fritz Krombach, Ludwig-Maximilians-Universität München and the Custos is professor Juha Partanen.

The thesis will be published in the series of Dissertationes Scholae Doctoralis Ad Sanitatem Investigandam Universitatis Helsinkiensis. 

The thesis is also an electronic publication and can be red on E-thesis-sevice