About me

I am an Associate Professor in Toxicology and research group leader at IMM. The research in my group is mainly about understanding the the toxicity of nanoparticles and underlying mechanisms. Another focus is the development of new cell-based assays to enable replacement of animal experiments (3R). I teach in the Master's Programme in Toxicology and have for many years worked with issues related to the environment and sustainable development at KI.

Research description

Genotoxic effects of nanoparticles. One main focus is to study whether nanoparticles can cause DNA damage in cells and elucidate underlying mechanisms. We mainly work with cultured lung cells and various methods for studying toxic effects. In a VR project, we have shown that reporter cell lines (ToxTracker) efficiently can be used to demonstrate whether the nanoparticles are genotoxic. Clear effects were for example observed for nanoparticles of nickel  and cobalt (Cappellini et al, 2018; Åkerlund et al., 2018; McCarrick et al., 2020).

Harmful effects of nanoparticles from different transport modes. In the EU project "nPETs", we study toxicity of nanoparticles formed by different modes of transport (road traffic, metro, aviation, etc.). More info here: https://www.npets-project.eu/

Can micro- and nanoplastics affect cultured human cells? In an ongoing project we focus on studying potentially toxic effects of micro- and nanoplastics on cultured human cells.

Toxic effects of welding particles and particles from 3D printing. In projects that are mainly financed by VINNOVA, and is a collaboration with KTH and several industry partners, we study the toxic effects of welding particles and of powders used in so-called "3D printing". Among other things, we have shown that the particles from different welding methods differ significantly in toxicity. New welding wires have been developed by industry partners, and we have shown that particles formed during welding with these release significantly less hexavalent chromium and they are also not as toxic as particles generated from welding with the traditional wires (McCarrick et al., 2019 and McCarrick et al., 2021). In a recent study we showed limited toxicity of particles formed during 3D-printing (see e.g. Vallabani et al., 2022).

Advanced cell methods for studying toxic effects of nanoparticles. Another focus is to investigate whether advanced cell models better can mimic a real situation and predict effects seen in animal experiments. The overall aim is to replace animal experiments (3R). In a project that funded by "Research without animal testing", we test various methods to study interactions between cells upon exposure to nanoparticles (co-cultures, conditioned medium etc., Åkerlund et al., 2019). We also expose the cells to airborne nanoparticles (air-liquid interface exposure) (Cappellini et al., 2020).

Can nanoparticles dissolve in cells? In collaboration with researchers at KTH, we study to what extent nanoparticles can dissolve in different fluids and in cells (bio-solubility), and whether it is the nanoparticles or the released ions that cause the cell damage (see e.g. Gliga et al., 2014). In a new project (FORMAS) we have studied gold nanoparticles that are considered insoluble in physiological environments. We showed that gold nanoparticles can dissolve in cell medium and in macrophages. The effect was particularly clear for small (5 nm) gold nanoparticles and if we simultaneously stimulated inflammation, see Carlander et al., 2019.

New cell-based test for determining the allergenic potency of chemicals. People exposed to skin sensitizing chemicals can develop contact allergy and eczema after re-contact with the substance. At the cellular level the chemical exposure causes toxicity to cells in the epithelium and these cells secrete signaling molecules that activate the immune system. In this project (VR-3R), this is studied in order to find a method that effectively can predict the skin sensitizing potential of various chemicals and mixtures. In a recent article we show that a co-culture of keratinocytes and immune cells could be a way forward, see Karri et al., 2021.


2016: Associate Professor in Toxicology at the Institute of Environmental Medicine (IMM)

2006: Dr.Med.Sci., Karolinska Institutet. Scientific field: Medicine/ Environmental medicine. Thesis title: Particularly Harmful Particles? - A study of airborne particles with a focus on genotoxicity and oxidative stress. 

2001: M.Sci. Chemistry from Karlstad University. Main subjects: Chemistry (Karlstad University), Environmental Sciences (Karlstad University), Human Biosciences/Biology (University of Newcastle, Australia) Toxicology (Karolinska Institutet)


Academic honours, awards and prizes

Receiver of stipend from ”Konung Carl XVI Gustafs 50-årsfond för vetenskap, teknik och miljö”, 2012

Main funding

EU Horizon 2020. nPETs: Nanoparticle emmissions from the transport sector (2021-2023). https://www.npets-project.eu/

KID-funding. Health effects of nano- and microplastic particles - studies using advanced cell models (2021-2023)

Naturvårdsverket. MixIT: Towards quantifying impacts of microplastics on environmental and human health (2019-2023)

VINNOVA. Health risks related to additiv manufacturing (3D-printing), HÄMAT (2018-2024)

VINNOVA. Project title "Minimized risk for release of harmful substances from welding fume in FCW stainless steels" (2018-2020)

FORMAS. Project title: "Nanoparticles in the lung – how can bio-solubility be measured and used in modelling?" (2018-2020)

VR. Project title: "Development of a novel cell-based assay for determination of skin sensitizing potency of chemicals" (2018-2020)

VR. Project title: “Nano-Cell interactions: DNA damage of well characterized metal and metal oxide nanoparticles investigated by using high-throughput comet assay and reporter cell lines” (2015-2018)