Promotores: Prof.dr. W.J.G.M. Peijnenburg & Dr. M.G. Vijver

Fate and toxicity of copper nanoparticles was related to the water chemistry of the environment and pristine size.

Gold nanoparticles show surprisingly strong interactions with light in the visible range, which can be divided into scattering, absorption, and photoluminescence.

Leiden University has developed a radically different method for large scale production of diverse nanoparticles and their alloys.

In this work, we investigate the minute circular dichroism effects of single nanoparticles.To this aim, we apply photothermal imaging with a polarization-modulated heating beam.

Promotor: E. Bouwman Co-Promotor: S. Bonnet

Artificial photosynthesis aims to produce fuels from solar energy using chemical processes. In semi-artificial photosynthesis, a hybrid approach is taken using both chemical and biotechnology approaches. We aim to develop hybrid systems between light-harvesting nanoparticles and redox-enzymes (oxidoreductases)…

1. To what extent do metallic NPs added to soil extractions change the activity, abundance, or community composition of microbes? 2. How do the effects of metallic NPs on soil microbes differ from the effects of the ions shedding from corresponding NPs?

Metal-based prodrugs based on ruthenium(II) polypyridyl complexes have proven to be very suitable for application in both photodynamic therapy (PDT) and photo-activated chemotherapy (PACT).

Hetterscheid

The electrochemical oxygen reduction reaction (ORR) is an essential half-reaction for the utilization of hydrogen as a sustainable fuel, via the conversion of hydrogen to electrons and protons facilitated by the ORR. In the most common fuel cells, the ORR is requires high loadings of non-abundant platinum…

Despite the fact that gold nanoparticles (GNPs) are one of the most studied nanoparticles, there is still a necessity for new approaches allowing for effective protective coating to enable wider use of GNPs in biomedical applications.

The aim is to discover where differently shaped metal nanoparticles distributes in Danio rerio, linking the distribution with genomic responses and so come up with a Mode of Action.

Promotor: G.P. van Wezel, Co-promotor: D. Claessen

Promotores: Prof.dr. W.J.G.M. Peijnenburg & Dr. M.G. Vijver

Promotor: M.A.G.J. Orrit

The work described in this dissertation contributes to a better mechanistic understanding of nanoparticles in vivo. To achieve that goal, we used the zebrafish as a highly predictive pre-screening model of nanoparticles.

A very large part of intravenously administered nanoparticles are cleared through the liver. Within the liver, most nanoparticles are thought to be sequestered by macrophages (Kupffer cells). To achieve effective cell-specific targeting of drugs and non-viral gene delivery vectors, improved mechanistic…

'Quality Nano' funded research of the Institute of Environmental Sciences to work in Exeter University for 20 working days, which allows the institute to access highly advanced equipment needed for evaluation the toxicity of nanoparticles.

Abdolreza Alamdar Baghini defended his thesis on 5 December 2019.

What is the mechanism of action preceding a physiological effects induced by metallic nanoparticles?

This thesis aimed to investigate the impact of exposure dynamics, relative contributions of ENPs(particle) and ENPs(ion), and dosing regimens on the toxicity of ENPs varying in different physico-chemical properties, on the composition and functioning of soil microbial communities.

Promotores: Prof.dr. W.J.G.M. Peijnenburg & Dr. M.G. Vijver

This thesis describes a study from both a theoreticaL and an experimental point of view.

Human civilization consumes a huge amount of fossil fuels, which has resulted in an atmospheric CO2 level which has not been higher in over 800 millennia.

Bet v1, the major allergen in birch pollen, is one of the main causes of allergies such as asthma and rhino-conjunctivitis. Additionally it is the main cause of birch pollen allergy in humans.

Promotor: Prof.dr. J.W.M. Frenken

Promotor: A. Kros

This thesis focuses on the application of lipid-based nanomedicine in drug delivery, including small molecular antitumor drugs and biomacromolecules including mRNA, and evaluates their biological performance.

Promotor: A. Kros, Co-promotor: R.R.C.L. Olsthoorn

Dendritic cells (DC) play a prominent role in the priming of CD8(+) T cells. Vaccination is a promising treatment to boost tumor-specific CD8(+) T cells which is crucially dependent on adequate delivery of the vaccine to DC.

SMR can be used to measure the mass of adsorbed protein to nanoparticles with a high precision in the presence of free protein.

The purpose of this study was to investigate the formation and growth kinetics of complexes between proteins and oppositely charged polyelectrolytes.

Exploring the mechanism of targeted nanoparticle-mediated drug delivery using the zebrafish model

Cationic peptide amphiphile nanoparticles are employed for co-delivery of immune modulator CpG and antigen. This results in better targeting to the antigen presenting cells and eliciting strong Th1 response, which is effective against the intracellular pathogens.

Alexander Kros and co-workers describe how mesoporous silica nanoparticles (MSNs) are delivered into cells via membrane fusion thereby omitting endocytosis pathways. Fusion is induced by a pair of complementary coiled-coil lipopeptides inserted into the membrane of cells and in the bilayer of lipid-coated…

The mechanism of the electrochemical reduction of dioxygen by a mononuclear pyridylalkylamine copper complex was investigated (see picture). It was shown that in neutral aqueous solution dioxygen undergoes stepwise reduction, wherein hydrogen peroxide plays a key role. The rate constants determined…

Promotor: J.M. van Ruitenbeek, Co-Promotor: S.J. van der Molen

In this thesis we have discussed several parameters that affect the electrochemical conversion of enviromentaly harmful molecules such as nitrates and carbon dioxide to more valuable and less deleterious compounds, in order to cast light onto the mechanism of the reaction to achieve an efficient and…

Tuberculosis (TB) is a major global health problem caused by the bacterium Mycobacterium tuberculosis (Mtb). In 2015, there were estimated to be 10.4 million new cases and 1.8 million deaths ascribed to TB, making it one of the top 10 causes of death worldwide. Unfortunately, the only current registered…

Describe and identify what dosimetry parameters are of importance to interpret dose-response relationships (eg., mortality, sub-lethal, growth or reproduction inhabitation, DNA damage and reactive oxygen species, etc. ) for metal-based nanoparticles? How to develop quantitative models that enable to…

Nanoparticles are widely used, but their effect on the environment is unclear because they are hard to track. Leiden physicists have developed a new method to detect conducting nanoparticles. Aquiles Carattino successfully defended his PhD thesis on the subject.

How to make a quantitative assessment of the relative contribution to toxicity of ions and particles? Is the toxicity of nanoparticles related to their size or shape? Which physicochemical property of nanoparticles is an appropriate dose metric of nanoparticles?

Mycobacterium tuberculosis (Mtb), the pathogen causing tuberculosis (TB), is the leader among all pathogens responsible for the most human deaths today and it is considered as one of the top 10 causes of death worldwide. There is an increasing occurrence of multidrug-resistant and even totally drug-resistant…

Gold nanorods are biocompatible nanoparticles that present an excellent two-photon signal that can be used to get high spatial resolution inside living cells. Gold nanorods are photostable and therefore can be followed inside cells for long time, with possible applications as trackers in live cells.

The large-scale project NanoInformatics will assess the risks associated with nanoparticles. The project will be funded by the EU with 6.8 million euros and was launched at the beginning of this year. Three scientists from Leiden are involved. 'For the first time, this project combines the various experts…

Nanoplastics influence the behaviour of larval zebrafish, says new research by the Institute of Biology Leiden (IBL) and the Institute of Environmental Sciences (CML). The researchers observed that a certain type of nanoparticles leads to stress reactions in the sugar balance, resulting in hyperactivity…

Professor of Ecotoxicology Martina Vijver of the Institute of Environmental Sciences has given a public talk at Paradiso Amsterdam for Science & Cocktails on 4 March 2019. Her presentation was called: 'The added value & added risk of size: nanomaterials'.

On Tuesday 4 September, Martina Vijver delivered the scientific lecture during the academic opening of the Faculty of Science. Martina is professor in Ecotoxicology at CML and would like to have collaborations with colleagues from the Leiden Centre of Data Science. We had a brief interview with her.

How safe are the nanoparticles in transparent sunscreen, anti-odour socks and bacteria-resistant plasters? Although microbes are present on all organisms, the tools that estimate the safety of nanomaterials still hardly take them into account. Bregje Brinkmann explored the role of these microbes during…