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

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

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)…

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.

Tuberculosis is a major global health problem caused by the Mycobacterium tuberculosis complex, claiming more than a million lives annually.

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).

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

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 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.

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

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.

The findings in this thesis improve the understanding of 1) the relationship between exposure characteristics and toxicity of ENPs, 2) the joint toxic action of ENP mixtures and the comparison to metal salt mixtures, 3) how NOM affects the individual and joint toxicity of ENPs, 4) the extent of trophic…

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.

Dissolution processes – next to aggregation processes - play an important role for fate prediction and environmental risk assessment of metal-based nanoparticles (MNPs). It is challenging to predict the kinetics of the dissolution process of MNPs in complex systems such as we can find in in vivo and…

Promotor: M.A.G.J. Orrit

Nanoparticles can be used as delivery systems for both small molecules and macromolecules such as proteins, peptides or oligonucleotides. This thesis focuses on the use of liposomes, nanometric vesicles formed by a lipid bilayer enclosing an aqueous core. Liposomes are highly versatile delivery syst…

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

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

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

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

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.

There is concern about the threat that nanoplastics (NPs) may pose to both wildlife and humans. This thesis explores the mechanisms of toxicity of polystyrene nanoparticles (PS-NPs) in chicken embryo.

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…

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

This doctoral thesis is an effort to understand how lipid phase-separation induced by diacylglycerol analogues in lipid-based nanoparticles affects their in vivo behavior, leading to specific nanoparticle-protein communications and selective cell targeting.

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.

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

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

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

Lipid nanoparticles (LNPs) have enabled the success of mRNA vaccines but remain limited in broader therapeutic use by challenges in delivery efficiency, targeting, and mechanistic understanding.

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.

Novel entities may pose risks to humans and the environment. The small particle size and relatively large surface area of micro- and nanoparticles (MNPs) make them capable of adsorbing other novel entities, leading to the formation of aggregated contamination.

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.

Leiden PhD student Xuequan Zhou has designed a new promising molecule that efficiently kills cancer cells, but does not harm healthy tissue. The trick: the drug is only active when irradiated with light. Zhou’s new compound does this extra efficiently by cleverly self-organising into nanoparticles.…

With an emphasis on developing novel miktoarm star polymers termed PeptoMiktoStars, this thesis leverages asymmetric polymeric polypept(o)ide frameworks to advance their effectiveness in delivering hydrophobic drugs and nucleic acids.

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…

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…

'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.

It's pretty hard to spot a single 5 nanometer particle. Leiden physicists pulled it off by turning a 120 nm gold rod into a detector.

Tiny selenium particles could have a therapeutic effect on ischemic brain strokes by promoting the recovery of brain damage. Pharmacologists, including Alireza Mashaghi from the Leiden Academic Centre for Drug Research discovered that selenium nanoparticles inhibit molecular mechanisms that are responsible…

If it’s up to PhD student Guangsheng Du, patients don’t need to worry about big needles anymore. At the Leiden Academic Center for Drug Research (LACDR), he studied the use of microneedles and nanoparticles as a new vaccination system. ‘I want to create a more patient-friendly delivery method.’ He defends…

Assessing the risks of engineered nanomaterials (ENMs) solely on the basis of experimental assays is time-consuming, resource intensive, and constrained by ethical considerations (such as the principles of the 3Rs of animal testing). The adoption of computational toxicology in this field is a high p…

Chemotherapy that does not harm the body, but effectively fights cancer cells: that is the goal of chemist Sylvestre Bonnet and his team. During his PhD research, chemist Xuequan Zhou brought that goal a little closer. He developed molecules that, upon injection in the bloodstream, self-assemble into…

Although nanoparticles are extensively used in various applications like consumer products and have most probably entered the environment, little is known about the effects of these particles on living organisms.

In summary, the collective results described in this thesis show that nanoparticulate vaccines can be delivered intradermally by coated and hollow microneedles and evoke antigen-specific immune responses.

This thesis focuses on the synthesis, characterization and performance towards CO2 electroreduction of mono and bi-metallic particles based on p-block metals

The external tissues of plants and animals are colonized by microbial communities termed microbiota. When organisms are exposed to environmental pollutants, these substances will therefore encounter microbiota at the exposure interface.