Promotor: A.H. Meijer, Co-promotor: B.E. Snaar-Jagalska

This thesis describes the antimicrobial discovery strategy developed in our group, the den Hertog Group at the Hubrecht Institute. It includes a cultivation-based screening approach for novel antimicrobial agents from the source of fungi, and a bacterial time-lapse imaging approach for antimicrobial…

Light-Harvesting Complex II (LHCII) is responsible for light absorption and excitation energy transfer in plants and photosynthetic algae, while in high light it undergoes conformational changes by which it quenches excitations to prevent photodamage.

This thesis focused on the exploration of monolayer graphene as a membrane in direct methanol fuel cell (DMFC) applications, with improvements achieved through plasma exposure or damage- free chemical functionalization.

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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 aim of this work was to study the applicability of antigen-coated pH-sensitive microneedle arrays for effective vaccination strategies. Therefore, a model antigen (ovalbumin) was coated onto pH-sensitive (pyridine-modified) microneedle arrays to test pH-triggered antigen release by applying the…

The emergence of complex diseases resulting from abnormal cell-cell signaling and the spread of infectious diseases caused by pathogens are significant threats to humanity. Unraveling the dynamic mechanisms underlying cell-cell signaling and infectious disease spreading is crucial for effective disease…

Poly(lactic-co-glycolic acid) (PLGA) particles have been extensively studied as biodegradable delivery system to improve the potency and safety of protein-based vaccines. In this study we analyzed how the size of PLGA particles, and hence their ability to be engulfed by dendritic cells (DC), affects…

Cell-based medicinal products (CBMPs) show great promise when it comes to the treatment of genetic disorders. However, there is limited knowledge about CBMP stability during their production, storage, and administration to patients. The main focus of my research is the characterization of CBMPs using…

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…

This thesis describes the development of a variety of mannosylated conjugates. Antigen presenting cells bear mannoside recognizing receptors that actively transport antigen into the cell. This thesis exploits this feature for the development of improved vaccines.

For effective cancer immunotherapy by vaccination, co-delivery of tumour antigens and adjuvants to dendritic cells and subsequent activation of antigen-specific cytotoxic T cells (CTLs) is crucial. In this study, a synthetic long peptide (SLP) harbouring the model CTL epitope SIINFEKL was encapsulated…

Three speakers, three fascinating science stories and a well-filled lecture hall. The Niko Tinbergen Lecture had a successful restart on 10 December 2019.

Advanced fluorescence microscopy techniques have revealed how steroid receptors move inside the nucleus. The results were published by a team from Leiden University and the Erasmus Medical Center in Rotterdam, led by IBL-researcher Marcel Schaaf.

The Leiden University Medical Center (LUMC), the Danstem Institute from the University of Copenhagen and the Murdoch Children’s Research Institute in Melbourne have received 300m euros from the Novo Nordisk foundation. The aim of this new international consortium is to bring stem-cell based therapies…

Kidney failure is a serious issue because kidneys cannot regenerate themselves after injury. A possible solution consists of artificially growing healthy kidney tissue. To achieve that, scientists first need to understand kidney development during the earliest stages, in the fetus. Leiden researchers…

A new mathematical model may explain how body cells get their shapes and what makes them move within a tissue. The model provides fundamental knowledge for applications in tissue engineering, amongst other things. Publication in open-access journal iScience.

Zebrafish-human communication shows that cancer cells lacking a signaling protein are less able to develop aggressive metastatic properties. This discovery has been made by molecular cell biologist Claudia Tulotta. PhD defence 14 June.

The main aim of this thesis was to unravel the signaling and regulatory networks that drive tumor cell migration during breast cancer metastasis.

Viral hemorrhagic fever (VHF) is a group of acute diseases caused by highly infectious viruses including Ebola, Lassa, Dengue viruses. Its high mortality rate poses high risk to public health, however, studies on VHF have been hampered due to the non-availability of proper models and incomplete knowledge…

Chemist Roxanne Kieltyka has received an ERC Starting Grant of 2 million euros. In her lab, she creates gels that mimic the instructive material that supports cells in our body. With the grant, she aims to make these gels stiff and tough, and to create a bio-printed miniature heart ventricle.

This dissertation contains four works during my PhD. Different biomaterials have been designed based on coiled-coil peptides. These biomaterials have a range of applications, inclusing drug delivery, cell sorting to cell-cell fusion.

The Netherlands Institute in Morocco (NIMAR) is an institute of the Faculty of Humanities of Leiden University, with a nationwide remit, located in Rabat, Morocco. NIMAR has four tasks.

Cardiovascular diseases are a leading cause of death worldwide, and better models are urgently needed for disease progression studies and drug development.

Multicellular giant algae Chara species have been widely used in physiological studies for decades.

Carbohydrates are present on the surface of bacteria making them suitable antigen candidates for vaccine development. This thesis deals with the synthesis of two carbohydrate-based components; the capsular polisaccharide of S. aureus type 5 and teichoic acids from staphilococci and enterococci speci…

The overall theme of this thesis is to complement the electrochemical data acquired in fuel cell research with in situ X-ray photoelectron spectroscopy (XPS) and soft X-ray absorption spectroscopy (XAS).

PhD defence

Biophysicist Rolf Harkes has developed a microscope to optically localize individual molecules in living cells. It improves monitoring of diseases like cancer and Parkinson’s at the cellular level. Defende PhD thesis on t13 January 2016.

Promotor: Prof.dr. J. Kuiper, Co-promotor: Saskia C.A. de Jager

Prison staff are working under high pressure. The current proposal for cell sharing is the final straw. Associate Professor Esther van Ginneken appeared on Dutch news programme ‘Nieuwsuur’: ‘Serious incidents have occurred, including the murder of a cellmate.’

Embryonic stem cells have the remarkable ability to develop into any type of cell. On their way to become for example a liver or a heart cell, they must repeatedly decide between alternative developmental paths. How they make these decisions is largely unknown. An international team of biophysicists…

The focus of the described research in this thesis is on the oxidative stress response (Nrf2 pathway). The aim of the research presented in this thesis is to obtain more information concerning microRNAs which are involved in the Nrf2 pathway, to determine and evaluate the application of microRNAs for…

Leiden molecular cell biologists in the research group of Annemarie Meijer have discovered novel early macrophage-specific genes in zebrafish, including a signal transducer pivotal for the migration of macrophages in the innate immune response to bacterial infection. Their findings were published on…

Leiden chemists, together with colleagues at the University of York (UK) and Technion (Israel) have discovered a small, sugar-like molecule that maintains the integrity of tissue around a tumour during cancer. This molecule prevents tumour cells from spreading from the primary cancer site to colonise…

With the necessary measures, researchers restart their work in various laboratories. The Leiden Cell Observatory is one of the places where scientists resume their lab work.

When the immune system attacks cancer, the tumour modifies itself to escape the immune reaction. Researchers at LUMC published on this subject in Nature on 28 June.