Central serous chorioretinopathy (CSC) is a multifactorial disease of the retina and the choroid in the human eye. The disease is characterized by a serous detachment of the neurosensory retina in... Show moreCentral serous chorioretinopathy (CSC) is a multifactorial disease of the retina and the choroid in the human eye. The disease is characterized by a serous detachment of the neurosensory retina in the central macula, which causes visual complaints including blurred vision, a central relative scotoma, metamorphopsia, and alterations in color and contrast vision. Multimodal imaging techniques have revealed that abnormally thickened, leaking choroidal blood vessels cause an excessive fluid outflow into the interstitial space, which presumably causes the characteristic thickened choroid. This thesis addresses the clinical spectrum of CSC including the acute CSC, the chronic CSC and the severe chronic CSC. Here we suggest a strict but practical classification of CSC phenotypes based on findings on multimodal imaging techniques. We also report on the outcome of treatment, especially photodynamic therapy (PDT), in all phenotypes of CSC and provide recommendation regarding disease management and therapy. Furthermore, in this thesis we assess the roll of genetic variations among different phenotypes of CSC for a better understanding of the pathogenesis of the disease. Despite the genetic associations found in CSC phenotypes, we conclude that the so far known genetic variations do not explain the different clinical disease presentation of CSC phenotypes. Show less
Photodynamic therapy (PDT) is a promising and clinically approved method for the treatment of cancer. However, the efficacy of PDT is often limited by the poor selectivity and distribution of the... Show morePhotodynamic therapy (PDT) is a promising and clinically approved method for the treatment of cancer. However, the efficacy of PDT is often limited by the poor selectivity and distribution of the photosensitizers (PS) toward the malignant tumors, resulting in prolonged periods of skin photosensitivity. In this work, we present a simple and straightforward strategy to increase the tumor distribution, selectivity, and efficacy of lipophilic PS zinc phthalocyanine (ZnPc) in colon cancer by their stabilization in purified, naturally secreted extracellular vesicles (EVs). The PS ZnPc was incorporated in EVs (EV-ZnPc) by a direct incubation strategy that did not affect size distribution or surface charge. By using co-culture models simulating a tumor microenvironment, we determined the preferential uptake of EV-ZnPc toward colon cancer cells when compared with macrophages and dendritic cells. We observed that PDT promoted total tumor cell death in normal and immune cells, but showed selectivity against cancer cells in co-culture models. In vivo assays showed that after a single intravenous or intratumoral injection, EV-ZnPc were able to target the tumor cells and strongly reduce tumor growth over 15 days. These data expose opportunities to enhance the potential and efficacy of PDT using simple non-synthetic strategies that might facilitate translation into clinical practice. Show less
The breakthrough of immunotherapy for cancer has introduced promising new options, but nonetheless only a minority of cancer patients show significant clinical benefit. This situation has inspired... Show moreThe breakthrough of immunotherapy for cancer has introduced promising new options, but nonetheless only a minority of cancer patients show significant clinical benefit. This situation has inspired two avenues of research to find solutions to this problem: mechanistic studies to decipher the working mechanisms of immunotherapies and to investigate why many patients do not respond, and studies developing combination treatments to achieve clinical benefit in situations where immunotherapy alone is not sufficient. This thesis explores both these avenues by investigating applications of visible light in immunotherapy of cancer in pre-clinical models. We developed optical imaging platforms for visualization of immune cells and immunotherapies, which can shed light on the immunological events after administration of immunotherapy. In addition, we investigated novel therapies based on the combination of tumor ablation by Photodynamic Therapy and different types of immunotherapy. Our findings may prove useful in understanding success and failure of immunotherapy, and provide new combination treatment options when the efficacy of monotherapy is insufficient. Show less
Conventional chemotherapy often suffers from a lack of specificity, affecting both normal and cancer cells. Light-activated drugs provide spatial and temporal control over their activity, providing... Show moreConventional chemotherapy often suffers from a lack of specificity, affecting both normal and cancer cells. Light-activated drugs provide spatial and temporal control over their activity, providing a possible solution for this problem. This dissertation describes the synthesis and biological applications of (blue/green/red) light-activated ruthenium polypyridyl drugs as potential prodrugs against cancer. Show less
