This thesis explores the use of the IL-6R specific RNA-aptamer AIR-3A for targeted delivery of gold nanoparticles to IL-6 receptor-expressing cells. The study optimizes the efficiency and specificity of this delivery method by examining various parameters, including nanoparticle design, functionalization, incubation conditions, and concentration dependence. Key factors such as particle size and the number of affinity molecules on the surface were analyzed to identify the most effective variant for gold particle accumulation in cells. The aptamer-mediated delivery system was compared to a traditional antibody-mediated approach targeting the same receptor, revealing that the aptamer system performs equally well, and often better, at physiological temperatures across most particle sizes. The effectiveness of these two molecules depends on the type of gold particles and the intended application. The research also investigated how the aptamer binds to the receptor when conjugated to gold nanoparticles, comparing it to a fluorescently labeled aptamer to assess the impact of nanoparticle conjugation on receptor interaction. Finally, the aptamer-based system was utilized in targeted plasmonic photothermal therapy with spherical gold nanoparticles and elongated gold nanorods, where the effects of targeted particle delivery on therapy efficiency were evaluated by visualizing cell death over time after irradiation of single cells with ac
