Some microorganisms, for example mycobacteria, are able to prevent their degradation after being phagocytosed by macrophages. Since many antibiotics fail to pass the cell membrane in sufficient quantities, microorganisms survive inside the cells. From there, they can spread again and cause disease. Colloidal lipid particles as drug carriers are recognized by the macrophages as foreign particles and are consequently endocytosed, delivering the incorporated drug to the pathogens located inside the cells in a targeted manner.
In the project, the interaction of different lipid nanoparticles with macrophages is investigated to identify properties that favor their endocytosis. THP-1 macrophages are used as a macrophage model and the phagocytosis of fluorescently labeled colloidal lipid particles is tracked by confocal microscopy and flow cytometry.
In addition to particle uptake, it is important that the drug remains associated with the nanoparticles until they reach the site of infection. Hence, the lipophilicity of drugs is modified in various ways to delay their release from lipid nanoparticles. For drug release studies, a method based on differential scanning calorimetry is used, which allows investigations in physiological media such as serum or blood.
Colloidal lipid particles are manufactured by high pressure homogenization or dual centrifugation and particle sizes are measured with photon correlation spectroscopy. Loading with drugs takes place during the production process of the nanoparticles or afterwards by incubation of powdered drug with the pre-formed nanodispersions.
Name of Doctoral Researcher
Nina Baumann
Name of Supervisor
Heike Bunjes
Institute / Department
Department of Pharmaceutics, TU Braunschweig
Contact details
nina.baumann@tu-braunschweig.de