Controlled and enhanced cytosolic uptake of active ingredients via collective niosomal encapsulation of drug and endosomal escape enhancers

• Applicants: Professor Dr. Hendrik Fuchs; Professor Dr. Georg Garnweitner
• Subject Area: Mechanical Process Engineering ; Cell Biology
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 567602777

Many active ingredients, such as the recently developed messenger RNA (mRNA)-based vaccines against SARS-CoV-2, must be taken up intracellularly in order to develop their pharmacological activity. The most common mechanism of cellular uptake for such macromolecular drugs is receptor-mediated endocytosis, in which the drugs are enclosed within clathrin-coated transport vesicles and thus enter the so-called early endosomes. However, a large proportion of the absorbed drugs remains ineffective within the endosomes, is returned to the cell surface, or is finally degraded in the lysosomes. In this way, an estimated 98 % of DNA or RNA drugs lose their pharmaceutical activity. To date, this effect can only be compensated for by systemic application of a high dose of active ingredient, which, however, leads to serious side effects. In recent years, various approaches have been presented to weaken the membrane integrity of endosomes, which however are often cell- or membrane-unspecific and therefore do not have a targeted effect. A promising alternative is the use of certain glycosylated triterpenoids that specifically accumulate in the endosomal membrane and can act as so-called endosomal escape enhancers (EEE). Until now, however, these have either been applied separately from the respective active ingredients or together with them were covalently bound to specific carrier systems such as antibodies or dendrimers. In both cases, adaptation to a specific active ingredient is required and therefore no broad application is possible. The aim of this project is to establish a platform technology based on niosomes as nanoscale transport particles that – as a carrier system – contain both an active ingredient and an enhancer (SO1861 as a highly efficient EEE). We use siRNA as a versatile active ingredient. The aim is to enable a rational design of niosomal carriers for low- and macromolecular, cytosolically active substances with enhanced endosomal release. Due to the amphiphilic and membrane-weakening properties of the EEE, first a fundamental clarification of the interaction with the niosomal components is required. Questions such as the effect of the incorporation of the EEE on the structure and physicochemical properties of the niosomes and the preservation of the functionality of the EEE even after integration into the niosome membrane must be answered, before the behavior of the drug-loaded particles in cell culture and ex vivo in serum or whole blood will provide initial insights into which formulations are promising and would be suitable for further experiments in a mouse model. For active targeting, the niosomes will be equipped with epidermal growth factor as a fusion protein to specifically address cancer cells. The optimization of the niosomes is carried out in iterative feedback cycles between the process engineering and cell biology parts of the project.

• DFG Programme: Research Grants