Reprogramming Tumor-Associated Macrophages through mannosylated glycopolymers as siRNA delivery systems

Recent advances in drug delivery systems (DDS) have improved drug release control and targeting, addressing issues like poor solubility, pharmacokinetics, toxicity, and drug resistance. Gene therapy, which uses nucleic acids (DNA or RNA) to treat or prevent disease, shows great promise, particularly for cancer. However, delivering therapeutic nucleic acids (TNAs) remains challenging due to biological instability, nuclease degradation, inefficient uptake, and poor targeting. Various DDS approaches, including viral vectors, nanoparticles, vesicles, and polymers, have been developed to overcome these barriers, addressing issues such as cell targeting and efficient endosomal escape. This project focus on evaluating targeted polymer-based delivery systems for small interfering RNA (siRNA), aimed at exerting immunomodulatory activity in tumor associated macrophages (TAMs). RAFT polymerization was employed to synthesized four acrylamidic block copolymers as drug delivery systems: they dispose of a mannose-bearing (Man) block for TAMs targeting via the over expressed mannose receptor (CD206), and of a piperazine-bearing block (Map) for siRNA complexation and endosomal escape through the proton sponge effect. This thesis project focused on two main areas: 1. Physico-chemical characterization of glycopolyplexes: their ability to complex TNAs was assessed by gel electrophoresis, while stability and encapsulation efficiency was evaluated through Heparin Displacement and RiboGreen assays, respectively. The size and morphology of the resulting glycopolyplexes were analyzed using dynamic light scattering (DLS). 2. In vitro studies: cellular uptake studies were performed using CHO (control) and CHO-MR+ cell lines to assess the efficiency and selectivity of genetic material delivery to MR-expressing cells. The preliminary results indicate good complexation efficiency and marked selectivity toward target cells. Future steps include studies on morphology (TEM), endosomal escape capability, and evaluation of gene silencing efficacy.