Layer-by-Layer Nanoparticles for Cytokine Therapy in Cancer Treatment

Technology

To achieve effective IL12 treatment with reduced side effects these inventors encapsulated IL12 in a nanoparticle using layer-by-layer technology. A liposomal core containing DGS-NTA-Ni is reacted with Histidine on recombinant, single chain IL12 (scIL-12) that contains a C-termininal 6xHIS tag. This liposome-scIL-12 core is then coated with poly(L-arginine) and an outer coating of polyanion using electrostatic interactions between layers. IL12 interacts with an extracellular receptor on immune cells, therefore the nanoparticles must not be internalized and must also be able to interact with the relatively rare immune cell populations. Outer polyanion coatings of either hyaluronic acid or poly(L-glutamic acid) maximize tumor and immune cell association, and nanoparticles with these external layers are able to activate downstream IL12 pathways, namely IFN-y production, in splenocytes in vitro, even after the nanoparticles are pre-challenged with tumor cells. Importantly, scIL-12 nanoparticles also display greatly reduced toxicity in vivo compared to soluble IL12. Finally, this technology is highly adaptive and can easily be applied to other cytokines and proteins for delivery or tailored for combination therapy.

Problem Addressed

The immune system has a variety of cell types that can target and kill cells identified as unhealthy. Cancer immunotherapy is a revolutionary new treatment modality that harnesses a patients’ own immune system to target cancer cells. An important step in priming an immune response against cancer is to deliver a general immunostimulatory compound. The cytokine IL12 was an attractive immunostimulatory candidate as it can stimulate both innate and adaptive immune cells, however early clinical trials with IL12 showed that very severe side effects prevent treatment at effective doses. These inventors describe nanoparticle encapsulation of IL12 that significantly reduces the systemic side effects of IL12.

Advantages

• Greatly reduced systemic IL12 toxicity by nanoparticle encapsulation
• Optimized immune cell and tumor targeting through choice of polyanion outer layer
• Efficient loading of recombinant IL12 (>90%)
• Adaptable to other cytokines/proteins and combination therapies through straightforward nanoparticle loading