Mannose-modified hyaluronic acid nanocapsules for the targeting of tumor-associated macrophages

Tumor-associated macrophages (TAMs), a class of immune cells that play a key role in tumor immunosuppression, are recognized as important targets to improve cancer prognosis and treatment. Consequently, the engineering of drug delivery nanocarriers that can reach TAMs has acquired special relevance. This work describes the development and biological evaluation of a panel of hyaluronic acid (HA) nanocapsules (NCs), with different compositions and prepared by different techniques, designed to target macrophages. The results showed that plain HA NCs did not significantly influence the polarization of M0 and M2-like macrophages towards an M1-like pro-inflammatory phenotype; however, the chemical functionalization of HA with mannose (HA-Man) led to a significant increase of NCs uptake by M2 macrophages in vitro and to an improved biodistribution in a MN/MNCA1 fibrosarcoma mouse model with high infiltration of TAMs. These functionalized HA-Man NCs showed a higher accumulation in the tumor compared to non-modified HA NCs. Finally, the pre-administration of the liposomal liver occupying agent Nanoprimer™ further increased the accumulation of the HA-Man NCs in the tumor. This work highlights the promise shown by the HA-Man NCs to target TAMs and thus provides new options for the development of nanomedicine and immunotherapy-based cancer treatments.

A Nanoprimer To Improve the Systemic Delivery of siRNA and mRNA

Despite tremendous interest in gene therapies, the systemic delivery of nucleic acids still faces substantial challenges. To successfully administer nucleic acids, one approach is to encapsulate them in lipid nanoparticles (LNPs). However, LNPs administered intravenously substantially accumulate in the liver where they are taken up by the reticuloendothelial system (RES). Here, we administer prior to the LNPs a liposome designed to transiently occupy liver cells, the Nanoprimer. This study demonstrates that the pretreatment of mice with the Nanoprimer decreases the LNPs' uptake by the RES. By accumulating rapidly in the liver cells, the Nanoprimer improves the bioavailability of the LNPs encapsulating human erythropoietin (hEPO) mRNA or factor VII (FVII) siRNA, leading respectively to more hEPO production (by 32%) or FVII silencing (by 49%). The use of the Nanoprimer offers a new strategy to improve the systemic delivery of RNA-based therapeutics.