Mannose- and Mannan-coated fucoidan/chitosan nanoparticles can activate macrophages

A group from LAQV, REQUIMTE, Departamento de Ciências Químicas, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira, Porto, Portugal, etc. has reported that mannose- and mannan-coated fucoidan/chitosan nanoparticles can activate macrophages.

In order to activate macrophages, mannose receptors on the macrophage surface were stimulated by drug-free fucoidan/chitosan (F/C) nanoparticles functionalized using mannose (M) and mannan (Mn). The polyelectrolyte complexed nanoparticles were electrostatically self-assembled through Coulombic interactions between cationic chitosan and anionic fucoidan.

A significant increase in CD11b expression on macrophages occurs in the presence of mannan and mannose-coated F/C nanoparticles, similar to exposure to LPS, and has a statistically significant difference compared to the non-stimulated (NS) and uncoated-F/C nanoparticles cases. Thus, it was demonstrated that the carbohydrate-coated nanoparticles elicit the activation of macrophages as observed for the LPS stimulation.

As a result, it was shown that targeting macrophage receptors via the functionalization of drug-free polymeric nanoparticles represents a promising approach to modulate the immune system.