Influence of Charge on Hemocompatibility and Immunoreactivity of Polymeric Nanoparticles

The benefits of nanomedicine may be restricted by hemocompatibility and immunoreactivity problems arising from administration of exogenous materials into the bloodstream. To understand how surface charge influences the interaction of polymeric nanoparticles with blood components, we synthesized three well-defined, charge-varied hyperbranched polymers (HBPs) of similar size and analyzed both hemocompatibility and immunoreactivity of these methacrylate-based HBPs ex vivo using primary human blood cell assays and image analyses following intravenous injection into mice. The results show that, regardless of charge, endotoxin-free HBPs had minimal effects on coagulation, platelet, complement, or T cell activation. However, high concentrations (100 μg mL–1) of cationic HBPs led to significant dendritic cell activation, suggesting the potential application of these nanoparticles as vaccine adjuvants to aid efficient antigen presentation. Biodistribution studies showed that intravenously administered charge-neutr...