Dendrimers to treat rheumatoid arthritis

In comparison with linear polymers, dendrimers' multivalency and nanostructure confer substantial advantages in drug delivery including rapid cell entry, targetability, and easier passage across biological barriers. Previous work has shown that phosphorus-containing dendrimers capped with anionic azabisphosphonate (ABP) end groups prompt anti-inflammatory activation of human monocytes. By using two mouse models of arthritis mimicking human rheumatoid arthritis (RA), Hayder et al. recently demonstrated that intravenous injection of dendrimer ABP inhibits the secretion of proinflammatory cytokines and osteoclastogenesis--two fundamental monocyte-dependent processes of inflammation and bone erosion in RA. While available biological therapies for RA target only one of the cytokines involved in inflammation or bone erosion, dendrimer ABP, by virtue of its double action on both processes in mice, might become a more active and cost-saving alternative for RA patients. This Perspective highlights this important development and the challenges that lie ahead.