Removal of Ruthenium-Initiator from Brush-Arm Star Polymers (BASPs) via Core-to-Surface Ring-Opening Methathesis Polymerization (ROMP)


This technology is an improved method for manufacturing nanoparticles that has applications as a research tool or therapeutic drug delivery platform

Problem Addressed

Small (<30 nm) nanoparticles are promising drug delivery carriers for cancer therapy. Brush arm star polymer (BASP) nanoparticles are simple to assemble and customize. This technology significantly expands upon the functionality of BASP nanoparticles.


BASP nanoparticles are typically assembled in two steps. First, bottlebrush-like structures with many polymer arms are synthesized using ring opening metathesis polymerization (ROMP) with a ruthenium initiator. Second, many bottlebrushes are crosslinked to form the nanoparticle structure. This technology adds a third step that simultaneously adds additional polymer arms to the nanoparticle thus providing a way to greatly improve the drug loading and functionality of BASPs. These improved BASP-out nanoparticles can be easily loaded with therapeutic drugs or imaging agents, and the inventors demonstrated highly efficient uptake of fluorophore labeled BASP-out nanoparticles into human cancer cells in vitro as well as outstanding efficacy and safety profiles in vivo.


  • Greatly increases the functionality of BASP nanoparticles for use in vivo
  • Highly efficient uptake into cancer cells
  • Nanoparticles can be loaded with therapeutics and/or imaging agents