A new class of bioactive nanoparticles for capable of spontaneous, linker-free multifunctionalisation

Michael PL1, Santos M1,2, Hung J1, Lam YT1,2, Bilek MM2 and Wise SG1,2

  1. The Heart Research Institute, NSW 2042, Australia.
  2. The University of Sydney, NSW 2006, Australia.

The large number of proposed nanocarriers share limitations in combining fine control of physical properties, low cytoxicity and simple functionalization in a single platform. Multifunctional carbon-based nanoparticles (nanoP3), manufactured in a custom-built plasma chamber, are a new platform that achieves multiple functionalities in a single, simple step enabling delivery of multiple molecular cargos into cells. Size, roughness, surface charge and chemical composition are readily controlled, giving rise to a versatile nanoparticle platform. Unfunctionalized nanoP3 penetrate a diverse range of cell types including cancer lines, fibroblasts, vascular cells and stem cells. nanoP3 accumulate in the cytoplasm, after rapid endosomal escape with no significant effect on viability or morphology, up to 3.1x108 particles per mm2. The presence of long-lived radicals formed during synthesis facilitates direct covalent immobilization of biomolecules by simple incubation. Binding is rapid with >80% coverage within 30 seconds, and has been demonstrated for a range of molecules including drugs, imaging agents, SiRNA, enzymes and antibodies. The addition of multiple functionalities is achieved by co-incubation in solution. To exemplify one possible utility of nanoP3, we delivered functional small interfering RNA targeted to VEGF in HUVECs, impairing the formation of tubules in an established Matrigel assay. To our knowledge this is the first platform to facilitate co-delivery of multiple surface bound cargos into diverse cell systems following one-step co-incubation without chemical pre-functionalization steps. This approach eliminates the trade-off between additional functionality and complexity and could facilitate the upscaling of nanoparticle-based therapies into the clinic.