Oncology Applications

  • Most chemotherapeutics are low molecular weight molecules with poor solubility that are easily excreted requiring higher concentrations
  • Most chemotherapeutics are not selective resulting in nonspecific distribution throughout the body including healthy tissues
  • As a result toxicity is unavoidable
  • Nanoparticles address these issues
Nanoparticles Exploit Abnormal Tumor Vascular Architecture
  • Tumors require blood supply and newly formed tumor vessels are usually abnormal in architecture
  • Nanoparticle strategy is to target tumors by exploiting abnormalities of tumor vasculature and the local tumor microenviroment
    • Aberrant vascular architecture
    • Extensive production of vascular permeability factors stimulating extravasation within tumor tissues
    • Lack of lymphatic drainage
Enhanced Perfusion Retention
  • Nanoparticles do not penetrate through tight endothelial junctions of normal blood vessels resulting in a longer plasma half-life
  • Nanoparticles can selectively extravasate into tumor tissues due to abnormal (leaky) vascular nature
  • Enhanced Perfusion Retention (EPR) effect is important for nanoparticle delivery to tumor tissue
  • Concentrations of particles build up in tumors several folds higher than that of the plasma - increases residence time of the chemo-agent at site of action
  • This selective high local concentration of nano-anticancer drugs in tumor tissues provides superior in therapeutic effect while reducing side effect

Safe Sustained Drug Delivery using Nanoporous Silicon Particles