Techniques: Engineered diatom-based biosilica particles for delivery of chemotherapeutics

Diatom-based biosilica nanoparticles could be used to deliver chemotherapies to tumors. The nanoparticles were created by incorporating a recombinant IgG-binding domain into the diatom's genome, labelling the diatom's biosilica wall with an antibody targeting a tumor cell surface marker and attaching a chemotherapy-loaded liposome or micelle to the biosilica wall via electrostatic charge. In a human neuroblastoma cell line, nanoparticles labeled with an antibody against the cell surface p75 neurotrophin receptor (p75 NTR) and loaded with the active metabolite of irinotecan increased cell death compared with unloaded nanoparticles or nanoparticles lacking the antibody label. In a xenograft mouse model of neuroblastoma, the same nanoparticles decreased tumor growth compared with the unloaded, antibody-labelled nanoparticles or the free metabolite. Next steps could include tested chemotherapy-loaded nanoparticles in models of other cancers...