Publication Barz Lab
Despite considerable progress in the design of multifunctionalized nanoparticles (NPs) that selectively target specific cell types, their systemic application often results in unwanted liver accumulation. The exact mechanisms for this general observation are still unclear.
In this article the labs of Stephan Grabbe (Department of Dermatology, University Medical Center Mainz) and Matthias Barz asked whether the number of cell-targeting antibodies per NP determines the extent of NP liver accumulation and also addressed the mechanisms by which antibody-coated NPs are retained in the liver. They used polysarcosine-based peptobrushes (PBs), which in an unmodified form remain in the circulation for >24 h due to the absence of a protein corona formation and low unspecific cell binding, and conjugated them with specific average numbers (2, 6, and 12) of antibodies specific for the dendritic cell (DC) surface receptor, DEC205, to assessed the time-dependent biodistribution of PB–antibody conjugates by in vivo imaging and flow cytometry. The authors observed that PB–antibody conjugates were trapped in the liver and that the extent of liver accumulation strongly increased with the number of attached antibodies. PB–antibody conjugates were selectively captured in the liver via Fc receptors (FcR) on liver sinusoidal endothelial cells, since systemic administration of FcR-blocking agents or the use of F(ab′)2 fragments prevented liver accumulation. Cumulatively, this study nicely demonstrates that liver endothelial cells play a yet scarcely acknowledged role in liver entrapment of antibody-coated NPs and that low antibody numbers on NPs and the use of F(ab′)2 antibody fragments are both sufficient for cell type-specific targeting of secondary lymphoid organs and necessary to minimize unwanted liver accumulation.
Cinja Kappel, Christine Seidl, Carolina Medina-Montano, Meike Schinnerer, Irina Alberg, Christian Leps, Julian Sohl, Ann-Kathrin Hartmann, Michael Fichter, Michael Kuske, Jenny Schunke, Gabor Kuhn, Ingrid Tubbe, David Paßlick, Dominika Hobernik, Rebekka Bent, Katharina Haas, Evelyn Montermann, Kerstin Walzer, Mustafa Diken, Manfred Schmidt, Rudolf Zentel, Lutz Nuhn, Hansjörg Schild, Stefan Tenzer, Volker Mailänder, Matthias Barz, Matthias Bros, and Stephan Grabbe
Density of Conjugated Antibody Determines the Extent of Fc Receptor Dependent Capture of Nanoparticles by Liver Sinusoidal Endothelial Cells
ACS Nano Article ASAP