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Density of Conjugated Antibody Determines the Extent of Fc Receptor Dependent Capture of Nanoparticles by Liver Sinusoidal Endothelial Cells.

Cinja KappelChristine SeidlCarolina Medina-MontanoMeike SchinnererIrina AlbergChristian LepsJulian SohlAnn-Kathrin HartmannMichael FichterMichael KuskeJenny SchunkeGabor KuhnIngrid TubbeDavid PaßlickDominika HobernikRebekka BentKatharina HaasEvelyn MontermannKerstin WalzerMustafa DikenManfred SchmidtRudolf ZentelLutz NuhnHansjörg SchildStefan TenzerVolker MailänderMatthias BarzMatthias BrosStephan Grabbe
Published in: ACS nano (2021)
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. Here we 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. We 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. We assessed the time-dependent biodistribution of PB-antibody conjugates by in vivo imaging and flow cytometry. We 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, our study 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.
Keyphrases
  • endothelial cells
  • dendritic cells
  • stem cells
  • cancer therapy
  • flow cytometry
  • computed tomography
  • cell therapy
  • photodynamic therapy
  • drug delivery
  • high resolution
  • transcription factor
  • density functional theory