Offered by the CRC 1066 core facility "Nanoparticle / Polymer Biocompatibility"


1. Suitability of nano-carriers for cellular assays


  • integrity of of fluorescence label(s) of the nano-carrier by FACS analysis (intensity and distribution; monitor all channels to assess "leakyness" of fluorophors used)
  • quantification of cargo of nano-carrier by applicable method (e.g., FACS analysis, ELISA, Bradford, functional cellular assays)


  • assessment of  microbial contaminations:
    • incubate nano-carriers in cell culture media (test for growth of microbia):
    • content of endotoxin (LAL assay)
    • bioassay: incubate nano-carriers with luciferase reporter-transduced indicator cells (luciferase expression is induced in response to microbia-derived stimuli recognized by cellular receptors (i.e., LPS))

Proapoptotic effects

  • metabolic activity of cells incubated with nano-carriers over a wide range of concentrations in suitable cell lines, spleen cells / human PBMCs (Transfusionszentrale) by quantitative colorimetric assay ("MTT assay")
  • apoptosis/necrosis of target cells preincubated with nano-carriers at pre-selected concentrations by Annexin V/7-AAD staining (FACS analysis)


2. Cellular assays

Cellular binding/uptake1,2

  • assessment of binding of fluorescence-labeled nano-carriers to intended target cell population by FACS analysis; parameters: dose and time course studies; perform control reactions at 4°C to monitor unspecific binding
  • evaluate cell type-specific binding: incubate with spleen cells / PBMCs; costain with a panel of cell lineage markers
  • preincubate cells with excess of free antibody / natural ligand prior to incubation with nano-carrier to block receptor-dependent specific binding
  • analyse interaction of evaluated nano-carrier with serum components on functional level: preincubate nano-carrier with native mouse / human serum prior to its incubation with cells
  • if nano-carrier shows serum-dependent alterations in cellular binding: preincubate nano-carrier in parallel with heat-inactivated serum, mixture of unspecific antiybodies, defined serum proteins prior to incubation with cells to identify potential nano-carrier binding factors

Cellular uptake3

  • confirm cell type-specific uptake of suitable nano-carriers by confocal microscopy: incubate nano-carrier with mixture of target and non-target cells; counterstain with cell lineage marker that binds target cell-specific surface receptor to clarify cell type-specific uptake

Intrinsic immunomodulatory effects1,2

  • assess potential intrinsic stimulatory/inhibitory effects of candidate nano-carriers: incubate with reporter cell line(s) with transcription factor-responsive luciferase/fluorescence responsiveness (e.g., NF-kB, AP-1, NFAT; biosensors indicative of pH value, redox state, calcium transients)
  • monitor cellular activation in response to dose titration of nano-carrier over time in terms of expression of surface markers and soluble mediators (ELISA/FACS)
  • assess potential activation of the inflammasome by detection of Caspase-1 activity (ELISA-based) and production of mature IL-1ß (ELISA/FACS-based)
  • monitor induction of reactive oxygen species (ROS) (FACS and ELISA assays available)
  • these methods are also applicable to assess intended immunostimulatory effects of nano-carriers functionalized with adjuvants


¹ Cell lines availabe: tumor (e.g., B16, panel of human melanoma cell lines), T cells (e.g., DO11.10; Jurkat), B cells (e.g., A20), DC-like (e.g. XS52, differentiated THP-1), macrophages (e.g., P388, RAW 264.7), endothelial (e.g., Endo, HUVEC), fibroblast. (e.g., WEHI 164), epithelial (e.g., EA.hy926, DLD-1).

² Primary immune cells: bone marrow- (mouse) or monocyte- (human) derived dendritic cells; other immune cell types: enriched by immuno-magnetic sorting from spleen cells / PBMCs.

³ Upon request: generation of derived reporter cells by lentiviral transduction with vectors that encode for