Tumor Model to Evaluate Drugs

Engineering the vascular tumor micro environment by patterning endothelial cells with sound

Highlights

  • A 3-dimensional cancer in vitro model is developed

  • The experimental setting enables for reproducible patterns at high through put

  • An image-based optical read-out allows to quantify the response to drugs

Translating basic research discoveries to clinical application in the field of drug development is accompanied with major challenges, and predictable in vitro model systems are urgently needed. In the scope of personalised medicine, in vitro models with patient-specific cells are particularly interesting to evaluate new treatment options.

There is general agreement that standard 2-dimensional cell cultures are inappropriate for drug screening and their response to drugs far from the in vivo situation. In cancer drug screening in particular, the tumor microenvironment (TME), formed by multiple cell types, extracellular matrix, and a vascular system, has been appreciated as a major player in a tumor's response to treatment. State-of-the art 3-dimensional in vitro models are based on micro fluidics and comprise spheroids based on patient-derived tumor cells, that are integrated within a perfusable microcapillary network within a hydrogel.

These models often lack reproducibility, scalability, and are labour intensive. (1)By use of sound, reproducible cell patterns at high spatial resolution can be engineered within multi-well dishes. The small reaction vessel, simultaneous patterning of multiple wells, and good optical red-out allows for high through put screening of different drugs at low consumption of reagents and cell number.

With cymatiX, we introduce a new biofabrication method to engineer patient-tailored in vitro model systems combining the tumor and surrounding vasculature, spatially organized in a Saturn-like configuration. (2)


 

Experimental Design

By use of sound, endothelial cells (green) were assembled in fibrin into rings with reproducible diameters of 1.9 ± 0.06 mm that were let to mature for 48 hours. Subsequently, a tumor spheroid was placed on top of the microvasculature.

Results

Figure 1A) Microscopy images after 6 days in culture. The circular microvasculature is displayed in green. Distinct cells within the tumor spheroid were stained in yellow or red, respectively. At higher magnification, tumor cell sprouting towards the micro vasculature can be observed, indicative for the cross talk between the two components within this model. B) In a reconstructed image, the three dimensional nature of the model is apparent. The tumor spheroid is embedded within the circular structure of endothelial cells formed with sound.


Figure 2 The green fluorescent area, formed by endothelial cells, was quantified over time based on image analysis. In response to applied drugs (Cisplatin or Bevacizumab), a distinct development of the microvasculature was observed, with an increased area after treatment with Cisplatin on day 6. Overall, the created model allows for drug evaluation with a fast, optical readout.


 
Experimental Conditions

Biomaterial: Fibrin

Cell Type: Endothelial cells, Pericytes, Fibroblasts, Cancer Cells

Labware: IBIDI µ-Slide Angiogenesis3


References

(1) Singh et al. In vitro experimental models of mesothelioma revisited. Transl. Lung Cancer Res. 2017.

(2)Results presented at TERMIS World Congress, 2021. https://termis.org/sites/default/files/20211207%20TERMIS%202021%20ABSTRACT%20BOOK%20RG%20v6.pdf

(3) https://ibidi.com/chambered-coverslips/41--slide-angiogenesis.html