Pancreatic Ductal Adenocarcinoma (PDAC) is one of the most lethal cancers due to a high chemoresistance and poor vascularization, which results in an ineffective systemic therapy. PDAC is characterized by a high intratumoral pressure, which is not captured by current 2D and 3D in vitro models. The OrganoPlate® is used to mimic the intratumoral pressure in PDAC in a 3D microfluidic interstitial flow model.
- Formation of 40 3D tumor tissues in the OrganoPlate®
- Investigate perfusion flow and interstitial flow
- Excellent automated imaging in 3D
- Enables personalized therapy response testing
An OrganoPlate® 3-lane with 40 microfluidic chips was used for a 3D cell culture of the non-metastatic PDAC cell-line S2-028. Cells were mixed with a collagen gel (blue in Figure 1a) as extracellular matrix (ECM) and inserted in the middle lane (gel inlet) of each chip. PhaseGuide technology allows selective patterning of the ECM gel without use of any artificial membranes. Following the addition of a medium in the adjacent channels (2), the plate is placed on the OrganoFlow® platform, which creates a height difference resulting in gravity driven, continuous, and bi-directional perfusion of the cultures. By placing the plate perpendicular to the perfusion flow condition, the flow is directed through the ECM gel generating an interstitial flow.
Interstitial flow inhibits proliferation
Pancreatic cancer cells were subjected to either the Perfusion or Interstitial flow profile. Rapid proliferation and spheroid formation were observed when the cells were subjected to perfusion flow (Figure 2a, top row). When the cells in ECM were subjected to interstitial flow, smaller spheroids were observed from day 3 onwards (Figure 2a, bottom row). Immunofluorescent viability staining for live (Calcein-AM) and dead (Propidium Iodide) cells showed a decreased cell count in the interstitial flow condition, whereas no difference was observed in the overall viability of cells, suggesting a decreased proliferation rate as a result of interstitial flow. Similarly, the PDAC cells showed a lower EdU incorporation under interstitial flow, as compared to the perfusion flow condition, also suggesting a decreased proliferation rate.
Interstitial flow increases chemoresistance
To assess the effect of different flow directions on the cytotoxic effect of gemcitabine, 72h dose response curves of gemcitabine were obtained (Figure 3). The results showed an EC50 of 85 nM and 277 nM for the perfusion and interstitial flow models, respectively, representing a 3-fold lower sensitivity with interstitial flow. When compared to the 31nM EC50 in 2D monolayers, EC50 values were almost 3- and 9-fold higher for perfusion and interstitial flow in 3D cultures, respectively.
This project received funding from the European Union’s Seventh Framework Programme for research, technological development, and demonstration under grant agreement no 602783. The full study was published in Int. J. Mol. Sci. 2019, 20, 4647.