Lead author Muhammad Zia Ullah Khan examines a Petri dish containing a cell suspension. Fluorescence and bright-field images of cells in microchannels, displayed on the monitor, visualize immune cell communication
Photo Credit: Technische Universität München
Scientific Frontline: Extended "At a Glance" Summary: CellTrap Microfluidic Platform
The Core Concept: CellTrap is an instrument-free, microfluidic lab-on-a-chip system designed to isolate and observe interactions between individual immune cells and cancer cells at the single-cell level.
Key Distinction/Mechanism: While conventional laboratory tests measure average values across large cell populations, CellTrap utilizes a continuously branching main channel terminating in 1,024 microscopic trapping chambers. These chambers spatially fix individual cells, allowing researchers to use standard fluorescence time-lapse microscopy to track precise interaction timing, activation signals, and cell death over 14-hour periods.
Major Frameworks/Components:
- Microfluidic Trapping Array: A branching chip architecture containing 1,024 isolated chambers designed to draw in and spatially fix living cells.
- Stochastic Effector-to-Target Observation: The capability to randomly generate and study varying ratios of immune cells to cancer cells within individual chambers.
- Time-Lapse Fluorescence Microscopy: An affordable, standard laboratory imaging method used to track cell-cell interactions over extended observation windows.
Branch of Science: Immunology, Oncology, Microfluidics, Biomedical Engineering, and Biophysics.
Future Application: The platform enables the direct comparison and refinement of cancer immunotherapies and can be adapted to observe temporal interactions between almost any combination of cell types beyond oncology.
Why It Matters: Immune responses vary significantly from cell to cell. By revealing the precise timing and conditions required for immune cells to activate and destroy cancer cells—such as how early activation signals correlate with later cell death—CellTrap provides the critical single-cell insights necessary to improve the efficacy of targeted cancer treatments.
Immunotherapies are a promising approach in the fight against cancer. Researchers at the Technical University of Munich (TUM) have developed a lab-on-a-chip system called CellTrap. It makes it possible to observe the interactions between immune cells and cancer cells at the single-cell level. The method is intended to help better understand fundamental processes in cancer immunology and answer key questions.
Lead author Muhammad Zia Ullah Khan examines a petri dish containing a cell suspension. Fluorescence and bright-field images of cells in microchannels, displayed on the monitor, visualize immune cell communication.
Established laboratory tests mainly capture average values across many cells and show, for example, how many cancer cells survive after contact with immune cells. What happens in detail—how each cell reacts and interacts with others—remains hidden. However, to better understand the effectiveness of immunotherapies, the precise timing of a cell–cell interaction is often crucial: when contact, activation, and, ultimately, the killing of the cancer cell occur.
How CellTrap Works
CellTrap consists of a microfluidic chip with a large main channel that branches out continuously. At the ends of the branching pathways are 1,024 small trapping chambers into which the cells are drawn. Within the chambers, individual immune cells and cancer cells are selectively brought together, spatially fixed, and their interactions are observed over many hours—up to 14 hours—using a time-lapse microscope. This creates a wide variety of situations: cancer cells alone, immune cells alone, or various ratios of immune cells to cancer cells.
"With CellTrap, we can not only measure whether immune cells kill cancer cells, but also track when and under what conditions this occurs. This matters, because immune responses can vary so much from one cell to the next," says Ghulam Destgeer, professor of control and manipulation of microscale living objects at the TUM School of Computation, Information, and Technology. "And we deliberately kept the platform simple and affordable: it runs on a standard fluorescence microscope of the kind most labs already have, with no specialized equipment."
What Individual Cell Contacts Reveal
Initial experiments with a glioblastoma cell line—a type of brain tumor—confirm that when multiple immune cells encounter a single cancer cell, it is attacked more frequently and more intensely. Furthermore, it appears that early activation signals in immune cells often indicate that a cell-damaging effect will occur later. This allows, for the first time, the observation of how early reactions are related to the later outcome within the same cell–cell interaction. Beyond this glioblastoma line, the team also tested CellTrap with two additional cancer cell lines: a chronic myeloid leukemia and an adenocarcinoma.
"The more we learn about what actually happens between individual cells, the better we can compare treatment strategies and develop new ones," adds Destgeer. "And although we focused on immune and cancer cells, the platform isn’t limited to them—almost any combination of cells can be loaded and observed in the chip."
Published in journal: RSC Advances
Authors: Muhammad Zia, Ullah Khan, Morteza Hasanzadeh Kafshgari, Ali Bashiri Dezfouli, Oliver Hayden, Gabriele Multhoff, and Ghulam Destgeer
Source/Credit: Technische Universität München
Edited by: Scientific Frontline
Reference Number: imgy061826_01