Navigating Into The Body

Sonia Monti BA

Living Bacteria as a Drug Delivery System

Today one might not be surprised anymore to hear about microscopic objects entering the human body to treat or diagnose diseases. However, the imagination of these objects at work remains limited, as they can be only observed through special microscopes. How could one create a window to this microscopic world inside the human body and visualize them in an effective way?

Design Mentor
Alessandro Holler

Cooperation Partner
Prof. Dr. Simone Schürle-Finke
Responsive Biomedical Systems lab (RBSL), 
ETH Zürich

Micro- and nano-scale engineering is an emerging field with the potential to tackle some of today’s most crucial challenges in medicine. In particular, recent research showed how micro- nano-scale medicine could play a game-changing role in cancer diagnostics and treatment.

Let us imagine that magnetic bacteria flowing through the human body until they reach a tumor. What if such type of living bacteria could serve as a drug delivery system to locally treat cancer while being externally controlled? Is it fiction? Not really.

Together with the Responsive Biomedical Systems Laboratory (RBSL) at ETH Zürich, directed by the Professor Simone Schürle-Finke, I developed a method to build a three-dimensional world to illustrate this complex scientific process. The result shows how magnetotactic bacteria can navigate into the body and go out through blood vessels into the tumor by the use of external magnetic fields. The visualization of this process aims at communicating the research in an effective way and aiding future public acceptance for this new fascinating method.

The Prototype

In the following you can find the interactive prototype of the model. You can replay the scenes and single animations as you like and take your time to understand the scientific topic.


The main character of the scene is the magnetotactic bacteria (MTB), with attached liposomes. One of the research projects of the RBSL focuses on this drug-delivery system which aims to bring a medicine directly inside a tumor. Liposomes containing drugs are attached to the MTB and conducted into the tumoral mass. But how? Well, this kind of bacteria naturally contains iron particles, thanks to which they can be externally controlled using magnetic fields. This way, they can be guided through the human body until they reach the tumor. The liposomes release the drug slowly while navigating inside the body, but most of it is released inside the cancer.
To better explain the composition and functionality of these particular objects, I created a series of schematic illustrations.
On the left, a schematic representation of an MTB-liposome. On the right, a magnification and inside view of a liposome.

MTB rotation. This type of bacteria can be externally controlled and guided to the tumoral mass using magnetic fields.

Inside view of a liposome. The little turquoise spheres represent the drug.

Inside view of an MTB. The dark grey spheres represent the iron particles.

The Cube: An Unusual Environment

The scene takes place hypothetically inside a three-dimensional cube. The choice of this environment is purely based on its utility. We usually do not know exactly what the inside of our living body is like. Although I can imagine it, the scene would be very bloody and perhaps not suitable for an audience or for the communication of a delicate scientific message, such as the one of cancer treatment. As a scientific illustrator I always have to find a tradeoff between the accuracy of the representation and its ability to deliver a concept. This project is an experiment with which I wanted to decontextualize an indefinite part of the human body, presenting it as a cube, and use it as a stage for the presentation of a scientific concept. This results in a representative series of elements, which convey a specific message: Magnetic bacteria bringing drugs into a tumoral mass.
Cubic representation of extracellular matrix (ECM) and blood vessels.

Representation of an interconnection of blood vessels within the ECM.

Representation of MTB in the bloodstream

Representation of MTB inside the tumor. The liposomes are releasing the drug.

Representation of MTB extravasating the blood vessel and entering the tumoral mass.
Color Coding

The choice of color is always very important for the success of an illustration-related project. In this experiment, I decided to use the color in a symbolic way. In other words, colors do not represent reality but are used to recognize elements within the scene. The use of red to characterize blood vessels is very common, and I wanted to maintain this convention in my project. The violet represents a set of elements within the ECM. The tumor is in a way part of this environment, that is why I decided to represent it with the same, but darker, color. For the other colors, I took decisions together with my cooperation partner. The lab already uses existing color conventions to represent these objects. For consistency we therefore dediced to keep them the same.

A Look Behind the Scene

In the following, you can take a look at my realization process. It was very important for me to take updated notes about the project and to share my contents with my mentor, to get valuable feedbacks. 

Experiment with two different representation methods to obtain an ECM.
Representation prototype of an  ECM.
Experiment to represent the blood vessel damaged by the tumor. Here I used symbolic holes to convey the message of a leaky blood vessel.
Experiment to represent the blood vessel damaged by the tumor. Here, instead, I tried to build the cells’ structure and to manipulate it to create “spaces” between them.

Experiment to represent the blood flow. Here, the focus was on the size and on the quantity of the blood cells.
Experiment to animate the blood cells. I focused on the speed and on the movement, trying to create a random movement.
Building a three-dimensional MTB with attached liposomes. Although in the final project I decided not to show the inside of the bacteria, for the sake of completeness, I wanted to build a model which included all the elements, such as iron particles.
Setting the bacteria for the animation. Here, the focus was on how to put them inside the tumor.