Let’s Talk About the Sticky Situation that is Transferring Organoids and Spheroids

For ages, we've been using 2D cell cultures grown in petri dishes to understand how cells behave. But cells in our body aren’t living on flat surfaces. They're in a dynamic 3D environment.

This is why 3D models like spheroids and organoids have become so popular. They offer a more realistic representation of human tissues and are a better platform for drug testing, disease modeling, and tissue engineering.

However, working with 3D culture is where things can get a little sticky!

^{This article is posted on our Science Snippets Blog} 

Growing 3D Models: A Labor of Love

3D models are a whole different ballgame. Aside from being more complex, they also require their own special growth conditions. So, before we get into why they are hard to work with, it’s important to understand how they are made. Here's a simplified version:

1. Cell Selection: The first step is to select the appropriate cells. These could be stem cells, cancer cells, or cells from specific organs, depending on the purpose of the model.
2. Cell Suspension: Next the cells are suspended in a special medium, often a type of gel or matrix. This acts as a supportive scaffold for the cells and lets them grow in all directions, unlike traditional 2D cultures where cells can only grow flat.
3. Cell Culture: The culture is kept in a controlled environment with the right conditions for cell growth, such as temperature, humidity, and carbon dioxide levels.
4. Self-Assembly: Over time, the cells start to interact with each other and the surrounding medium, forming 3D structures. This is called self-assembly.
5. Maturation: Over days and weeks, the 3D structures continue to grow and form complex models that closely resemble an original tissue, or miniature organs.

All hands on deck: isolating organoids manually

Removing and transferring organoids or spheroids is a routine part of the workflow. For example, during cultivation, it’s normal to check them for cellular structures, protein expression, or other features. Once mature, 3D models are used for genetic analysis, drug dosing studies, and other downstream tests.  

One common way to do this is by manual pipetting using a standard laboratory pipette. All you need is a steady hand and lots of practice. We actually shared useful pipetting tips for 3D cultures in this blog.

There are also micromanipulation protocols that use a microscope with precision tools to manipulate and pick individual organoids. These methods also require expertise and are mainly useful in low-throughput applications. Let’s dig into why this is so hard, even for the steadiest of hands.

Challenges of isolating and moving 3D complexes

Isolating and picking single cells is always a delicate process, but 3D structures come with their own set of unique challenges:

1. Fragility: Organoids and spheroids have intricate architecture to mimic actual organs, which means even slight changes can damage their structure or function.
2. Viscous Environment: 3D structures are often grown in hydrogel or other gel-like mediums, making the picking process harder.
3. Size Variation: Organoids can vary in size, so the picking technique needs to be adaptable to different sizes and shapes.
4. Sterility: Naturally, manual methods have a higher risk of contamination, which can skew results or harm the 3D structures.
5. Efficiency: Especially in research where hundreds of samples might be needed, the speed of the isolation process becomes a significant factor. Automated methods can really help save time.

Automated systems can fix a sticky situation

Knowing the risks and challenges, now imagine that you've grown hundreds of tumor spheroids to test a potential new cancer drug. Can you imagine fishing them out one by one, manually?

Automated image-based systems for single-cell isolation can deliver excellent results in high-throughput applications with 3D culture.

They can detect organoids and spheroids automatically based on morphological parameters, such as area, diameter, and sphericity. Once the target is locked, the system gently retrieves the structures by suction and deposits them into a destination well with great accuracy.

Industrial applications are where automated systems really shine. In a recent study, Papantoniou et al. used the image-based CellCelector Flex Platform as part of building a high-throughput biomanufacturing roadmap for tissue fabrication. They were able to automatically target, pick, and transfer single cartilaginous spheroids into a receiver microwell.

You can find a link to this study as well as other published examples with the CellCelector Platform here.

Pick up single organoids in every size

As far as automated cell pickers go, the CellCelector Flex Platform is by far the most flexible. It’s used in cell line development and rare-cell workflows and can eliminate all the pain points in manipulating 3D cell culture structures.

You can set it up to operate fully automatically or take the joystick in your hands to gently pick structures ranging from 80 μm to 3.5 mm in diameter. The precision robotic arm can transfer the cells into any destination medium, including hydrogel, with temperature control options to keep cells happy.

Most importantly, the 3D structures remain intact, and the entire process is documented for your records. Learn more by exploring the resources below.

Automate Your Organoid Workflow