They help cook dinner, clean the dishes, and sweep up afterward. They also build our cars, help us explore space, and now they may be on the verge of aiding in highly complex tasks in the laboratory. In particular, robot-based automation is being explored as a means to enhance efficiency in laboratories studying pluripotent stem cells (PSCs).
Pluripotent Stem Cell Culture – The State of Play
Researchers across the globe are currently using vast numbers of PSCs, such as embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs), to study the molecular basis of pluripotency, to model diseases, to screen drugs, to study human development, and to generate patient-specific replacement cells and tissues. This success has now led to human PSC-derived products entering into phase I/II clinical trials as treatments for diseases such as diabetes and vision loss.
For these reasons, the differentiation of PSCs has garnered a huge amount of the focus in the field, and each passing week delivers a new strategy to raise efficiency past a few measly percent. While this low efficiency is an obvious problem to tackle, there is another larger problem that the field also needs to address.
Pluripotent Stem Cell Problems – The Costs of Culture
All the above-mentioned applications necessitate the care and culture of huge numbers of notoriously fussy PSCs. This entails a huge monetary expense, including expensive growth factors, media formulations, and growth substrates, as well as a huge labor and time cost, with some laboratories employing several staff members only to take care of PSC culture. The large amount of time taken to maintain and passage PSCs can also lead to the generation of heterogeneous PSC cultures, which has a knock-on effect that can alter differentiation potential and heightens the risk of contamination.
Many see the automation of PSC culture as a viable strategy to improve efficiency whilst also maintaining a high level of care and reproducibility. However, the complex nature of this process and the sensitivity of PSCs has meant slow progress, and the few published studies have not reported on the long-term cellular effects of automated PSC culture [1-5]. Are robots better than humans when it comes to cellular care?
Optimized Pluripotent Stem Cell Culture Solutions
A new study published recently in Scientific Reports now suggests that long-term automated culture without loss of pluripotency or differentiation potential is possible [6] and could be the savior of many a harassed scientist and a relief to some tight budget strings. Specifically, researchers from the laboratory of Hiroo Iwata at the University of Kyoto, Japan have created a robot-based system for automated cell seeding, medium changing, cell imaging, and cell harvesting to safely and effectively culture human iPSCs (hiPSCs) over 60 days and 20 passages.
The authors created a modular, self-contained fully automated system controlled via an external touch panel interface, employing a multi-functional robotic arm to allow the mechanical passaging of cells, daily media change, and phase microscopy analysis of cell growth and quality. This represented a highly stable, efficient, and sanitary means to culture hiPSCs with no alterations in growth rate or loss of pluripotency over the 60 days of the experiment, which represented a more than 1000-fold increase in cell number. Encouragingly, cells at passage 20 were highly homogenous and demonstrated no significant changes in cell surface markers expression, global gene expression, karyotype, or differentiation potential as compared to cells at the first passage.
Where next forPluripotent Stem Cells?
Now that robot-based automation has given stem cell scientists a little more time on their hands and cells and money to spare, where do they go next? Given the clinical aspirations of hPSCs, automated culture using medium, substrates, and growth factors free of animal products may be the next logical step forward. However, there are some other tantalizing areas that merit further exploration:
- 3D culture and differentiation of PSCs
- It is becoming clear that cells in 2D react differently to cells grown in 3D, which more faithfully mimics in vivo
- Furthermore, the recent trend of 3D organoid production from PSCs promises to enhance our knowledge of development, disease progression, and the production of clinically relevant cell types.
- Automated iPSC production
- Can we automate both the initial production and the laborious colony monitoring and care during iPSC emergence?
- Can we further enhance the inefficient reprogramming process?
- Enhanced growth/differentiation substrates
- It is becoming clear that what we grow cells on, and not just what we grow cells in, is vitally important; discovering the ideal substrate for our differentiation needs may be vital.
- Why use hPSCs if we can be more direct?
- Enhanced direct differentiation of one somatic cell to another type, forgoing the iPSC stage, may represent an easier, quicker, and cheaper means to produce therapeutically relevant cells, and could be amenable to automation.
As always, Epigenie hopes to keep you updated on all the latest advancements in this ever-changing field. Stay tuned form more on robot-based automation and all the other exciting advances in the stem cells field!
References
- Hussain W, Moens N, Veraitch FS, et al. Reproducible culture and differentiation of mouse embryonic stem cells using an automated microwell platform. Biochem Eng J 2013;77:246-257.
- Soares FA, Chandra A, Thomas RJ, et al. Investigating the feasibility of scale up and automation of human induced pluripotent stem cells cultured in aggregates in feeder free conditions. J Biotechnol 2014;173:53-58.
- Terstegge S, Laufenberg I, Pochert J, et al. Automated maintenance of embryonic stem cell cultures. Biotechnol Bioeng 2007;96:195-201.
- Thomas RJ, Anderson D, Chandra A, et al. Automated, scalable culture of human embryonic stem cells in feeder-free conditions. Biotechnol Bioeng 2009;102:1636-1644.
- Kami D, Watakabe K, Yamazaki-Inoue M, et al. Large-scale cell production of stem cells for clinical application using the automated cell processing machine. BMC Biotechnol 2013;13:102.
- Konagaya S, Ando T, Yamauchi T, et al. Long-term maintenance of human induced pluripotent stem cells by automated cell culture system. Sci Rep 2015;5:16647.