Regenerative Medicine

Regenerative medicine is the medical field concerned with the development of cell-based therapies for replacing/repairing/treating diseased or injured tissues and organs. Stem cells are principally utilized due to their capacity for differentiation into multiple cell types. Both multipotent stem cells, such as mesenchymal stem cells (MSCs), and pluripotent stem cells, including embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs), are used to manufacture therapeutics.

The reliable culture, differentiation, and application of stem cells is thus of great importance in regenerative medicine. “Cell manufacturing” of stem cells at scale is most reliably performed using a light microscope to quantitatively determine and assess key indicators related to culture state and quality. Such indicators may include proliferation rate, colony formation characteristics, morphological features, etc.

Products for Regenerative Medicine

137-hour time-lapse video (40-minute intervals) of human iPS cells using phase contrast.

Image credit: Dr. Masahiro Kino-Oka and Dr. Mee Hae Kim, Osaka University, Graduate School of Engineering, Dept. Biotech, BioProcess Systems Engineering Lab

The Nikon BioStudio-T Cell Observation Device fits in most incubators and biosafety cabinets used for cell culture. Whole-vessel phase contrast imaging is performed using a unique objective lens-scanning approach that keeps the vessel stationary and allows for vessel exchange without losing position information. It is designed to support applications in stem cell culture and can be integrated with the Cell Analysis Module for the NIS-Elements software, which enables the measurement of hPSC colony count, coverage area, and other factors for different assays.

The BioStudio-mini Cell Observation System is a compact cell imaging solution intended for cell manufacturing facilities. Several of Nikon’s strategic partners in the field have integrated this system within their biosafety cabinets with the stage flush with the work surface.

The Nikon ECLIPSE Ts2 and Ts2-FL inverted microscopes are award-winning compact inverted microscopes designed for routine cell culture-related work. The Ts2-FL has all the features of the Ts2 but additionally provides built-in LED-based epifluorescence. These microscopes are the usual choice for more routine cell culture work and used more widely in basic research than manufacturing.

●: included, ⚬: option

BioStudio-T
Cell Observation Device
BioStudio-mini
Cell Observation System
ECLIPSE Ts2
Inverted Microscopes
Diascopic Illumination Source Red LED Red LED Blue LED-excited white phosphor
Position Control Motorized XYZ Motorized Z (optional) Manual
Camera Integration Built-in monochrome CMOS detector Built-in monochrome CMOS detector Free Selection (Optional)
Accommodates well plates, dishes, and flasks yes yes yes
Compatible with decontamination using vaporized H2O2 yes yes no
Suitable for cell manufacturing facilities yes yes no
Compatible Contrasting Techniques BioStudio-T BioStudio-mini ECLIPSE Ts2
Brightfield no no yes
Widefield Fluorescence no no TS2-FL
Nikon Emboss Contrast no no yes
Phase Contrast yes yes yes

Discussion of Regenerative Medicine

Masked Image
Phase Contrast

Application of the Cell Analysis Module to create a mask image of iPSC colonies present in phase contrast data, allowing for measurement of the number of colonies and their respective area.

From Cell Culture to Cell Manufacturing

Cell culture/manufacturing to produce a therapeutic product is very different than cell culture as routinely performed in an academic or basic research setting. Manufacturing in the healthcare and pharmaceutical industries requires a greater level of quality control and operational efficiency and is subject to significantly more regulation. Predictable production of a quality product that meets the required standards while minimizing cost is the ideal.

The application of image analysis to inform decision-making helps remove one of the greatest barriers towards predictable manufacturing – the reliance on human operators, which inherently introduces variability, even with an experienced staff. Qualitative methods, e.g., “shaking the vessel three times after seeding” can be put to the test using quantitative image analysis techniques and thus formalized.

Application of engineered 3D stem cell-derived systems for patient implantation is already happening, e.g., the culture of skin grafts. Clinical testing of more complicated cell systems is underway. The eventual goal is to be able to culture fully functional complex organs such as the heart. Note that 3D engineered tissues, including various types of organoids, are also applied towards drug discovery testing.

Animation of how the BioStudio-mini can be installed in a biosafety cabinet for culture work.

Minimizing Perturbation to Sensitive Cell Cultures

A variety of cell types are cultured in vitro, including primary cells recently obtained from tissue, immortalized cell lines, and stem cells. Cultures of immortalized cell lines, as often used for basic biological research, can be quite capable of withstanding significant insult, such as improper seeding density, being left outside of the incubator for extended periods, etc. Stem cells tend to be more sensitive to perturbation. Stringent attention to culture conditions is thus important when working with stem cells, especially when cultured for use as part of a therapeutic.

A top factor to consider is the incubation conditions, and consistency thereof. Nikon's BioStudio-T and BioStudio-mini are instead manufactured to be compact enough to fit in existing incubators and biosafety cabinets.

Vibration is another concern. Among other factors, vibration can cause cells stress and influence their seeding pattern following passage. To minimize vibration, the BioStudio-T uses an objective-scanning strategy for tiled acquisition, rather than moving the sample.

Phototoxicity is also a concern. For this reason, a low illumination intensity technique such as phase contrast is usually favored. Fluorescence labeling can be an invasive procedure and fluorescence imaging can be phototoxic. Nikon’s BioStudio series instruments take advantage of phase contrast imaging using a red LED for illumination. Red light carries less energy and is less phototoxic than a similar quantum of blue light.

Cell x Image Lab – A Resource for Cell Culture Success

Supporting the regenerative medicine field is a strategic goal of Nikon Healthcare. To this end, we have launched the Cell x Image Lab website, which details how microscopy imaging and analysis can be used to give cell culture processes and procedures a quantitative edge – enhancing the success rate and reproducibility of cell manufacturing. Imaging and analysis are also useful for quality assurance and developing new processes and procedures.

The Cell x Image Lab website includes both an introductory section with basic information about the field as well as numerous case studies detailing specific imaging and analysis applications for cell culture and manufacturing.

Glossary

Accommodates well plates, dishes, and flasks
These are the common types of vessels used for culturing cells. This category refers to the availability of Nikon stages/inserts for standard size vessels.
Camera Integration
Nikon provides a variety of camera options, including fast color and monochrome CMOS options.
Compatible Contrasting Techniques
Phase contrast is the standard for cell culture and manufacturing, however sometimes other techniques (e.g., fluorescence) are required.
Compatible with decontamination using vaporized H2O2
Vaporized hydrogen peroxide decontamination is an industry standard for enclosed spaces. It is widely applied in hospitals and other medical facilities.
Diascopic Illumination Source
Illumination sources for diascopic transmitted light-based contrast techniques are usually either light emitting diodes (LEDs) or halogen lamps. LEDs are a bright, eco-friendly, and more energy efficient choice.
Position Control
The ability to translate the sample or scan position using motorized system components, for example, using a motorized Z drive to move the objective lens and corresponding focal plane.
Suitable for cell manufacturing facilities
This refers to whether systems can perform common types of assays applied in cell manufacturing facilities (e.g., stem cell colony identification).