When Winston Churchill first published his thoughts on growing protein and animals in laboratories, the idea seemed futuristic and implausible. Fast forward to 2013 and the first lab-grown meat was successfully cultivated and formed into the world’s most expensive burger patty, which cost $330,000 to create.
Since then, cultivated meat has made great strides in terms of research and technology; innovations such as Steakholder Food’s (formerly MeaTech) multi-nozzle 3D bioprinting system, which has been made available to third parties in the food tech sector, continue to accelerate lab-grown meat toward commercialization.
Needless to say, while cell cultivation techniques and tissue engineering have rapidly progressed, major bottlenecks remain throughout the process of bioprinting meat.
The purpose of this article, therefore, is to give an overview of the current climate of bioprinted meat, examine some of the biggest hurdles holding it back and discuss what is required to overcome these challenges.
Bioprinted meat is a structured meat analog made from the assembly of a variety of living animal cells that have been cultivated in vitro. In other words, it’s real meat that has been grown without the use of an animal and 3D-printed into steak-like products.
It’s made using an additive manufacturing approach that offers precise control of the meat’s macroscopic geometry using bioink (an ink formulation that enables the printing of living cells) that is formulated layer-by-layer.
This enables the production of consistently high-quality meat made to desired specifications, including the texture, taste, and nutritional content.
Bioprinted meat begins with cell line development, whereby suitable starter cells are isolated from an animal tissue sample and cultivated in large volume bioreactors to increase biomass.
These cells are then differentiated into specific edible cell types, such as muscle and fat cells, and undergo a structuring process that can be achieved using various methods. In the case of bioprinted meat, the differentiated cells are printed according to a digital model, which can be manipulated according to requirements, such as to increase marbling or to lower fat content for leaner cuts of meat.
Once printed, the meat is matured in a tissue maturation bioreactor to allow the cells to further differentiate until the product has reached the desired density and size and resembles the whole cut of meat it aims to replace.
The end product must be food safe, acceptable to consumers, regulatory-approved, and ready to be cooked to perfection.
Possibly the biggest advantage of bioprinted meat is that it can be tailored to desired specifications, from satisfying dietary requirements to producing consistently premium, gristle-free, whole cuts of meat.
Since it doesn’t require raising livestock, slaughtering, or the processing of meat, it also has the potential to reduce transport costs and be far less resource and time intensive.
Naturally, many challenges remain, such as regulatory approval, scalability, and cost. To address these, the entire production process must be optimized to build a robust infrastructure and promote standardization.
Below, we’ve discussed some of the key areas that require attention within the bioprinting meat industry:
Optimizing your bioprinting process begins with selecting the right cell line. Ideally, to enable the scaling up of production, manufacturers will want to immortalize their cell lines, whereby the cells are customized to proliferate indefinitely and thus be cultured for long periods of time.
In addition, the ability to manipulate cell behavior (e.g. differentiation and metabolism) and sensory properties can help to determine which cell lines are suitable for your bioprinted meat production process.
Digital holographic microscopy has demonstrated great promise in the prediction of production yields, as well as enabling easy comparison of cell lines and cell culture media formulations. Various spectrometry techniques can also be applied to ensure your cell line will produce desired properties, such as a deep red coloring or a high protein concentration.
The next step is to design an efficient and scalable cultivation process.
Selecting food-safe material reagents that comply with food regulations and satisfy consumer expectations, such as sourcing ethical ingredients and not negatively influencing taste, is essential.
Deep dive into cell culture media for cultivated meat by reading our article on how to develop an industry-standard optimized media.
One must also consider the forces and stresses cells undergo within bioreactors. While the dynamic culture enables nutrient transport and waste removal, this also exposes the cells to greater fluid shear stresses. Depending on the cell type, external stimuli can influence cell viability, growth, and cell behavior both positively and negatively. Therefore, it’s important to consider how to optimize the environment within the bioreactor to suit your cell type.
Once the cells have been cultivated, they must be temporarily or permanently supported to facilitate their adhesion, proliferation, and differentiation during the maturation stage. This can be achieved through the development of bioink formulations. Natural or synthetic polymers can be used and are selected based on their ability to mimic an animal’s extracellular matrix (e.g. hydrogels such as collagen, hyaluronic acid, and alginate).
The optimal bioink formulations will depend on your cell type, bioprinting method, and desired end product. They must also balance printability with the specific requirements of different tissues. For example, support bioinks are recommended for connective tissue or hard tissues, whereas sacrificial bioinks are designed for removal during post-processing stages and are best suited for vascular networks.
Once again, the ingredients used to formulate the bioinks must comply with material reagent selection considerations, such as food safety and consumer acceptance.
It’s important to note here that 2D modeling doesn’t always translate to 3D or 4D modeling. Even if your cell line demonstrates great promise after cultivation, this does not necessarily mean that it will perform well in the bioprinting stage; cells must maintain and engage in complex cellular behavior to produce a histologically correct meat replica.
There are, of course, many different types of bioprinters available. Extrusion-based, inkjet, stereolithography, and laser/light-based methods are some of the most common, all with their own advantages and disadvantages.
For example, extrusion-based printers offer printability of a wide range of high-viscosity materials and high cell concentration but provide lower resolution in comparison to other methods and are prone to nozzle clogging.
Watch this video for more information about different bioprinting methods:
Steakholder Foods use a modular bioprinting design, which employs hundreds of nozzles and numerous bioinks with varying viscosity to provide precise spatial control. This bioprinting technology has high throughput and is agnostic for a wide variety of cultivated meat products based on desired specifications.
As mentioned in the introduction, this printing system is now available to third parties, further accelerating the progress of bioprinted meat toward commercialization.
To overcome the challenge of maintaining optimal temperature during printing, they recently revealed the development of temperature-controlled print beds, which receive contactless electromagnetic power to regulate and monitor the temperature.
This stage is critical to cell adhesion and the creation of functional cuts of meat. Maturation bioreactors act as organ care systems to promote the continued development of the living cells and to stimulate the production of any extracellular matrices required to replace hydrogels used in the bioinks.
Mechanical, chemical, and electrical stimuli can all be manipulated for precise control to produce desired traits and functionality.
As promising as bioprinting technology is, the majority of bioprinted meat brands remain in the initial research and development stages. Further research is needed to overcome these hurdles, requiring significant time and investment.
Nevertheless, despite the industry being in its infancy, Bright Green Partners are perfectly positioned to support new and established industry players. With our in-depth knowledge base of bioprinted meat facility development and our network of in-house consultants and global expert network, we can create custom solutions for our clients.
If you’re ready to develop your strategy, build a robust facility, and form beneficial partnerships to accelerate your growth, reach out to us today.