Bioprinting for animal-free meat
The concept of animal-free meat production using tissue-engineering becomes the subject of extensive media coverage. Animal proteins represent 40% of total global protein consumption (Sans & Combris, 2015). While the demand for animal protein is expected to be doubled by 2050 that is associated with the increase of globe population (FAO, 2009), current livestock production is facing several problems such as pollution, shrinking of animal habitat, increased soil erosion, and greenhouse gas emissions (Kumar, & Bhat, 2017). Many researchers are now proposing to shift toward more sustainable meat resources such as in vitro meat production.
In vitro meat production offers a safe way to meet the increasing demand for protein without involving animal sacrifices and reducing the impact of the issues mentioned above. However, the associated high cost of production, public neophobia may limit its commercial viability in the near future [Gaydhane et al, 2018]. Conventional edible meat mainly consists of skeletal muscles along with adipocytes, fibroblasts and endothelial, which give it a nutritional value. The technique to generate muscle tissues in vitro relies on various cell types for initiating the production of meat, with the most promising being myosatellite cells, which are the primary adult stem cells for muscle [Islam et al, 2014]. Myosatellite are separated from a biopsy that is taken from a suitable animal and cultured in a proper culture condition that involves a continuous supply of nutrients, growth factors to induce multinuclear myotubes growth. Maturation of myotube and further growth by continued differentiation and merging of new myoblasts which results in the formation of muscle fibres. A key requirement of tissue engineering involves scaffold to support cell proliferation. Similarly, myoblasts proliferation also requires a flexible scaffold with a large surface area that can be easily dissociated from the final meat product and enable contraction and maximize medium diffusion [Engler et al, 2004]. Alternatively, the scaffold material needs to be natural-based and edible. A major challenge in in vitro meat production is to define food-grade culture media that is affordable in large quantities. Animal-based sera have been used as standard supplements for cell culture media for decades. However, adopting this methodology raises ethical and regulatory concerns. Alternatively, plant-based growth media substitution may eliminate the controversial animal-based growth media [AndroMed (Minitub, Germany)]. In order to be accepted by the end customer, the nutritional value of the in vitro produced meat must be equivalent or higher than that of conventional meat. It is noteworthy that in vitro meat can be supplemented with even desired nutrients such as vitamins, minerals [Young et al., 2013].
The biggest technical challenge for the in vitro meat industry lies in scaling up the product toward commercialization. The current price of lab-grown meat is extremely high which hinders its commercial value. However, with the advance of bioreactor technology, the last few years witnessed a decline in the prices, which is a good sign for commercialization. The primary obstacles that are holding back the IVM technology from scaling up are the high-cost culture medium and microcarriers and implementing the suitable large-scale bioreactor for mass production. Finally, public acceptance of IVM needs to be preceded by regulatory standards and guidelines that bring comfort amongst consumers and reduce scepticism amongst start-ups working in the field.