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.