What are scaffolds and what are they for?

Are scaffolds really necessary? What value add, if any, do they bring to the endeavour of cultivated meat? Before attempting to answer the question, let's take a step back and consider the definition of scaffolds. The scaffolds that we are familiar with in our daily use of language would refer to the structures that are erected on the outside of buildings when they undergo renovation or reconstruction. By climbing on these scaffolds, the workmen are able to apply the construction materials- the bricks and mortar to construct the building. The category of scaffolds that concern cultivated meat are those that are used for tissue engineering, that can be referred to as tissue scaffolds. Instead of workmen, these scaffolds act to support cells; and the building materials in this case are the extracellular matrix molecules that are secreted by the cells.

Scaffolds are useful as they are able to define the shape and structure of tissue that the cells eventually form. Without scaffolds, some cell types might still be able to proliferate, but the most that they would be able to produce would be a shapeless mass. Where cultivated meat is concerned, comminuted (or minced) meat products are possible without the use of scaffolds. However, to obtain whole meat cuts, the use of scaffolds at the stage of cell culture, is still beneficial. Is it possible to obtain cultivated whole meat cuts without scaffolds? Yes, it is. It is possible to apply modern extrusion technologies, such as high moisture extrusion, to shape cultivated meat biomass into products that resemble whole meat cuts, in the same way that extrusion is used to process plant proteins to obtain plant-based meat analogues.

But as mentioned, the use of scaffolds is beneficial, in a few ways:

1. Some cell types used in cultivated meat are anchorage-dependent, i.e. they require a solid substrate upon which to attach and grow. Good scaffolds provide a cell-culture substrate that allow the cells to proliferate and differentiate in the 3D volume of a bioreactor, which is more cost-efficient that growing cells on the 2D surface of a cell culture flask.

2. Scaffolds, when appropriately designed, allow the cells to form muscle tissue structures, such as myofibers, that provide the texture and mouthfeel to cultivated meat products.

3. Scaffolds can incorporate additional nutrients, vitamins and/or supplements to enrich the nutritional value of the cultivated meat product.

   
   

   Of course, a very important function of scaffolds with regard to commercialization is the fact that their cost, on the basis of mass, is substantially lower than the present cost of producing cultivated cells. This aspect, and how it affects the commercialization potential of cultivated meat, is discussed in greater depth in a following blog post.