here is what I call the meat in that it answers the question I had on seeing the title:

"In the end, designers settled on two types of fungi—one to supply the foamlike, malleable sole, and another for the shoe’s leathery upper section.

“This is a conceptual object intended to frame what is currently possible with the material,” VUB designer Lars Dittrich explained in a statement. “It reflects…addressing how we grow and craft this material, made from a microorganism, into a functional three-dimensional form.”

“While the initial material samples posed a real challenge and did not immediately meet the technical requirements of a complex shoe construction, the progress we have made is truly inspiring,” added De Ryck."