Variable-volume reactor-type device and process for culturing cellular material

A process for culturing cellular biological material in the form of solid particles, said process comprising the steps of:

• (a) providing a liquid culture medium in a culture chamber having a variable volume;
• (b) bringing said solid particles into contact with said liquid culture medium in said culture chamber;
• (c) increasing the volume of said culture medium contained in said culture chamber as appropriate during culturing and a corresponding increase in a volume of said biological material, by supplying additional culture medium and varying accordingly the volume of said culture chamber, thereby keeping the density by volume of said biological material substantially constant relative to the volume of said culture medium in contact with said particles in said culture chamber.