Abstract: Weighted microsponges formed of a porous, biostable matrix of a biocompatible polymer containing an inert weighing material are prepared suitable for use in culturing organisms in motive reactor systems. The matrix has an open to the surface pore structure with an average pore size in the range of from about 1 to about 150 microns and the pores occupy from about 70 to about 98% by volume of the microsponge. The microsponges have an average particle size of from about 100 to about 1000 microns and a specific gravity of above about 1.05. Biocompatible polymers that can be used are polysaccharides, proteins and synthetic polymers and the weighing material can be metals, metal alloys, metal oxides or ceramics.

Abstract: Weighted collagen microsponges having a highly crosslinked collagen matrix are described suitable for use in culturing organisms in motive reactor systems. The microsponges have an open to the surface pore structure, and pore sizes and volumes suitable for immobilizing a variety of bioactive materials. The microsponges also have an average particle size in the range of about 100 to about 1000 microns and a specific gravity above about 1.05.

Abstract: A fluidized bed reactor and reaction process, particularly well-suited for culturing cells, for example, for tissue culture and fermentation processes, are described which involve the treatment of at least a portion of the fluid exiting the fluidized bed reactor in a side loop in a manner to alter its temperature or composition, e.g., oxygenation, with recirculation of this treated fluid to the reactor as a portion of the fluid causing bed fluidization.

Abstract: Weighted collagen microsponges having a highly crosslinked collagen matrix are described suitable for use in culturing organisms in motive reactor systems. The microsponges have an open to the surface pore structure, and pore sizes and volumes suitable for immobilizing a variety of bioactive materials. The microsponges also have an average particle size in the range of about 100 to about 1000 microns and a specific gravity above about 1.05.

Abstract: Weighted collagen microsponges having a highly crosslinked collagen matrix are described suitable for use in culturing organisms in motive reactor systems. The microsponges have an open to the surface pore structure, and pore sizes and volumes suitable for immobilizing a variety of bioactive materials. The microsponges also have an average particle size in the range of about 100 to about 1000 microns and a specific gravity above about 1.05.