Provided are compositions and methods for in vitro generation and in vivo use of tissue for the repair of defective tissue, especially cartilage. Chondrocytes or other cells are cultured in vitro in a biodegradable amorphous carrier within the confines of a space bounded by a semi-permeable membrane with a molecular weight cut-off of greater than 100 kDa. The culture can be subjected to physical/physicochemical conditions that mimic in vivo conditions of the tissue in need of repair or replacement. In one embodiment the invention provides an amorphous preparation of chondrocytes and their extracellular products, suitable for injection.