Via Nanowerk: researchers have "developed a fast and cost-efficient method for producing sufficient amounts of bone and cartilage tissue using the body's own cells ... Damage to larger joints such as knees, feet, hips and shoulders is often the beginning of a painful process during which mobility continues to decrease. Because cartilage cannot regenerate after the body has stopped growing, defects caused by injuries and 'wear and tear' cannot be absorbed by producing new cartilage. Genetic engineering and molecular biology have now made it possible to remove healthy cartilage cells and grow these outside the body in special solutions. This cartilage tissue is then applied to the defective cartilage where it attaches and grows. Repairing cartilage and bone damage using the body's own cells is still a difficult process. Cultivating the body's own tissue is still time-consuming and expensive, and much time is needed until the implant has reached its desired functionality. [Researchers now] present a strategy for the 'de novo engineering' of cartilage and bone tissue which requires only three weeks."