A new trick for an old delivery system

The use of liposomes has spread wider than drug delivery to more unusual settings, such as ripening cheese, producing hydrolysed-lactose milk and extracting oil from wells (PJ, 24/31 December 2005, p 809 PDF (50K)). Now liposomes are being applied to tissue engineering — growing tissue from cells, using engineering materials and biochemical factors. With the shortage of donor organs, tissue engineering offers the opportunity to create functional replicas of failing or damaged tissues and, perhaps, the possibility of overcoming problems of tissue rejection. To grow tissue, a small sample of cells can be harvested from a patient and cultured in the laboratory. These cells are then implanted (seeded) into an artificial structure — called a scaffold — where the tissue is grown. This regrown tissue can then be used in the patient. In this way, tissue engineering has been used to replace tissues, such as skin and cartilage, and this year the Lancet (2006;367:1241–6) reported that scientists had successfully tissue engineered autologous bladders for patients needing cystoplasty.