Three-dimensional polymeric systems for cancer cell studies

Three-dimensional (3-D) culture of cancer cells and of normal mammalian cells in a polymeric matrix is generally a better alternate model for understanding the regulation of cancer cell proliferation and for evaluation of different anticancer drugs. A substantial amount of evidence demonstrates important differences in the behavior of cells grown in monolayer, i.e., two-dimensional (2-D), and in 3-D cultures. Cancer cells grown in 3-D culture are more resistant to cytotoxic agents than cells in 2-D culture; growth of cells in vitro in 3-D requires a suitable polymer that provides a structural scaffold for cell adhesion and growth. Many naturally derived polymers as well as synthetic polymers have been investigated as scaffolds. The aim of this review is to overview the polymeric materials of natural and synthetic origin that are of specific interest to 3-D cell cultures, and discuss the development of new polymers that should be specifically designed for 3-D culture applications.