Tissue engineering as a platform for controlled release of therapeutic agents: implantation of microencapsulated dopamine producing cells in the brains of rats

Tissue engineering can lend to novel controlled release devices and control led release strategies (e.g., of growth factors) can enhance the performanc e of tissue engineered constructs. There are however a number of technical challenges that must be overcome before these goals can be realized. The ap parently 'simple' challenge of implanting the device (e.g., capsules) in th e optimal site must be met. In addition, adequate nutrient supply to the ca psules is required to maintain cell viability. To illustrate this problem w e describe a guide and delivery cannula technique to provide reliable and r eproducible delivery of up to 120 PC12 cell containing capsules into the ca udate putamen (CPu). Microencapsulation of mammalian cells is potentially a powerful means of delivering therapeutically important molecules such as i nsulin. It can also have numerous applications as a platform fur gene thera py. However, realizing this potential has been more difficult than first an ticipated. (C) 2001 Elsevier Science B.V. All rights reserved.