RECONSTRUCTIVE UROLOGY

Immune response to biologic scaffold materials
Badylak SF, Gilbert TW
McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, United States
Semin Immunol. 2007; Dec 11; [Epub ahead of print]

• Biologic scaffold materials composed of mammalian extracellular matrix are commonly used in regenerative medicine and in surgical procedures for the reconstruction of numerous tissue and organs. These biologic materials are typically allogeneic or xenogeneic in origin and are derived from tissues such as small intestine, urinary bladder, dermis, and pericardium. The innate and acquired host immune response to these biologic materials and the effect of the immune response upon downstream remodeling events has been largely unexplored. Variables that affect the host response include manufacturing processes, the rate of scaffold degradation, and the presence of cross species antigens. This manuscript provides an overview of studies that have evaluated the immune response to biologic scaffold materials and variables that affect this response.
  
  
• Editorial Comment
  Biologic scaffold materials in the currently available form are unsatisfactory for reconstruction of the lower urinary tract. They are to some extend an obstacle to vascularization and re-innervation of the reconstructed segment, but they also lead to a reaction of intact surrounding tissue due to a normal immune and inflammatory response. In the two papers selected here, the authors have tried to develop a model for a quantitative determination of the degradation process and the tracking of extracellular matrix used as scaffold for urinary bladder reconstruction, for example. Furthermore the host response which is or maybe responsible for scaffold degradation has been worked up. These data are very important and very timely because due to the problems with artificial matrix acellular derived from human or animal sources are currently the most commonly used materials in tissue engineering for clinical purposes.

Dr. Arnulf Stenzl &
Dr. Karl-Dietrich Sievert
Department of Urology
Eberhard-Karls-University Tuebingen
Tuebingen, Germany
E-mail: arnulf.stenzl@med.uni-tuebingen.de