RECONSTRUCTIVE UROLOGY

A quantitative method for evaluating the degradation of biologic scaffold materials
Gilbert TW, Stewart-Akers AM, Badylak SF
McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA
Biomaterials. 2007: 28: 147-50

• Scaffolds derived from naturally occurring extracellular matrix (ECM) have found extensive use in the fields of tissue engineering and regenerative medicine. Many of these scaffolds are designed to degrade rapidly as they are replaced by new host tissue. Other scaffolds are chemically crosslinked to slow the rate of degradation or add strength to the scaffold. Commercially available ECM scaffolds have considerable variability with regards to tissue origin and methods of processing, and little is known about their rate of degradation and the fate of their degradation products. A novel method is described herein to integrally label ECM with a radioactive isotope ((14)C). It was found that a number of tissues are efficiently labeled, including heart, liver, trachea, pancreas, small intestine, and urinary bladder tissue. Of the tissues analyzed, only spleen was not found to contain detectable levels of (14)C. The technique is extremely sensitive, accurate, and safe, but requires access to accelerator mass spectrometry, and is expensive and time consuming. This model represents the first described quantitative method to determine the rate of degradation for an ECM scaffold and to track the fate of the degradation products.
  
  
• 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