Evaluation of decellularized porcine aortic valves : matrix changes due to different decellularization methods

Background Several decellularisation techniques have been developed to produce acellular matrix scaff olds for the purpose of tissue engineering, mostly comprising (non-)ionic detergents or enzymatic extraction methods. However, the eff ect of chemically induced decellularisation on the major structural and adhesion molecules as well as glycosaminoglycans, and the possible replenishment of lost compounds has escaped attention. Methods Porcine aortic valves were treated with two diff erent methods: detergent Triton X-100 and enzymatic Trypsine cell extraction. (Immuno-) histochemistry was used to address changes in extracellular matrix constitution (elastin, collagen, glycosaminoglycans, chondroitin sulfate, fi bronectin and laminin) and the production of extracellular matrix components by seeded endothelial cells. Results The Trypsine treated group showed a fragmentation and distortion of elastic fi bers. Changes in collagen distribution were observed in both groups. An almost complete washout of glycosaminoglycans and chondroitin sulfate was observed in the Triton and Trypsin treated group, but the latter with a smaller glycosaminoglycans reduction. Both treatments resulted in a considerable washout of the adhesion molecules laminin and fi bronectin. Furthermore, seeded endothelial cells were capable of synthesizing laminin, fi bronectin and chondroitin sulfate. Conclusions Chemically induced decellularisation by Triton or Trypsine resulted in changes in the extracellular matrix constitution, which could lead to problems in valve functionality and cell growth and migration. Seeded endothelial cells were capable of synthesizing extracellular matrix components lost by cell extraction. Further studies on tissue engineering should focus more on the eff ect of chemically induced cell extraction on the extracellular matrix of the remaining scaff old and the in vitro or in vivo replenishment of lost compounds.