Effect of sterilization methods on the mechanical stability and extracellular matrix constituents of decellularized brain tissues

The cell and matrix content in the central nervous system (CNS) regulates a number of fundamental neural processes and decellularized brain matrices have drawn attention for biomedical applications. However, the effect of sterilization methods on the structural/mechanical stability and cell/matrix contents have yet to be addressed. In this study, supercritical carbon dioxide (SC-CO2), ultraviolet (UV) irradiation and ethylene oxide (EtO) sterilizations were applied to SDS-decellularized sheep brain cortical slices, then subjected to mechanical test, quantification of DNA and extracellular matrix (ECM) protein contents. The cell and matrix morphology were quantitatively analyzed at light and scanning electron microscopical levels. The optimum parameters for SC-CO2 sterilization were 150 bar, 37 degrees C and 60 min, which ensured complete sterility along with EtO sterilization unlike UV treatment. Although histomorphometry revealed no significant alterations on cellular nuclear content of decellularized matrices, SC-CO2 entrained with 6% ethanol yielded better results with respect to preservation of ECM proteins.