A multi-step method for preparation of porcine small intestinal submucosa (SIS)

Porcine small intestinal submucosa (SIS) has been widely used in repairing various tissues and organs Despite this some SIS products have the capacity to cause variable inflammatory responses after implantation resulting in severe adverse effects due to porcine cell existence In this study we described a multi-step method including mechanical disassociation degrease enzyme digestion detergent treatment freeze-drying and sterilization by irradiation for preparation of SIS The efficacy of acellularization was evaluated by histological observation and the content of porcine immunoreceptor DAP12 gene The change of growth factors contents within SIS accompanying with decellularization was quantitatively assessed by ELISA. Inflammatory reaction of SIS implanted subcutaneously in a rat was investigated The histological examination revealed no remaining cells after enzyme digestion Moreover qPCR analysis demonstrated that the content of a porcine immunoreceptor gene DAP12 DNA in final SIS product (SISv) was only 1 05% of that in SIS samples (SISi) prepared by mechanical disassociation Degrease with methanol/chloroform dramatically reduced the contents of VEGF b-FGF TGF-beta and TNF-alpha within SISii but further treatment could not significantly reduced the contents of growth factors SIS implanted into rats showed that inflammatory cells was more accumulated surrounded to SISi at 1 and 2 weeks but reduced in SISv samples The degree of inflammatory reaction for SISv was significantly less than that of SISi (C) 2010 Elsevier Ltd All rights reserved