CALCIFICATION POTENTIAL OF SMALL-INTESTINAL SUBMUCOSA IN A RAT SUBCUTANEOUS MODEL

Glutaraldehyde treatment of collagen biomaterials promotes calcificati on, poor host-tissue incorporation, and ultimately mechanical failure of bioprostheses. Porcine small-intestinal submucosa (SIS) is a biomat erial which has been investigated for several applications including a rterial and venous grafts and repair of tendon, ligament, body wall, a nd urinary bladder defects. The calcification potential of peracetic a cid (PAA)-sterilized SIS was studied. Four test samples, (1) native (c leaned, untreated) SIS, (2) SIS sterilized with 0.1% PAA, (3) SIS trea ted with 0.25% glutaraldehyde for 20 min, and (4) commercially availab le glutaraldehyde-preserved porcine bioprosthetic heart valve cusp seg ments (GPV), were each implanted subcutaneously in each of 24 weanling rats. Six rats were euthanatized at 1, 2, 4, and 8 weeks. Evaluation of calcium concentration by atomic absorption spectroscopy and extent of mineralization and fibrosis by light microscopy were performed. Ato mic absorption revealed no calcification in native or peracetic acid-t reated SIS at any time point compared with preimplant calcium concentr ation. Statistically significant (P<0.0001) calcification occurred in glutaraldehyde-treated materials (SIS and GPV) at each evaluation as c ompared to native and peracetic acid-treated samples. Histopathology i ndicated native and peracetic acid-treated SIS showed no implant miner alization (P<0.0001) and little peri-implant fibrosis (P<0.0001). Resu lts suggested that native and peracetic acid-treated SIS have a low ca lcification potential and further study of this biomaterial is warrant ed. (C) 1997 Academic Press.