Nonaldehyde Sterilization of Biologic Tissue for Use in Implantable Medical Devices

Biologic tissue stabilized by dye-mediated photooxidation has found application in implantable devices. The desire to avoid aldehydes in the processing of photooxidized tissues led to the development of a nonaldehyde, iodine based sterilant. The interaction of tissue with iodine was indicated by a change in tissue shrinkage temperature, dependent upon solution and incubation parameters. The amino acid tyrosine also was altered, presumably because of aromatic ring iodination. Transmission electron microscopic study indicated no change in the quarter staggered array structure of collagen under controlled iodine treatment conditions. The D10 values for iodine kill of several organisms, in the absence of tissue, were determined in 0.1% iodine (pH 6.5) at 37°C for Bacillus subtilis (12 min), Aspergillus niger, Escherichia coli, Candida albicans, Staphylococcus aureus, and Pseudomonas aeruginosa (all