RESUMO
BACKGROUND AND AIM OF THE STUDY: The ionic detergent sodium dodecyl sulfate (SDS) is a proposed treatment for the removal of antigenic proteins from unfixed biological scaffolds used in tissue engineering. However, questions remain about possible cytotoxic effects of SDS-treated tissues. The study aims were to: (i) develop a sensitive SDS assay for physiological solutions; (ii) measure SDS concentrations in the washing media of SDS-treated tissue; and (iii) determine cytotoxic SDS concentrations in cultured ovine vascular cells. METHODS: An assay was developed to monitor SDS concentrations at microM levels, based on attenuated total reflectance infrared spectroscopy. Bovine pericardium was treated with SDS (1.0 to 0.01%) and washed for 96 h. The SDS concentration in the washing media was measured at 24-h intervals; data were expressed as microM/g tissue. Ovine vascular cells were cultured in DME media at 37 degrees C for 48 h in various SDS concentrations (10 to 1000 microM). The cells were then counted, and the percentage live cells expressed, based on trypan blue exclusion (n=5). RESULTS: SDS concentrations > or =10 microM significantly reduced (p < 0.05) the total cell number, while concentrations > or =100 microM reduced (p < 0.05) the percentage live cells of ovine vascular cell cultures. SDS was present in the washing media of SDS-treated bovine pericardium. SDS leaching from bovine pericardium was found to depend on the SDS concentration used for the treatment, and diminished with time. CONCLUSION: SDS leaches from SDS-treated bovine pericardium at concentrations that are potentially cytotoxic. An understanding of the dynamics of SDS washout, based on a sensitive SDS assay, may lead to the creation of protocols for the preparation of biological scaffolds that are free from cytotoxic leaching.
