Effects of antibiotics on cellular viability in porcine heart valve tissue

The purpose of this study was to find an antibiotic disinfecting solution for cardiovascular tissues which would allow maximal cellular viability while maintaining antibacterial and antifungal activity. Cellular viability of porcine heat valves sterilised using antibiotics was assessed by radiolabelled proline transport assays. The results show that storage of valve tissues in RPMI 1640 tissue culture medium (4 degrees C) alone decreases the cellular viability by 50%, 60% and 90% within 12, 24, and 72 h, respectively. Amphotericin B was shown to be the toxic component of the antibiotic sterilising solution recommended by Strickett and coworkers, accounting for all the observed antibiotic toxicity. It reduced the cellular viability by 100% within 12 h of storage at 4 degrees C. Our study also showed that streptomycin is responsible for the loss of cellular viability in the antibiotic medium utilised by O'Brien's group. The results show that after storage of valve tissues for 12 h in O'Brien's antibiotic solution, the cellular viability was reduced by 60%, and after 24 h by 90%. Cefoxitin, lincomycin, polymyxin B, vancomycin and penicillin had no apparent effects on viability of cells in the cardiovascular tissues utilised in this study. In conclusion, heart valve tissue may be sterilised effectively using selective antibiotics without causing significant damage to cellular viability.