Statistically significant differences were found between non-fixed leaflets, 0.001% genipin-and 0.6% glutaraldehyde (GA)-fixed leaflets for work to maximum load (non-fixed 0.00646 J; genipin-fixed 0.00509 J; GA-fixed 0.00543 J) and stiffness (non-fixed 9281 N/m; genipin-fixed 16214 N/m; GA-fixed 14401 N/m). Genipin-treated matrices were not cytotoxic. For all concentrations of genipin a high proportion of viable cells was present (79-100%). Low-dose GA (10 microg/ml) showed a distinct cytotoxicity (24