INHIBITION OF CALCIFICATION OF GLUTARALDEHYDE PRETREATED PORCINE AORTIC-VALVE CUSPS WITH SODIUM DODECYL-SULFATE - PREINCUBATION AND CONTROLLED-RELEASE STUDIES

Calcification of bioprosthetic heart valves fabricated from glutaralde hyde pretreated bovine pericardium or porcine aortic valves (PAV) is a frequent cause of the failure of these devices. Of all strategies con sidered thus far, only detergent preincubations using compounds such a s sodium dodecyl sulfate (SDS) inhibited PAV bioprosthetic mineralizat ion in circulatory sheep bioprosthetic valve replacements. The present study sought to characterize the mechanism of action of SDS preincuba tion. Results of transport and material characterization studies showe d that SDS had a relatively high affinity for PAV, with a maximum upta ke of 167.1 +/- 6.8 mu g SDS/mg tissue over 24h at 37 degrees C with a partition coefficient of 19.3. The PAV diffusion of SDS was 1.95 +/- 0.35 10(-6) cm(2)/sec. The principal effect of SDS on PAV was phosphol ipid extraction. The residual organic phosphate in the SDS pretreated tissue was 2.22 +/- 0.72 nmol/mg tissue compared to the control untrea ted group with 18.52 +/- 2.1 nmol/mg tissue. Incubations of PAV specim ens in a 1% SDS solution for 24 h significantly inhibited calcificatio n after 21 days in subdermal implants in 3-week-old male rats (PAV Ca2 + = 18.0 +/- 11.8 mu g/mg) compared to control (177.8 +/- 6.0 mu g/mg) . In contrast, coimplants of 30% SDS silicone rubber polymers, for reg ional sustained SDS administration, did not impede PAV calcification i n 21 day implants Ca2+ = 166.0 +/- 14.0 mu g/mg compared to the nondru g silicone matrix controls, Ca2+ = 173.0 +/- 6.6 mu g/mg). Thus, we co nclude that the mechanisms of SDS inhibition of PAV calcification is d ue to material effects which occur during preincubation, and is not fa cilitated by sustained SDS administration. (C) 1993 John Wiley and Son s, Inc.