Zeta potential of synthetic and biological skin substitutes: effects on initial adherence.

Early adherence of a skin substitute to the wound surface is paramount if it is to function as a skin equivalent. A surface electrical property (the zeta potential) was evaluated, and a positive correlation was found in which 5-hour adherence properties increased as the zeta potential became more positive. The following materials were tested: nylon-silicone composite (Z = -24.8 mV), Biobrane (Z = -15.2 mV), fresh-frozen porcine skin (Z = +12.5 mV), Opsite (Z = +14.9 mV), human amnion (Z = +18.2 mV), and human skin (Z = +23.0 mV). This order was also followed for increasing adherence values at 5 hours, which ranged from a low of 48.9 gm/cm2 for the nylon-silicone composite to a high of 88 gm/cm2 for human skin. Also determined was that both adherence and zeta potential decreased as increasing concentrations of glutaraldehyde were used to cross-link fresh-frozen porcine skin. Values ranged from a maximum of 85.5 gm/cm2 (0% glutaraldehyde; Z = +12.5 mV) to a minimum of 42.5 gm/cm2 (10% glutaraldehyde; Z = -26.4 mV). Additionally, deliberate biochemical modifications of porcine skin were undertaken in an attempt to increase zeta potential and adherence.