Effects of endogenous absorption in human albumin solder for acute laser wound closure.

Abstract

Human albumin is currently being used as a biological solder in laser tissue welding. Experiments were performed to characterize the effects of differing albumin concentrations on wound closure when a 1.32 microm Nd:YAG laser is used to repair skin incisions. In vivo comparison of acute tensile strength was made in full thickness porcine skin wounds using different solder concentrations. Histology of the repairs was also completed to evaluate the thermal denaturation of the tissue and solder. Transmission measurements were completed for nondenatured and denatured albumin solders. Finally, the real time denaturation pattern of different solder concentrations during laser irradiation was investigated. A tissue solder consisting of 50% albumin provides the greatest tensile strength for acute in vivo skin closure. The transmission measurements verify that the primary absorber of 1.32-microm laser light was the solder solvent (water). A significant decrease in power transmission occurs when the 25% albumin solder was denatured. The real time denaturation profiles demonstrate that 1.32-microm laser light denatures 25% albumin solder from the outer surface, while in 50% albumin solder, denaturation occurs from within the solder bulk. Wound histology corroborates the pattern of denaturation seen in vitro. The combination of 1.32-microm laser light and 50% human albumin solder can be used to create a deep tissue weld resulting in higher acute repair tensile strength. This permits a deep to superficial closure of wounds, which may result in an optimal method of acute closure for full-thickness wounds.