Solubility study of albumin solders for laser tissue-welding

Background/Objective Current albumin solders for tissue‐welding are soluble in physiological fluids, prior to laser irradiation. These solders are therefore subjected to mechanical alterations, which can weaken the solder‐tissue repair. In this study, an albumin solder (laser activated) was developed with low solubility and with the ability to retain (partially) its mechanical characteristics in saline solution. Study Design/Materials and Methods Gauged protein samples of solder were immersed into 0.5 ml saline solution for fixed intervals of time. The solder samples contained four Bovine Serum Albumin (BSA) concentrations: 56%, 66%, 70%, and 75% (by weight). A Bradford protein assay measured the BSA solubility of the solders. The 70% and 75% BSA solders were also used to weld in vitro Wistar rat intestine sections with a diode laser (λ = 810 nm, power = 270 mW). Results The solubility of the 75% BSA solder was significantly decreased with respect to the other solders (Anova, P < 0.05). This solder also showed comparable weld strength (13 gm) to the 70% BSA solder. Conclusion The 75% BSA solder strongly reduced the albumin solubility in saline solution, without affecting its tissue‐welding properties. Lasers Surg. Med. 23:258‐262, 1998. © 1998 Wiley‐Liss, Inc.