Repair strength dependence on solder protein concentration: A study in laser tissue-welding

Background and Objective: A novel laser-activated solid solder has been coupled with a diode laser to investigate the dependence of the solder protein concentration on the tensile strength of the soldered tissues. The uncertainty of laser welding, due to the fluid glue, was overcome using the solid solder. Study Design/Materials and Methods: Sixty-two severed rat tibial nerves and vas deferens were repaired using rectangular protein bands with two different albumin concentrations (58% and 68% by weight). The laser power (90 mW and 140 mW), dose (12.9 ± 0.7 J/mg, mean ± s.d.), and solder dimensions (thickness = 0.15 ± 0.01 mm, surface area = 7.8 ± 0.4 mm²) were kept constant during the operations. Results: The laser welds with high protein solder concentration were significantly (P < 0.05) stronger (28 ± 3.5 g) than the welds with low protein solder concentration (23 ± 5 g). Conclusions: The average tensile strength of the laser soldered tissues increased as the protein solder concentration increased.