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The ability to reproduce strong repairs is essential to establishing the reliability of laser-tissue soldering techniques and advancing their use to the clinical setting. While some thermal damage is necessary to achieve a viable solder-tissue bond, excessive thermal damage leads to decreased flexibility and strength of the repair. In addition, if the temperature at the solder/tissue interface is too low, inadequate solder-tissue bonding will occur to provide a strong repair. This suggests the presence of an optimal temperature for laser-tissue repair. The choice of solder material presents another challenge to the reproducibility of strong repairs. The emerging use of chromophore-enhanced solder-doped polymer scaffolds offers numerous advantages over more traditional liquid and solid solders composed of serum albumin and an absorbing chromophore mixed in deionized water. Polymer scaffolds, fabricated from poly(L-lactic-co-glycolic acid) using a solvent casting and particulate leaching technique, are porous enough to absorb serum albumin and can also be doped with various hemostatic and thrombogenic agents to aid in tissue healing. Use of the polymer scaffolds allows one to combine the strength of solid solders and the flexibility of liquid solders without the common “runaway” problems. An in vitro study was performed to correlate tissue temperature with the tensile strength of arterial repairs formed using the chromophore-enhanced solder-doped polymer scaffolds. Laser irradiance was varied and the solder surface and solder/tissue interface temperatures were monitored by an IR temperature monitoring system and a type-K thermocouple, respectively. The solder/tissue interface temperature required for optimized tensile strength was determined to be 67 ± 5°C. This value was in agreement with previous studies using serum albumin solders alone, where the optimal solder/tissue interface temperature was found to be 65°C.
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