Application of albumin protein and indocyanine green chromophore for tissue soldering by using an IR diode laser: ex vivo and in vivo studies.
OBJECTIVE
We sought to examine the impact of different parameters of laser soldering on the thermophysical properties of the skin and to optimize these parameters for sealing a full-thickness incision in the rat skin under closed feedback control under in vivo conditions.


BACKGROUND
Laser tissue soldering based on protein as biologic glues and other compounds can provide greater bond strength and less collateral damage. Endogenous and exogenous materials such as indocyanine green (ICG) are often added to solders to enhance light absorption.


METHODS
In ex vivo study, the temperature increase, number of scan (Ns), and scan velocity (Vs) were investigated. In ex vivo studies, four skin incisions were made over rat dorsa and were closed by using two different methods: (a) wound closure by suture and (b) closure by using an automated temperature-controlled system. An automated soldering system was developed based on a diode laser, IR detector, photodiode, digital thermocouple, and camera. The true temperature of heated tissue was determined by using a calibration software method.


RESULTS
The results showed that at each laser irradiance (I), the tensile strength (σ) of incisions repaired in the static mode is higher than in the dynamic mode. It must also be noted that the tensile strength of the repaired skin wound was increased by increasing the irradiance in both static and dynamic modes. However, in parallel, an increase in the corresponding temperature was observed. The tensile strength was measured for sutured and laser-soldered tissue after 2 to 10 postoperative days. Histopathologic studies showed a better healing and less inflammatory reactions than with those caused by standard sutures after day 7.


CONCLUSIONS
It is demonstrated that automated laser soldering technique can be practical provided the optothermal properties of tissue is carefully optimized.
Khosroshahi
M E
ME
Amirkabir University of Technology, Faculty of Biomedical Engineering, Tehran, Iran. Khosro@aut.ac.ir
Nourbakhsh
M S
MS
Saremi
S
S
Hooshyar
A
A
Rabbani
Sh
Sh
Tabatabai
F
F
Anvari
M Sotudeh
MS
D000418:Albumins; D000818:Animals; D004396:Coloring Agents; D062109:Dermatologic Surgical Procedures; D007208:Indocyanine Green; D053685:Laser Therapy; D054023:Lasers, Semiconductor; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013537:Sutures; D013718:Tensile Strength; D014014:Tissue Adhesives
D000418:Albumins; D004396:Coloring Agents; D014014:Tissue Adhesives; D007208:Indocyanine Green