研究目的
To compare the changes undergone by the dermal collagen framework when heated by IR laser radiation and by traditional means and to reveal the specific features of the dermal matrix modification under moderate IR laser irradiation.
研究成果
The IR laser treatment of the skin causes a specific low-temperature transformation of its collagen framework, with some collagen macromolecules remaining intact. The collagen denaturation and dermal matrix amorphization temperature in the case of IR laser heating is lower by 10°C than that on heating in the calorimeter furnace. These results are associated with the nonequilibrium phenomena accompanying the nonuniform and nonstationary laser heating.
研究不足
The study was limited to rabbit skin specimens and may not fully represent human skin responses. The effects of laser heating were compared only to traditional heating methods, and other potential heating methods were not explored.
1:Experimental Design and Method Selection:
Rabbit skin specimens were heated to 50°C, 55°C, 60°C, and 65°C in a calorimeter furnace and with a
2:68-μm fiber Raman laser. The proportion of the degraded collagen macromolecules was determined by differential scanning calorimetry. Changes in the architectonics of the collagen framework were revealed by using standard, phase-contrast, polarization optical and scanning electron microscopy techniques. Sample Selection and Data Sources:
Skin samples were cut from the flank of rabbits no more than 12 months of age. The specimens were stored at 4°C and used within 36 hours of excision.
3:List of Experimental Equipment and Materials:
A
4:68-μm fiber Raman laser (IRE-Polyus, Russia), a Model FLIRA655*sc infrared scanner, a Model FOL25 objective lens, a Model Phoenix DSC 204 (Netzsch, Germany) differential scanning calorimeter, a LEICA DM4000 B LED microscope, a LEICA DFC7000 T digital camera, and a Model JEOL JSM--6000 NeoScope electron microscope. Experimental Procedures and Operational Workflow:
The laser treatment of the specimens was performed using a
5:68-μm fiber Raman laser. The temperature distribution on the skin surface under laser heating was determined by means of an infrared scanner. Some samples were heated by traditional means, in a calorimeter furnace. The specimens for histological examination were fixed in a 4% neutral formaldehyde solution and then used to prepare 4-μm-thick paraffin sections. Data Analysis Methods:
The DSC analysis results were processed with the NETZSCH Proteus Thermal Analysis software. The transition enthalpy was referred to the dry mass of the specimen.
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