کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1958880 1057921 2006 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Wavelength-Dependent Collagen Fragmentation during Mid-IR Laser Ablation
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
Wavelength-Dependent Collagen Fragmentation during Mid-IR Laser Ablation
چکیده انگلیسی

Mid-infrared free-electron lasers have proven adept in surgical applications. When tuned to wavelengths between 6 and 7 μm, such lasers remove defined volumes of soft tissue with very little collateral damage. Previous attempts to explain the wavelength-dependence of collateral damage have invoked a wavelength-dependent loss of protein structural integrity. However, the molecular nature of this structural failure has been heretofore ill-defined. In this report, we evaluate several candidates for the relevant transition by analyzing the nonvolatile debris ejected during ablation. Porcine corneas were ablated with a free-electron laser tuned to 2.77 or 6.45 μm—wavelengths with matched absorption coefficients for hydrated corneas that respectively target either tissue water or protein. The debris ejected during these ablations was characterized via gel electrophoresis, as well as Fourier transform infrared spectroscopy, micro-Raman and 13C-NMR spectroscopy. We find that high-fluence (240 J/cm2) ablation at 6.45 μm, but not at 2.77 μm, leads to protein fragmentation accompanied by the accumulation of nitrile and alkyne species. The candidate transition most consistent with these observations is scission of the collagen protein backbone at N-alkylamide bonds. Identifying this transition is a key step toward understanding the observed wavelength-dependence of collateral damage in mid-infrared laser ablation.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: - Volume 91, Issue 4, 15 August 2006, Pages 1424–1432
نویسندگان
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