Is silicone oil truly inert? Spectroscopic evidence of microstructural alterations in retrieved 1,000-cSt PDMS tamponades
Description
The objective of this study is to investigate potential microstructural changes in 1000-cSt retrieved intraocular silicone oil samples retrieved from human eyes using ¹H-NMR and FT-IR spectroscopy. Dataset includes FT-IR and 1H-nmr spectra. Clinical data, corresponding to spectral data, is available in Table 1.docx
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For FT-IR analysis, samples were examined using the ATR (attenuated total reflectance) technique. Accordingly, 0.1 mL of each SO sample was placed directly onto a diamond-ATR crystal, and spectra were recorded at room temperature using a PerkinElmer Spectrum Two FT-IR spectrometer (Waltham, MA, USA). Spectral acquisition parameters were set to a wavenumber range of 4000–400 cm⁻¹ with a spectral resolution of 4 cm⁻¹. Within the obtained spectral dataset, characteristic transmission bands specific to the PDMS structure were evaluated, including C–H stretching vibrations of methyl groups (approximately 2960 cm⁻¹), symmetric deformation vibrations of Si–CH₃ groups (approximately 1260 cm⁻¹), the broad Si–O–Si stretching vibration band of the siloxane backbone (around 1110 cm⁻¹), and vibrations corresponding to dimethylsilyl groups at approximately 860 and 790 cm⁻¹. For ¹H-NMR analysis, SO samples were prepared as a 1:1000 (v/v) dilution by mixing 1 µL of SO with 999 µL of deuterated chloroform (CDCl₃). The spectra were recorded using a 5 mm standard probe on a 500 MHz JEOL JNM-ECZR NMR spectrometer (Tokyo, Japan). The use of CDCl₃ as the solvent was chosen to facilitate the detection of the main PDMS polymer backbone as well as LMWC that may remain soluble in the organic phase following possible polymer chain degredation.9,12,13 Tetramethylsilane (TMS, δ = 0.00 ppm) was used as the internal reference standard. In the spectral analysis, chemical shifts, signal multiplicity patterns, and signal line-shape alterations were evaluated as indicators of potential changes in molecular mobility and polymer chain organization. Clinical data, corresponding to spectral data, is available in Table 1.docx
Institutions
- Eskişehir Osmangazi Üniversitesi Tıp Fakültesi HastanesiEskişehir, Eskişehir