Bioatr 2 thermostated cell

The spectra were recorded using a Tensor 27 ATR-FTIR spectrometer (Bruker, Bremen, Germany) equipped with an MCT detector cooled with liquid nitrogen and a thermostat (Huber, Offenburg, Germany). The measurements were carried out in a BioATR II thermostated cell (Bruker, Germany) using a single reflection ZnSe element at 22 °C and under the continuous purging of the system with dry air using a compressor (JUN-AIR, Redditch, UK). An aliquot (50 µL) of the corresponding solution was applied to the internal reflection element, the spectrum was recorded three times in the range of 4000 to 950 cm⁻¹ with a resolution of 1 cm⁻¹; then, 70-fold scanning and averaging were performed. The background was registered in the same way and was automatically subtracted using the program. The spectra were analyzed using the Opus 7.0 software, Bruker.

The FTIR spectra of RrA and its conjugates were recorded using a Tensor 27 IR Fourier spectrometer (Bruker, Ettlingen, Germany) equipped with an MCT detector cooled with liquid nitrogen and a thermostat (Huber, Offenburg, Germany). The measurements were carried out in a BioATR II thermostated cell (Bruker, Ettlingen, Germany) using a single reflection ZnSe element at 22 °C and continuous purging of the system with dry air using a compressor JUN-AIR (Gast Inc., Benton Harbor, MI, USA). An aliquot (40 µL) of the corresponding enzyme solution (0.5–1.5 mg/mL in 10 mM sodium phosphate buffer) was applied to the internal reflection element, the spectrum was recorded three times in the range from 4000 to 950 cm⁻¹ with a resolution of 1 cm⁻¹; performed 70-fold scanning and averaging. The background was registered in the same way and was automatically subtracted by the program. The resulting spectra were smoothed by the Savitzky–Golay method [40 (link)] to a spectral resolution of 2 cm⁻¹. The spectra were analyzed using the Opus 7.0 software (Bruker, Ettlingen, Germany).

ATR-FTIR spectra were obtained from a Tensor 27 ATR-FTIR Fourier spectrometer (Bruker, Germany) equipped with a MCT detector cooled with liquid N₂ and a thermostat (Huber, Raleigh, NC, USA). The measurements were carried out in a BioATR II thermostated cell (Bruker, Germany) using a single reflection ZnSe element at 22 °C and continuous purging of the system with dry air using a compressor (Redditch, UK). In a typical experiment, the volume of the sample was 50 µL, and the spectra were recorded three times in the range from 4000 to 950 cm⁻¹ with a resolution of 1 cm⁻¹, with 70 scans in each spectrum. The background spectra were obtained in the same way and were automatically subtracted by the software (Opus 7.0 Bruker). When recording the ATR-FTIR spectra of drug-loaded or polymer-coated vesicles, a solution of drug and polymer in equal concentration was used as a background solution. For phase transition studies, the temperature was varied by means of a thermostat in the range from 20 °C to 55 °C. For each temperature, the background spectra were recorded.