The attached archive encounters the FTIR data used for the calculation of the β-sheet content of the silk fibroin hydrogels in the in-vitro experiments. Such data is used in main Figures 2c and 2d, 4a and 7a as well as Supplementary Figure 2a of the associated article. The acquisition of the files has been performed as indicated below: Equipment: Thermo Scientific™ Nicolet™ iS™ 5 Spectrometer (Thermofisher, United States) Acquisition Software: OMNIC 9.2.86 (Thermofisher, United States) Number of Scans: 64 Data Spacing: 0.482 cm -1 The files have been reported as raw complete spectrum including the absorbances in the wavenumbers from 600 to 1500 cm -1 in the format of “.SPA”. In the following lines, we provide examples of software to process and analyze the spectra files included in the database. Python version 3.8 to 3.10 upon the availability of the “SpectroChemPy” (Travert and Christian, 2023) function. Matlab R2016a and newer upon the availability of the “LoadSpectra” (Oldenburg, 2023) function. OMNIC 9 (Thermofisher, United States). Essential FTIR (Operant LLC, United States). Provision of the data in other formats is available upon request. Inquiries may be directed to Daniel González-Nieto or Mahdi Yonesi. References: OLDENBURG, K. 2023. LoadSpectra. MATLAB Central File Exchange. TRAVERT, A. & CHRISTIAN, F. 2023. SpectroChemPy, a framework for processing, analyzing and modeling spectroscopic data for chemistry with Python. Github.