The new small-angle X-ray scattering beamline for materials research at PETRA†III: SAXSMAT beamline P62.

The SAXSMAT beamline P62 (Small-Angle X-ray Scattering beamline for Materials Research) is a new beamline at the high-energy storage ring PETRA III at DESY. This beamline is dedicated to combined small- and wide-angle X-ray scattering (SAXS/WAXS) techniques for both soft and hard condensed matter systems. It works mainly in transmission geometry. The beamline covers an energy range from 3.5 keV to 35.0 keV, which fulfills the requirements of the user community to perform anomalous scattering experiments. Mirrors are used to reduce the intensity of higher harmonics. Furthermore, the mirrors and 2D compound refracting lenses can focus the beam down to a few micrometres at the sample position. This option with the high photon flux enables also SAXS/WAXS tensor tomography experiments to be performed at this new beamline in a relatively short time. The first SAXS/WAXS pattern was collected in August 2021, while the first user experiment was carried out two months later. Since January 2022 the beamline has been in regular user operation mode. In this paper the beamline optics and the SAXS/WAXS instrument are described and two examples are briefly shown.

SAXS-CT: a nanostructure resolving microscopy for macroscopic biologic specimens.

SAXS-CT is an emerging powerful imaging technique which bridges the gap between information retrieved from high-resolution local techniques and information from low-resolution, large field-of-view imaging, to determine the nanostructure characteristics of well-ordered tissues, e.g., mineralized collagen in bone. However, in the case of soft tissues, features such as poor nanostructural organization and high susceptibility to radiation-induced damage limit the use of SAXS-CT. Here, by combining the freeze-drying the specimen, preceded by formalin fixation, with the nanostructure survey we identified and monitored alterations on the hierarchical arrangement of triglycerides and collagen fibrils three-dimensionally in breast tumor specimens without requiring sample staining. A high density of aligned collagen was observed precisely on the invasion front of the breast carcinoma, showing the direction of cancer spread, whereas substantial content of triglycerides was identified, where the healthy tissue was located. Finally, the approach developed here provides a path to high-resolution nanostructural probing with a large field-of-view, which was demonstrated through the visualization of characteristic nanostructural arrangement and quantification of content and degree of organization of collagen fibrils in normal, benign and malignant human breast tissue.

The influence of hydration on the architectural rearrangement of normal and neoplastic human breast tissues.

In adult women, the water-content represents between 50% and 70% of the mass in normal breast tissues and this percentage is increased within diseased tissues. Water molecules play an essential role in the structural organization of biological tissues such as breast. Then, in this study, we have investigated the influence of the water molecules on the breast tissue organization and their role on the hierarchical tissue rearrangement promoted by tumor growth. SAXS and WAXS techniques were used to analyze healthy, benign and malignant human breast samples in native and lyophilized conditions. The scattering profiles in SAXS and WAXS regime of each tissue type in both conditions were compared in order to identify the structural transformation in these tissues and verify the water influence on the morphological arrangement of normal and pathological human breast tissues. From SAXS, changes at the axial periodicity of collagen fibrils were revealed. Additionally, when the water content has removed a peak at q = 4.17 nm-1 (that was present only in pathological samples) shifted in opposite directions within benign and malignant lesions. From WAXS, water and fatty acids were identified within native samples. However, after freeze-drying, only the fat component was observed in the scattering profiles. Therefore, when the water molecules were removed from the samples, structural changes associated with pathological progression were visible. From this, insights about their influence over the changes promoted by the tumor growth have been proposed. Finally, the findings of this study have the potential to provide valuable information to the development of new target therapy.

Study of electron densities of normal and neoplastic human breast tissues by Compton scattering using synchrotron radiation.

Electron densities of 33 samples of normal (adipose and fibroglangular) and neoplastic (benign and malignant) human breast tissues were determined through Compton scattering data using a monochromatic synchrotron radiation source and an energy dispersive detector. The area of Compton peaks was used to determine the electron densities of the samples. Adipose tissue exhibits the lowest values of electron density whereas malignant tissue the highest. The relationship with their histology was discussed. Comparison with previous results showed differences smaller than 4%.

Compton scattering spectrum as a source of information of normal and neoplastic breast tissues' composition.

In this work we measured X-ray scatter spectra from normal and neoplastic breast tissues using photon energy of 17.44 keV and a scattering angle of 90°, in order to study the shape (FWHM) of the Compton peaks. The obtained results for FWHM were discussed in terms of composition and histological characteristics of each tissue type. The statistical analysis shows that the distribution of FWHM of normal adipose breast tissue clearly differs from all other investigated tissues. Comparison between experimental values of FWHM and effective atomic number revealed a strong correlation between them, showing that the FWHM values can be used to provide information about elemental composition of the tissues.

Preliminary study of human breast tissue using synchrotron radiation combining WAXS and SAXS techniques.

Using synchrotron radiation, we combined simultaneously wide angle X-ray scattering (WAXS) and small angle X-ray scattering (SAXS) techniques to obtain the scattering profiles of normal and neoplastic breast tissues samples at the momentum transfer range 6.28 nm(-1)