Water dynamics in human cancer and non-cancer tissues

Normal-to-malignant transformation is a poorly understood process associated with cellular biomechanical properties. These are strongly dependent on the dynamical behaviour of water, known to play a fundamental role in normal cellular activity and in the maintenance of the three-dimensional architecture of the tissue and the functional state of biopolymers. In this study, quasi-elastic neutron scattering was used to probe the dynamical behaviour of water in human cancer specimens and their respective surrounding normal tissue from breast and tongue, as an innovative approach for identifying particular features of malignancy. This methodology has been successfully used by the authors in human cells and was the first study of human tissues by neutron scattering techniques. A larger flexibility was observed for breast versus tongue tissues. Additionally, different dynamics were found for malignant and non-malignant specimens, depending on the tissue: higher plasticity for breast invasive cancer versus the normal, and an opposite effect for tongue. The data were interpreted in the light of two different water populations within the samples: one displaying bulk-like dynamics (extracellular and intracellular/cytoplasmic) and another with constrained flexibility (extracellular/interstitial and intracellular/hydration layers).

Profiling of human burned bones: oxidising versus reducing conditions

Complementary optical and neutron-based vibrational spectroscopy techniques (Infrared, Raman and inelastic neutron scattering) were applied to the study of human bones (femur and humerus) burned simultaneously under either aerobic or anaerobic conditions, in a wide range of temperatures (400 to 1000 °C). This is the first INS study of human skeletal remains heated in an oxygen-deprived atmosphere. Clear differences were observed between both types of samples, namely the absence of hydroxyapatite's OH vibrational bands in bone burned anaerobically (in unsealed containers), coupled to the presence of cyanamide (NCNH2) and portlandite (Ca(OH)2) in these reductive conditions. These results are expected to allow a better understanding of the heat effect on bone´s constituents in distinct environmental settings, thus contributing for an accurate characterisation of both forensic and archaeological human skeletal remains found in distinct scenarios regarding oxygen availability.

Role of intracellular water in the normal-to-cancer transition in human cells-insights from quasi-elastic neutron scattering

The transition from normal to malignant state in human cells is still a poorly understood process. Changes in the dynamical activity of intracellular water between healthy and cancerous human cells were probed as an innovative approach for unveiling particular features of malignancy and identifying specific reporters of cancer. Androgen-unresponsive prostate and triple-negative breast carcinomas were studied as well as osteosarcoma, using the technique of quasi-elastic neutron scattering. The cancerous cells showed a considerably higher plasticity relative to their healthy counterparts, this being more significant for the mammary adenocarcinoma. Also, the data evidence that the prostate cancer cells display the highest plasticity when compared to triple-negative mammary cancer and osteosarcoma, the latter being remarkably less flexible. Furthermore, the results suggest differences between the flexibility of different types of intracellular water molecules in normal and cancerous cells, as well as the number of molecules involved in the different modes of motion. The dynamics of hydration water molecules remain virtually unaffected when going from healthy to cancer cells, while cytoplasmic water (particularly the rotational motions) undergoes significant changes upon normal-to-cancer transition. The results obtained along this study can potentially help to understand the variations in cellular dynamics underlying carcinogenesis and tumor metastasis, with an emphasis on intracellular water.

First analysis of ancient burned human skeletal remains probed by neutron and optical vibrational spectroscopy

Burned skeletal remains are abundant in archaeological and paleontological sites, the result of fire or of ancient funerary practices. In the burning process, the bone matrix suffers structural and dimensional changes that interfere with the reliability of available osteometric methods. Recent studies showed that these macroscopic changes are accompanied by microscopic variations are reflected in vibrational spectra. An innovative integrated approach to the study of archaeological combusted skeletal remains is reported here, where the application of complementary vibrational spectroscopic techniques-INS (inelastic neutron scattering), FTIR (Fourier transform infrared), and micro-Raman-enables access to the complete vibrational profile and constitutes the first application of neutron spectroscopy to ancient bones. Comparison with data from modern human bones that were subjected to controlled burning allowed identification of specific heating conditions. This pioneering study provides archaeologists and anthropologists with relevant information on past civilizations, including regarding funerary, burial, and cooking practices and environmental settings.

Human bone probed by neutron diffraction: the burning process

The first neutron diffraction study of human burned bone – for understanding heat-induced changes, relevant for archaeology, biomaterials and forensic science.

Heat-induced Bone Diagenesis Probed by Vibrational Spectroscopy

Complementary vibrational spectroscopic techniques - infrared, Raman and inelastic neutron scattering (INS) - were applied to the study of human bone burned under controlled conditions (400 to 1000 °C). This is an innovative way of tackling bone diagenesis upon burning, aiming at a quantitative evaluation of heat-induced dimensional changes allowing a reliable estimation of pre-burning skeletal dimensions. INS results allowed the concomitant observation of the hydroxyl libration (OHlibration), hydroxyl stretching (ν(OH)) and (OHlibration + ν(OH)) combination modes, leading to an unambiguous assignment of these INS features to bioapatite and confirming hydroxylation of bone's inorganic matrix. The OHlib, ν(OH) and ν4(PO43-) bands were identified as spectral biomarkers, which displayed clear quantitative relationships with temperature revealing heat-induced changes in bone's H-bonding pattern during the burning process. These results will enable the routine use of FTIR-ATR (Fourier Transform Infrared-Attenuated Total Reflectance) for the analysis of burned skeletal remains, which will be of the utmost significance in forensic, bioanthropological and archaeological contexts.

Biomaterials from human bone – probing organic fraction removal by chemical and enzymatic methods

Two different deproteination and defatting processes of human bone were investigated, by combined infrared and neutron techniques: a previously reported hydrazine extraction and a newly developed multi-enzymatic treatment. Complementary Fourier transform infrared total attenuated reflectance and inelastic neutron scattering spectroscopies were applied, allowing access to all vibrational modes of the samples. The effectiveness of the different experimental protocols for removing the organic constituents of bone (lipids and protein) was probed, as well as their effect on bone's structural and crystallinity features. The results thus gathered are expected to have an impact on bioanthropological, archaeological and medical sciences, namely regarding the development of novel biocompatible materials for orthopaedic xenografts.

The effectiveness of two defatting & deproteination processes of human bone were assessed by combined infrared and inelastic neutron scattering spectroscopies.