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.

One of the biggest struggles of biological anthropology is to estimate the biological profile from burned human skeletal remains. Bioanthropological methods are seriously compromised due to bone heat-induced alterations in shape and size. Therefore, it is urgent to improve our ability to estimate sex, age at death, stature and ancestrality, to recognize peri mortem traumas and differentiate them from fractures due to fire, and to determine what was the intensity of burning, namely maximum temperature and heat exposure length. This review focuses on different methodologies to assess heat prompted changes in bone submicrostructure. Some of these are extensively used in burned bones research, namely infrared and Raman spectroscopy and X-ray diffraction, while others such as neutron spectroscopy and diffraction are rarely applied to bone samples although their contribution may be crucial for establishing new bioanthropological methods for a reliable examination of burned victims.

The relatively large heterogeneity, especially at the intrabone level, is possibly the consequence of microstructural bone differences. The dissimilarities observed between our investigation and other published studies are probably due to the fact that the samples used here came from human rather than faunal bones. Also, our samples were buried previously to the experimental burning so this may also partly explain our contrasting results, since previous research was mostly performed on fresh bone. Future inferences based on vibrational spectroscopy analyses should take into account the possible effect of all these sources.

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.

This study aimed at the development of improved drugs against human osteosarcoma, which is the most common primary bone tumor in children and teenagers with a low prognosis available treatment. New insights into the impact of an unconventional Pd(II) anticancer agent on human osteosarcoma cells were obtained by synchrotron-based infrared microspectroscopy (SR-microFTIR) and quasi-elastic neutron scattering (QENS) experiments from its effect on the cellular metabolism to its influence on intracellular water which can be regarded as a potential secondary pharmacological target. Specific infrared biomarkers of drug