Bone Chemistry Research Articles

Shining light on the Mary Rose: Identifying chemical differences in human aging and handedness in the clavicles of sailors using Raman spectroscopy.

The Mary Rose, for many years the flagship of the Tudor king, Henry VIII, sank during the battle of the Solent on the 19th July 1545. 437 years later, the remains of the hull and associated contents were recovered following a four-year excavation, all dated to a precise point in history. The assemblage is a valuable resource, as the environment preserved over 19,000 objects and the remains of a minimum of 179 crew members. This remarkable preservation allows for the crew of the Mary Rose to be studied holistically; their belongings, appearance, and even their health. Using Raman spectroscopy, this study investigated the clavicle bone chemistry of 12 men, aged 13-40, who died on the Mary Rose. Specifically looking at any changes with age or that could be linked to handedness. Results found that bone mineral increased with age and bone protein decreased. The mineral increase was found to be more substantial than the protein decrease. When the left and right side were considered, these findings maintained and were more pronounced in the right clavicle. This suggests that handedness influences clavicle bone chemistry; offering an important modern consideration for fracture risk. These results enhance our understanding of the lives of Tudor sailors, but also contribute to modern scientific investigation in the drive for a clearer understanding of changes in bone chemistry and potential links to aging related skeletal diseases such as osteoarthritis.

Laser-Induced Breakdown Spectroscopy as an Accurate Forensic Tool for Bone Classification and Individual Reassignment.

This article provides a detailed discussion of the evidence available to date on the application of laser-induced breakdown spectroscopy (LIBS) and supervised classification methods for the individual reassignment of commingled bone remains. Specialized bone chemistry studies have demonstrated the suitability of bone elemental composition as a distinct individual identifier. Given the widely documented ability of the LIBS technique to provide elemental emission spectra that are considered elemental fingerprints of the samples analyzed, the analytical potential of this technique has been assessed for the investigation of the contexts of commingled bone remains for their individual reassignment. The LIBS bone analysis consists of the direct ablation of micrometric portions of bone samples, either on their surface or within their internal structure. To produce reliable, accurate, and robust bone classifications, however, the available evidence suggests that LIBS spectral information must be processed by appropriate methods. When comparing the performance of seven different supervised classification methods using spectrochemical LIBS data for individual reassociation, those employing artificial intelligence-based algorithms produce analytically conclusive results, concretely individual reassociations with 100% accuracy, sensitivity, and robustness. Compared to LIBS, other techniques used for the purpose of interest exhibit limited performance in terms of robustness, sensitivity, and accuracy, as well as variations in these results depending on the type of bones used in the classification. The available literature supports the suitability of the LIBS technique for reliable individual reassociation of bone remains in a fast, simple, and cost-effective manner without the need for complicated sample processing.

Mechanical study reinforced magnesium-yttrium alloys by eggshell powder using resistance casting

Magnesium-based alloys are relatively new materials for orthopedic implants. One common component that makes magnesium-based alloys biocompatible and chemically stable is the addition of minor compositions of rare earth metals like yttrium to anchor other chemically active components. From an orthopedic perspective, two goals are of primary concern. One is sufficient mechanical support to stabilize the fracture and reduce inflammation. Another is assistance for the transition of osteogenesis and intramembranous ossification for bone production and remodeling. To attain both goals and further improve the current magnesium-yttrium alloys, adding extra ingredients to improve osseointegration is a common and effective approach. By the nature of bone chemistry, calcium is the top choice as calcium is the key element in maintaining bone integrity and biochemical metabolism. In this study, the mechanical behaviors of a calcium-added magnesium-based alloy (Mg-Y3.5 wt%) are investigated by experiments. This inventive idea for the natural source of calcium is obtained from chicken eggs due to their (1) cost-effective and abundant availability, and (2) naturally synthesized calcium carbonate along with a minor content of organic materials. The fabrication processes involved are the ball-milling of eggshells as an additive at 1, 3, and 5 wt%. into magnesium-yttrium alloys and resistance casting to form composites. Material characterization includes microstructural analysis by X-ray diffraction, morphological/elemental analysis via optical microscopy, field emission scanning electron microscopes, energy-dispersive X-ray spectroscopy, mechanical properties by uniaxial compression and Vickers microhardness tests. Experimental results supplemented by statistical and finite element analysis indicate that the new composite exhibits enhanced ductility; and the 3 wt% eggshell-added alloys show better reinforcement of mechanical properties among all samples with an ultimate compression strength of 161.19 MPa, maximum elongation of 17.53 %, and hardness of 457.48 (N/mm2). Note that the comparable mechanical strength of the composite to that of human bones could reduce the stress shielding on bones and further help the process of bone remodeling.

Effect of Heating on Avian (Cortical and Medullary) Bone Chemistry, Mineralogy and Structural Organization

Effect of Heating on Avian (Cortical and Medullary) Bone Chemistry, Mineralogy and Structural Organization

Effective investigation of murine femoral bone development utilizing correlative light and electron microscopy (CLEM)

BackgroundFor effective investigation of the developing structure and chemistry of bone, comprehensive studies including compositional analysis can be achieved through the gradual observation from the micro- to nanometer scale via correlative light and electron microscopy (CLEM). This technique is particularly useful considering the complex hierarchical arrangement of bioapatite and collagen fibrils which may vary according to specific bone tissue types (i.e., lamellar bone and woven bone) and different growth stages. Scanning electron microscopy (SEM) accompanied with the attachment of the scanning transmission electron microscopy (STEM) detector, referred to as the STEM-in-SEM can be utilized to produce high contrast images from materials composed of light elements, and efficiently allows the selection of suitable accelerating voltage for energy-dispersive spectroscopy (EDS). This study aims to emphasize the efficacy of CLEM techniques through applying STEM-in-SEM and EDS analyses, and its application to comparative murine bone investigation in differing ontogenetic stages.FindingsWe have designed a new grid-holder which can be used for both light and electron microscopy, and we presented an imaging technique for TEM specimens via reflective light microscopy (RLM). For performing CLEM, ultra-thin-sections (UTS) prepared from the femoral bones of 1- to 16-week old of Sprague-Dawley (SD) rats provided light and electron micrographs that can be correlated based on the regions of interest (ROIs). STEM-in-SEM micrographs revealed information not attainable by secondary electron (SE) and back-scattered electron (BSE) micrographs. In addition, for analyzing chemical variation according to growth and development of femoral bones from 1- to 16-week-old rats, comparative chemical analysis was performed through STEM-in-SEM EDS with two reference materials.ConclusionHerein, from femoral bones of SD rats, we have confirmed the rapid chemical and structural variations within the first 8 weeks after birth. STEM-in-SEM micrographs revealed the bone development process of the early stage porous bone matrix subsequently being filled with collagen fibrils and bioapatite. In addition, chemical analysis for carbon and oxygen showed the ratios of inorganic to organic phases according to growth and progress in bone mineralization. As a result, we were able to postulate the growth mechanism of murine femoral bone in the neonatal stages of development. We also anticipate that our CLEM techniques can be further utilized for more thorough investigation of bone structure and chemistry in diverse scales.

What can hippopotamus isotopes tell us about past distributions of C4 grassy biomes on Madagascar?

Societal Impact StatementToday, expansive C4 grassy biomes exist across central, western, and northern Madagascar. Some researchers have argued that the island's now‐extinct pygmy hippopotamuses belonged to a megaherbivore grazing guild that maintained these grasslands prior to human arrival. However, the chemistry of hippo bones indicates that C4 grasses were only a minor part of hippo diet. This, in turn, suggests that C4 grasses were present but not widespread when hippos were alive and that grasses expanded only after Malagasy people shifted from hunting and foraging to agropastoralism approximately 1000 years ago. These results have important implications for environmental reconstructions and biodiversity management.Summary Extinct hippopotamuses (Hippopotamus spp.) were part of Madagascar's megaherbivore guild. Stable carbon (δ13C) and nitrogen (δ15N) isotopes in radiometrically dated bone collagen track spatial and temporal variation in diet and habitat. If hippos helped maintain C4 grassy biomes, then they should have regularly consumed C4 grasses, which have high δ13C values. However, if expansive C4 grassy biomes are anthropogenic, then forests would have been more extensive in the past, and hippos would have predominantly consumed C3 plants with low δ13C values. Nitrogen isotopes can clarify foraging habitat (moist or dry). We assessed δ13C and δ15N values for hippos from different ecoregions of Madagascar and compared these with data for extinct herbivorous lemurs from the same ecoregions. We further explored the effects of wet/dry transitions on isotopic trends for hippos from the central highlands and spiny thicket ecoregions. Carbon isotopes suggest (1) limited C4 consumption by hippos in the central highlands, dry deciduous forest, and succulent woodland ecoregions; and (2) moderate consumption of C4 resources in the spiny thicket. Nitrogen data indicate that hippos foraged in wetter habitats than sympatric lemurs in all regions. Malagasy hippos did not regularly graze C4 grasses in dry, open habitats, even in regions blanketed by C4 grassy biomes today. Malagasy grasses are adapted to grazing and fire, but these are likely ancient adaptations that accompanied grasses when they initially spread to Madagascar. C4 grassy biomes were spatially limited in extent in the past and only expanded after the Late Holocene introduction of domesticated ungulates.

Independent Evidence for the Preservation of Endogenous Bone Biochemistry in a Specimen of Tyrannosaurus rex.

Biomolecules preserved in deep time have potential to shed light on major evolutionary questions, driving the search for new and more rigorous methods to detect them. Despite the increasing body of evidence from a wide variety of new, high resolution/high sensitivity analytical techniques, this research is commonly met with skepticism, as the long standing dogma persists that such preservation in very deep time (>1 Ma) is unlikely. The Late Cretaceous dinosaur Tyrannosaurus rex (MOR 1125) has been shown, through multiple biochemical studies, to preserve original bone chemistry. Here, we provide additional, independent support that deep time bimolecular preservation is possible. We use synchrotron X-ray fluorescence imaging (XRF) and X-ray absorption spectroscopy (XAS) to investigate a section from the femur of this dinosaur, and demonstrate preservation of elements (S, Ca, and Zn) associated with bone remodeling and redeposition. We then compare these data to the bone of an extant dinosaur (bird), as well as a second non-avian dinosaur, Tenontosaurus tilletti (OMNH 34784) that did not preserve any sign of original biochemistry. Our data indicate that MOR 1125 bone cortices have similar bone elemental distributions to that of an extant bird, which supports preservation of original endogenous chemistry in this specimen.

Mussel-inspired polydopamine decorated silane modified-electroconductive gelatin-PEDOT:PSS scaffolds for bone regeneration.

This study seeks to simulate both the chemistry and piezoelectricity of bone by synthesizing electroconductive silane-modified gelatin-poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) scaffolds using the freeze drying technique. In order to enhance hydrophilicity, cell interaction, and biomineralization, the scaffolds were functionalized with polydopamine (PDA) inspired by mussels. Physicochemical, electrical, and mechanical analyses were conducted on the scaffolds, as well as in vitro evaluations using the osteosarcoma cell line MG-63. It was found that scaffolds had interconnected porous structures, so the PDA layer formation reduced the size of pores while maintaining scaffold uniformity. PDA functionalization reduced the electrical resistance of the constructs while improving their hydrophilicity, compressive strength, and modulus. As a result of the PDA functionalization and the use of silane coupling agents, higher stability and durability were achieved as well as an improvement in biomineralization capability after being soaked in SBF solution for a month. Additionally, the PDA coating enabled the constructs to enhance viability, adhesion, and proliferation of MG-63 cells, as well as to express alkaline phosphatase and deposit HA, indicating that scaffolds can be used for bone regeneration. Therefore, the PDA-coated scaffolds developed in this study and the non-toxic performance of PEDOT:PSS present a promising approach for further in vitro and in vivo studies.

Bacterial bioerosion of bones is a post-skeletonisation phenomenon and appears contingent on soil burial

The post-mortem changes that take place during the decomposition of corpses are extremely complex and have been the subject of considerable research because of their obvious importance to forensic scientists. Considerable advances have been made in understanding the interplay of the various factors that influence decay, and the timescales over which they operate. Similarly, changes to the chemistry and microstructure of bones, post-skeletonisation, are of intense interest to archaeological scientists and the past few decades has seen tremendous advances in our understanding of how post-burial diagenesis may impact endogenous evidence within ancient and fossil bones.In recent years it has been postulated that the early stages of putrefaction of a body have a profound effect on the microstructure of bones and that these changes persist over archaeological timescales. One of the most important mechanisms for post-depositional degradation of bones is bacterial bioerosion. The question of the origin of the bacteria responsible, and why some archaeological bones are bioeroded while others are not, has received considerable attention in recent years. The assertion by some that the bacteria originate in the gut, and infiltrate bone tissues via the vascular network during the putrefactive stages of decay, has led to a number of claims as to what can be inferred by the presence, or absence, of bacterial tunnelling in bones. These claims include evidence for human mummification, identification of stillborns and infanticide, and animal sacrifices.Here we present evidence from SEM histological examinations of bones from field experiments using intact pig carcasses interred in brick lined tombs; a forensic case of a body exposed on a concrete floor for ten years; together with de-fleshed bones from freshly slaughtered cows buried in tropical soils for 1-10 years. None of the decomposing pig carcasses, nor the human corpse, showed any signs of bacterial tunnelling in their bones. By contrast, the de-fleshed bones buried directly in soils showed evidence of tunnelling after only one year and considerable tunnelling after ten years. Our results cannot support the “enteric hypothesis” that the bone tunnelling microorganisms that degrade buried bones originate in the gut microbiota but rather suggest that gut bacteria play no role in the post-mortem degradation of buried bones. It therefore follows that no conclusions about post-mortem treatment of human or animal corpses can be deduced from the presence, or absence, of microbial tunnelling in skeletonised remains from an archaeological (or forensic) context.

Social Identity and Dental Modification at the Postclassic Maya Urban Centre of Mayapan

Dental modification represents one interesting aspect of corporeal adornment in human history that directly reflects personal social identity. Tooth filing choices distinguished certain individuals at the urban, Maya political capital of Mayapan from 1150 to 1450ad, along with cranial modification, nose and ear piercings, tattoos and body paint. Here we examine how filing teeth, considered a beautification practice for women at Spanish Contact in the sixteenth century, is distributed across a skeletal sample of males, females, elites and commoners in this city. We evaluate the normative claim of the Colonial period and determine that while predominantly females filed their teeth, most women chose not to. Sculptural art further reveals that male personages associated with the city's feathered serpent priesthood exhibited filed teeth, and we explore the symbolic meaning of filed tooth shape. Assessing the practice in terms of associated archaeological contexts, chronology and bone chemistry reveals that it did not correlate with social class, dietary differences, or birthplace. Residents of Mayapan, a densely inhabited, multi-ethnic city of 20,000, engaged with multiple material expressions of belonging to intersecting imagined communities that crosscut competing influences of polity, city, hometown and family scale identity. Tooth filing reflects identities at the individual or family scale.

Mapping Bone Surface Composition Using Real-Time Surface Tracked Micro-Raman Spectroscopy

The surface of bone tells a story – one that is worth a thousand words – of how it is built and how it is repaired. Chemical (i.e., composition) and physical (i.e., morphology) characteristics of the bone surface are analogous to a historical record of osteogenesis and provide key insights into bone quality. Analysis of bone chemistry is of particular relevance to the advancement of human health, cell biology, anthropology/archaeology, and biomedical engineering. Although scanning electron microscopy remains a popular and versatile technique to image bone across multiple length scales, limited chemical information can be obtained. Micro-Raman spectroscopy is a valuable tool for nondestructive chemical/compositional analysis of bone. However, signal integrity losses occur frequently during wide-field mapping of non-planar surfaces. Samples for conventional Raman imaging are, therefore, rendered planar through polishing or sectioning to ensure uniform signal quality. Here, we demonstrate ν₁ PO₄^3- and ν₁ CO₃^2- peak intensity losses where the sample surface and the plane of focus are offset by over 1–2 μm when underfocused and 2–3 μm when overfocused at 0.5–1 s integration time (15 mW, 633 nm laser). A technique is described for mapping the composition of the inherently irregular/non-planar surface of bone. The challenge posed by the native topology characteristic of this unique biological system is circumvented via real-time focus-tracking based on laser focus optimization by continuous closed-loop feedback. At the surface of deproteinized and decellularized/defatted sheep tibial cortical bone, regions of interest up to 1 mm² were scanned at micrometer and submicrometer resolution. Despite surface height deviations exceeding 100 μm, it is possible to seamlessly probe local gradients in organic and inorganic constituents of the extracellular matrix as markers of bone metabolism and bone turnover, blood vessels and osteocyte lacunae, and the rope-like mineralized bundles that comprise the mineral phase at the bone surface.

Were domestic camelids present on the prehispanic South American agricultural frontier? An ancient DNA study.

The southern boundary of prehispanic farming in South America occurs in central Mendoza Province, Argentina at approximately 34 degrees south latitude. Archaeological evidence of farming includes the recovery of macrobotanical remains of cultigens and isotopic chemistry of human bone. Since the 1990s, archaeologists have also hypothesized that the llama (Lama glama), a domesticated South American camelid, was also herded near the southern boundary of prehispanic farming. The remains of a wild congeneric camelid, the guanaco (Lama guanicoe), however, are common in archaeological sites throughout Mendoza Province. It is difficult to distinguish bones of the domestic llama from wild guanaco in terms of osteological morphology, and therefore, claims that llama were in geographic areas where guanaco were also present based on osteometric analysis alone remain equivocal. A recent study, for example, claimed that twenty-five percent of the camelid remains from the high elevation Andes site of Laguna del Diamante S4 were identified based on osteometric evidence as domestic llama, but guanaco are also a likely candidate since the two species overlap in size. We test the hypothesis that domesticated camelids occurred in prehispanic, southern Mendoza through analysis of ancient DNA. We generated whole mitochondrial genome datasets from 41 samples from southern Mendoza late Holocene archaeological sites, located between 450 and 3400 meters above sea level (masl). All camelid samples from those sites were identified as guanaco; thus, we have no evidence to support the hypothesis that the domestic llama occurred in prehispanic southern Mendoza.

Establishing a minimum PMI for bone sun bleaching in a UK environment with a controlled desert-simulated comparison

Microenvironments play a significant part in understanding the post-mortem interval in forensic taphonomy. Recently, the value of weathering factors in relation to obtaining a PMI has been investigated further. In this study, observations were made to calculate the length of time it takes for three different bone elements (femur, rib, and scapula) to bleach in a UK summer and winter. This research also investigated whether there were any physicochemical modifications to the bone caused by bleaching. Porcine femora, scapulae, and ribs were placed into open and shaded areas of an outdoor research facility located in Oxfordshire, UK, during summer (July–Sep) and winter months (Dec–Mar). The specimens were monitored at 3-week intervals using photography, and an observational scoring method was developed to quantify the extent of bleaching. As temperatures are typically much lower in the UK compared with warmer climates, a controlled indoor-simulated desert experiment was also undertaken to be used as a control. This allowed sun bleaching and changes to the bone chemistry to be monitored in a controlled, high-UV environment for comparison with the UK outdoor experiments. Fourier transform infrared spectroscopy (FTIR) was employed to analyze physicochemical modifications to both the mineral and organic components of the bone. The FTIR was used to calculate crystallinity index (CI), mineral to organic ratio, and the relative amount of carbonate concentrations. Weather data was collected and a positive correlation was found between both ultraviolet (UV) levels and accumulated degree days (ADD) when compared with observational bleaching scores. Bleaching (whitening) of the bone samples occurred in both seasons but at different rates, with the bleaching process occurring at a slower rate in winter. During summer, the initial bleaching process was evident at 6 weeks, and by 9 weeks, the bones were an off-white colour. During the winter period, whitening of the bone started at 9 weeks; however, only the scapula and rib samples displayed a similar off-white colour. This colouration was observed at 13 weeks rather than at 9 weeks. The desert simulation samples started bleaching in a similar pattern to the outdoor samples after 1 week but the bones did not fully bleach. The bone chemistry, based on physicochemical properties obtained from the FTIR, showed a significant statistical difference between the simulated desert and winter season when compared against a control sample. For the winter samples, the mineral to organic ratio was significantly higher than that in the control, suggesting a reduction in the proportion of organic. For the samples in the simulated desert environment, the crystallinity index was significantly higher than that in the control samples, suggesting an increase in crystallinity. The results of this experiment support the fact that it is possible to achieve bleaching in a UK environment and that the minimal time frame for this to occur differs in seasons.

Association of VDBP rs4701 variant, but not VDR/RXR-α over-expression with bone mineral density in pediatric β-Thalassemia patients

BackgroundThe reduced rate of bone formation despite the availability of vitamin D has been reported in β-thalassemia. Genetic factors, together with environmental ones, could be implicated in this condition. Since vitamin D binding protein (VDBP) maintains bioavailability of vitamin D which binds to vitamin D receptor (VDR)-retinoid X receptor alpha (RXRA) heterodimer to exert its molecular actions, we speculated that vitamin D metabolic-axis expression signature and variants could be potential molecular candidates for bone turnover/disease in thalassemia. To this end, this study aims to analyze VDR/RXRA expression signature, and two VDBP variants in a pilot sample of Egyptian β-thalassemia children in correlation with bone mineral density (BMD).Patients and methodsForty-four well-chelated β-thalassemia children and 40 unrelated controls were enrolled. The serum bone chemistry profile was measured. Peripheral blood mononuclear cells (PBMN) VDR/RXRA expression levels were quantified by Real-Time quantitative reverse transcription-polymerase chain reaction (qRT-PCR). VDBP rs7041 and rs4588 variants were identified by Real-Time allelic discrimination assay. All patients were subjected to lumbar-spine Dual-energy X-ray absorptiometry (DEXA).ResultsVDR/RXRA expressions were significantly higher in β-thalassemia children compared to controls (P = 0.001 and <0.001, respectively) and showed higher values in β-thalassemia major relative to β-thalassemia intermedia. Expression levels of both genes were not associated with sex or BMD. However, VDBP rs4701 genotyping revealed lower BMD-L4 and a higher frequency of osteoporosis.Conclusionsβ-Thalassemia children had higher expression levels of PBMN VDR/RXRA. VDBP rs4701 variant was associated with osteoporosis in our β-thalassemia patients on vitamin D supplementation. Further large-scale studies in other ethnic populations are warranted.

Copper exposure in medieval and post-medieval Denmark and northern Germany: its relationship to residence location and social position

For medieval and post-medieval Denmark and northern Germany, trace elements can potentially contribute to our understanding of diet, migration, social status, exposure to urban settings, and disease treatment. Copper, of particular interest as a marker of access to everyday metal items, can be used to clarify socioeconomic distinctions between and within communities. Postmortem alteration of bone (diagenesis), however, must be ruled out before the elements can be used to characterize life in the past. Femoral cortical bone samples of ca. 40 mg were thoroughly decontaminated, and the concentrations of Al, Ca, Mn, Fe, Cu, As, Sr, Ba, and Pb were measured using inductively coupled plasma mass spectrometry. The concentrations of these elements were quantified in bone samples from 553 skeletons from 9 rural and urban cemeteries, and 34 soil samples obtained near three burials. Copper, the primary element of interest in this work, is generally absent from the femoral cortical bone of rural people, although it occurs in high concentrations in the skeletons of the inhabitants of towns. The Cu in medieval to post-medieval bones likely originated from everyday objects, notably kitchen utensils. A rural to urban distinction in Cu concentrations, found repeatedly at two sites, likely resulted from differential access to much-desired, although still utilitarian, household items. An uneven distribution of metal objects used in domestic contexts, demonstrated through bone chemistry, was greater between rural and urban communities than it was within urban centres, at least among the socioeconomic positions sampled in this study.

Changes with age (from 0 to 37 D) in tibiae bone mineralization, chemical composition and structural organization in broiler chickens

ABSTRACTBroiler chickens have an extreme physiology (rapid growth rates) that challenges the correct bone mineralization, being an interesting animal model for studying the development of bone pathologies. This work studies in detail how the mineralization, chemistry, and structural organization of tibiae bone in broiler chickens change with age during the first 5 wk (37 D) from hatching until acquiring the final weight for slaughter. During the early growth phase (first 2 wk), the rapid addition of bone tissue does not allow for bone organic matrix to fully mineralize and mature, and seems to be a critical period for bone development at which bone mineralization cannot keep pace with the rapid growth of bones. The low degree of bone mineralization and large porosity of cortical bone at this period might be responsible of leg deformation and/or other skeletal abnormalities commonly observed in these birds. Later, cortical bone porosity gradually decreases and the cortical bone became fully mineralized (65%) at 37 D of age. At the same time, bone mineral acquires the composition of mature bone tissue (decreased amount of carbonate, higher crystallinity, Ca/P = 1.68). However, the mineral part was still poorly organized even at 37 D. The oriented fraction was about 0.45 which means that more than half of apatite crystals within the mineral are randomly oriented. Mineral organization (crystal orientation) had an important contribution to bone-breaking strength. Nevertheless, locally determined (at tibia mid-shaft) bone properties (i.e., cortical thickness, crystal orientation) has only a moderate correlation (R2 = 0.33) with bone breaking strength probably due to large and highly heterogeneous porosity of bone that acts as structural defects. On the other hand, the total amount of mineral (a global property) measured by total ash content was the best predictor for breaking strength (R2 = 0.49). Knowledge acquired in this study could help in designing strategies to improve bone quality and reduce the incidence of skeletal problems in broiler chickens that have important welfare and economic implications.

Magnesium Silicate Bioceramics for Bone Regeneration: A Review

With the increase in need of ideal bone graft materials, magnesium silicate has been explored as resorbable bioceramics. Calcium phosphate-based bioceramics are well studied and being implemented for several orthopaedic applications as they mimic the chemistry of the natural bone. Although extensively used, these materials do not satisfy all the essential requirements of an ideal temporary bone replacement material. Materials, such as tricalcium phosphate (TCP) and hydroxyapatite (HA), have low solubility and often the resorption rate is quite slow when implanted in vivo. The research on magnesium silicate for bone regenerative application is quite relatively young and a new area compared to traditional calcium phosphate-based materials. Although limited research findings have been reported, it is believed that magnesium silicate-based bioceramics may be an alternative to calcium phosphate for bone tissue engineering applications. Thus in this review, we have highlighted the importance of magnesium silicate bioceramics and compared with existing calcium phosphate ceramics. We have also analysed the future directions and the need for clinical implementations.

Correlative vibrational spectroscopy and 2D X-ray diffraction to probe the mineralization of bone in phosphate-deficient mice.

Bone crystallite chemistry and structure change during bone maturation. However, these properties of bone can also be affected by limited uptake of the chemical constituents of the mineral by the animal. This makes probing the effect of bone-mineralization-related diseases a complicated task. Here it is shown that the combination of vibrational spectroscopy with two-dimensional X-ray diffraction can provide unparalleled information on the changes in bone chemistry and structure associated with different bone pathologies (phosphate deficiency) and/or health conditions (pregnancy, lactation). Using a synergistic analytical approach, it was possible to trace the effect that changes in the remodelling regime have on the bone mineral chemistry and structure in normal and mineral-deficient (hypophosphatemic) mice. The results indicate that hypophosphatemic mice have increased bone remodelling, increased carbonate content and decreased crystallinity of the bone mineral, as well as increased misalignment of crystallites within the bone tissue. Pregnant and lactating mice that are normal and hypophosphatemic showed changes in the chemistry and misalignment of the apatite crystals that can be related to changes in remodelling rates associated with different calcium demand during pregnancy and lactation.

Osteobiographies: Local Biologies, Embedded Bodies, and Relational Persons

In this contribution I explore what osteobiographies represent by investigating them through the lens of local biologies, embedded bodies, and relational personhood. Rather than resulting from processes and events that happen to skeletons, osteobiographies are produced through the continuing interaction of genes, environment, culture, and society over time. Osteobiographies thus represent the result of the interplay between “local biologies” (Lock 1993) and the individual life course. Drawing on the interaction of the biological and the social, I argue that bone is not overwritten by social action but continually emerges through interactions of the social and the biological, which can be related to the creation and maintenance of personhood. The skeleton after death acts as a fossilization of a personhood that is dynamic during life. The future potential of this approach is exploredthrough consideration of the skeleton of King Richard III of England. Richard’s body acted as a locale in which elite biologies played out in combination with the specific factors embedding his body in its milieu. At the same time, isotopic analysis of Richard’s skeleton illustrates how his negotiation of his personhood as king caused changes in his lifestyle that altered his bone chemistry. While evidence for increased consumption of high-status food and drink could be interpreted as resulting from increased access to these resources, such consumption was in fact a central aspect of his approach to building and maintaining alliances; an embodied political act.

Strontium-incorporated mineralized PLLA nanofibrous membranes for promoting bone defect repair

Mineralized scaffolds, which are fabricated by electrodeposition, mimic the chemistry of natural bone and have attracted a great amount of attention due to their rapid and simple production. In this study, mineralized electrospun polylactic acid (PLLA) nanofibrous membranes containing different amounts of strontium (Sr) were fabricated by an electrodeposition method for potential use in bone regeneration applications. In vitro assays, including cell proliferation and osteogenic differentiation of rat bone marrow-derived mesenchymal stem cells (BMSCs) grown on these membranes and in vivo cranial bone defect repair assays, were carried out. It was found that mineral crystals could be uniformly deposited onto the electrospun nanofibrous membranes, while the morphologies of the formed crystals were affected by the amount of Sr. By analysis of the X-ray diffraction (XRD) measurements, the formed crystalline phase was dramatically affected by the incorporation of Sr, which drove a conversion from the hydroxyapatite (HA) phase to the dicalcium phosphate dehydrate (DCPD) phase. The release of Sr2+ from the Sr/PLLA nanofibrous membranes was monitored over 20 d, and the release rates of Ca2+ and PO43− from the Sr-incorporated samples were higher compared with those of the mineralized sample without Sr. In vitro cell proliferation experiments demonstrated that mineralized Sr/PLLA nanofibrous membranes could facilitate BMSC proliferation. Furthermore, the mineralized Sr/PLLA nanofibrous membranes induced a higher degree of osteogenic differentiation in the BMSCs compared with those of pure PLLA and mineralized PLLA, as determined by the results of alkaline phosphatase (ALP) activity, alizarin red (AR) and osteocalcin (OCN) staining and the expression of osteogenesis-related genes. More importantly, in vivo cranial defect experiments revealed that mineralized Sr/PLLA nanofibrous membranes promoted bone regeneration. These findings indicated that mineralized Sr/PLLA nanofibrous membranes are a promising material for bone tissue engineering.