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Every year, millions of tons of fish waste are generated from fishing activities, and a similar amount is discarded and returned to the sea as unwanted catches. This material can be used as a biological source for many potential new added-value products, such asobtaining hyaluronic acid from fish eyeballs or extracting collagen from fish skin, but there are not many utilities for fish bones yet. This work tackles the transformation of fish discards into calcium phosphates. Discards from scorpionfish (Scorpaena scrofa) and Atlantic horse mackerel (Trachurus trachurus), as well as by-products generated from aquaculture activities (heads and trimmings frames) of salmon (Salmon salar), were used to obtain calcium phosphate. Biphasic carbonated hydroxyapatite (HA) /beta-tricalcium phosphate (TCP) material was obtained. The biphasic HA-TCP material has a promising range of applications in the biomedical field based on its similarity to calcium phosphates found in human bones in terms of crystallite size and carbonate content. The presence of Na, Mg, Sr, and K ions in the HA-TCP material is very beneficial, since they contribute to bone metabolism and cell adhesion. [ABSTRACT FROM AUTHOR]

Reconstructing the living environment of extinct vertebrates is often challenging due to the lack of proxies. We propose a new proxy to the living environment based on the combined oxygen and sulphur stable isotope analysis of vertebrate hydroxyapatite. We tested this isotopic proxy to 64 biogenic apatite (bones) samples that represent a wide spectrum of the extant vertebrate phylogenetic diversity including crocodiles, snakes, turtles, mammals, birds, lizards, fish and amphibians. We show that the combination of these two isotopic systems allows the living environment of all these vertebrates to be unambiguously distinguished between freshwater (aquatic vs semi-aquatic), seawater (aquatic vs semi-aquatic) and terrestrial. The main goal of this study is to provide a present-day isotopic reference frame and to discuss methodological issues that will serve to interpret future oxygen and sulphur isotope results obtained either from fossil or modern skeletal material. This new isotopic approach of combined oxygen and sulphur isotope analysis will be particularly useful to document major aquatic-terrestrial transitions in the fossil record but also to better constrain the living environment of some present-day species. [ABSTRACT FROM AUTHOR]

Every year, millions of tons of fish waste are generated from fishing activities, and a similar amount is discarded and returned to the sea as unwanted catches. This material can be used as a biological source for many potential new added-value products, such asobtaining hyaluronic acid from fish eyeballs or extracting collagen from fish skin, but there are not many utilities for fish bones yet. This work tackles the transformation of fish discards into calcium phosphates. Discards from scorpionfish (Scorpaena scrofa) and Atlantic horse mackerel (Trachurus trachurus), as well as by-products generated from aquaculture activities (heads and trimmings frames) of salmon (Salmon salar), were used to obtain calcium phosphate. Biphasic carbonated hydroxyapatite (HA) /beta-tricalcium phosphate (TCP) material was obtained. The biphasic HA-TCP material has a promising range of applications in the biomedical field based on its similarity to calcium phosphates found in human bones in terms of crystallite size and carbonate content. The presence of Na, Mg, Sr, and K ions in the HA-TCP material is very beneficial, since they contribute to bone metabolism and cell adhesion.

Oxygen isotope fractionation factors for phosphates were calculated by means of the increment method. The results suggest that Ag3PO4and BiPO4are enriched in18O relative to AgPO4, and the three phosphates are consistently depleted in18O relative to Ba3[PO4]2; fluorapatite and chlorapatite exhibit a similar behaviour of oxygen isotope fractionation with consistent enrichment of18O relative to hydroxyapatite. The valence, radii and coordination of metal cations play a quantitative role in dictating the18O/16O partitioning in these phosphates of different compositions. The calculated fractionation factors for the Ag3PO4–H2O system are in agreement with experimental determinations derived from enzyme-catalysed isotope exchange between dissolved inorganic phosphate and water at the longest reaction durations at low temperatures. This demonstrates that the precipitated Ag3PO4has completely captured the oxygen isotope fractionation in the dissolved inorganic phosphate. The calculated fractionation factors for the F/Cl-apatite–water systems are in agreement with the enzyme-catalysed experimental fractionations for the dissolved phosphate–water system at the longest reaction durations but larger than fractionations derived from bacteria-facilitated exchange and inorganic precipitation experiments as well as natural observations. For the experimental calibrations of oxygen isotope fractionation involving the precipitation of dissolved phosphate species from aqueous solutions, the fractionation between precipitate and water is primarily dictated by the isotope equilibration between the dissolved complex anions and water prior to the precipitation. Therefore, the present results provide a quantitative means to interpret the temperature dependence of oxygen isotope fractionation in inorganic and biogenic phosphates. [ABSTRACT FROM AUTHOR]

Fossil biogenic apatites display trace element (TE) compositions that can record environmental and biological signals, give insights into past water compositions, or be used for dating paleontological and archeological bones and teeth. Processes of TE incorporation into apatites of skeletal phosphatic tissues are described, ranging from those active in living organisms to those active during diagenesis. Abiotic incorporation mechanisms have been modeled theoretically and experimentally and include crystallographic controls on TE partitioning coefficients, inorganic surface adsorption and adsorption mediated through chelation and diffusion–adsorption processes, each leading to specific fractionation patterns. Predictions from models and experiments have been tested against TE concentration and isotopic composition data on remains of contemporary wild or raised animals and on fossils of various ages and environments. In living organisms, TEs incorporated in apatite are separated in two categories, non-essential elements whose concentration is compared to that of an essential element with similar behavior (e.g. Sr/Ca) to reconstruct trophic chains, and essential elements whose isotopic ratios are used to trace metabolic activity, diet, etc. In fossils, elements are incorporated during diagenesis, such as rare earth elements (REEs), and trace diagenetic processes ranging from very early quantitative adsorption likely mediated by chelators, protracted diagenesis through inorganic adsorption and fractionation through diffusion–adsorption, to low-grade metamorphism associated with intense redistribution under crystal-chemical control. These different steps are also identified as steps of radionuclide incorporation. Only samples where the earliest steps can be deciphered are useful for determining stratigraphic and archeological ages. Other samples will date late diagenetic events that have obliterated the paleoenvironmental signals, but may be of geological significance, e.g. tectonic events. [ABSTRACT FROM AUTHOR]

Altered iguanodontian dinosaur teeth have been studied to analyse the unusual replacement of biogenic apatite and to deduce how the alterations affect the preservation of these fossils. The fossils were recovered from alluvial lacustrine facies (Barremian, Early Cretaceous) in Teruel (Spain). Mandibular teeth and sediments were studied in hand sample, by X-ray diffraction ( XRD) and by scanning electron microscopy ( SEM). The combination of the different techniques shows that the teeth have undergone at least three pseudomorphic stages: (1) replacement of the organic component of the dentine and enamel by fluorapatite; (2) replacement of the fluorapatite by aluminium sulphate phosphate phases (crandallite-woodhouseite series); and (3) replacement of part of the tooth by gypsum and Al- and Fe-rich phosphates (vauxite) as a consequence of the superficial weathering of the fossil-rich outcrop. The presence of organic matter and sulphides in the host rocks was the main factor promoting the dissolution of the previous phases and crystallization of the new ones. This is the first description of the replacement of biogenic apatite in dinosaur teeth by aluminium and iron phosphates as a result of fossil diagenetic processes; these minerals are scarce in sedimentary environments and may have economic interest because they contain rare earth or radioactive elements. Additionally, our results indicate that, to ensure proper curating of the specimens from this fossil site, it is crucial to completely remove the host rock and strictly control storage humidity. [ABSTRACT FROM AUTHOR]

Abstract: Since the early trials in the 50''s, the reliability of 14C dates obtained from bioapatites has always been questioned. However, methodological attempts at dating biological apatites are rare. The compilation of the radiocarbon dates published in Radiocarbon over the period 1959–2009 shows that less than 6% of all the bone dates were performed on purified bioapatite. Crucial for the validation of the approach, is the design of tests for the preservation of the geochemical signal in biological apatites that are relevant for 14C dating. Because carbonate in apatite can exchange isotopically with dissolved carbon present in the environmental fluids, pretreatments are necessary but not sufficient and preservation criteria based on mineral integrity are of limited help. In this case, only an indirect approach, based on the dating of different bone/tooth fractions of the same individual and/or associated material is able to distinguish between preserved and altered fossils. In case of alteration, it is unlikely that the rate of isotopic exchange/recrystallization will be identical in skeletal tissues with different physico-chemical properties and any intra-individual difference measured in 14C age must result from differential diagenesis. We applied this strategy to more than 100 Holocene and Late Pleistocene localities worldwide. This approach confirms that carbonate in calcined bone is very resistant to post-burial isotopic exchange and is the most reliable source of inorganic carbon for 14C dating regardless of the environmental conditions. Large intra-individual differences in 14C age are found in several European and American localities, showing that both bone and enamel apatite can suffer from rejuvenation due to isotopic exchange during fossilization. On the contrary, the absence of significant intra-individual differences in 14C age in most of the localities from arid environments (Africa, Arabic Peninsula) attests to the good preservation of bone apatite in these regions. This contrasting situation confirms that bone diagenesis must be treated on a site-by-site basis, and demonstrates that bioapatite is a reliable material to date skeletal remains in arid environments. [Copyright &y& Elsevier]

Abstract: Phosphate minerals and specifically apatite show promise for environmental cleanup because they can form stable compounds with a wide range of cationic contaminants. However, phosphate minerals naturally accumulate some heavy metals that may cause additional contamination of the environment if used improperly. Nine commercially available phosphate materials were evaluated for remediation of contaminated soil based on solubility, concentration of metal/metalloid impurities, and leachability of impurity metal/metalloids. The phosphate materials consisted of three groups: processed (i.e., fertilizers), mined (rock phosphates from different formations), and biogenic (ground fish bone). Processed and mined rock phosphates contained relatively high total concentrations of As, Co, Cr, and Cu but did not exceed the RCRA toxicity characteristic leaching procedure (TCLP) limits. Biogenic apatite contained much lower metal concentrations than processed and mined rock phosphate and was appreciably more soluble. By combining biogenic and mined phosphate it is possible to obtain a wide range of phosphate release rates, permitting rapid immobilization of contaminants while providing a slow release of phosphate for continued long-term treatment. [Copyright &y& Elsevier]

Biogenic apatite preserved in 148 samples of conodonts and organophosphatic-shelled brachiopods from Cambrian through Ordovician successions of the Baltoscandian Basin (Baltica Plate) preserves a sensitive record of early Palaeozoic sea-water chemistry interpreted via neodymium isotope ratios. Consistent εNd(t) values of -9.6 to -8.3 for Lower to Middle Cambrian samples suggest no significant lateral or temporal variation across the region. Average Upper Cambrian values arc -7.2 to -7.7. Sedimentary analysis suggests that the influence of continental weathering from Baltica as a major source of radiogenic Nd was negligible. Ordovician samples show a rise to -5 to -6 in the early Arenig, early -mid Llanvirn and late Caradoc. Sea-water mixing from the southeast Iapetus Ocean was a constant factor throughout Cambrian-Ordovician times. The rise reflects erosion of obducted volcanic arc complexes along the Caledonian margin, and probably also relates to pollution of the Baltica sector of Iapetus from the approaching Avalonia Plate. Patterns of evolutionary biodiversity and palaeobiogeographical linkages support the geochemical signatures in interpreting the tectonic history of the region. Extinction of lingulate brachiopod faunas in the Tremadoc, followed by subsequent recovery and emergence of benthic assemblages typical of the Ordovician Evolutionary Fauna in the Billingen-early Volkhov regional stages coincide with significant changes in geochemical characteristics of water masses across the Baltoscandian basin. The early and mid Ordovician (Arenig to Llandeilo) brachiopod faunas of the North Estonian Confacies Belt are characterized by high endemism and low turnover rates, whereas increased immigration resulted in the extinction of a number of local lineages in the late Llanvirn. From the mid Caradoc to mid Ashgill, when Baltica was drifting on a course to collide eventually with Avalonia and gradually approach Laurentia, brachiopod assemblages were characterized by higher turnover rates. At the same time they gradually became more cosmopolitan and less influenced by the invasion of new faunas. [ABSTRACT FROM AUTHOR]

The choice of the appropriate material having suitable compositional and morphological surface characteristics, is a crucial step in the development of orthopedic implants. The purpose of this paper is to elucidate, on this regard, the influence of two important hits, i.e. , biogenic apatite with bone-like composition and nanostructured morphology, providing the evidence of the efficacy of nanostructured biogenic apatite coatings in favoring adhesion, growth, proliferation, and in vitro osteogenic differentiation of human mesenchymal stromal cells (hMSCs) isolated from the bone marrow. The specific features of this coating in terms of topographical and biochemical cues, obtained by Ionized Jet Deposition, are perceived by hMSCs, as suggested by changes in different morphologic parameters as Aspect Ratio or Elongation index, suggesting the impact exerted by the nanostructure on early adhesion events, cytoskeleton organization, and cells fate. In addition, the nanostructured CaP coating sustained the metabolic activity of the cells and facilitated the osteogenic differentiation of MSC by supporting the osteogenesis-related gene expression. These findings support the use of a combined approach between technological advancement and instructive surfaces, both from the topographical and the biochemical point of view, in order to manufacture smart biomaterials able to respond to different needs of the orthopedic practice. • Ionized Jet Deposition (IJD) is a plasma-assisted technique producing submicrometric films. • Biomimetic, nanostructured coating can be obtained with IJD for orthopedic applications. • Topographical and biochemical cues of coating were perceived by MSCs. • Smart biomaterials with instructive surfaces can be obtained with IJD. [ABSTRACT FROM AUTHOR]

Reconstructing the living environment of extinct vertebrates is often challenging due to the lack of proxies. We propose a new proxy to the living environment based on the combined oxygen and sulphur stable isotope analysis of vertebrate hydroxyapatite. We tested this isotopic proxy to 64 biogenic apatite (bones) samples that represent a wide spectrum of the extant vertebrate phylogenetic diversity including crocodiles, snakes, turtles, mammals, birds, lizards, fish and amphibians. We show that the combination of these two isotopic systems allows the living environment of all these vertebrates to be unambiguously distinguished between freshwater (aquatic vs semi-aquatic), seawater (aquatic vs semi-aquatic) and terrestrial. The main goal of this study is to provide a present-day isotopic reference frame and to discuss methodological issues that will serve to interpret future oxygen and sulphur isotope results obtained either from fossil or modern skeletal material. This new isotopic approach of combined oxygen and sulphur isotope analysis will be particularly useful to document major aquatic-terrestrial transitions in the fossil record but also to better constrain the living environment of some present-day species.