Study of biphasic calcium phosphate (BCP) ceramics of tilapia fish bones by age.

Biphasic calcium phosphate (BCP), consisting of bioceramics such as HAp + ß-TCP and Ca10(PO4)6(OH)2 + Ca3(PO4)2, is a popular choice for optimizing performance due to its superior biological reabsorption and osseointegration. In this study, BCP was produced by calcining the bones of tilapia fish (Oreochromis niloticus) reared in net cages and slaughtered at an age ranging from 15 to 420 days. The bones were cleaned and dried, calcined at 900 °C for 8 h, and then subjected to high-energy grinding for 3 h to produce BCP powders. After the calcination process, the crystalline phase's hydroxyapatite (HAp) and/or beta-tricalcium phosphate (ß-TCP) were present in the composition of the bioceramic. The age-dependent variation in phase composition was confirmed by complementary vibrational spectroscopy techniques, revealing characteristic peaks and bands of the bioceramic. This variation was marked by an increase in HAp phase and a decrease in ß-TCP phase. Thermogravimetric Analysis (TGA) and Differential Thermal Analysis (DTA) from 25 to 1400 °C showed the characteristic mass losses of the material, with a greater loss observed for younger fish, indicating the complete removal of organic components at temperatures above 600 °C. Comparison of the results obtained by X-Ray Diffraction (XRD) and Rietveld refinement with Raman spectroscopy showed excellent agreement. These results showed that with temperature and environment control and adequate fish feeding, it is possible to achieve the desired amounts of each phase by choosing the ideal age of the fish. This bioceramic enables precise measurement of HAp and ß-TCP concentrations and Ca/P molar ratio, suitable for medical orthopedics and dentistry.

Life histories in Fiji as reconstructed from first millennium CE Sigatoka Sand Dune burials using isotopes.

This paper aims to re-examine the dietary practices of individuals buried at Sigatoka Sand Dunes site (Fiji) in Burial Ground 1 excavated by Simon Best in 1987 and 1988 using two approaches and a reassessment of their archaeological, bioarchaeological and chronological frame. First, stable carbon and nitrogen isotope analysis was applied to document dietary changes between childhood and adulthood using an intra-individual approach on paired bone-tooth. Second, the potential adaptation of the individuals to their environment was evaluated through regional and temporal comparisons using inter-individual bone analysis. Ten AMS radiocarbon dates were measured directly on human bone collagen samples, placing the series in a range of approximately 600 years covering the middle of the first millennium CE (1,888 to 1,272 cal BP). δ13C and δ15N ratios were measured on bone and tooth collagen samples from 38 adult individuals. The results show that δ15N values from tooth are higher than those s from bone while bone and tooth δ13C values are similar, except for females. Fifteen individuals were included in an intra-individual analysis based on paired bone and tooth samples, which revealed six dietary patterns distinguished by a differential dietary intake of marine resources and resources at different trophic levels. These highlight sex-specific differences not related to mortuary practices but to daily life activities, supporting the hypothesis of a sexual division of labour. Compared to other Southwest Pacific series, Sigatoka diets show a specific trend towards marine food consumption that supports the hypothesis of a relative food self-sufficiency requiring no interactions with other groups.

Unravelling social status in the first medieval military order of the Iberian Peninsula using isotope analysis.

Medieval Iberia witnessed the complex negotiation of religious, social, and economic identities, including the formation of religious orders that played a major role in border disputes and conflicts. While archival records provide insights into the compositions of these orders, there have been few direct dietary or osteoarchaeological studies to date. Here, we analysed 25 individuals discovered at the Zorita de los Canes Castle church cemetery, Guadalajara, Spain, where members of one of the first religious orders, the Order of Calatrava knights, were buried between the 12th to 15th centuries CE. Stable carbon (δ13C) and nitrogen (δ15N) isotope analyses of bone collagen reveal dietary patterns typical of the Medieval social elite, with the Bayesian R model, 'Simmr' suggesting a diet rich in poultry and marine fish in this inland population. Social comparisons and statistical analyses further support the idea that the order predominantly comprised the lower nobility and urban elite in agreement with historical sources. Our study suggests that while the cemetery primarily served the order's elite, the presence of individuals with diverse dietary patterns may indicate complexities of temporal use or wider social interaction of the medieval military order.

Diets, stress, and disease in the Etruscan society: Isotope analysis and infantile skeletal palaeopathology from Pontecagnano (Campania, southern Italy, 730-580 BCE).

Susceptibility to morbidity and mortality is increased in early life, yet proactive measures, such as breastfeeding and weaning practices, can be taken through specific investments from parents and wider society. The extent to which such biosocialcultural investment was achieved within 1st millennium BCE Etruscan society, of whom little written sources are available, is unkown. This research investigates life histories in non-adults and adults from Pontecagnano (southern Italy, 730-580 BCE) in order to track cross-sectional and longitudinal breastfeeding and weaning patterns and to characterize the diet more broadly. Stable carbon and nitrogen isotope analysis of incrementally-sampled deciduous and permanent dentine (n = 15), bulk bone collagen (n = 38), and tooth enamel bioapatite (n = 21) reveal the diet was largely based on C3 staple crops with marginal contributions of animal protein. Millet was found to play a role for maternal diet and trajectories of breastfeeding and feeding for some infants and children at the site. The combination of multiple isotope systems and tissues demonstrates exclusive breastfeeding was pursued until 0.6 years, followed by progressive introduction of proteanocius supplementary foods during weaning that lasted between approximately 0.7 and 2.6 years. The combination of biochemical data with macroscopic skeletal lesions of infantile metabolic diseases and physiological stress markers showed high δ15Ndentine in the months prior to death consistent with the isotopic pattern of opposing covariance.

Hypertonic saline- and detergent-accelerated EDTA-based decalcification better preserves mRNA of bones.

Ethylenediaminetetraacetic acid (EDTA), a classically used chelating agent of decalcification, maintains good morphological details, but its slow decalcification limits its wider applications. Many procedures have been reported to accelerate EDTA-based decalcification, involving temperature, concentration, sonication, agitation, vacuum, microwave, or combination. However, these procedures, concentrating on purely tissue-outside physical factors to increase the chemical diffusion, do not enable EDTA to exert its full capacity due to tissue intrinsic chemical resistances around the diffusion passage. The resistances, such as tissue inner lipids and electric charges, impede the penetration of EDTA. We hypothesized that delipidation and shielding electric charges would accelerate EDTA-based penetration and the subsequent decalcification. The hypothesis was verified by the observation of speedy penetration of EDTA with additives of detergents and hypertonic saline, testing on tissue-mimicking gels of collagen and adult mouse bones. Using a 26% EDTA mixture with the additives at 45°C, a conventional 7-day decalcification of adult mouse ankle joints could be completed within 24 h while the tissue morphological structure, antigenicity, enzymes, and DNA were well preserved, and mRNA better retained compared to using 15% EDTA at room temperature. The addition of hypertonic saline and detergents to EDTA decalcification is a simple, rapid, and inexpensive method that doesn't disrupt the current histological workflow. This method is equally or even more effective than the currently most used decalcification methods in preserving the morphological details of tissues. It can be highly beneficial for the related community.

Isotopic evidence of high reliance on plant food among Later Stone Age hunter-gatherers at Taforalt, Morocco.

The transition from hunting-gathering to agriculture stands as one of the most important dietary revolutions in human history. Yet, due to a scarcity of well-preserved human remains from Pleistocene sites, little is known about the dietary practices of pre-agricultural human groups. Here we present the isotopic evidence of pronounced plant reliance among Late Stone Age hunter-gatherers from North Africa (15,000-13,000 cal BP), predating the advent of agriculture by several millennia. Employing a comprehensive multi-isotopic approach, we conducted zinc (δ66Zn) and strontium (87Sr/86Sr) analysis on dental enamel, bulk carbon (δ13C) and nitrogen (δ15N) and sulfur (δ34S) isotope analysis on dentin and bone collagen, and single amino acid analysis on human and faunal remains from Taforalt (Morocco). Our results unequivocally demonstrate a substantial plant-based component in the diets of these hunter-gatherers. This distinct dietary pattern challenges the prevailing notion of high reliance on animal proteins among pre-agricultural human groups. It also raises intriguing questions surrounding the absence of agricultural development in North Africa during the early Holocene. This study underscores the importance of investigating dietary practices during the transition to agriculture and provides insights into the complexities of human subsistence strategies across different regions.

Mass Spectrometry-Based Proteomics of Poly(methylmethacrylate)-Embedded Bone.

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is a widely employed technique in proteomics research for studying the proteome biology of various clinical samples. Hard tissues, such as bone and teeth, are routinely preserved using synthetic poly(methyl methacrylate) (PMMA) embedding resins that enable histological, immunohistochemical, and morphological examination. However, the suitability of PMMA-embedded hard tissues for large-scale proteomic analysis remained unexplored. This study is the first to report on the feasibility of PMMA-embedded bone samples for LC-MS/MS analysis. Conventional workflows yielded merely limited coverage of the bone proteome. Using advanced strategies of prefractionation by high-pH reversed-phase liquid chromatography in combination with isobaric tandem mass tag labeling resulted in proteome coverage exceeding 1000 protein identifications. The quantitative comparison with cryopreserved samples revealed that each sample preparation workflow had a distinct impact on the proteomic profile. However, workflow replicates exhibited a high reproducibility for PMMA-embedded samples. Our findings further demonstrate that decalcification prior to protein extraction, along with the analysis of solubilization fractions, is not preferred for PMMA-embedded bone. The biological applicability of the proposed workflow was demonstrated using samples of human PMMA-embedded alveolar bone and the iliac crest, which revealed anatomical site-specific proteomic profiles. Overall, these results establish a crucial foundation for large-scale proteomics studies contributing to our knowledge of bone biology.

Predicting lamb carcase composition from tissue depth measured at a single point with an ultrawide-band microwave scanner.

This study evaluated the ability of portable ultra-wide band microwave system (MiS) to predict lamb carcase computed tomography (CT) determined composition % of fat, lean muscle and bone. Lamb carcases (n = 343) from 6 slaughter groups were MiS scanned at the C-site (45 mm from spine midline at the 12th /13th rib) prior to CT scanning to determine the proportion of fat, muscle and bone. A machine learning ensemble stacking technique was used to construct the MiS prediction equations. Predictions were pooled and divided in 5 groups stratified for each CT composition trait (fat, lean or bone%) and a k-fold cross validation (k = 5) technique was used to test the predictions. MiS predicted CT fat% with an average RMSEP of 2.385, R2 0.78, bias 0.156 and slope 0.095. The prediction of CT lean% had an average RMSEP of 2.146, R2 0.64, bias 0.172 and slope 0.117. CT bone% prediction had an average RMSEP of 0.990, R2 0.75, bias 0.051 and slope 0.090. Predictions for CT bone% met AUS-MEAT device accreditation error tolerances on the whole range of the dataset. Predictions for CT lean% and fat% met AUS-MEAT error tolerances on a constrained dataset.

Exploring the potential of chitosan/aragonite biocomposite derived from cuttlebone waste: Elaboration, physicochemical properties and in vitro bioactivity.

Cuttlefish bone biowaste is a potential source of a composite matrix based on chitin and aragonite. In the present work, we propose for the first time the elaboration of biocomposites based on chitosan and aragonite through the valorization of bone waste. The composition of the ventral and dorsal surfaces of bone is well studied by ICP-OES. An extraction process has been applied to the dorsal surface to extract ß-chitin and chitosan with controlled physico-chemical characteristics. In parallel, aragonite isolation was carried out on the ventral side. The freeze-drying method was used to incorporate aragonite into the chitosan polymer to form CHS/ArgS biocomposites. Physicochemical characterizations were performed by FT-IR, SEM, XRD, 1H NMR, TGA/DSC, potentiometry and viscometry. The ICP-OES method was used to evaluate in vitro the bioactivity level of biocomposite in simulated human plasma (SBF), enabling analysis of the interactions between the material and SBF. The results obtained indicate that the CHS/ArgS biocomposite derived from cuttlefish bone exhibits bioactivity, and that chitosan enhances the bioactivity of aragonite. The CHS/ArgS biocomposite showed excellent ability to form an apatite layer on its surface. After three days' immersion, FTIR and SEM analyses confirmed the formation of this layer.

Cellulose separation from ramie bone by one step process with green hydrogen peroxide-citric acid.

Ramie bone (RB), an agricultural waste generated in the textile industry, is a vastly productive renewable natural resource with the potential to be used as a source of cellulose. In this study, ramie bone cellulose (RB-CE) was obtained in one step using a simple and ecologically friendly hydrogen peroxide-citric acid (HPCA) treatment procedure that avoided the use of halogenated reagents and strong acids while also streamlining the treatment processes. Various analytical methods were used to investigate the chemical composition and structure, crystallinity, morphology, thermal properties, surface area and hydration properties of cellulose separated at different treatment temperatures. HPCA successfully removed lignin and hemicellulose from RB, according to chemical composition analysis and FTIR. RB-CE had a type I cellulose crystal structure, and the crystallinity improved with increasing treatment temperature, reaching 72.51 % for RB-CE90. The RB-CE showed good thermal stability with degradation temperatures ranging from 294.2 °C to 319.1 °C. Furthermore, RB-CE had a high water/oil binding capacity, with RB-CE90 having WHC and OBC of 9.68 g/g and 7.24 g/g, respectively. The current work serves as a model for the environmentally friendly and convenient extraction of cellulose from biomass, and the cellulose obtained can be employed in the field of food and composite materials.

Bone Proteomics Method Optimization for Forensic Investigations.

The application of proteomic analysis to forensic skeletal remains has gained significant interest in improving biological and chronological estimations in medico-legal investigations. To enhance the applicability of these analyses to forensic casework, it is crucial to maximize throughput and proteome recovery while minimizing interoperator variability and laboratory-induced post-translational protein modifications (PTMs). This work compared different workflows for extracting, purifying, and analyzing bone proteins using liquid chromatography with tandem mass spectrometry (LC-MS)/MS including an in-StageTip protocol previously optimized for forensic applications and two protocols using novel suspension-trap technology (S-Trap) and different lysis solutions. This study also compared data-dependent acquisition (DDA) with data-independent acquisition (DIA). By testing all of the workflows on 30 human cortical tibiae samples, S-Trap workflows resulted in increased proteome recovery with both lysis solutions tested and in decreased levels of induced deamidations, and the DIA mode resulted in greater sensitivity and window of identification for the identification of lower-abundance proteins, especially when open-source software was utilized for data processing in both modes. The newly developed S-Trap protocol is, therefore, suitable for forensic bone proteomic workflows and, particularly when paired with DIA mode, can offer improved proteomic outcomes and increased reproducibility, showcasing its potential in forensic proteomics and contributing to achieving standardization in bone proteomic analyses for forensic applications.

The impact of hydroxyapatite crystal structures and protein interactions on bone's mechanical properties.

Hydroxyapatite (HAP) constitutes the primary mineral component of bones, and its crystal structure, along with the surface interaction with proteins, significantly influences the outstanding mechanical properties of bone. This study focuses on natural hydroxyapatite, constructing a surface model with calcium vacancy defects. Employing a representative model of aspartic acid residues, we delve into the adsorption mechanism on the crystal surface and scrutinize the adsorption forms of amino acid residues on HAP and calcium-deficient hydroxyapatite (CDHA) surfaces. The research also explores the impact of different environments on adsorption energy. Furthermore, a simplified sandwich structure of crystal-polypeptide-crystal is presented, analyzing the distribution of amino acid residue adsorption sites on the crystal surface of the polypeptide fragment. This investigation aims to elucidate how the stick-slip mechanism of polypeptide molecules on the crystal surface influences the mechanical properties of the system. By uncovering the interface mechanical behavior between HAP and osteopontin peptides, this article offers valuable theoretical insights for the construction and biomimetic design of biocomposites.

Guidelines derived from biomineralized tissues for design and construction of high-performance biomimetic materials: from weak to strong.

Living organisms in nature have undergone continuous evolution over billions of years, resulting in the formation of high-performance fracture-resistant biomineralized tissues such as bones and teeth to fulfill mechanical and biological functions, despite the fact that most inorganic biominerals that constitute biomineralized tissues are weak and brittle. During the long-period evolution process, nature has evolved a number of highly effective and smart strategies to design chemical compositions and structures of biomineralized tissues to enable superior properties and to adapt to surrounding environments. Most biomineralized tissues have hierarchically ordered structures consisting of very small building blocks on the nanometer scale (nanoparticles, nanofibers or nanoflakes) to reduce the inherent weaknesses and brittleness of corresponding inorganic biominerals, to prevent crack initiation and propagation, and to allow high defect tolerance. The bioinspired principles derived from biomineralized tissues are indispensable for designing and constructing high-performance biomimetic materials. In recent years, a large number of high-performance biomimetic materials have been prepared based on these bioinspired principles with a large volume of literature covering this topic. Therefore, a timely and comprehensive review on this hot topic is highly important and contributes to the future development of this rapidly evolving research field. This review article aims to be comprehensive, authoritative, and critical with wide general interest to the science community, summarizing recent advances in revealing the formation processes, composition, and structures of biomineralized tissues, providing in-depth insights into guidelines derived from biomineralized tissues for the design and construction of high-performance biomimetic materials, and discussing recent progress, current research trends, key problems, future main research directions and challenges, and future perspectives in this exciting and rapidly evolving research field.

Loss of the glycosyltransferase Galnt11 affects vitamin D homeostasis and bone composition.

O-glycosylation is a conserved posttranslational modification that impacts many aspects of organismal viability and function. Recent studies examining the glycosyltransferase Galnt11 demonstrated that it glycosylates the endocytic receptor megalin in the kidneys, enabling proper binding and reabsorption of ligands, including vitamin D-binding protein (DBP). Galnt11-deficient mice were unable to properly reabsorb DBP from the urine. Vitamin D plays an essential role in mineral homeostasis and its deficiency is associated with bone diseases such as rickets, osteomalacia, and osteoporosis. We therefore set out to examine the effects of the loss of Galnt11 on vitamin D homeostasis and bone composition. We found significantly decreased levels of serum 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D, consistent with decreased reabsorption of DBP. This was accompanied by a significant reduction in blood calcium levels and a physiologic increase in parathyroid hormone (PTH) in Galnt11-deficient mice. Bones in Galnt11-deficient mice were smaller and displayed a decrease in cortical bone accompanied by an increase in trabecular bone and an increase in a marker of bone formation, consistent with PTH-mediated effects on bone. These results support a unified model for the role of Galnt11 in bone and mineral homeostasis, wherein loss of Galnt11 leads to decreased reabsorption of DBP by megalin, resulting in a cascade of disrupted mineral and bone homeostasis including decreased circulating vitamin D and calcium levels, a physiological increase in PTH, an overall loss of cortical bone, and an increase in trabecular bone. Our study elucidates how defects in O-glycosylation can influence vitamin D and mineral homeostasis and the integrity of the skeletal system.

Isotopic biographies reveal horse rearing and trading networks in medieval London.

This paper reports a high-resolution isotopic study of medieval horse mobility, revealing their origins and in-life mobility both regionally and internationally. The animals were found in an unusual horse cemetery site found within the City of Westminster, London, England. Enamel strontium, oxygen, and carbon isotope analysis of 15 individuals provides information about likely place of birth, diet, and mobility during the first approximately 5 years of life. Results show that at least seven horses originated outside of Britain in relatively cold climates, potentially in Scandinavia or the Western Alps. Ancient DNA sexing data indicate no consistent sex-specific mobility patterning, although three of the five females came from exceptionally highly radiogenic regions. Another female with low mobility is suggested to be a sedentary broodmare. Our results provide direct and unprecedented evidence for a variety of horse movement and trading practices in the Middle Ages and highlight the importance of international trade in securing high-quality horses for medieval London elites.

Quantitative color analysis of burned bone to predict DNA quantity, quality, and genotyping success.

Badly burned skeletal remains are commonly submitted to forensic laboratories for victim identification via DNA analysis methods. Burned skeletal remains present many challenges for DNA analysis as they can contain low amounts of DNA which can also be damaged and degraded, resulting in partial or no STR profiles. Therefore, a simple, but effective screening method that identifies which samples may provide the most successful STR or mtDNA typing results for identification would enable forensic laboratories to save time, money, and resources. One metric that can be used and a screening method is the color of burned bone, as bone color changes with exposure to fire as temperature and length of exposure increase. This research developed a quantitative screening method based on the surface color of burned bone. The different visual bone colors (light brown, dark brown, black, gray, and white) were quantified using the Commission on Illumination L*a*b color space. These values were then compared to DNA yield, STR, and mtDNA profile completeness to identify whether the L*a*b values can predict genotyping success. A Bayesian network was constructed to determine the probability of STR typing success, given a set of L*a*b values. Results demonstrated that samples with an a* value greater than or equal to one and b* value greater than eight (light brown and dark brown burned samples) were the most predictive of STR typing success and mtDNA typing success. A decision tree for processing burned bones was constructed based on the color value thresholds.

Metals accumulation affects bone and muscle in osteoporotic patients: A pilot study.

Osteoporosis is the most common bone disease, characterized by decreased bone mineral density (BMD) and often associated to decreased muscle mass and function. Metal exposure plays a role in the pathophysiology of osteoporosis and affects also muscle quality. The aim of this study was to assess the association between metal levels in bone and muscle samples and the degeneration of these tissues. A total of 58 subjects (30 male and 28 female) was enrolled and classified in osteoporotic (OP, n = 8), osteopenic (Ope, n = 30) and healthy (CTR, n = 20) subjects, according to BMD measures. Femoral head bone samples and vastus lateralis muscle samples were collected during hip arthroplasty surgeries. Inductively Coupled Plasma Mass Spectrometry (ICP-MS) analysis showed increased levels of Al, Cd and Pb in OP and Ope bone tissue compared to CTR subjects (p = 0.04, p = 0.005 and p = 0.01, respectively). Whereas, increased levels of Co, Cd and Pb were measured in OP and Ope muscle tissues, compared to CTRs (p < 0.001, p = 0.02 and p = 0.01, respectively). In addition, Al, Cd and Pb levels in bone and Cd and Co levels in muscle were negatively correlated with BMD. A negative association among Co, Cd, Cr and Hg levels and muscle fibers diameter was also observed in muscle tissues. This study assessed that metal exposure can affects bone and muscle tissue quality and may contribute to the onset and progression of musculoskeletal diseases such as osteoporosis. Therefore, it is important to implement metal exposure assessment and their impact on disease development, in order to manage and prevent metal accumulation effects on bone and muscle quality.

The ecology, subsistence and diet of ~45,000-year-old Homo sapiens at Ilsenhöhle in Ranis, Germany.

Recent excavations at Ranis (Germany) identified an early dispersal of Homo sapiens into the higher latitudes of Europe by 45,000 years ago. Here we integrate results from zooarchaeology, palaeoproteomics, sediment DNA and stable isotopes to characterize the ecology, subsistence and diet of these early H. sapiens. We assessed all bone remains (n = 1,754) from the 2016-2022 excavations through morphology (n = 1,218) or palaeoproteomics (zooarchaeology by mass spectrometry (n = 536) and species by proteome investigation (n = 212)). Dominant taxa include reindeer, cave bear, woolly rhinoceros and horse, indicating cold climatic conditions. Numerous carnivore modifications, alongside sparse cut-marked and burnt bones, illustrate a predominant use of the site by hibernating cave bears and denning hyaenas, coupled with a fluctuating human presence. Faunal diversity and high carnivore input were further supported by ancient mammalian DNA recovered from 26 sediment samples. Bulk collagen carbon and nitrogen stable isotope data from 52 animal and 10 human remains confirm a cold steppe/tundra setting and indicate a homogenous human diet based on large terrestrial mammals. This lower-density archaeological signature matches other Lincombian-Ranisian-Jerzmanowician sites and is best explained by expedient visits of short duration by small, mobile groups of pioneer H. sapiens.

Identification and tentative removal of collagen glue in Palaeolithic worked bone objects: implications for ZooMS and radiocarbon dating.

Collagen glue has been used for nearly two centuries to consolidate bone material, although its prevalence in museum collections is only now becoming visible. Identifying and removing collagen glue is crucial before the execution of any geochemical or molecular analyses. Palaeolithic bone objects from old excavations intended for radiocarbon dating were first analysed using ZooMS (Zooarchaeology by Mass Spectrometry) to identify the animal species, however peaks characteristic of both cattle and whale were discovered. Two extraction methods for ZooMS were tested to identify the authentic animal species of these objects, which revealed that these were originally whale bone objects that had been consolidated with cattle collagen glue. This is the first time animal collagen glue has been identified in archaeological remains with ZooMS, illustrating again the incredible versatility of this technique. Another technique, Fourier Transform Infrared Spectroscopy in Attenuated Total Reflectance mode (FTIR-ATR), was also tested if it could rapidly identify the presence of collagen glue in archaeological bone material, which was not the case. Two other cleaning methods were tested to remove bone glue contamination prior to radiocarbon dating, along with two modified collagen extraction methods for ZooMS. These methods were applied to bone blank samples (FmC = 0.0031 ± 0.0002, (n = 219), 47 336 ± 277 yr BP) that were experimentally consolidated with collagen glue and to the Palaeolithic bone material (ca. 15 000 and 12 000 yr BP). The experimental bone blanks produced excellent 14C ages, suggesting the cleaning methods were successful, however the 14C ages for some of the Palaeolithic material remained too young considering their contextual age, suggesting that the collagen glue contamination had most likely cross-linked to the authentic collagen molecule. More research is needed in order to gain a deeper understanding of the occurrence and elimination of cross-linked collagen-based glues in material from museum collections.

Estudio de biocompatibilidad de matrices poliméricas combinadas, responsivas al pH, con aplicación en Ingeniería de Tejido Óseo / Biocompatibility study of combined pH-responsive polymeric matrices with application in Bone Tissue Engineering

El presente trabajo muestra la obtención de un material a partir de un polímero sintético (TerP) y otro natural, mediante entrecruzamiento físico y su caracterización fisicoquímica y biológica, con el fin de emplearlos para regeneración de tejido óseo. Las membranas fueron obtenidas por la técnica de evaporación del solvente y caracterizadas por espectroscopia FTIR, ensayos de hinchamiento, medidas de ángulo de contacto y microscopia electrónica de barrido (SEM). Se encontró que la compatibilidad entre los polímeros que la constituyen es estable a pH fisiológico y que, al incorporar mayor cantidad del TerP a la matriz, esta se vuelve más hidrofóbica y porosa. Además, teniendo en cuenta la aplicación prevista para dichos materiales, se realizaron estudios de biocompatibilidad y citotoxicidad con células progenitoras de médula ósea (CPMO) y células RAW264.7, respectivamente. Se evaluó la proliferación celular, la producción y liberación de óxido nítrico (NO) al medio de cultivo durante 24 y 48 horas y la expresión de citoquinas proinflamatorias IL-1ß y TNF-α de las células crecidas sobre los biomateriales variando la cantidad del polímero sintético. Se encontró mayor proliferación celular y menor producción de NO sobre las matrices que contienen menos proporción del TerP, además de poseer una mejor biocompatibilidad. Los resultados de este estudio muestran que el terpolímero obtenido y su combinación con un polímero natural es una estrategia muy interesante para obtener un biomaterial con posibles aplicaciones en medicina regenerativa y que podría extenderse a otros sistemas estructuralmente relacionados. (AU)

In the present work, the preparation of a biomaterial from a synthetic terpolymer (TerP) and a natural polymer, physically crosslinked, is shown. In order to evaluate the new material for bone tissue regeneration, physicochemical and biological characterizations were performed. The membranes were obtained by solvent casting and characterized using FTIR spectroscopy, swelling tests, contact angle measurements, and scanning electron microscopy (SEM). It was found that the compatibility between the polymers is stable at physiological pH and the incorporation of a higher amount of TerP into the matrix increases hydrophobicity and porosity.Furthermore, considering the intended application of these materials, studies of biocompatibility and cytotoxicity were conducted with Bone Marrow Progenitor Cells (BMPCs) and RAW264.7 cells, respectively. Cell proliferation, NO production and release into the culture medium for 24 and 48 hours, and proinflammatory cytokine expression of IL-1ß and TNF-α from cells grown on the biomaterials while varying the amount of the synthetic polymer were evaluated. Greater cell proliferation and lower NO production were found on matrices containing a lower proportion of TerP, in addition to better biocompatibility. The results of this study demonstrate that the obtained terpolymer and its combination with a natural polymer is a highly interesting strategy for biomaterial preparation with potential applications in regenerative medicine. This approach could be extended to other structurally related systems. (AU)