Thermal Analysis Study of Human Bone (original) (raw)
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Thermal Properties of Mineralized and Non Mineralized Type I Collagen in Bone
2002
The research about the structural stability of bone, as a composite material, compromises a complete understanding of the interaction between the mineral and organic phases. The thermal stability of human bone and type I collagen extracted from human bone by different methods was studied in order to understand the interactions between the mineral and organic phases when. is affected by a degradation/combustion process. The experimental techniques employed were calorimetry and infrared spectroscopy (FTIR) techniques. The extracted type I collagens result to have a bigger thermal stability with a Tmax at 500 and 530 Celsius degrees compared with the collagen present in bone with Tmax at 350 Celsius degrees. The enthalpy value for the complete degradation/combustion process were similar for all the samples, being 8.4 +-0. 11 kJ/g for recent bones diminishing with the antiquity, while for extracted collagens were 8.9 +-0.07 and 7.9 +-1.01 kJ/g. These findings demonstrate that the stability loss of type I collagen is due to its interactions with the mineral phase, namely carbonate hydroxyapatite. This cause a change in the molecular properties of the collagen during mineralization, specifically in its cross-links and other chemical interactions, which have a global effect over the fibers elasticity, but gaining tensile strength in bone as a whole tissue. We are applying this characterization to analyze the diagenetic process of bones with archaeological interest in order to identify how the environmental factors affect the molecular structure of type I collagen. In bone samples that proceed from an specific region with the same environmental conditions, the enthalpy value per unit mass was found to diminish exponentially with respect to the bone antiquity.
Advances in Biological Chemistry, 2013
An insight into the interaction of collagen type I with apatite in bone tissue was performed by using differential scanning calorimetry, Fourier transform infrared spectroscopy, and molecular modeling. Scanning electron microscopy shows that bone organic content incinerate gradually through the different temperatures studied. We suggest that the amide regions of the type I collagen molecule (mainly C=O groups of the peptide bonds) will be important in the control of the interactions with the apatite from bone. The amide I infrared bands of the collagen type I change when interacting to apatite, what might confirm our assumption. Bone tissue results in a loss of thermal stability compared to the collagen studied apart, as a consequence of the degradation and further combustion of the collagen in contact with the apatite microcrystals in bone. The thermal behavior of bone is very distinctive. Its main typical combustion temperature is at 360˚C with a shoulder at 550˚C compared to the thermal behavior of collagen, with the mean combustion peak at ca. 500˚C. Our studies with molecular mechanics (MM+ force field) showed different interaction energies of the collagen-like molecule and different models of the apatite crystal planes. We used models of the apatite (100) and (001) planes; additional two planes (001) were explored with phosphate-rich and calcium-rich faces; an energetic preference was found in the latter case. We preliminary conclude that the peptide bond of collagen type I is modified when the molecule interacts with the apatite, producing a decrease in the main peak from ca. 500˚C in collagen, up to 350˚C in bone. The combustion might be related to collagen type I, as the ΔH energies present only small variations between mineralized and non-mineralized samples. The data obtained here give a molecular perspective into the structural properties of bone and the change in collagen properties caused by the interaction with the apatite. Our study can be useful to understand the biological synthesis of minerals as well as the organic-inorganic interaction and the synthesis of apatite implant materials.
Calcified Tissue International, 2004
Thermogravimetric analysis linked to mass spectrometry (TGA-MS) shows changes in mass and identifies gases evolved when a material is heated. Heating to 600°C enabled samples of bone to be classified as having a high (cod clythrum, deer antler, and whale periotic fin bone) or a low (porpoise ear bone, whale tympanic bulla, and whale ear bone) proportion of organic material. At higher temperatures, the mineral phase of the bone decomposed. High temperature X-ray diffraction (HTXRD) showed that the main solids produced by decomposition of mineral (in air or argon at 800°C to 1000°C) were b-tricalcium phosphate (TCP) and hydroxyapatite (HAP), in deer antler, and CaO and HAP, in whale tympanic bulla. In carbon dioxide, the decomposition was retarded, indicating that the changes observed in air and argon were a result of the loss of carbonate ions from the mineral. Fourier transform infrared (FTIR) spectroscopy of bones heated to different temperatures, showed that loss of carbon dioxide (as a result of decomposition of carbonate ions) was accompanied by the appearance of hydroxide ions. These results can be explained if the structure of bone mineral is represented by
Brief notes on previous and recent results of thermoanalytical research of bone
The understanding of inorganic phases of bone is of high importance for the treatment of bone diseases, and for the development of biocompatible bone replacements as well. This paper gives a brief overview about the thermoanalytical research of bone and bone replacements and shows the results of our research on swine bone. Three calculation models were developed in order to determine the chemical formula of bone apatites. Our results support the theory of the occurrence of distinct calcite phase in bones, along with carbonate containing hydroxylapatite.
Thermal Properties of Animal Bone – A Brief Review
The paper reviews the work done on thermal properties of human and animal bone in the disciplines of physics, chemistry, biology and medicine. The review may be useful to the researchers whose interest lies in the development of bone technology.
Medical & Biological Engineering, 1976
The specific heat of dry bone, as well as decalcified bone, obtained from bovine femur samples are measured as a function of temperature in the range 200 to 3901(, using a differentialscanning-calorimetry technique, Special sample pans for volatile materials were used to provide a uniform thermal environment and to eliminate errors due to the evaporation of the moisture contained in the bone samples; the rate of heating was 10 K/min. From measurements of the c onstant pressure values, and using the Nernst-Lindermann equation, the constant-volume specific heat of both the collagen and hydroxyapatite components are evaluated in the given temperature range.
Thermal Degradation of Type I Collagen from Bones
Journal of Renewable Materials, 2016
The denaturation processes of collagen in the temperature range between 450 K and 670 K are revealed through studies performed on cow rib bones by means of mechanical spectroscopy, differential scanning calorimetry, thermogravimetry, scanning electron microscopy and infrared spectroscopy. The conformational change of the collagen molecules from a triple helix structure to a random coil was found at around 510 K. It was determined that the transformation is developed through the viscous movement of fibrils with an activation energy of (127 ± 8) kJ/mol. The second stage of massive bulk deterioration of the collagen was found at around 600 K, which leads to the loss of the mechanical integrity of the bulk collagen. In addition, an easy-to-handle viscoelastic procedure for obtaining the activation energy of the denaturation process from mechanical spectroscopy studies was also shown.
Structural and chemical changes of thermally treated bone apatite
Journal of Materials …, 2007
The thermal behaviour of the animal by-product meat and bone meal (MBM) has been investigated in order to assess how it is affected structurally and chemically by incineration. Initially composed of intergrown collagen and hydroxyapatite (HAP), combustion of the organic component is complete by 650°C, with most mass loss (50-55%) occurring by 500°C. No original proteins were detected in samples heated at 400°C or above. Combustion of collagen is accompanied by an increase in HAP mean crystallite size at temperatures greater than 400°C, from 10 nm to a constant value of 120 nm at 800°C or more. Newly formed crystalline phases appear beyond 400°C, and include b-tricalcium phosphate, NaCaPO 4 , halite (NaCl) and sylvite (KCl). Crystallite thickness as judged by small angle X-ray scattering (SAXS) increases from 2 nm (25-400°C) to 8-9 nm very rapidly at 550°C, and then gradually increases to approximately 10 nm. The original texture of HAP within a collagen matrix is progressively lost, producing a porous HAP dominated solid at 700°C, and a very low porosity sintered HAP product at 900°C.
This article is focused on the study of cooling rate effects on the thermal, structural, and microstructural properties of hydroxyapatite (HAp) obtained from bovine bone. A three-step process was used to obtain BIO-HAp: hydrothermal, calcinations, and cooling. Calcined samples in a furnace and cooling in air (HAp-CAir), water (HAp-CW), and liquid nitrogen (HAp-CN2), as well as an air cooled sample inside the furnace (HAp-CFAir), were studied. According to this study, the low cooling rate that was achieved for air cooled samples inside the furnace produce single crystal BIO-HAp with better crystalline quality; other samples exhibited polycrystalline structures forming micron and submicron grains. V C 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 339–344, 2016.