scholarly journals Synthesis of Organic-Inorganic Hybrid Material with a Synergistic Interface as a Release Agent for Free Acid β-Hydroxy-β-Methyl Butyrate

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Beatriz A. Andrade-Espinoza ◽  
Gregorio G. Carbajal-Arizaga ◽  
Selma Rivas-Fuentes ◽  
Karla Nuño ◽  
José Benito Pelayo-Vázquez ◽  
...  

We report the preparation and characterization of a new organic-inorganic hybrid system composed of type-I collagen and ZnAl layered double hydroxide (LDH) particles loaded with β-hydroxy-β-methyl butyrate (HMB) by coprecipitation reaction. X-ray diffraction (peaks well agree with those reported in the literature), infrared spectroscopy (stretching bonds for both organic-inorganic compounds), and X-ray photoelectron spectroscopy confirmed the hybrid system retained HMB in the carboxylate form, and a small fraction turned to the acid form. In both cases, the HMB molecules are assembled to the LDH surface. The hybrid compound results in improved thermal stability for HMB and collagen, as shown by thermal analysis. Scanning electron microscopy data reflects different arrangements from LDH sheets with interesting physicochemical properties since LDH and collagen protect free HMB and make it more bioavailable and functional. In vitro studies as part of high-throughput screening strategies indicated that LDH hybrids reduced cell viability around 75-90%, which is an acceptable viability value because of the L6 cell line susceptibility. However, all new nanomaterials must be carefully analyzed by different toxicity tests because a single test does not evaluate complete physiological compartments.

1981 ◽  
Vol 1 (10) ◽  
pp. 801-810 ◽  
Author(s):  
Karl A. Piez ◽  
Benes L. Trus

A specific fibril model is presented consisting of bundles of five-stranded microfibrils, which are usually disordered (except axially) but under lateral compression become ordered. The features are as follows (where D = 234 residues or 67 nm): (1) D-staggered collagen molecules 4.5 D long in the helical microfibril have a left-handed supercoil with a pitch of 400–700 residues, but microfibrils need not have helical symmetry. (2) Straight-tilted 0.5-D overlap regions on a near-hexagonal lattice contribute the discrete x-ray diffraction reflections arising from lateral order, while the gap regions remain disordered. (3) The overlap regions are equivalent, but are crystallographically distinguished by systematic displacements from the near-hexagonal lattice. (4) The unit cell is the same as in a recently proposed three-dimensional crystal model, and calculated intensities in the equatorial region of the x-ray diffraction pattern agree with observed values.


2020 ◽  
Vol 20 (5) ◽  
pp. 2000017 ◽  
Author(s):  
Alberta Terzi ◽  
Nunzia Gallo ◽  
Simona Bettini ◽  
Teresa Sibillano ◽  
Davide Altamura ◽  
...  

2009 ◽  
Vol 8 ◽  
pp. 157-172 ◽  
Author(s):  
Céline Chadefaux ◽  
Ina Reiche

The present work focuses on the characterization of structural modifications in bone material induced by heating at low temperatures (90 - 250°C). This is of outmost importance when archaeological bone material is concerned. Changes occurring in the structure of the type I collagen and of the mineral-organic arrangement are especially investigated. This precise characterization required the combination of complementary analytical techniques: Differential Scanning Calorimetry (DSC) for global analysis of the collagen state of conservation, Scanning Electron Microscopy coupled with an Energy Dispersive X-Ray system (SEM-EDX), micro-Proton-Induced X-ray and Gamma-ray Emission (micro-PIXE/PIGE) for chemical analysis of the mineral fraction, Infrared microspectroscopy in attenuated total reflectance mode (micro-ATR-FT-IR) combined with curve-fitting for microscopic investigations and Transmission Electron Microscopy (TEM) on ultrathin sections to characterize the modifications in the mineral/organic interface at nanoscale. New criteria characterizing the effect of a thermal treatment at low temperatures on the bone structure from the macroscopic to the nanoscale were determined. There are namely a broadening of the Haversian canals, the inversion of the turns to -sheet ratio in the collagen structure determined by decomposition of the amide I IR band as well as a shift of amide II IR band position with the heating temperature to lower wavenumbers. At nanoscale, melting of the organic phase and clustering of hydroxyapatite (HAP) bone crystals can be observed. For comparison, unheated archaeological bones have been analyzed in order to test if the heat-induced modification can be distinguished from diagenetic alterations, generally dissolution-recrystallisation processes, in soils.


2008 ◽  
Vol 87 (8) ◽  
pp. 762-766 ◽  
Author(s):  
M. Hayashi ◽  
E.V. Koychev ◽  
K. Okamura ◽  
A. Sugeta ◽  
C. Hongo ◽  
...  

The flexural strength of Type I collagen, the major organic component of human dentin, increases with heat. We hypothesized that human dentin can be strengthened by heating, which may help prevent fracture of non-vital teeth after restoration. Beam-shaped dentin specimens were obtained from the crowns of human third molars. The dentinal tubular orientations were arranged to run parallel or perpendicular to loading surfaces. The flexural and microtensile strengths of dentin in the parallel specimens were 2- to 2.4-fold greater after being heated between 110°C and 140°C for 1 hr. The stress intensity factors at fracture also increased after specimens were heated. The x-ray diffraction analyses suggested that shrinking of the lateral packing of the collagen triple-helices from 14 Å to 11 Å was the probable cause of the strengthening of heated dentin. We conclude that heat treatment strengthens human dentin.


2017 ◽  
Vol 11 (04) ◽  
pp. 496-502 ◽  
Author(s):  
Isadora S. Deschamps ◽  
Gabriel L. Magrin ◽  
Ricardo S. Magini ◽  
Márcio C. Fredel ◽  
Cesar A.M. Benfatti ◽  
...  

ABSTRACT Objectives: After tooth loss, dimensional alterations on the alveolar bone ridge can occur that can negatively affect the placement of dental implants. The purpose of this study was to evaluate the synthesis, and mechanical properties of β-tricalcium phosphate (β-TCP) scaffolds coated with bioabsorbable polymers, namely, collagen and poly (D, L-lactic acid) (PDLLA). Materials and Methods: β-TCP powder was obtained by reactive milling and then characterized by X-ray diffraction and scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS). β-TCP scaffolds were obtained by replica method, in which polyurethane foams are immersed in β-TCP suspension and thereafter submitted to a thermal treatment to remove the polyurethane and sinter the ceramic. Type-I collagen or PDLLA were used to coat the β-TCP scaffolds by dip-coating method. Scaffolds were separated in four groups depending on the coating material: noncoated (Group A), double immersion in collagen (Group B), double immersion in PDLLA (Group C), and ten immersions in PDLLA (Group D). Samples were characterized by compressive tests and SEM/EDS. Data were statistically analyzed through two-way ANOVA (p = 0.05). Results: Chemical and microscopic analyses revealed proper morphology and chemical composition of powder particles and scaffolds with or without polymeric coatings. Scaffolds coated with PDLLA showed higher compressive strength (0.11 ± 0.054 MPa) than those of collagen (0.022 ± 0.012 MPa) or noncoated groups (0.024 ± 0.012 MPa). Conclusions: The coating method of β-TCP with PDLLA revealed a potential strategy to increase the mechanical strength of porous ceramic materials while collagen can enhance cell migration.


2009 ◽  
Vol 610-613 ◽  
pp. 1104-1108 ◽  
Author(s):  
Jian Ye Han ◽  
Zhen Tao Yu ◽  
Lian Zhou

Hydroxyapatite/TiO2 composite material was coated onto Ti25Nb3Mo2Sn3Zr (TLM) alloy substrate. To study the effects of hydroxyapatite/TiO2 composite coatings on bone-related protein expression, the osteoblast were cultured with composite coatings for different times. The phase transformation and compound formation of the HA/TiO2 coatings were investigated using XRD (X-ray diffraction). The mRNA expression of Type I collagen, alkaline phosphatase (ALP) and osteocalcin were studied by RT-PCR (reverse transcriptional polymerase chain reaction). The titania delayed the crystallization of HA. The mRNA expressions of Type I collagen are decreased as the increasing of TiO2 percentage. The mRNA expressions of osteocalcin are approached. The ALP expression on H4 coating (HA/TiO2 mol ration is 5) after the osteoblast cultured with composite coating for 6 days is the highest. The increasing of TiO2 amount decreases the bioactivity of the composite coatings.


1991 ◽  
Vol 69 (8) ◽  
pp. 531-536
Author(s):  
Roy J. Baerwald ◽  
Lura C. Williamson ◽  
E. Stevens ◽  
C. Rike ◽  
S. Trabanino ◽  
...  

Highly concentrated extracellular filaments in the perineurium of the Florida spiny lobster, Panulirus argus, were isolated using ultracentrifugation and linear sucrose gradients. The pellet obtained was highly enriched for the filaments as observed by transmission electron microscopy. Fibril diameter and axial periodicity measurements were obtained from filaments positively and negatively stained with uranyl acetate. A period between 14.0 and 25.0 nm and an average fibril diameter of 15.0 nm were observed. The filaments proved resistant to solubilization by most conventional agents and by several collagenases. NaOH (0.1 M at 100 °C) safely dissolved the filaments for measurements of protein content by the Lowry method and carbohydrate content with anthrone reagent. These tests revealed a protein content of ≈ 84% and a high carbohydrate content of ≈ 15%. Polyacrylamide electrophoresis of an acid-pepsin filament extract revealed a highly concentrated band (approximately 100 000) corresponding to the α-1 and α-2 bands of vertebrate type I collagen. Wide angle X-ray diffraction yielded meridional reflections that confirmed the filaments as collagen when compared with mammalian collagen X-ray diffraction. The amino acid composition was determined with a computer-assisted Beckman amino acid analyzer, which showed a glycine content of 279 residues/1000. Hydroxylysine and hydroxyproline were present in lower concentrations than expected.Key words: perineurium, lobster, collagen, extracellular matrix.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Elizabeth M. Boatman ◽  
Mark B. Goodwin ◽  
Hoi-Ying N. Holman ◽  
Sirine Fakra ◽  
Wenxia Zheng ◽  
...  

Abstract The idea that original soft tissue structures and the native structural proteins comprising them can persist across geological time is controversial, in part because rigorous and testable mechanisms that can occur under natural conditions, resulting in such preservation, have not been well defined. Here, we evaluate two non-enzymatic structural protein crosslinking mechanisms, Fenton chemistry and glycation, for their possible contribution to the preservation of blood vessel structures recovered from the cortical bone of a Tyrannosaurus rex (USNM 555000 [formerly, MOR 555]). We demonstrate the endogeneity of the fossil vessel tissues, as well as the presence of type I collagen in the outermost vessel layers, using imaging, diffraction, spectroscopy, and immunohistochemistry. Then, we use data derived from synchrotron FTIR studies of the T. rex vessels to analyse their crosslink character, with comparison against two non-enzymatic Fenton chemistry- and glycation-treated extant chicken samples. We also provide supporting X-ray microprobe analyses of the chemical state of these fossil tissues to support our conclusion that non-enzymatic crosslinking pathways likely contributed to stabilizing, and thus preserving, these T. rex vessels. Finally, we propose that these stabilizing crosslinks could play a crucial role in the preservation of other microvascular tissues in skeletal elements from the Mesozoic.


2005 ◽  
Vol 284-286 ◽  
pp. 39-42 ◽  
Author(s):  
Ahmed H. Touny ◽  
Paul W. Brown

Composite material composed of hydroxyapatite (HAp) and structural proteins, such as type I collagen or cross-linked gelatins, were synthesized at 37.4°C by hydrolysis of alpha tricalcium phosphate (α-TCP) in the presence of these protein structures. X-ray diffraction (XRD)and isothermal calorimetry were used as tools to evaluate the rate of HAp formation. Rates of HAp formation depend on protein structure. Gelatin enhances HAp formation while collagen delays it. Changes in pH during the hydrolysis α-TCP are unlikely to have an aggressive effect on the surrounding tissue. The presence of the protein improves the ductility of the HAp/protein composite but it decreases the tensile strength.


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