HA Formation Research Articles

Fabrication and Characterization of LaF3-Reinforced Porous HA/Ti Scaffolds

To improve the performance of porous hydroxyapatite/titanium (HA/Ti) composites, LaF3 reinforced porous HA/Ti scaffolds with a porosity of approximately 60% were prepared via a powder metallurgical method, using NH4HCO3 as the pore-forming agent. The scaffolds induced HA formation and showed high bioactivity, and the compressive strength could be regulated by changing the LaF3 dosage. When the LaF3 dosage was 0.3%, the compressive strength of the porous scaffold was 65 MPa. Moreover, LaF3 reinforced porous HA/Ti scaffolds can further induce the deposition of calcium phosphate after immersion in simulated body fluid (SBF) for 7 days, indicating that the corresponding scaffold is an ideal choice for spongy bone repair.

Analysis of Polycyclic Aromatic Hydrocarbons via GC-MS/MS and Heterocyclic Amines via UPLC-MS/MS in Crispy Pork Spareribs for Studying Their Formation during Frying.

This study aims to explore the effects of frying conditions on the formation of HAs and PAHs in crispy pork spareribs, a popular meat commodity sold on Taiwan's market. Raw pork spareribs were marinated, coated with sweet potato powder, and fried in soybean oil and palm oil at 190 °C/6 min or 150 °C/12 min, followed by an analysis of HAs and PAHs via QuEChERS coupled with UPLC-MS/MS and GC-MS/MS, respectively. Both HAs and PAHs in pork spareribs during frying followed a temperature- and time-dependent rise. A total of 7 HAs (20.34-25.97 μg/kg) and 12 PAHs (67.69-85.10 μg/kg) were detected in pork spareribs fried in soybean oil and palm oil at 150 °C/12 min or 190 °C/6 min, with palm oil producing a higher level of total HAs and a lower level of total PAHs than soybean oil. The content changes of amino acid, reducing sugar, and creatinine played a vital role in affecting HA formation, while the degree of oil unsaturation and the contents of precursors including benzaldehyde, 2-cyclohexene-1-one, and trans,trans-2,4-decadienal showed a crucial role in affecting PAH formation. The principal component analysis revealed that HAs and PAHs were formed by different mechanisms, with the latter being more liable to formation in pork spareribs during frying, while the two-factorial analysis indicated that the interaction between oil type and frying condition was insignificant for HAs and PAHs generated in crispy pork spareribs. Both CcdP (22.67-32.78 μg/kg) and Pyr (16.70-22.36 μg/kg) dominated in PAH formation, while Harman (14.46-17.91 μg/kg) and Norharman (3.41-4.55 μg/kg) dominated in HA formation in crispy pork spareribs during frying. The outcome of this study forms a basis for learning both the variety and content of HAs and PAHs generated during the frying of pork spareribs and the optimum frying condition to minimize their formation.

Aeration intensity drives dissolved organic matter transformation and humification during composting by regulating the organics metabolic functions of microbiome

Oxygen levels are critical for composting success and improving humification. Whereas aeration intensity driving the structural heterogeneity and formation mechanism of humus in the dissolved organic matter (DOM) transformation process during kitchen waste with hydrothermal pretreatment composting remains unclear. In this study, the potential mechanisms of aeration intensity on humification were explored by Fourier transform infrared spectroscopy and fluorescence spectroscopy combined with functional microbial prediction analysis. The results showed that moderate aeration intensity (AR0.05, 0.05 L min−1 kg−1 DM) achieved a highly matured fertilizer with a humification index of 0.83 and a humic acid / fulvic acid (HA/FA) of 1.99. Partial least-squares path model demonstrated that environmental factors and humus-like substances were the two most critical factors to improve humification levels. According to the heterogeneous-2DCOS analysis, the biopolymers in DOM were preferentially decomposed into low molecular weight HA precursors through a series of biochemical reaction processes, and then formed the carbon skeleton of HA through condensation reactions, and finally polymerized into complex macromolecular HA. Bugbase analysis showed that AR0.05 treatment reduced 58.52 % of potentially pathogenic bacteria in the thermophilic phase. Moreover, functional bacterial communities in composting systems with AR0.05 were more favorable to drive the organic matter decomposition and HA formation. The mantel test revealed temperature and pH were key drivers in the composition of phenotypic and functional bacterial communities. This study provided unique insights into a deeper understanding of the aeration intensity on the humification pathways of kitchen waste composting.

Partial ozonation enhanced the content and aromatization of humic substances in activated sludge through chemical and microbial effects

Influences of partial ozonation on characteristics of humic substances (HS) in activated sludge (AS) was systematically investigated. It was firstly found that partial ozonation not only reduced sludge production, but also increased content and aromatization of HS in AS. The total extractable carbon of HS (TEC) in AS subjected to partial ozonation (i.e., an increasing O3 dosage, from 25 to 125 mg O3/g VS) considerably increased, from 138.7 ± 2.4 mg/L (SBR-25) to 151.6 ± 2.7 mg/L (SBR-125), which were 1.01–1.10 times the TEC of the control (SBR-0). In which the organic carbon of fulvic acids (FAC) and humic acids (HAC) increased from 30.9 ± 4.8 and 106.3 ± 4.6 mg/L (SBR-0) to 34.7 ± 1.3 and 116.9 ± 1.4 mg/L (SBR-125), respectively. SUVA254 values of both FA and HA in SBR-25∼SBR-125 were greater than their values in SBR-0. Mechanisms were clarified from chemical and microbial perspectives. During O3 treatment, organic nitrogenous substances and aliphatic compounds in HA were more mineralized and fused by O3; FA were more formed from soluble proteins and polysaccharides than mineralized. Consequently, HA content in AS was reduced with enhanced aromaticity, while FA content was increased with maintained aromaticity after O3 treatment. Then, after the ozonated AS was returned to SBR systems, the enhanced microorganism-led formation of HA in SBR from more accessible FA played a dominating role in the final increased TEC. Enhanced relative abundance (RA) of genera Lactococcus and Thauera after partial ozonation was possibly responsible for the increased RA of K00615 (tktA) and K00873 (pyk), promoting production of intermediates including phosphoenolpyruvate and erythrose-4-phosphate (initial metabolites for shikimate pathway) from glucose, enhancing HA formation related with shikimate pathway, and finally increasing the content and aromatization of HS. The results could guide researchers on improving sludge management by decreasing sludge production yield and enhancing sludge utilization potential through partial ozonation during wastewater treatment.

Effects of emulsifiers on heterocyclic amine formation and water distribution in roasted chicken patties

The present study aimed to investigate the effects of five emulsifiers, including DATEM, DMG, PL, SDS, and SPP, on HA formation in chemical models and roasted chicken patties. UPLC-MS analysis showed that DMG and SPP were the most promising among them. In particular, at 0.15–0.9% (w/w) in roasted chicken patties, they effectively reduced the contents of PhIP (21–43%), MeIQx (26–50%) and 4,8-DiMeIQx (16–43%) relative to the control, whereas DATEM, PL and SDS promoted their formation. Low-Field Nuclear Magnetic Resonance and Magnetic Resonance Imaging analysis revealed that the inhibitory effect of SPP and DMG was partly mediated through their capability to help retain water in the macromolecular structures of the muscle tissue. This favorable effect was also supported by the significantly improved adhesiveness of the SPP and DMG samples relative to other samples. These findings suggest that SPP and DMG are effective additives for attenuation of HA contents in meat-based products.

Municipal Sewage Sludge Composting in the Two-Stage System: The Role of Different Bulking Agents and Amendments

This study assessed the effect of different lignocellulosic amendments and bulking agents on compost stability (based on a 4 day respiration activity test, AT4, and self-heating factor, SHF) and maturity (based on the nitrification index Initr and the ratio of C in humic acids, HA, to total organic carbon, TOC, in compost, CHA/TOC). With all feedstock compositions (FCs), the share of sewage sludge was 79% (wet mass). For FC1, wood chips (13.5%) and wheat straw (7.5%) were used as bulking agents and amendments; for FC2, instead of wood chips, energy willow was added; for FC3, pine bark (13.5%) and conifer sawdust (7.5%) were used. All FCs produced stable and mature compost; however, with FC2, the thermophilic phase last 3 days longer than with the other FCs. Moreover, an AT4 value below 10 g O2/kg dry mass (d.m.) was obtained the earliest with FC2 (after 45 days, ca. 15–20 days earlier than with other FCs). With FC2, Initr below 0.5 was obtained in ca. 60 days, 10 days earlier than with FC3 and 30 days earlier than with FC1. The highest net increases in HS (86.0 mg C/g organic matter (OM)) and HA (56.3 mg C/g OM) were also noted with FC2; with other FCs, the concentrations of these compounds were from 1.3- to 1.5-fold (HS) and from 1.4- to 1.9-fold (HA) lower. With FC2, the highest CHA/TOC (15.5%) was also noted, indicating that this compost contained the largest share of the most stable form of organic carbon. The rates of OM removal in the bioreactor ranged from 7.8 to 10.1 g/(kg d.m.·day). The rates of SH and HA formation ranged from 1.63 to 4.83 mg C/(g OM·day) and from 1.23 to 1.80 mg C/(g OM·day), respectively. This means that, through the choice of the amendments and bulking agents, the length of the composting time needed to obtain a stable and mature product can be controlled.

Reduced pH is the primary factor promoting humic acid formation during hyperthermophilic pretreatment composting

Hyperthermophilic pretreatment composting (HPC) has the advantages of enhanced composting efficiency and accelerated humic substance (HS) over conventional composting (CC). However, the mechanisms towards the accelerated humification process by HPC are still not clear. By means of sterilization technology, the roles of abiotic and biotic components on the formation of HS can be distinguished. The study investigated the humification degree and the succession of microbial community during HPC of pig manure. The mechanisms underlying the accelerated humification by HPC was identified using gamma sterilization. Results showed that HS content increased significantly by 13.72% in HPC and 29.93% in sterilized HPC inoculated with 1% CC (HPC_I), compared with 8.76% increase in CC and 7.12% increase in sterilized CC inoculated with 1% HPC during composting (CC_I). Compared with CC and CC_I, stronger intensities of HA-like and fulvic acid-like components were observed in HPC and HPC_I. Results showed that physicochemical properties, especially pH, were the key factors in accelerating the humification in HPC, while both physicochemical properties and microbial community contributed to the HA formation in CC. The study contributed to a better understanding of the mechanism towards the accelerated humification degree in HPC.

Hydrothermal synthesis of similar mineral-sourced humic acid from food waste and the role of protein

Food waste is a challenging biomass resource due to its high moisture content, low calorific value, and complex composition. Natural humification of animal and plant residues is highly related to microorganism activity, but natural hydrothermal conditions are also speculated to play a significant role. In this work, a novel method for the conversion of food waste into artificial humic acid (HAa) under hydrothermal conditions is proposed. The results revealed that an optimum HAa yield of 43.5% from food waste was successfully obtained at 215 °C for only 1 h. Detailed analyses, including elemental analysis (EA), X-ray photoelectron spectroscopy (XPS), nuclear magnetic resonance (NMR), and Fourier transform infrared (FT-IR) spectroscopy, showed that the produced HAa had similar structures and compositions with natural HA extracted from minerals. Moreover, the proteins contained in the food waste significantly promoted HA formation through the reaction of saccharides with amino acids, in which Maillard-like reactions were the key steps. These results not only provide experimental evidence for verifying the role of hydrothermal reactions in transforming food waste into humic acid but also provide insight into effective resource utilization of food waste.

Chitosan and flavonoid glycosides are promising combination partners for enhanced inhibition of heterocyclic amine formation in roast beef

The effects of different kinds of chitosan, oligomer (ChiO) and monomer (Gluco), and the combinations of polymer (Chi) or ChiO with flavonoid aglycones and glycosides against the formation of major HAs were investigated to find out potential combination partners for enhanced suppression of HA formation. Results in roast beef patties showed ChiO and Gluco significantly inhibited PhIP and MeIQx formation by 43–80% and 31–57%, respectively. Of which, ChiO was the most effective. In combinations with flavonoid glycosides (phloridzin, rutin and hesperidzin, respectively), Chi, but not ChiO, generated enhanced inhibitory effects. Further analysis showed Chi and phloridzin combined at a ratio of 1:1 was the most promising, especially in inhibiting PhIP, and the mechanism behind involved: 1) water retention by Chi, and 2) reduction of phenylalanine availability by phloridzin. These findings suggest that appropriate combination of Chi and flavonoid glycosides contributes to significant improvement in the safety of meat products.

Evaluation of the experimental parameters for the morphological tunning of monodispersed calcium hydroxyapatite

The new era of science and technology signifies the control over the size and shape of materials. The size and shape variation plays a crucial role in determining the properties of the material and promises a potential application of these materials. The present study focuses on the fabrication of the most important inorganic biomaterial, namely, calcium hydroxyapatite (Ca10(PO4)6(OH)2) (HA) in a nano range having uniform morphology and high surface to volume ratio. HA particles were successfully synthesized by the hydrothermal homogenous precipitation, having whiskers and cubic shaped particle morphology with high crystallinity in size range of 6.1 nm and 9.7 nm, respectively. The morphological features of the particles were further analyzed by Scanning electron microscope (SEM), and the structural evolution was studied by Fourier transform infrared spectroscopy (FT-IR) and X-Ray diffraction analysis (XRD). Urea was used as a precipitating agent to raise pH and promote nucleation & rapid growth of HA crystals at low supersaturation. The effect of different reaction parameters on HA particle morphology was also investigated. Aging time showed a sensitive dependence on the morphological features of HA particles, and the pH of a solution had a vital role in the formation of various crystal phases of calcium phosphate, which served as a precursor in HA formation.

Effects of High-Concentration Alkali Treatment on Surface Bioactivity of Porous Titanium

Various surface treatment methods have been used to modify the surface activation of dense titanium. In this study, a high concentration of sodium hydroxide solution was used to treat porous titanium prepared by adding porous agent at different times. The results of the study showed that after alkali treatment, porous titanium was implanted into the back muscle of the dog and the implanted sample was taken out for bone formation protein-2 enzymatic immunoassay after 6 months. The porous titanium inner wall has been covered. The microstructures vary with the treatment time. The treated surface can induce the formation of hydroxyapatite deposition and promote the expression of BMP-2, which shows good bone induction. High concentration alkali treatment of porous titanium, the method is simple, can shorten the HA formation time, can effectively activate porous titanium inner and outer surfaces, is an effective method to prepare bioactive porous titanium.

Synthesis of nickel – hydroxyapatite by electrochemical method

The electrochemical method in two chambers with the bipolar membrane has been used to produce the nickel – hydroxyapatite particle. Hydroxyapatite is used as the supported catalyst for nickel catalyst. In this work, in-situ electrochemical synthesis in two chambers with bipolar membrane has been used in the formation of nickel-hydroxyapatite. A simple electrolysis cell from acrylic was used. The anode and the cathode were set parallel with a distance of 3 cm and immersed in the solution at a depth of 2 cm. The anode and the cathode were connected to a DC power supply. The particle was produced in the electrolysis cell. In the anode chamber, the pH solution decreases for the time of electrolysis while in the cathode chamber the pH solution increases. The nickel – hydroxyapatite particle is formed in the cathode chamber. There is no particle in the anode chamber. At the lower current density, the first formed is brushite. At the higher current density, brushite converts to HA. The higher current density the greater the chances of HA formation. The increase in the initial concentration of NiCl2 accelerates the increase of the pH of the electrolysis solution.

Preparation and performance of hydroxyapatite/Ti porous biocomposite scaffolds

Abstract Hydroxyapatite/titanium (HA/Ti) porous biocomposite scaffolds were prepared via a powder metallurgical method using NH 4 HCO 3 as the pore-forming agent. The scaffolds induced HA formation and showed high bioactivity, and their porosity and compressive strength could be regulated by changing the NH 4 HCO 3 dosage. When the NH 4 HCO 3 dosage was 40.0%, the porosity was 67.0 ± 0.8%, and compressive strength was 19.0 ± 0.6 MPa, indicating the corresponding scaffold was an ideal choice for spongy bone repair.

Collagen/hydroxyapatite bone grafts manufactured by homogeneous/heterogeneous 3D printing

This paper presents a new way to obtain collagen/hydroxyapatite (COLL/HA) composite materials by 3D printing. Because of high tendency of segregation of COLL/HA composite materials, printing was done using COLL/Ca2+ gel (even COLL/Ca(OH)2) followed by precipitation of HA and crosslinking of COLL. The HA precipitation occurs simultaneously with crosslinking of COLL molecules, these processes being assured by the presence of glutaraldehyde supplemented PBS solution. By printing with COLL/Ca2+ at acidic pH homogeneity was increased. FTIR spectroscopy and microscopy reveal HA formation as the main inorganic phase these nanoparticles being homogeneously dispersed in the volume. In vitro biocompatibility assays were performed on Vero cells (ISO10993-5/2009). Results show that the extract of the developed biomaterial in cell culture medium elicited a similar cellular response to standard culture medium demonstrating its potential for biomedical applications. The described procedure and proposed ink can be used for developing 3D bone scaffolds and open new perspectives for COLL/Ca2+ homogeneous inks.

Formation mechanism of hydroxyacetone in glucose pyrolysis: A combined experimental and theoretical study

During fast pyrolysis of biomass, hydroxyacetone (HA, also known as 1-hydroxy-2-propanone) is a vital linear ketone product from fragmentation (ring scission) of cellulose. In this study, density functional theory (DFT) calculations are employed to reveal the HA formation mechanisms and pathways from fast pyrolysis of glucose that is the cellulose-based monosaccharide. Moreover, isotopic labeling fast pyrolysis experiments were conducted to confirm the theoretical calculation results from glucose. The results indicate that during glucose pyrolysis, HA is mainly derived from C1–C2–C3 and C4–C5–C6 segments, with C1 or C6 in the methyl group of HA. The HA from C1–C2–C3 is mainly generated via the 3-ketohexose intermediate, while the formation of the HA from C4–C5–C6 mainly involves the d-fructose intermediate. In addition, the formation of HA is parallel and competitive with the formation of levoglucosan (LG, the most important pyrolytic product of glucose), and the secondary decomposition of LG will result in trace of the HA from C4–C5–C6.

The effect of serum proteins on apatite growth for 45S5 Bioglass and common sol-gel derived glass in SBF

Abstract The inhibitive effects of serum proteins on apatite growth was compared between melt-derived 45S5 Bioglass® and sol-gel derived bioactive glass of the 70S30C (70 mol% SiO2, 30 mol% CaO). By using techniques of XRD, TEM and Raman spectroscopy, the transformation of amorphous calcium phosphate to crystalline apatite, and the resulting size and aspect ratio of the crystals, in simulated body fluid (SBF), was seen to decrease in the presence of serum. XRD showed more rapid HA formation on Bioglass particles, compared to that forming on 70S30C particles, however TEM showed similar size and frequency of the needle-like crystals. Phosphate reduction in SBF was similar for Bioglass and 70S30C. Calcium carbonate formation was more likely on the phosphate-free sol-gel glass than on Bioglass.

Comparative hydrothermal synthesis of hydroxyapatite by using cetyltrimethylammonium bromide and hexamethylenetetramine as additives

Comparative synthesis ways for preparing HA (Ca10(PO4)6(OH)2) nanoparticles in presence of hexamethylenetetramine (HMTA) and cetyltrimethylammonium bromide (CTAB) were carried out. The reactions were performed in a Teflon-lined stainless-steel reactor at 120°C during 12h. The effects of the additive concentration and the cooling mode (fast and slow) were analyzed. The obtained powders were characterized by X-ray Diffraction (XRD), Raman Spectroscopy, Dynamic Light Scattering (DLS) and Scanning Electron Microscopy (SEM). The two hydrothermal ways carried out for preparing HA nano powders produced a pure crystalline phase of HA. When the fast cooling mode was used, the obtained particles exhibited smaller mean particle sizes. The highest concentrations of used additives (HTMA or CTAB) resulted in opposite effect on the obtained mean particle size of HA particles. These observations were associated to the different behavior of these additives in the HA formation processes.

Biodegradability and antibacterial properties of MAO coatings formed on Mg-Sr-Ca alloys in an electrolyte containing Ag doped hydroxyapatite

Magnesium-based alloys are promising materials as next generation biodegradable implants, however low corrosion resistance and inadequate mechanical properties are limiting their application as a biodegradable implant material. In this study, Mg-Sr-Ca ternary alloys were prepared in a vacuum/atmosphere controlled furnace and coated by microarc oxidation (MAO) process for 5min to decrease the degradation rate and enhance the biocompatibility. Moreover, Ag doped Hydroxyapatite nano powder (Ag-HA) was also added to alkaline MAO solution by amount of 1 and 10g/l to improve the antibacterial properties while enhancing their bioactivity in a one single process. XRD, SEM-EDS, FTIR spectroscopy, simulated body fluid (SBF) immersion and antibacterial tests were employed for the characterization of the coated alloys. The results showed that, the addition of more Ag-HA increased the HA formation both before and after SBF immersion test and enhanced their antibacterial properties. However, Ag-HA addition decreased the corrosion resistance of the coated alloys in SBF compared to Ag-HA free coating. The results indicated that the present Ag-HA nano powder added MAO coating is a good combination to enhance the corrosion resistance, bioactivity and the antibacterial properties of Mg based biodegradable alloys.

Inducing bioactivity of dental ceramic/bioactive glass composites by Nd:YAG laser

ObjectivesAims of this study were to investigate the optimal conditions of laser irradiation of a novel Bioactive Glass/Dental Ceramic-BP67 composite for acceleration of hydroxyapatite-HA formation and to assess cellular responses on the precipitated HA region. MethodsBP67 (Bioactive Glass: 33.3%, Dental Ceramic: 66.7%) was fabricated by the sol–gel method. A laser assisted biomimetic-LAB process was applied to BP67 sintered specimens immersed in 1.5-times concentrated simulated body fluid-1.5×-SBF. The effect of various energy densities of pulsed nanosecond Nd-YAG (1064nm) laser and irradiation exposure times (30min, 1 and 3h) were evaluated for HA precipitation. The HA film was characterized by FTIR, XRD, SEM and micro Raman techniques. ICP-AES was used for revealing changes in chemical composition of the 1.5×-SBF during irradiation. Cell viability and morphological characteristics of periodontal ligament fibroblasts-PDLFs, human gingival fibroblasts-HGFs and SAOS-2 osteoblasts on the HA surface were evaluated by MTT assays and SEM. ResultsAt optimal energy fluence of 1.52J/cm2 and irradiation time for 3h followed by immersion in 1.5×-SBF at 60°C, a dense HA layer was formed on laser-irradiated BP67 within 7 days. The resulting HA film was tightly bonded to the underlying substrate and had mineral composition similar to cementum. MTT assay showed a consistent reduction of cell proliferation on the HA layer in comparison to conventional control ceramic and BP67 for all 3 cell lines studied. SignificanceThese findings suggest LAB is an effective method for acceleration of HA formation on materials with low bioactivity, while cellular responses need further investigation.

Fabrication of micro/nano-textured titanium alloy implant surface and its influence on hydroxyapatite coatings

We put forward a protocol combining laser treatment and acid etching to obtain multiscale micro/nano-texture surfaces of titanium alloy implant. Firstly, the operational parameters of the laser were optimized to obtain an optimum current. Secondly, the laser with the optimum operational parameters was used to fabricate micro pits. Thirdly, multiple acid etching was used to clean the clinkers of micro pits and generate submicron and nanoscale structures. Finally, the bioactivity of the samples was measured in a simulated body fluid. The results showed that the micropits with a diameter of 150 μm and depth of 50 μm were built successfully with the optimized working current of 13 A. In addition, submicron and nanoscale structures, with 0.5-2 μm microgrooves and 10-20 nm nanopits, were superimposed on micro pits surface by multiple acid etching. There was thick and dense HA coating only observed on the multiscale micro/nano-textured surface compared with polished and micro-textured surface. This indicated that the multiscale micro/nano-texture surface showed better ability toward HA formation, which increased the bioactivity of implants.