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1.
J Colloid Interface Sci ; 630(Pt B): 473-486, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36334484

RESUMO

Evidence collected to date by our group has demonstrated that tin(II)-functionalized hydroxyapatites (Sn/HAP) are a newly discovered class of ecofriendly reductive adsorbents for Cr(VI) removal from wastewaters. In this work an upgraded series of Sn/HAP materials assured a maximum removal capacity of ≈ 20 mgCr/g, doubling the previously reported value for Sn/HAP materials, thanks to higher Sn-dispersion as proved by X-ray photoelectron spectroscopy and electron microscopy. Insights on kinetics and thermodynamics of the reductive adsorption process are provided and the influence of pH, dosage, and nature of Cr(VI) precursors on chromium removal performances have been investigated. Pseudo-second-order kinetics described the interfacial reductive adsorption process on Sn/HAP, characterized by low activation energy (21 kJ mol-1), when measured in the 278-318 K range. Tests performed in the 2-6 pH interval showed similar efficiency in terms of Cr(VI) removal. Conventional procedures of recycling and regeneration resulted ineffective in restoring the pristine performances of the samples due to surface presence of both Sn(IV) and Cr(III). To overcome these weaknesses, the used samples (Sn + Cr/HAP) were upcycled into catalysts in a circular economy perspective. Used samples were tested as catalysts in gas-phase catalytic processes for air pollution remediation: selective catalytic reduction of NOx (NH3-SCR), NH3 selective catalytic Oxidation (NH3-SCO), and selective catalytic oxidation of methane to CO2. Catalytic tests enlightened the interesting activity of the upcycled Sn + Cr/HAP samples in catalytic oxidation processes, being able to selectively oxidize methane to CO2 at relatively low temperature.


Assuntos
Estanho , Poluentes Químicos da Água , Adsorção , Durapatita/química , Poluentes Químicos da Água/química , Dióxido de Carbono , Cromo/química , Cinética , Metano , Concentração de Íons de Hidrogênio
2.
J Hazard Mater ; 443(Pt A): 130167, 2023 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-36270188

RESUMO

Due to the coexistence of various heavy metals in the contaminated environment, it is essential to comprehensively study the multicomponent adsorption of heavy metals in order to tackle these combined pollutants. Herein, the adsorption processes of Pb(Ⅱ), Cu(Ⅱ) and Cd(Ⅱ) by biogenic hydroxyapatite (BHAp) were investigated in single and multicomponent systems. The maximum adsorption capacity for Pb(Ⅱ), Cu(Ⅱ) and Cd(Ⅱ) by BHAp in single system reached 311.16, 82.05 and 92.54 mg g-1, respectively, while adsorption capacity for Cu(Ⅱ) and Cd(Ⅱ) in multicomponent system decreased more obviously than that of Pb(Ⅱ). Furthermore, the stability of Cu(Ⅱ) and Cd(Ⅱ) adsorbed on BHAp was indeed influenced in multicomponent system. By means of the characterization analysis, it was found that ion exchange was more instrumental in the adsorption processes of Cu(Ⅱ) and Cd(Ⅱ) in single system than in multicomponent system. Significantly, it was observed that the proportion of generally stable Pb(II) adsorbed on BHAp exceeded 95% in both single and multicomponent systems. This result might be due to the in-site growth of stable crystals of PbxCa10-x(PO4)6(OH)2, which was synergistically induced by surface functional groups and inorganic mineral of BHAp, and was unaffected by the coexistence of Cu(Ⅱ) and Cd(Ⅱ).


Assuntos
Metais Pesados , Poluentes Químicos da Água , Adsorção , Chumbo , Cádmio/análise , Durapatita , Metais Pesados/química , Poluentes Químicos da Água/análise , Concentração de Íons de Hidrogênio
3.
Colloids Surf B Biointerfaces ; 221: 112969, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36335822

RESUMO

Functionally-designed nanotextured and copolymer (COP) mediated PLA/PCL (70:30 w/w) blend-based interface-engineered electrospun mats (EMs) based constructs, with phase-specific interactions, have been successfully developed. The thermal stability of constructs remained up to ∼300-350 °C, while the crystallinity reduced to ∼12-23 %, indicating enhanced pliability. The tensile strength increased by ∼75 % without much compromise in the tensile modulus whereas the dynamic relaxation response of the constructs shifted to lower temperatures upon the incorporation of ≥ 2.5 phr (parts per hundred parts of resin) of COP. The zeta potential evaluated from radial surface exposure intensity could be manipulated by controlling the extent of COP content (-60 mV for ∼5 phr COP) which in turn led to the dynamics of site-specific charge neutralization driven attachment of Ca2+ ions (∼13 % for ∼5 phr COP) of the nano-hydroxyapatite (n-HA). Such uniformly dispersed, n-HA attached, and surface-decorated (COP ≤ 5 phr) EMs enabled the selective L929 fibroblast cell attachment (∼200 % cell viability for ∼2.5 phr COP). Thus, the approach may prove to augment the biomineralization of Ca and apatite-driven healing kinetics amongst implant-seeking and inflammation-prone sites and thereby, paving a new pathway for controlled and targeted healing of bone, cartilage, dental gums, and other sites demanding n-HA and/or calcium-phosphorus assisted healing mechanism.


Assuntos
Durapatita , Poliésteres , Polímeros , Engenharia Tecidual
4.
Environ Res ; 216(Pt 3): 114683, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36341797

RESUMO

In biomedical exploration, the predominant characteristic is synthesizing and fabricating multifunctional nanostructure with intensified biocompatibility and excellent antibacterial applications to avoid post-surgical implant failure. The objective of the current study is to examine ideal mesoporous zinc-doped hydroxyapatite (HAp) for future use in the field of biomedical research. In the present investigation, we synthesized mesoporous Zn-doped HAp nanorods with varied mole concentrations using a profound microwave hydrothermal method utilizing bio-waste Nodipecten nodosus scallop as a calcium source and CTAB as an organic modifier. Bio-waste Nodipecten nodosus scallop is a widely available cheap calcium precursor which is converted into pure and zinc-doped hydroxyapatite nanorods with the help of the microwave hydrothermal method. Different analytical techniques like spectroscopy and electron microscopy were employed to evaluate and precisely characterize the structural and morphological characteristics in synthesized pure and mesoporous Zn-doped HAp nanorods. CTAB and microwave hydrothermal methods successfully create mesoporous Zn-doped hydroxyapatite nanorods with different sizes and morphology. Mesoporous Zinc-doped HAp nanorods show excellent antibacterial activity against Klebsiella pneumoniae (MTCC 7407) and Bacillus subtilis (MTCC 1133), compared to other nanorods. ZnHAp-3 shows notable excellent results of antibacterial effect towards K. pneumoniae and B. subtilis, by exhibiting 12.36 ± 0.12 and 13.12 ± 0.16 mm zone of inhibition. Furthermore, ZnHAp-1 shows the lower zone of inhibition, while the ZnHAp-3 sample shows the highest zone of inhibition. A foremost study performed was toxicity assays to validate safe attributes of mesoporous zinc-doped HAp intensified with the proliferation function of the zebrafish model. The results reveal the non-toxic behavior of pure and mesoporous zinc-doped HAp samples. Thus, our studies provide evidence for the synthesis technique for the mesoporous zinc-doped HAp nanorods using a novel CTAB-enabled microwave hydrothermal method utilizing bio-waste Nodipecten nodosus scallop as a calcium source will be alternative affordable biocidal antibacterial materials for controlling post-surgical implant failures.


Assuntos
Nanotubos , Pectinidae , Animais , Durapatita/química , Micro-Ondas , Cetrimônio , Cálcio , Peixe-Zebra , Difração de Raios X , Nanotubos/química , Zinco , Antibacterianos/farmacologia , Antibacterianos/química
5.
J Mech Behav Biomed Mater ; 137: 105526, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36343520

RESUMO

Natural hydroxyapatite provides certain strength and stiffness to biological bones, and most of the studies on the strength of bone tissues have been carried out on hydroxyapatite (HAP). However, the Ca/P ratio of hydroxyapatite in bones is actually about 1.50, and the natural hydroxyapatite belongs to calcium-deficient hydroxyapatite (CDHA) with Ca vacancy defects. Therefore, this work focused on the effect of Ca vacancy defects on CDHA crystals through investigating the generation and expansion of microcracks under uniaxial tensile loading by combining molecular dynamics and first principles method. A series of crystal models with different Ca vacancy ratios are constructed and find that Ca vacancies degrade the mechanical properties of hydroxyapatite. Meanwhile the fracture behavior of crystals is detailed and find that the cracks arise at vacancies and extend along the direction of vacancies. Also, first-principles calculation is performed to reveal the mechanism of crack formation in MD simulations. It is found that the decrease of Ca-O bonding of CDHA causes the decrease of the stability of the crystal structure by analyzing the DOS of HAP and CDHA, and the cracks originate from Ca vacancies. This work performs more realistic simulations of CDHA with calcium vacancy defects in actual bone tissue and directly reveals the development and progression of bone fragility at the nanometer scale.


Assuntos
Cálcio , Simulação de Dinâmica Molecular , Cálcio/química , Durapatita/química , Osso e Ossos
6.
J Mech Behav Biomed Mater ; 137: 105539, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36343522

RESUMO

PURPOSE: The effect of hydroxyapatite (HAp) coating layer on mechanical and optical properties at bonding interface of high-performance polymers (HPPs) used in computer-aided design (CAD)/computer-aided manufacture (CAM) technology was investigated in this in vitro study. MATERIALS AND METHODS: Two hundred-twenty specimens were divided into two material groups (n = 110): polyetheretherketone (PEEK, KERA® starPEEK) and polyetherketoneketone (PEKK, Pekkton® ivory). For mechanical testing, each group was divided into five surface pretreatment subgroups and a control group (n = 10): HAp coating (1%,3%, 5%, and 10% concentrations) and sandblasting with 110-µm Al2O3 particles. For optical testing, each group was divided into five subgroups (n = 10): HAp coating (1%, 3%, 5%, and 10% concentrations) and control. The effects of the HAp coating on the optical changes and shear bond strength (SBS) of the specimens were investigated. Data was statistically analyzed by one-way ANOVA and Tukey's post-hoc test. Failure modes and surface properties of the specimens were examined by scanning electron microscopy (SEM) and coupled electron dispersive spectroscopy (EDS). RESULTS: Average translucency and color change values increased with increasing HAp coating concentration in HPPs. As a result of the data, statistically significant differences were observed in terms of the effect of the HAp coating on SBS of HPPs (p < 0.05). Failure modes were examined, and mixed failure mode was observed. CONCLUSION: HAp coating can contribute to the improvement of both the optical properties and bond strength of the HPPs to resin composite. CLINICAL SIGNIFICANCE: Adhesion and color problems of high performance polymers are still under discussion. In order to solve these problems, generally focused on surface modifications of these polymers, but the effect of the HAp coating has not been investigated.


Assuntos
Colagem Dentária , Durapatita , Cimentos de Resina/química , Teste de Materiais , Resistência ao Cisalhamento , Polímeros , Propriedades de Superfície , Resinas Compostas/química , Cetonas , Polietilenoglicóis , Microscopia Eletrônica de Varredura
7.
J Hazard Mater ; 443(Pt B): 130291, 2023 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-36345064

RESUMO

Improper application of phosphorus (P) fertilizer during soil cadmium (Cd) immobilization reduces the efficiency of fertilizer and Cd remediation. In this study, we synthesized three types of nano-hydroxyapatite (NHAP) with different surface charges as slow-release P fertilizers during Cd immobilization. We also evaluated the effects of wollastonite application with or without NHAP addition, in comparison with triple superphosphate (TSP) or bulk hydroxyapatite, on Cd accumulation in Amaranthus tricolor L. The results showed that adding wollastonite significantly reduced P availability (23.5%) in the soil, but it did not inhibit plant P uptake. In wollastonite-amended soil, the application of negatively/positively charged NHAP significantly increased plant biomass by 643-865% and decreased Cd uptake by 74.8-75.1% compared to the unamended soil as well as showed greater efficiency than those with TSP. This was ascribed to the increased soil pH (from 3.94 to 6.52-6.63) and increased abundance of organic acids (including citric acid, malic acid, lactic acid, and acetic acid) secreted by plants. In addition, the P-preferring bacterial class Bacteroidia was specific to soils amended with both wollastonite and NHAP-. These results suggest that NHAP- may be an appropriate P fertilizer for soil Cd immobilization using wollastonite.


Assuntos
Fertilizantes , Poluentes do Solo , Fertilizantes/análise , Cádmio/análise , Solo , Fósforo , Durapatita , Poluentes do Solo/análise
8.
J Mech Behav Biomed Mater ; 137: 105550, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36356422

RESUMO

Various hydroxyapatite (HA) powders synthesized at different temperatures are deposited on titanium alloy by using an atmospheric plasma spray process. These different HA powders were synthesized from Indian clam seashells through the hydrothermal technique at varying temperatures from 700 to 1000 °C for a 2 h time duration in our previous study. The synthesized HA powders are spray-dried to obtain agglomerated powders suitable for spraying during the coating application. Crystallite size, Ca/P ratio, and crystallinity of agglomerated HA powders and their respective coatings are estimated by standard methods. The microstructure and phases of the feedstock and coating materials are investigated by using a field-emission scanning electron microscope (FESEM) and X-ray diffractometer (XRD), respectively. Further, the HA coatings are characterized in terms of surface roughness, microhardness, porosity, adhesion strength, and wear resistance through the stylus profilometer, Vickers micro-hardness tester, image analysis technique, scratch tester, and ball-on-disc tribometer, respectively. The average surface roughness (Ra) and porosity of the coating are decreased with an increase in the synthesis temperature. The minimum Ra and porosity obtained for the 1000 °C coating sample suggest a high degree of melting of such powder particles. However, the highest adhesion strength noticed in the case of the 900 °C coating sample is due to the high compatibility of such coating material with Ti-alloy substrate in terms of thermal properties. The 900 °C coating sample has also shown the highest microhardness and wear-resistance properties due to its maximum crystallinity among all the HA coatings.


Assuntos
Ligas , Bivalves , Animais , Ligas/química , Durapatita/química , Titânio/química , Pós , Exoesqueleto , Materiais Revestidos Biocompatíveis/química , Teste de Materiais , Propriedades de Superfície
9.
Food Chem ; 404(Pt A): 134535, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36240570

RESUMO

The milk fat globule membrane (MFGM), which surrounds and stabilizes the fat globules, is released in buttermilk during cream churning. MFGM has many health benefits due to its composition rich in phospholipids and membrane proteins. Many techniques have been tried to separate the MFGM from the remaining milk solids non-fat, but they are challenging to carry out at an industrial scale. This research proposes a new approach to separating MFGM from buttermilk. This paper assessed the efficacy of hydroxyapatite (HA) cristal in interacting with MFGM isolates obtained from either raw or pasteurized cream. Different HA to MFGM ratios were used (10:1 and 20:1) to determine the impact of HA concentration on the adsorption. The results showed a very high affinity of the MFGM for HA and suggested the potential for its separation from buttermilk to improve its valorization.


Assuntos
Leitelho , Durapatita , Glicolipídeos , Gotículas Lipídicas , Proteínas do Leite
10.
Carbohydr Polym ; 300: 120235, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36372503

RESUMO

By calcining CO32--doped hydroxyapatite (CHAp), oxygen vacancies (OVs) can be introduced to endow the formed OV-HAp with a visible light response. By the hetero-junction with chitosan membrane (CSM), the degradation rate of tetracycline (TC) by the formed OV-HAp/CS membrane can reach 0.0168 min-1 under visible light, much faster than that of its counterparts. The significantly enhanced photocatalytic performance of OV-HAp/CS was resulted from its better adsorption capacity and faster photogenerated charge separation. Meanwhile, DFT calculation results revealed that OVs occurrence caused the generation of the defect levels, leading to a narrowed band gap of OV-HAp. Moreover, it confirmed that the tightly contacted interface between OV-HAp and CSM provided charge separation channel. All DFT results are consistent with the experimental results. Importantly, OV-HAp/CS is easily separated from the water and exhibited a great recyclability. We believe this work could provide valuable thoughts for developing abundant insulator-based photocatalysts with high efficiency.


Assuntos
Quitosana , Catálise , Durapatita , Oxigênio , Luz
11.
Sci Total Environ ; 857(Pt 3): 159596, 2023 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-36280073

RESUMO

An oxalate-doped hydroxyapatite (O-HAP) was hydrothermally synthesized for aqueous lead (Pb) removal based on the solubility-limiting ability of oxalate and phosphate over pH range 4-9. Free Pb2+ activities in oxalate and/or phosphate systems were controlled by oxalate to form soluble ion pairs Pb-Ox (aq) and Pb-Ox22- at pH 4-7 while in preference to persist as PbHPO4 (aq) when pH ≥ 8. Both phosphate and oxalate exhibited excellent efficiency in reducing Pb solubility, causing over 99 % of Pb precipitated from solution following oxalate < oxalate-phosphate < phosphate. The Visual MINTEQ model overestimated dissolved Pb and free Pb2+ in nearly all of the reaction systems due to the ill-defined stability constants and solubility products for Pb ion-pair formation. The addition of phosphate acting as a buffer in Pb-oxalate systems tended to lessen the spontaneous pH shifts within 24 h to equilibrate proton release from Pb precipitation and hydrolysis, indicating lower solubility products and faster kinetics of Pb-phosphate mineral formation. The TEM-EDS, FTIR and XRD identified a block-shaped Pb-oxalate mineral phase as the only precipitate at acidic pH while substituted by phosphate to form rod-shaped Pb5(PO4)3OH and Pb3(PO4)2 precipitates as pH increased. The optimum hydrothermal conditions of O-HAP were 433 K, pH 9 and P/Ox doping ratio of 0.5 for 24 h. Batch experiments revealed the endothermic process of O-HAP toward Pb with the maximum adsorption capacity reaching 2333 mg/g at a pH of 7, reaction time of 12 h, initial Pb concentration of 600 mg/L and temperature of 308 K, which were best fitted with the pseudo-second-order kinetic model and Langmuir isotherm. The synergetic mechanisms of O-HAP for Pb removal involved dissolution-precipitation, adsorption and ion exchange. This study provides an insight in developing effective remediation strategies for heavy metal contamination by interacting between low-molecular-weight organic acids and secondary mineral phases.


Assuntos
Durapatita , Poluentes Químicos da Água , Chumbo , Oxalatos , Concentração de Íons de Hidrogênio , Compostos Orgânicos , Adsorção , Cinética
12.
J Biomed Mater Res B Appl Biomater ; 111(1): 203-219, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35906778

RESUMO

The use of 3D-printed hydroxyapatite (HA) scaffolds for stimulating bone healing has been increasing over the years. Although all the promising effects of these scaffolds, there are still few studies and limited understanding of their interaction with bone tissue and their effects on the process of fracture healing. In this context, this study aimed to perform a systematic literature review examining the effects of different 3D-printed HA scaffolds in bone healing. The search was made according to the preferred reporting items for systematic reviews and meta-analysis (PRISMA) orientations and Medical Subject Headings (MeSH) descriptors "3D printing," "bone," "HA," "repair," and "in vivo." Thirty-six articles were retrieved from PubMed and Scopus databases. After eligibility analyses, 20 papers were included (covering the period of 2016 and 2021). Results demonstrated that all the studies included in this review showed positive outcomes, indicating the efficacy of scaffolds treated groups in the in vivo experiments for promoting bone healing in different animal models. In conclusion, 3D-printed HA scaffolds are excellent candidates as bone grafts due to their bioactivity and good bone interaction.


Assuntos
Durapatita , Engenharia Tecidual , Animais , Durapatita/farmacologia , Tecidos Suporte , Osso e Ossos , Impressão Tridimensional , Regeneração Óssea
13.
Phys Chem Chem Phys ; 24(45): 27989-28002, 2022 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-36373734

RESUMO

Protein adsorption is the first key step in cell-material interactions. The initial phase of such an adsorption process can only be probed using modelling approaches like molecular dynamics (MD) simulations. Despite a large number of studies on the adsorption behaviour of proteins on different biomaterials including calcium phosphates (CaP), little attention has been paid towards the quantitative assessment of the effects of various physicochemical influencers like surface modification, pH, and ionic strength. In the case of doped CaPs, surface modification through isomorphic substitution of foreign ions inside the apatite structure is of particular interest in the context of protein-HA interactions, as it is widely used to tailor the biological response of HA. Given this background, we present here the molecular-level understanding of the fibronectin (FN) adsorption mechanism and kinetics on a Sr2+-doped hydroxyapatite, HA, (001) surface at 300 K by means of all-atom molecular dynamics simulations. Electrostatic interactions involved in the adsorption of FN on HA were found to be significantly modified due to Sr2+ doping into the apatite lattice. In harmony with the published experimental observations, the Sr-doped surfaces were found to better support FN adhesion compared to pure HA, with 10 mol% Sr-doped HA exhibiting the best FN adsorption. The observed altered adsorption behaviour of FN on Sr-doped HA was correlated with the Hofmeister effect. Moreover, the non-monotonous trend of the FN-material interaction energy can be attributed to the spatial rearrangement of the functional groups (PO43-, OH-) in the apatite crystal. Sr2+ ions also influence the stability of the secondary structure of FN, as observed from the root mean square deviation (RMSD) and root mean square fluctuation (RMSF) analysis. The presence of Sr2+ enhances the flexibility of specific residues (residue nos. 20-44, 74-88) of the FN module. Rupture forces to disentangle FN from the biomaterial surface, obtained from steered molecular dynamics (SMD) simulations, were found to corroborate well with the results of equilibrium MD simulations. One particular observation is that the availability of an RGD motif (Arginine-Glycine-aspartate sequence, which interacts with cell surface receptor integrin to form a focal adhesion complex) for the interaction with cell surface receptor integrin is not significantly influenced by Sr2+ substitution.


Assuntos
Durapatita , Estrôncio , Durapatita/química , Estrôncio/química , Fibronectinas/química , Íons , Adsorção , Apatitas , Materiais Biocompatíveis , Integrinas
14.
Hua Xi Kou Qiang Yi Xue Za Zhi ; 40(6): 668-675, 2022 Dec 01.
Artigo em Inglês, Chinês | MEDLINE | ID: mdl-36416319

RESUMO

OBJECTIVES: The purpose of the study was to evaluate the effect of hydroxyapatite (HA)-based desensiti-zing agents and determine their influence on the bonding performance of mild universal adhesives. METHODS: Mid-coronal dentin samples were sectioned from human third molars and prepared for a dentin-sensitive model. According to desensitizing applications, they were randomly divided into four groups for the following treatments: no desensitizing treatment (control), Biorepair toothpaste (HA-based desensitizing toothpaste) treatment, Dontodent toothpaste (HA-based desensitizing toothpaste) treatment, and HA paste treatment. Dentin tubular occlusion and occluded area ratios were evaluated by scanning electron microscopy (SEM). Furthermore, All-Bond Universal, Single Bond Universal, and Clearfil Universal Bond were applied to the desensitized dentin in self-etch mode. The wettability and surface free energy (SFE) of desensitized dentin were evaluated by contact angle measurements. Bonded specimens were sectioned into beams and tested for micro-tensile bond strength to analyze the effect of desensitizing treatment on the bond strength to dentin of universal adhesives. RESULTS: SEM revealed that the dentin tubule was occluded by HA-based desensitizing agents, and the area ratios for the occluded dentin tubules were in the following order: HA group>Biorepair group>Dontodent group (P<0.05). Contact angle analysis demonstrated that HA-based desensitizing agents had no statistically significant influence on the wettability of the universal adhesives (P>0.05). The SFE of dentin significantly increased after treatment by HA-based desensitizing agents (P<0.05). The micro-tensile bond strength test showed that HA-based desensitizing toothpastes always decreased the µTBS values (P<0.05), whereas the HA paste group presented similar bond strength to the control group (P>0.05), irrespective of universal adhesive types. CONCLUSIONS: HA-based desensitizing agents can occlude the exposed dentinal tubules on sensitive dentin. When mild and ultra-mild universal adhesives were used for subsequent resin restoration, the bond strength was reduced by HA-based desensitizing toothpastes, whereas the pure HA paste had no adverse effect on bond strength.


Assuntos
Dentina , Cremes Dentais , Humanos , Dentina/química , Durapatita/farmacologia , Cimentos Dentários/farmacologia , Cimentos Dentários/análise , Resistência à Tração
15.
Sci Rep ; 12(1): 19997, 2022 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-36411306

RESUMO

A fully hydroxyapatite (HA)-coated stem such as Corail stem, that compacts the cancellous bone around the stem in total hip arthroplasty (THA), is reported to have good long-term results for more than 20 years. Although various fully HA-coated stems have being used recently, it is unclear whether there are differences in the postoperative outcomes. In this study, 224 patients (234 hips) with THA using either the Corail collarless stem or the Hydra stem were enrolled. And then we performed a retrospective comparison of the data at 2 years postoperatively using propensity score matching analysis. The postoperative modified Harris hip scores in 84 hips each group were 93.6 ± 8.2 points in the Corail group and 92.8 ± 10.1 points in the Hydra group, and there was no significant difference between the two groups. However, there was significantly less stem subsidence and rate of 3rd degree or greater stress shielding in the Corail group. Although these two stems were similar collarless fully HA-coated stems and clinical outcomes were favorable results in both groups at 2 years postoperatively, radiographic evaluations showed statistically significant differences between the two groups.


Assuntos
Artroplastia de Quadril , Prótese de Quadril , Humanos , Artroplastia de Quadril/métodos , Durapatita , Estudos Retrospectivos , Seguimentos , Pontuação de Propensão
16.
Sci Rep ; 12(1): 19506, 2022 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-36376430

RESUMO

The ongoing and unrestrained application of nitrogen fertilizer to agricultural lands has been directly linked to climate change and reductions in biodiversity. The agricultural sector needs a technological upgrade to adopt sustainable methods for maintaining high yield. We report synthesis of zinc and magnesium doped and undoped hydroxyapatite nanoparticles, and their urea nanohybrids, to sustainably deliver nitrogen to wheat. The urea nanohybrids loaded with up to 42% nitrogen were used as a new source of nitrogen and compared with a conventional urea-based fertilizer for efficient and sufficient nitrogen delivery to pot-grown wheat. Doping with zinc and magnesium manipulated the hydroxyapatite crystallinity for smaller size and higher nitrogen loading capacity. Interestingly, 50% and 25% doses of urea nanohybrids significantly boosted the wheat growth and yield compared with 100% doses of urea fertilizer. In addition, the nutritional elements uptake and grain protein and phospholipid levels were significantly enhanced in wheat treated with nanohybrids. These results demonstrate the potential of the multi-nutrient complexes, the zinc and magnesium doped and undoped hydroxyapatite-urea nanoparticles, as nitrogen delivery agents that reduce nitrogen inputs by at least 50% while maintaining wheat plant growth and nitrogen uptake to the same level as full-dose urea treatments.


Assuntos
Fertilizantes , Nitrogênio , Fertilizantes/análise , Nitrogênio/metabolismo , Triticum , Ureia/metabolismo , Magnésio/metabolismo , Zinco/metabolismo , Durapatita/metabolismo , Agricultura/métodos , Solo
17.
Sci Rep ; 12(1): 19509, 2022 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-36376498

RESUMO

Mesenchymal stem cells (MSCs) are a promising candidate for bone repair. However, the maintenance of MSCs injected into the bone injury site remains inefficient. A potential approach is to develop a bone-liked platform that incorporates MSCs into a biocompatible 3D scaffold to facilitate bone grafting into the desired location. Bone tissue engineering is a multistep process that requires optimizing several variables, including the source of cells, osteogenic stimulation factors, and scaffold properties. This study aims to evaluate the proliferation and osteogenic differentiation potentials of MSCs cultured on 2 types of 3D-printed hydroxyapatite, including a 3D-printed HA and biomimetic calcium phosphate-coated 3D-printed HA. MSCs from bone marrow (BM-MSCs) and umbilical cord (UC-MSCs) were cultured on the 3D-printed HA and coated 3D-printed HA. Scanning electron microscopy and immunofluorescence staining were used to examine the characteristics and the attachment of MSCs to the scaffolds. Additionally, the cell proliferation was monitored, and the ability of cells to differentiate into osteoblast was assessed using alkaline phosphatase (ALP) activity and osteogenic gene expression. The BM-MSCs and UC-MSCs attached to a plastic culture plate with a spindle-shaped morphology exhibited an immunophenotype consistent with the characteristics of MSCs. Both MSC types could attach and survive on the 3D-printed HA and coated 3D-printed HA scaffolds. The MSCs cultured on these scaffolds displayed sufficient osteoblastic differentiation capacity, as evidenced by increased ALP activity and the expression of osteogenic genes and proteins compared to the control. Interestingly, MSCs grown on coated 3D-printed HA exhibited a higher ALP activity and osteogenic gene expression than those cultured on the 3D-printed HA. The finding indicated that BM-MSCs and UC-MSCs cultured on the 3D-printed HA and coated 3D-printed HA scaffolds could proliferate and differentiate into osteoblasts. Thus, the HA scaffolds could provide a suitable and favorable environment for the 3D culture of MSCs in bone tissue engineering. Additionally, biomimetic coating with octacalcium phosphate may improve the biocompatibility of the bone regeneration scaffold.


Assuntos
Células-Tronco Mesenquimais , Osteogênese , Humanos , Osteogênese/genética , Durapatita/metabolismo , Medula Óssea , Tecidos Suporte , Células Cultivadas , Diferenciação Celular/fisiologia , Cordão Umbilical , Proliferação de Células , Impressão Tridimensional
18.
Int J Mol Sci ; 23(22)2022 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-36430842

RESUMO

Biodegradable polymer-based composite materials may be successfully utilised to fabricate fiducial markers (FMs), which are intended to precisely label tumour margins during image-guided surgery or radiotherapy. However, due to matrix degradability, the stability of the functional properties of FMs depends on the chosen polymer. Thus, this study aimed to investigate novel radiopaque composites which varied in the polymeric matrix-polycaprolactone (PCL), poly(L-lactide-co-caprolactone) (P[LAcoCL]) with two molar ratios (70:30 and 85:15), and poly(L-lactide-co-glycolide) (with molar ratio 82:18). The radiopaque component of the materials was a mixture of barium sulphate and hydroxyapatite. The changes in water contact angle, stiffness, and radiopacity occurring during the 24-week-long degradation experiment were examined for the first time. This study comprehensively analyses the microstructural causes of composites behaviour within degradation experiments using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), gel permitted chromatography (GPC), and scanning electron microscopy (SEM). The obtained results suggest that the utilized biodegradable matrix plays an essential role in radiopaque composite properties and stability thereof. This long-term in vitro assessment enabled a comparison of the materials and aided in choosing the most favourable composite for FMs' fabrication.


Assuntos
Durapatita , Marcadores Fiduciais , Varredura Diferencial de Calorimetria , Polímeros/química , Microscopia Eletrônica de Varredura
19.
Biomolecules ; 12(11)2022 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-36421691

RESUMO

BACKGROUND: Natural (bovine-/equine-/porcine-derived) or synthetic hydroxyapatite (HA) biomaterials appear to be the preferred technologies among clinicians for bone augmentation procedures in preparation for implant dentistry. The aim of this study was to screen candidate HA biomaterials intended for alveolar ridge augmentation relative to their potential to support local bone formation/maturation and to assess biomaterial resorption using a routine critical-size rat calvaria defect model. METHODS: Eighty adult male Sprague Dawley outbred rats obtained from a approved-breeder, randomized into groups of ten, were used. The calvaria defects (ø8 mm) either received sham surgery (empty control), Bio-Oss (bovine HA/reference control), or candidate biomaterials including bovine HA (Cerabone, DirectOss, 403Z013), and bovine (403Z014) or synthetic HA/ß-TCP (Reprobone, Ceraball) constructs. An 8 wk healing interval was used to capture the biomaterials' resolution. RESULTS: All biomaterials displayed biocompatibility. Strict HA biomaterials showed limited, if any, signs of biodegradation/resorption, with the biomaterial area fraction ranging from 22% to 42%. Synthetic HA/ß-TCP constructs showed limited evidence of biodegradation/erosion (biomaterial area fraction ≈30%). Mean linear defect closure in the sham-surgery control approximated 40%. Mean linear defect closure for the Bio-Oss reference control approximated 18% compared with 15-35% for the candidate biomaterials without significant differences between the controls and candidate biomaterials. CONCLUSIONS: None of the candidate HA biomaterials supported local bone formation/maturation beyond the native regenerative potential of this rodent model, pointing to their limitations for regenerative procedures. Biocompatibility and biomaterial dimensional stability could suggest their potential utility as long-term defect fillers.


Assuntos
Substitutos Ósseos , Durapatita , Animais , Masculino , Bovinos , Cavalos , Ratos , Suínos , Durapatita/farmacologia , Osteogênese , Materiais Biocompatíveis/farmacologia , Substitutos Ósseos/farmacologia , Regeneração Óssea , Fosfatos de Cálcio , Ratos Sprague-Dawley , Crânio/cirurgia
20.
J Phys Chem B ; 126(46): 9726-9736, 2022 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-36378585

RESUMO

Biphasic calcium phosphate (BCP) is used as a bone substitute and bone tissue repair material due to its better control over bioactivity and biodegradability. It is crucial to stabilize the implanted biomaterial while promoting bone ingrowth. However, a lack of standard experimental and theoretical protocols to characterize the physicochemical properties of BCP limits the optimization of its composition and properties. Computational simulations can help us better to learn BCP at a nanoscale level. Here, the Voronoi tessellation method was combined with simulated annealing molecular dynamics to construct BCP nanoparticle models of different sizes, which were used to understand the physicochemical properties of BCP (e.g., melting point, infrared spectrum, and mechanical properties). We observed a ∼20 to 30 Å layer of calcium-deficient hydroxyapatite at the HAP/ß-TCP interface due to particle migration, which may contribute to BCP stability. The BCP model may stimulate further research into BCP ceramics and multiphasic ceramics. Moreover, our study may facilitate the optimization of compositions of BCP-based biomaterials.


Assuntos
Simulação de Dinâmica Molecular , Nanopartículas , Biomimética , Hidroxiapatitas/química , Fosfatos de Cálcio/química , Durapatita/química , Cerâmica/química , Materiais Biocompatíveis/química , Nanopartículas/química
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