Search

Copyright of Chinese Journal of Tissue Engineering Research / Zhongguo Zuzhi Gongcheng Yanjiu is the property of Chinese Journal of Tissue Engineering Research and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Drug‐coated balloons (DCBs), serving as a superior alternative to stents, are at the cutting edge of clinical innovations in atherosclerosis management. Nevertheless, the prevalent high flow rates in arterial vascular result in short drug residence times, significantly compromising DCBs' therapeutic effectiveness. Drawing inspiration from the mechanisms of vascular calcification, a rapamycin‐loaded calcium phosphate nanoparticle (CaP@Rapa) coating for balloons is pioneered. This coating functions as a potent drug anchor in arteries, facilitating the adhesion of rapamycin to plaques and thereby enhancing the local concentration of the rapamycin. To evaluate its therapeutic efficacy in vivo, the rabbit iliac artery atherosclerosis model is innovatively developed, which authentically mirrors the pathological progression of atherosclerosis in humans. The enhanced localized rapamycin retention, along with its pH‐sensitive sustained release characteristics, culminate in substantial reductions in plaque volume, a decrease in intimal hyperplasia, and mitigation of local inflammation in model rabbits. To further substantiate the translational potential of CaP@Rapa balloons, the research on the pig coronary atherosclerosis model is expanded, which yielded results solidifying the clinical promise of CaP@Rapa balloons. In summary, this research not only offers a more effective and reliable alternative to traditional DCB but also paves the way for further clinical trials. [ABSTRACT FROM AUTHOR]

Zr-50Ti alloys are promising biomaterials due to their excellent mechanical properties and low magnetic susceptibility. However, Zr-50Ti alloys do not inherently bond well with bone. This study aims to enhance the bioactivity and bonding strength of Zr-50Ti alloys for orthopedic implant materials. Initially, the surface of Zr-50Ti alloys was treated with a sulfuric acid solution to create a microporous structure, increasing surface roughness and area. Subsequently, low crystalline calcium phosphate (L-CaP) precipitation was controlled by adding Mg2+ and/or CO32− ions in modified simulated body fluid (m-SBF). The treated Zr-50Ti alloys were then subjected to cold isostatic pressing to force m-SBF into the micropores, followed by incubation to allow L-CaP formation. The apatite-forming process was tested in simulated body fluid (SBF). The results demonstrated that the incorporation of Mg2+ and/or CO32− ions enabled the L-CaP to cover the entire surface of Zr-50Ti alloys within only one day. After short-term soaking in SBF, the L-CaP layer, modulated by Mg2+ and/or CO32− ions, formed a uniform hydroxyapatite (HA) coating on the surface of the Zr-50Ti alloys, showing potential for optimized bone integration. After soaking in SBF for 14 days, the bonding strength between the apatite layer and alloy has the potential to meet the orthopedic application requirement of 22 MPa. This study demonstrates an effective method to enhance the bioactivity and bonding strength of Zr-50Ti alloys for orthopedic applications. [ABSTRACT FROM AUTHOR]

Fluorine, depending on its concentration and chemical form, is essential or toxic to humans and animals. Therefore, it is crucial to be able to determine it reliably. In this study, fluorine was determined in animal feed after extraction with HCl (gastric juice simulation). The standard potentiometric method with a fluoride-selective electrode (ISE) and newly developed high-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS GFMAS) method was applied. Feed samples turned out to be a challenge for HR-CS GFMAS. Chemical interferences (formation of competing molecules, CaF, GaCl, and GaP, instead of the target GaF molecule) and spectral effects (including a phosphorous molecule spectrum and atomic lines) were identified. An additional difficulty was caused by reagent contamination with F and memory effects. Difficulties were eliminated/reduced. The quality of ISE analysis was multi-directionally verified (including comprehensive proficiency testing). A risk of inaccuracy at low F concentration, where the calibration relationship is nonlinear, was investigated. The results of both methods were consistent, which confirms the accuracy of the methods and informs that the extracted fluorine is in fluoride form. The results of extensive ISE tests conducted in Poland in 2021–2023 have shown that, in most cases, the fluoride content is significantly lower than the threshold values. [ABSTRACT FROM AUTHOR]

Materials based on highly reactive α-tricalcium phosphate (α-TCP) powder were developed and evaluated. Furthermore, the impact of different polymeric additives, such as citrus pectin or polyacrylamide (PAAM) modified with sago starch, neem flower, or rambutan peel, on the physiochemical and biological properties of the developed materials was assessed. The addition of modified PAAM shortened the setting process of bone cements and decreased their compressive strength. On the other hand, the addition of citrus pectin significantly enhanced the mechanical strength of the material from 4.46 to 7.15 MPa. The improved mechanical properties of the bone cement containing citrus pectin were attributed to the better homogenization of cementitious pastes and pectin cross-linking by Ca2+ ions. In vitro tests performed on L929 cells showed that 10% extracts from α-TCP cements modified with pectin are more cytocompatible than control cements without any additives. Cements containing PAAM with plant-derived modifiers show some degree of cytotoxicity for the highly concentrated 10% extracts, but for diluted extracts, cytotoxicity was reduced, as shown by a resazurin reduction test and live/dead staining. All the developed bone substitutes exhibited in vitro bioactivity, making them promising candidates for further biological studies. This research underscores the advantageous properties of the obtained biomaterials and paves the way for subsequent more advanced in vitro and in vivo investigations. [ABSTRACT FROM AUTHOR]

With respect to other fields, bone tissue engineering has significantly expanded in recent years, leading not only to relevant advances in biomedical applications but also to innovative perspectives. Polycaprolactone (PCL), produced in the beginning of the 1930s, is a biocompatible and biodegradable polymer. Due to its mechanical and physicochemical features, as well as being easily shapeable, PCL-based constructs can be produced with different shapes and degradation kinetics. Moreover, due to various development processes, PCL can be made as 3D scaffolds or fibres for bone tissue regeneration applications. This outstanding biopolymer is versatile because it can be modified by adding agents with antimicrobial properties, not only antibiotics/antifungals, but also metal ions or natural compounds. In addition, to ameliorate its osteoproliferative features, it can be blended with calcium phosphates. This review is an overview of the current state of our recent investigation into PCL modifications designed to impair microbial adhesive capability and, in parallel, to allow eukaryotic cell viability and integration, in comparison with previous reviews and excellent research papers. Our recent results demonstrated that the developed 3D constructs had a high interconnected porosity, and the addition of biphasic calcium phosphate improved human cell attachment and proliferation. The incorporation of alternative antimicrobials—for instance, silver and essential oils—at tuneable concentrations counteracted microbial growth and biofilm formation, without affecting eukaryotic cells' viability. Notably, this challenging research area needs the multidisciplinary work of material scientists, biologists, and orthopaedic surgeons to determine the most suitable modifications on biomaterials to design favourable 3D scaffolds based on PCL for the targeted healing of damaged bone tissue. [ABSTRACT FROM AUTHOR]

Silicate-based bioactive glass nano/microspheres hold significant promise for bone substitution by facilitating osteointegration through the release of biologically active ions and the formation of a biomimetic apatite layer. Cu-doping enhances properties such as pro-angiogenic and antibacterial behavior. While sol-gel methods usually yield homogeneous spherical particles for pure silica or binary glasses, synthesizing poorly aggregated Cu-doped ternary glass nano/microparticles without a secondary CuO crystalline phase remains challenging. This article introduces an alternative method for fabricating Cu-doped ternary microparticles using sol-gel chemistry combined with spray-drying. The resulting microspheres exhibit well-defined, poorly aggregated particles with spherical shapes and diameters of a few microns. Copper primarily integrates into the microspheres as Cu0 nanoparticles and as Cu2+ within the amorphous network. This doping affects silica network connectivity, as calcium and phosphorus are preferentially distributed in the glass network (respectively as network modifiers and formers) or involved in amorphous calcium phosphate nano-domains depending on the doping rate. These differences affect the interaction with simulated body fluid. Network depolymerization, ion release (SiO 4 4−, Ca2+, PO 4 3−, Cu2+), and apatite nanocrystal layer formation are impacted, as well as copper release. The latter is mainly provided by the copper involved in the silica network and not from metal nanoparticles, most of which remain in the microspheres after interaction. This understanding holds promising implications for potential therapeutic applications, offering possibilities for both short-term and long-term delivery of a tunable copper dose. A novel methodology, scalable to industrial levels, enables the synthesis of copper-doped ternary bioactive glass microparticles by combining spray-drying and sol-gel chemistry. It provides precise control over the copper percentage in microspheres. This study explores the influence of synthesis conditions on the copper environment, notably Cu0 and Cu2+ ratios, characterized by EPR spectroscopy, an aspect poorly described for copper-doped bioactive glass. Additionally, copper indirectly affects silica network connectivity and calcium/phosphorus distribution, as revealed by SSNMR. Multiscale characterization illustrates how these features impact acellular degradation in simulated body fluid, highlighting the therapeutic potential for customizable copper dosing to address short- and long-term needs. [Display omitted] [ABSTRACT FROM AUTHOR]

The comprehensive approach using both pull-off tensile and scratch tests provided a detailed understanding of the adhesion and cohesion properties of the 3D-porous calcium phosphate (CaP) coatings deposited on a Ti substrate by the ultrasound-assisted micro-arc oxidation (UMAO) method. Using the pull-off tensile test which takes into account tensile stresses directed normally to the coating surface, it was found that the ultrasound (US) employing during the the micro-arc oxidation (MAO) process led to a slight decrease in the adhesion of the coating to the substrate from 23.4 to 19.3 MPa as well as to a change in the failure mechanism from the cohesive type characteristic for the control MAO coatings to the adhesive-cohesive type for the UMAO coatings. On the contrary, the results of the scratch test, which takes into account compressive stresses directed normally and tangentially to the coating surface, showed that the US employed during the MAO process led to an increase in the critical loads LC2 and LC3 to 6.7 and 30.6 N, respectively, promoting the adhesive-cohesive and adhesive failures of the coatings. Thus, the US employed during the MAO process led to an increase in the critical shear stresses of the UMAO coatings, thereby increasing their abrasion resistance. [ABSTRACT FROM AUTHOR]

Micellar calcium phosphate (MCP) plays an important role in maintaining the structure and stability of the casein micelle and its properties during processing. The objective of this study was to investigate how heating (10 min at 80 or 90 °C) at different pH levels (6.3, 6.6, 6.9, or 7.2) impacted the acid-induced gelation of MCP-adjusted milk, containing 67 (MCP67), 100 (MCP100), or 113 (MCP113) % of the original MCP content. The unheated sample MCP100 at pH 6.6 was considered the control. pH acidification to pH 4.5 at 30 °C was achieved with glucono delta-lactone while monitoring viscoelastic behaviour by small-amplitude oscillatory rheology. The partitioning of calcium and proteins between colloidal and soluble phases was also examined. In MCP-depleted skim milk samples, the concentrations of non-sedimentable caseins and whey proteins were higher compared to the control and MCP-enriched skim milk samples. The influence of MCP adjustment on gelation was dependent on pH. Acid gels from sample MCP67 exhibited the highest storage modulus (G′). At other pH levels, MCP100 resulted in the greatest G′. The pH of MCP-adjusted skim milk also impacted the gel properties after heating. Overall, this study highlights the substantial impact of MCP content on the acid gelation of milk, with a pronounced dependency of the MCP adjustment effect on pH variations. [ABSTRACT FROM AUTHOR]

Novel crystalline and thermally stable chitosan-N-acetylisatin (Chs-NAI) polymer derivatives were synthesized by chitosan modification. These polymers were formed by insertion of β-cyclodextrin (βCD) and doping with zinc oxide nanoparticles (ZnO NPs) yielding pseudopolyrotaxane (Chs-NAI/βCD), Chs-NAI/ZnO-NPs, and Chs-NAI/βCD/ZnO NP composites. The chemical structure and morphology of the newly prepared polymers were investigated by FTIR, XRD, and SEM analyses. Also, the optical properties and thermal stability analysis of the synthesized polymers were examined. These results showed that the use of β-CD or ZnO NPs to modify the polymer (Chs-NAI) dramatically improves the thermal stability and optical properties of the synthesized polymer. The weight losses of the synthesized polymers are 66%, 56%, 48%, and 59% in Chs-NAI, Chs-NAI/βCD, Chs-NAI/ZnO, and Chs-NAI/βCD/ZnO, respectively. For mineral deposition, Chs-NAI/βCD/ZnO was presoaked with a PO43− containing solution before being immersed in a Ca2+ containing solution. The properties of Chs-NAI/βCD/ZnO nanoparticles/calcium phosphate materials were examined to confirm the deposition of the calcium phosphate on the Chs-NAI/βCD/ZnO nanoparticles surface using different techniques. Based on the results of the tests on the Vero cell lines, Chs-NAI/βCD/ZnO NPs)/calcium phosphate demonstrated very mild cytotoxicity. In addition, the feasibility of a wide variety of hybrid was assessed with an MTT test, and it was determined that they were noncytotoxic under a variety of hybrid concentrations. [ABSTRACT FROM AUTHOR]

Hydroxyapatite (HA) scaffolds produced by the accumulation of HA fibers were separately treated hydrothermally in three calcium phosphate solutions to form coatings of different micro/nano-structures. Different micro/nano-structure and morphologies have been regulated on the surface of treated HA scaffolds. Plate-like compromise flower-like morphology was obtained with solution 1 (Ca-sufficient) i.e., ratio: Ca/Ca=1%; Ca/P=1.67. Full coatings (flower-like) morphology treated after Cu-doped coating solution 2 (Cu/(Cu+Ca) = 5%; ratio: (Cu+Ca)/P = 1.67). Furthermore, partial coatings (flower-like) morphology fabricated with solution 3 (Ca-deficient and Cu-replacement), i.e., ratio: Ca/Ca=0.95%; Ca/P=1.58. The results showed the effect of hydrothermal coatings on HA scaffolds. Cultured human endothelial cells spread and proliferated better on the treated HA scaffolds than on the uncoated scaffolds, suggesting a potential effect of calcium phosphate surface morphology on endothelial cell response. Thus, it can provide an appropriate micro/nanostructure approach supporting angiogenesis capacity, which is a necessity to accelerate the time of bone healing and regeneration. [ABSTRACT FROM AUTHOR]

The research aims to develop and evaluate an immediate-release dosage form of sapropterin dihydrochloride to improve efficacy, stability, and patient acceptance in treating hyperphenylalaninemia (HPA), ensuring rapid therapeutic action upon administration. Formulation development began with a pre-formulation study to evaluate drug-excipient compatibility, solubility, and compressibility, followed by feasibility trials to create a prototype formulation. Dissolution tests and optimization methods, including DoE and OFAT, were employed to refine the formulation based on critical quality attributes. Process optimization involved identifying and fine-tuning critical parameters through sequential unit operations and risk assessments, ensuring uniformity and quality during scale-up for commercial production. The prototype formulation development for a tablet product based on the reference product Kuvan involved strategic excipient selection to meet critical quality attributes (CQA) and mitigate concerns like mottling. The formulation deviates from the reference by using LH 21 as a binder, colloidal silicon dioxide as a glidant, and omitting anhydrous dibasic calcium phosphate, with Mannitol SD (Pearlitol 200) chosen for its flowability and compressibility. The feasibility trial aimed at achieving pharmaceutical equivalence to Kuvan tablets, focusing on bioequivalence, stability, and API distribution, and involved top spray fluid bed granulation with roller compaction and blending identified as high-risk steps. Optimization of tablet formulation considered drug substance particle size, blend ratios, and excipient selection, with adjustments in intra and extra-granular ratios significantly impacting tablet characteristics. [ABSTRACT FROM AUTHOR]

Deep-sea sediments enriched in rare earth elements and yttrium (REY) are gaining interest as new sources of REY. The northwestern Pacific is considered as one of the most promising regions with high REY resource potential; however, information on this region outside of the Japanese exclusive economic zone around Minamitorishima is limited. This study aimed to perform bulk chemical analyses on ten sediment cores obtained from the Ogasawara Fracture Zone, and Eastern Mariana and Pigafetta basins in northwestern Pacific. A noticeable peak of total REY content (∑REY) > 1600 ppm was found in a core, indicating the possible distribution of highly REY-enriched mud in the area; moreover, the low sedimentation rate in this region, resulting from a water depth of 6000 m, is also favorable for the development of REY-rich mud. Correlations between elemental concentrations and shale-normalized REY patterns strongly suggest that REY enrichment is primarily associated with biogenic calcium phosphates. The downcore profiles of ∑REY content were not consistent in the depths and the number of REY-enriched layers among the studied cores, presumably affected by core penetration depth, supply of detrital materials from nearby topographic highs and physical erosion by bottom currents. Our results provide a better understanding of the REY-rich mud properties and its distribution in the deep-sea sediments of these regions of the northwestern Pacific. [ABSTRACT FROM AUTHOR]

Purpose: Older adults with removable dentures experience high rates of both caries (when the natural dentition remains) and salivary gland dysfunction. While many commercial dental therapeutic agents target these two interrelated problems, none have been labeled for use on the fitting surface of removable dentures. Off‐label use of MI Paste (GC America, Alsip, IL), a dental therapeutic containing casein‐phosphopeptide‐amorphous‐calcium‐phosphate (CPP‐ACP), was investigated following its application to the fitting surface of complete denture(s) with subsequent effects on salivary conditions measured. Materials and methods: Salivary flow rate and pH were recorded at baseline and 15 min following the application of 1 mL of CPP‐ACP paste to the fitting surface of each participant's denture through whole saliva collection. To assess buffering capacity, equivalent volumes of 0.01 M lactic acid were added to the collected saliva samples, and pH reduction was measured. Comparisons of salivary parameters between baseline and post‐CPP‐ACP paste application and between subjects with and without self‐reported xerostomia were conducted using a paired‐sample t‐test, Wilcoxon signed‐rank test, or two‐sample t‐test as appropriate. Results: Of the 28 participants (mean age = 70.3 ± 13.7 years, 17 males), 11 reported xerostomia. CPP‐ACP‐paste application was associated with decreased pH reduction during acid challenge compared to baseline (0.95 ± 0.24 vs. 1.54 ± 0.53, p < 0.001), and a higher final pH following acid challenge (5.93 ± 0.34 vs. 5.40 ± 0.66, p < 0.001). While the flow rates observed at post‐CPP‐ACP paste application were greater than those at baseline, the difference was not statistically significant (0.67 ± 0.44 mL/min vs. 0.55 ± 0.34 mL/min, p = 0.053). No significant differences were found in any salivary parameters between participants with or without self‐reports of xerostomia. Conclusions: The findings highlight potential positive effects on salivary conditions following the application of the CPP‐ACP‐containing product, MI Paste, to the fitting surface of a removable complete denture as a potential caries‐risk‐management tool when natural dentition remains. Determining the caries‐preventive clinical significance will require longer‐term trials. [ABSTRACT FROM AUTHOR]

As a promising antitumor strategy, combination oncotherapy can achieve better therapeutic efficacy. However, given the different properties of drugs, carriers need to meet requirements for efficient encapsulation and controllable release of multi-drugs. Herein, we propose a graphene oxide (GO)-templated biomineralization nanosystem to optimize oncotherapy. For preparation, GO is conjugated with polyethylene glycol (PEG) to improve biostability, and glyeyrrhetinic acid (GA) is further grafted onto PEG chains for site-specific targeting. The generated nanosheet structure and large specific surface area support high doxorubicin (DOX) encapsulation and mineralized deposition of siRNA via π-π stacking and calcium phosphate co-precipitation, respectively. Followed by highly efficient penetration into tumor cells, GO-templated nanosystem performs swift drug release in response to tumor acidic microenvironment through dissolution of calcium phosphate and disruption of molecular interactions. After administration, the GO-templated nanosystem performs superior pharmacy properties and significant antitumor efficacy via the synergy of chemotherapy and RNA interference therapy. Collectively, a GO-templated biomineralization nanosystem provides an innovative delivery system for multi-drug administration in combinative tumor therapy. [ABSTRACT FROM AUTHOR]

Background: The risk of impaired bone–pin interface strength in titanium (Ti) pins coated with fibroblast growth factor (FGF)–calcium phosphate (CP) composite layers is yet to be evaluated in a clinical study. This retrospective study used Weibull plot analysis to evaluate bone–pin interface strength in Ti pins coated with FGF-CP layers for external distal radius fracture fixation. Methods: The distal radial fractures were treated with external fixation. The FGF-CP group comprised five patients (all women, aged 70.4 ± 5.9 (range: 62–77) years), and the uncoated pin group comprised ten patients (eight women and two men, aged 64.4 ± 11.7 (range: 43–83) years). The pins were removed after six weeks. The insertion and extraction peak torques were measured. The extraction peak torque was evaluated using Weibull plot analysis. Results: We compared the extraction torque of the two groups at or below 506 Nmm for a fair comparison using Weibull plot analysis. The Weibull plots were linear for both the FGF-CP and uncoated pin groups. The slope of the regression line was significantly higher in the FGF-CP group (1.7343) than in the uncoated pin group (1.5670) (p = 0.011). The intercept of the regression line was significantly lower in the FGF-CP group (−9.847) than in the uncoated pin group (−8.708) (p = 0.002). Thus, the two regression lines significantly differed. Conclusions: Ti pins coated with FGF-CP layers exhibit the potential to reduce the risk of impaired bone–pin interface strength in the external fixation of distal radius fractures. [ABSTRACT FROM AUTHOR]

Our objective is to achieve a new good-quality and mechanically durable high-transparency material that, when activated by rare earth ions, can be used as laser sources, scintillators, or phosphors. The best functional transparent ceramics are formed from high-symmetry systems, mainly cubic. Considering hexagonal hydroxyapatite, which shows anisotropy, the particle size of the initial powder is extremely important and should be of the order of several tens of nanometers. In this work, transparent micro-crystalline ceramics of non-cubic Ca10(PO4)6(OH)2 calcium phosphate were fabricated via Spark Plasma Sintering (SPS) from two types of nanopowders i.e., commercially available (COM. HA) and laboratory-made (LAB. HA) via the hydrothermal (HT) protocol. Our study centered on examining how the quality of sintered bodies is affected by the following parameters: the addition of LiF sintering agent, the temperature during the SPS process, and the quality of the starting nanopowders. The phase purity, microstructure, and optical transmittance of the ceramics were investigated to determine suitable sintering conditions. The best optical ceramics were obtained from LAB. HA nanopowder with the addition of 0.25 wt.% of LiF sintered at 1000 °C and 1050 °C. [ABSTRACT FROM AUTHOR]

Objective: This study investigated the effect of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) on the shear bond strength (SBS) of a universal adhesive in self-etch mode to demineralized dentin. Methods: Seventy-five dentin specimens were randomly divided into five groups (n=15) as follows: Group 1, intact dentin; Group 2, demineralized dentin receiving no remineralization agent; and Groups 3-5, demineralized dentin receiving CPP-ACP for 30, 90, and 180 seconds, respectively. All groups were bonded by Adper Single Bond Universal adhesive in self-etch mode. After 24 hours, the SBS test was conducted, and failure modes were recorded. The data were analyzed by one-way ANOVA, Tukey post-hoc test, and chi-square test at the significance level of P<0.05. Results: The highest and lowest mean SBS values were observed in groups 1 (intact dentin: 29.58 ± 8.13 MPa) and 2 (demineralized dentin: 13.41 ± 4.85 MPa), respectively. ANOVA revealed a significant difference in SBS among the groups (P< 0.001). A pairwise comparison revealed that the SBS of demineralized groups (groups 2-5) was significantly lower than that of the intact samples (P< 0.05). Group 5, with CPP-ACP, applied for 180 seconds, showed a significantly higher SBS (20.74 ± 4.54 MPa) compared to group 2 (P< 0.05). Conclusions: Applying CPP-ACP paste for three minutes can increase the bond strength of the universal adhesive in self-etch mode to demineralized dentin, whereas shorter application times are not effective. [ABSTRACT FROM AUTHOR]

A 3‐year‐old, male, neutered, domestic shorthair cat with a history of chronic intermittent vomiting, diarrhoea and constipation was referred for abdominal ultrasound of a mid‐abdominal mass identified on palpation. Findings included a densely shadowing structure within the distal ileum with severe local muscularis thickening, mild diffuse small intestinal muscularis thickening, and an enlarged right ileocolic lymph node. Abdominal radiographs showed the structure to be most consistent with an enterolith. Enterolithiasis is a rare condition in companion animals, but common in horses and selected populations of human patients. Enterectomy was performed, and histopathology results of intestinal biopsies were consistent with chronic inflammatory enteropathy. Chemical analysis of the enterolith revealed a predominantly calcium phosphate composition. At the 3‐month follow‐up, the cat had gained weight and showed marked improvement in gastrointestinal signs. Screening for underlying structural intestinal disease may be beneficial in cats diagnosed with enteroliths. [ABSTRACT FROM AUTHOR]

Calcium-containing crystal deposition diseases are extremely common in rheumatology. However, they are under-explored compared to gout or other inflammatory rheumatic diseases. Major advances have been made in 2023 that will undoubtedly stimulate and facilitate research in the field of calcium pyrophosphate (CPP) deposition disease (CPPD): the ACR/EULAR classification criteria for CPPD and a semi-quantitative OMERACT score for ultrasound assessment of the extent of CPP deposition have been validated and published. A large randomized controlled trial compared the efficacy and safety of colchicine and prednisone in acute CPP arthritis. Preclinical studies have elucidated the pro-inflammatory and anti-catabolic effects of basic calcium phosphate (BCP) crystals on mononuclear cells and chondrocytes. The association between osteoarthritis (OA) and IA calcifications has been the subject of several epidemiological publications, suggesting that calcium crystals are associated with a greater risk of progression of knee OA. Research in the field of calcium crystal deposition diseases is active: the areas of investigation for the coming years are broad and promising. [ABSTRACT FROM AUTHOR]

Over the past three decades, bioresorbable ceramics such as beta-tricalcium phosphate (β-TCP)-based porous scaffolds have been extensively studied. β-TCP-based scaffolds or cements for bone tissue applications have proved to be an outstanding alternative to repair and regenerate bone tissue defects caused by trauma or injury. In this study, an investigation on submicron β-TCP powders derived from prawn shell (Fenneropenaeus indicus, a source of marine biowaste) via solid-state reaction approach was carried out, which has calcite (CaCO3) in its exoskeleton (nonedible). The prawn shell-derived β-TCP can be prepared conventionally with dicalcium phosphate (CaHPO4) at different temperatures 900, 1000, 1100, and 1200 °C. The EDX spectra detect the Ca:P ratio of 1.5 confirming the formation of pure β-TCP at 1100 °C, which is in complete agreement with theoretical ratio. X-ray diffraction pattern revealed the phase-pure crystalline rhombohedral crystal structure of β-TCP with an average crystallite size of ~ 25.8 nm, prepared at 1100 °C. The field emission scanning electron microscopy images showed a homogeneous distribution of β-TCP powders with an average grain size of 3.07 µm at 1100 °C. Furthermore, Raman spectroscopy and Fourier transform infrared spectroscopy confirm the characteristics peaks of β-TCP. Differential scanning calorimetry and thermogravimetric analysis are performed to study the thermal behavior of the initial precursors mixture to synthesize β-TCP. β-TCP scaffolds sintered at 1100 °C exhibited compressive strength of ~ 6.2 MPa, for which Ca/P ratio is 1.51. Biodegradation study conducted on β-TCP scaffolds sintered at 1100 °C has shown slow degradation rate up to 5 days. Therefore, the prawn shell-derived β-TCP has physical and morphological properties which projects it as a promising implantable biomaterial for synthetic bone graft substitutes. [ABSTRACT FROM AUTHOR]

This research focuses on the bonding between calcium phosphate cement (CPC) composites designed as a thin repair overlay material and old ordinary portland cement (OPC) as a concrete substrate. The OPC concrete substrate was prepared to have a 28-day compressive strength of 50 MPa at room temperature. In order to select a suitable surface condition of the substrate to receive the repair material and the age to determine the bond strength, the development of the bond strength of the CPC overlay cast on five different preconditioned old concrete substrates was measured after 7, 14, and 28 days under laboratory conditions. It was found that the prepared saturated surface dry (SSD) substrate surface had the optimum bond strengths with the CPC material after 14 days. Subsequently, the intimate bonding relationships between the in situ cast CPC composites and the precast concrete (conditioned as the prepared SSD substrate surface) were investigated through pull-off, slant shear, and bi-shear bond tests. Results indicate a high bond between the CPC repair material and the OPC concrete substrate at room temperature. It was also found that rubber aggregates and fiber inclusions reduced such bond, with the most significant detrimental effect in composites that contained rubber aggregates and fiber reinforcements. Finally, a high positive correlation was observed among the tensile bond strength, slant shear bond strength, and bi-shear bond strength of the CPC-OPC composite systems, with cohesion and coefficient of friction values ranging from 1.37–2.94 MPa and 0.78–1.07, respectively. [ABSTRACT FROM AUTHOR]

Fixed appliance (FA) therapy predisposes patients to white spot lesions (WSLs). The F-ACP complex (amorphous calcium phosphate nanoparticles enriched with carbonate and fluorine and coated with citrate) has been effective for in vitro enamel remineralization. The aim of this study was to evaluate the efficacy of the F-ACP complex in remineralizing WSLs after FA therapy. One hundred and six adolescents (aged 12–20 years) were randomized into study and control groups after FA therapy. Patients in the study group were advised to use dental mousse containing F-ACP applied within Essix retainers for six months. The presence of WSLs was recorded at baseline (T0), 3 months (T1), and 6 months (T2) according to the International Caries Detection and Assessment System (ICDAS). Visual Plaque Index (VPI) and Gingival Bleeding Index (GBI) were recorded. Among 106 study participants, 91 (52 and 39 in study and control groups, respectively) completed the study. The results showed that the ICDAS score was significantly lower (p < 0.001) in the study group than in the control group between T0 and T2. The application of mousse containing the F-ACP complex inside Essix retainers for six months is effective in remineralizing white spot lesions in patients after FA therapy without side effects. [ABSTRACT FROM AUTHOR]

The micro-arc oxidation (MAO) technique was employed to produce calcium phosphate coatings on titanium surfaces using an electrolyte composed of hydroxyapatite and calcium carbonate in an aqueous solution of orthophosphoric acid. The coatings' morphology and composition were regulated by adjusting electrical parameters, specifically the duty cycle and voltage. This study examined the effects of the duty cycle and voltage during the MAO process on the microstructure and composition of calcium phosphate coatings on VT1–0 titanium substrates. Scanning electron microscopy (SEM) was utilized to analyze the microstructure and thickness of the coatings, while X-ray diffraction (XRD) was employed to determine their phase composition. The findings reveal that the surface morphology of the calcium phosphate coatings transitions from a porous, sponge-like structure to flower-like formations as the duty cycle and voltage increase. A linear increase in the voltage within the applied duty cycles led to a rise in the size of the forming particles of amorphous/crystalline structures containing phases of monetite (CaPO3(OH)), monocalcium phosphate monohydrate (Ca(H2PO4)2·H2O), and calcium pyrophosphate (γ–Ca2P2O7). [ABSTRACT FROM AUTHOR]

In this article, the process of creating calcium phosphate coatings through plasma electrolytic oxidation was investigated. Calcium phosphate coatings were deposited onto titanium substrates fabricated via the selective laser melting (SLM) method. The correlation between the characteristics of the coating and the applied voltage (200, 250, and 300 V) of PEO was studied. The surface morphology analysis indicates that an increase in applied voltage results in a larger pore size. It was discovered that, when a voltage of 300 V was applied, a layer of hydroxyapatite formed. However, at 300 V, the coating cracked, producing a significantly rough surface. Our analysis of the elemental composition of sample cross sections indicates the presence of TiO2 layers that are enriched with calcium (Ca) and phosphorus (P). The coefficient of friction and wear rate are primarily influenced by the morphology, pore size, and density of the titanium dioxide layer. Furthermore, a rise in the quantity of the beta phase of the titanium on the surface can be noticed as the applied voltage increases. As a result, it also affects the mechanical and tribological characteristics of the coating. The sample treated to a voltage of 250 V demonstrates a higher resistance to wear and a lower elastic modulus in comparison to the other two coatings. [ABSTRACT FROM AUTHOR]

Bioactive degradable scaffolds that facilitate bone healing while fighting off initial bacterial infection have the potential to change established strategies of dealing with traumatic bone injuries. To achieve this a composite material made from calcium phosphate graphene (CaPG), and MXene was synthesized. CaPG was created by functionalizing graphene oxide with phosphate groups in the presence of CaBr with a Lewis acid catalyst. Through this transformation, Ca2+ and PO43− inducerons are released as the material degrades thereby aiding in the process of osteogenesis. The 2D MXene sheets, which have shown to have antibacterial properties, were made by etching the Al from a layered Ti3AlC2 (MAX phase) using HF. The hot‐pressed scaffolds made of these materials were designed to combat the possibility of infection during initial surgery and failure of osteogenesis to occur. These two failure modes account for a large percentage of issues that can arise during the treatment of traumatic bone injuries. These scaffolds were able to retain induceron‐eluting properties in various weight percentages and bring about osteogenesis with CaPG alone and 2 wt% MXene scaffolds demonstrating increased osteogenic activity as compared to no treatment. Additionally, added MXene provided antibacterial properties that could be seen at as little as 2 wt%. This CaPG and MXene composite provides a possible avenue for developing osteogenic, antibacterial materials for treating bone injuries. [ABSTRACT FROM AUTHOR]

Ex vivo tissue engineering is an effective therapeutic approach for the treatment of severe cartilage diseases that require tissue replenishment or replacement. This strategy demands scaffolds that are durable enough for long‐term cell culture to form artificial tissue. Additionally, such scaffolds must be biocompatible to prevent the transplanted matrix from taking a toll on the patient's body. From the viewpoint of structure and bio‐absorbability, a β‐tricalcium phosphate (β‐TCP) fiber scaffold (βTFS) is expected to serve as a good scaffold for tissue engineering. However, the fragility and high solubility of β‐TCP fibers make this matrix unsuitable for long‐term cell culture. To solve this problem, we developed an alginate‐coated β‐TCP fiber scaffold (βTFS‐Alg). To assess cell proliferation and differentiation in the presence of βTFS‐Alg, we characterized ATDC5 cells, a chondrocyte‐like cell line, when grown in this matrix. We found that alginate coated the surface of βTFS fiber and suppressed the elution of Ca2+ from β‐TCP fibers. Due to the decreased solubility of βTFS‐Alg compared with β‐TCP, the former provided an improved scaffold for long‐term cell culture. Additionally, we observed superior cell proliferation and upregulation of chondrogenesis marker genes in ATDC5 cells cultured in βTFS‐Alg. These results suggest that βTFS‐Alg is suitable for application in tissue culture. [ABSTRACT FROM AUTHOR]

Objective: To compare implant stability and clinical outcome in implant placement between osteotome sinus floor elevation (OSFE) with biphasic calcium phosphate (BCP) which consisted of 30% of hydroxyapatite (HA) and 70% of beta-tricalcium phosphate (β -TCP) grafting material and OSFE without using bone grafting material. The research questions is whether the BCP provides any benefit in OSFE or not. Materials and methods: Thirty patients (30 implants) with a single edentulous area of upper premolar or molar were randomly separated into OSFE with BCP (n = 15) and OSFE without grafting (n = 15). The patients were reevaluated 3, 6, 9, and 12 months after implant loading. The clinical assessments (implant stability quotient (ISQ), implant survival-failure rate, and surgical complication) were analyzed. Together with radiographic assessments in 2D (endo-sinus bone gain (ESBG), mean marginal bone change (MMBC)) and 3D (endo-sinus bone gain in CBCT (ESBG-CT)) were evaluated, with a mean follow-up time of at least 12 months of functional loading and prosthetic complication. Results: 20 remaining implants (OSFE with BCP, n = 10; OSFE without grafting, n = 10) were analyzed. Mean ISQ was 79.18 ± 3.43 in 1-year follow-up (ISQ; OSFE with BCP = 78.72 ± 3.46, OSFE without grafting = 79.65 ± 3.52). ISQ in both groups increased steadily without significant differences in each follow-up. (p = 0.56). In radiographic evaluation, at 6-, 9-, and 12-month, OSFE without grafting group showed statistically significant lower MMBC (p < 0.05). The 1-year clinical results showed that 2 implants failed in OSFE with BCP, and 1 implant failed in OSFE without grafting. Conclusions: Graft material “BCP” (HA30:TCP70) coupled with OSFE presents no extraordinary benefit in implant stability, clinical and radiographic outcome in 1-year follow-up. Clinical relevance: Clinically, OSFE with grafting materials provides no additional benefit. Clinical trial registration number: TCTR20210517008 (date of registration: May 17, 2021) [ABSTRACT FROM AUTHOR]

The use of scaffolds, three-dimensional porous, biodegradable and biocompatible structures, that can be produced from natural polymers, synthetics, ceramics and metals is crucial in the tissue engineering field. Chitosan is a polysaccharide of natural origin, found in the exoskeleton of marine arthropods and in the cell wall of fungi, with enormous popularity in the production of three-dimensional materials for Tissue Engineering, in particular bone repair. This polymer has several advantages in the production of these structures in bone regeneration and repair: biodegradability, biocompatibility, non-toxicity and antimicrobial properties. This study aimed to prepare porous scaffolds, for bone repair of degenerative diseases in the spine with better performance and less secondary effects, based on chitosan and another biopolymer (sodium alginate) with the incorporation of calcium phosphates (hydroxyapatite and β-tricalcium phosphate), for tissue engineering application. The obtained scaffolds were object of a detailed characterization, namely with regard to their porosity through the ethanol method, degradation, positron annihilation spectroscopy (PAS), mechanical properties, scanning electronic microscope (SEM), thermal stability through thermogravimetric analysis (TGA), chemical composition through X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The results obtained showed that the different scaffolds presented pores able to support osteoid matrix growth. The crosslinking of scaffolds was also evaluated and resulted in pores with smaller dimensions and higher regularity in the chitosan-sodium alginate polymer without calcium phosphate scaffold. It was also possible to observe the effect of inorganics on mixed-matrix scaffolds, both morphologically and chemically. These scaffolds showed promising results in terms of mechanical and chemical properties, along with promising porosity for tissue regeneration applications. [ABSTRACT FROM AUTHOR]

Arterial media calcification or pathological deposition of calcium-phosphate crystals in the vessel wall contributes significantly to the high mortality rate observed in patients with CKD. Extracellular nucleotides (ie, ATP or UTP) regulate the arterial calcification process by interacting with (1) purinergic receptors and (2) breakdown via ecto-nucleotidases, such as ectonucleotide pyrophosphatase/phosphodiesterase NPP1 or NPP3, affecting the local levels of calcification inhibitor, pyrophosphate, and stimulator inorganic phosphate (PPi/Pi ratio). Also, it has been shown that ATP analogs (ie, β,γ-methylene-ATP [β,γ-meATP]) inhibit vascular smooth muscle cell calcification in vitro. In the first experiment, daily dosing of β,γ-meATP (2 mg/kg) was investigated in rats fed a warfarin diet to trigger the development of non–CKD-related arterial medial calcifications. This study showed that β,γ-meATP significantly lowered the calcium scores in the aorta and peripheral vessels in warfarin-exposed rats. In a second experiment, daily dosing of 4 mg/kg β,γ-meATP and its metabolite medronic acid (MDP) was analyzed in rats fed an adenine diet to promote the development of CKD-related arterial medial calcification. Administration of β,γ-meATP and MDP did not significantly decrease aortic calcification scores in this model. Moreover, both compounds induced deleterious effects on physiological bone mineralization, causing an imminent risk for worsening the already compromised bone status in CKD. Due to this, it was not possible to raise the dosage of both compounds to tackle CKD-related arterial calcification. Again, this points out the difficult task of targeting solely ectopic calcifications without negatively affecting physiological bone mineralization. On the other hand, aortic mRNA expression of Enpp1 and Enpp3 was significantly and positively associated with aortic calcification scores, suggesting that normalizing the aortic NPP1/3 activity to control values might be a possible target to treat (CKD-induced) arterial media calcifications. [ABSTRACT FROM AUTHOR]

This study introduces microbiologically induced calcium phosphate precipitation (MICPP) as a novel and environmentally sustainable method of soil stabilization. Using Limosilactobacillus sp., especially NBRC 14511 and fish bone solution (FBS) extracted from Tuna fish bones, the study was aimed at testing the feasibility of calcium phosphate compounds (CPCs) deposition and sand stabilization. Dynamic changes in pH and calcium ion (Ca2+) concentration during the precipitation experiments affected the precipitation and sequential conversion of dicalcium phosphate dihydrate (DCPD) to hydroxyapatite (HAp), which was confirmed by XRD and SEM analysis. Sand solidification experiments demonstrated improvements in unconfined compressive strength (UCS), especially at higher Urea/Ca2+ ratios. The UCS values obtained were 10.35 MPa at a ratio of 2.0, 3.34 MPa at a ratio of 1.0, and 0.43 MPa at a ratio of 0.5, highlighting the advantages of MICPP over traditional methods. Microstructural analysis further clarified the mineral composition, demonstrating the potential of MICPP in environmentally friendly soil engineering. The study highlights the promise of MICPP for sustainable soil stabilization, offering improved mechanical properties and reducing environmental impact, paving the way for novel geotechnical practices. [ABSTRACT FROM AUTHOR]

Enamel remineralization, which attempts to generate a mineral layer structurally similar to native enamel and restore its mechanical properties, remains a significant challenge. Here, rationally designed peptide amphiphile (PA) molecules bind to amorphous calcium phosphate (ACP) particles via electrostatic interactions, imparting anisotropic properties that drive PA‐modified ACP to form spindle‐shaped aggregates. Furthermore, some residual PA molecules may further regulate crystallization and facilitate the formation of well‐aligned hydroxyapatite bundles. Additionally, the involvement of PA can mediate the ordered deposition and fusion of ACP on the enamel surface, and construct the crystalline‐amorphous mineralization front with a continuous structure. This mineralization front ensures epitaxially oriented growth of enamel crystals and achieves a structurally ordered mineral layer similar to that of native enamel, while the mechanical performance is effectively restored. More significantly, the thickness of the newly formed mineral layer can be augmented through cyclic remineralization, benefitting the design of products intended for practical enamel repair. [ABSTRACT FROM AUTHOR]

Porous β-tricalcium phosphate (Ca3(PO4)2; β-TCP) was prepared via freeze-drying and the effects of this process on pore shapes and sizes were investigated. Various samples were prepared by freezing β-TCP slurries above a liquid nitrogen surface at −180 °C with subsequent immersion in liquid nitrogen at −196 °C. These materials were then dried under reduced pressure in a freeze-dryer, after which they were sintered with heating. Compared with conventional heat-based drying, the resulting pores were more spherical, which increased both the mechanical strength and porosity of the β-TCP. These materials had a wide range of pore sizes from 50 to 200 µm, with the mean and median values both approximately 100 µm regardless of the freeze-drying conditions. Mercury porosimetry data showed that the samples contained small, interconnected pores with sizes of 1.24 ± 0.25 µm and macroscopic, interconnected pores of 25.8 ± 4.7 µm in size. The effects of nonionic surfactants having different hydrophilic/lipophilic balance (HLB) values on foaming and pore size were also investigated. Materials made with surfactants having lower HLB values exhibited smaller pores and lower porosity, whereas higher HLB surfactants gave higher porosity and slightly larger macropores. Even so, the pore diameter could not be readily controlled solely by adjusting the HLB value. The findings of this work indicated that high porosity (>75%) and good compressive strength (>2 MPa) can both be obtained in the same porous material and that foaming agents with HLB values between 12.0 and 13.5 were optimal. [ABSTRACT FROM AUTHOR]

Aging society demands advanced bone implants that can achieve long‐term success through osseointegration at the bone‐implant interface. Polyetheretherketone (PEEK), a bioinert implant material, often struggles with connecting to existing bone tissue, leading to inflammation and implant replacement. Following nature's lessons, a new strategy is introduced that masks the surface of bio‐ and chemically inert Polyetheretherketone implants with a covalently anchored bone‐mimetic surface. This method transforms PEEK into a bone‐integrative material by grafting a ≈300 nm thick gelatin layer onto its surface, subsequently mineralized with calcium phosphate. Herein, it is showed that this surface modification for implant materials combines excellent bulk implant properties with the characteristic structure and functional properties of natural bone. In vitro biocompatibility assays, employing NIH‐3T3 fibroblast and MC3T3‐E1 osteoblast cell lines, confirm the enhanced biocompatibility of the modified material. This strategy offers promising prospects for improving bone implants and exemplifies the adaptation of a non‐osseointegrative material to a bone‐like interface. [ABSTRACT FROM AUTHOR]

Simple Summary: Amputation or limb-sparing are the main surgical options for removing the primary tumor in canine appendicular osteosarcoma (OSA). Usually, these surgeries are complemented by adjuvant therapy to help to prevent metastatic dissemination. However, in some cases, these procedures may not be possible due to various factors such as the limitation of the surgical procedure, the dog's medical condition, or the owner's refusal. Herein, a study was carried out to assess the safety and efficacy of an alternative surgical approach called cementoplasty, which uses a calcium phosphate bone substitute. Involving 12 dogs, the study focused on evaluating its ability to reduce pain and lower the risk of pathological fractures. The results indicated an enhanced quality of life post-treatment, along with a decrease in the incidence/occurrence of pathological fractures. This study highlights cementoplasty as a safe palliative alternative to conservative surgical methods, offering potential benefits in the overall management of canine osteosarcoma. Cementoplasty is a minimally invasive procedure that consists of injecting a bone substitute into the tumor lesion to provide bone reinforcement and alleviate pain. This study aimed to demonstrate the feasibility, safety, and efficacy of cementoplasty with a calcium phosphate cement in osteosarcoma to reduce pain and preserve limb function. Throughout the 6-month study, dogs received no adjuvant therapy, and dogs' evaluations included a clinical examination, monitoring of postoperative complications, radiographic follow-up, and assessment of limb function and pain scores. Out of 12 dogs enrolled, 10 were withdrawn before study completion due to deterioration in their general condition. Nine (9) dogs were followed until D28, six until D56, and two until D183. Compared to D0, more than 50% of the dogs showed improvement in both veterinarian and owner scores at their final visit. Throughout the study, 10 major and 4 minor complications were reported, all unrelated to the procedure. This open non-controlled study provides first evidence of the feasibility, safety, and efficacy of cementoplasty procedure using a calcium phosphate bone cement to relieve pain and preserve limb function in dogs suffering from appendicular osteosarcoma. [ABSTRACT FROM AUTHOR]

Simple Summary: Calcium and phosphorus are essential minerals required for animal health, especially in laying hens since they are important components in bone and eggshell formation. Diets with inadequate calcium and phosphorus can interfere with their absorption and digestibility, resulting in eggshell quality losses and reduced productive life, affecting egg production and welfare. Although mineral metabolism has been widely studied in young laying hens, the mechanisms of absorption, reabsorption, and mineral homeostasis of laying hens with advancing age are not well known. Therefore, we studied eight genes involved in Ca and P metabolism and observed that two of them (CYP24A1 and TRPC3) showed differential expression according to the Ca/P ratios provided in the diet. These results contribute to understanding how Ca and P metabolism are regulated in hens during their late laying cycle, allowing the development of new nutritional strategies to improve hens' productive life as well as their egg quality. Ca and P homeostasis across the egg-laying cycle is a complex process involving absorption in the small intestine, reabsorption/excretion in the kidneys, and eggshell gland secretion. Diets with inadequate calcium and phosphorus can interfere with their absorption and digestibility, resulting in eggshell quality losses and reduced productive life, affecting egg production and welfare. A better understanding of gene expression profiles in the kidneys of laying hens during the late egg-laying period could clarify the renal role in mineral metabolism at this late stage. Therefore, the performance, egg quality and bone integrity-related traits, and expression profiles of kidney candidate genes were evaluated in 73-week-old laying hens receiving different Ca and P ratios in their diet: a high Ca/P ratio (HR, 22.43), a low ratio (LR, 6.71), and a medium ratio (MR, 11.43). The laying hens receiving the HR diet had improved egg production and eggshell quality traits compared to the other two groups. Humerus length was shorter in the HR than in the other groups. The CYP24A1 and TRPC3 genes were differentially expressed (p.adj ≤ 0.05) among the groups. Therefore, their expression profiles could be involved in calcium and phosphate transcellular transport in 73-week-old laying hens as a way to keep mineral absorption at adequate levels. [ABSTRACT FROM AUTHOR]

The implantation of 3D-printed scaffolds for bone repair could be ineffective due to the early inflammatory response. In this work, porous amorphous calcium phosphate (ACP) nanospheres were employed to not only load quercetin (Que) but also mix with octacalcium phosphate (OCP) to form biphasic calcium phosphate (BCP). Afterward, the drug-loaded nanospheres (AQ) were combined with BCP and sodium alginate (SA) to fabricate the AQ-BCP/SA scaffolds with an interconnected structure for solving the anti-inflammatory challenge and thus promoting osteogenesis. The scaffolds obtained excellent mineralizing properties due to the interaction of ACP and the OCP in the component. Additionally, the stable and continuous release of Que enabled the scaffolds to synergistically induce osteogenesis and immunoregulation. The scaffolds were capable of directly promoting osteogenic differentiation in vitro by upregulating the expression of related genes Runx2, ALP, BMP2, and OCN. Meanwhile, they were also demonstrated to be beneficial in immunoregulation by inducing macrophages to transform into M2 polarization rather than M1 polarization. In vivo evaluation also confirmed the significant osteogenic and immunoregulatory effects of the scaffolds, which were helpful for ideal bone repair. Thus, the AQ-BCP/SA scaffolds have the potential to be applied in the future bone tissue engineering area. [ABSTRACT FROM AUTHOR]

Copyright of Polimery is the property of Industrial Chemistry Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

• Ca/P antibacterial coatings with vancomycin were formed on Mg alloy. • Coatings improve corrosion properties of Mg alloy. • Coatings have superior antibacterial effect against both S. aureus. • Formed coatings do not have any cytotoxic effect according to MTT assay. • In vivo studies demonstrated that coatings do not have systemic toxicity. In this study, a calcium-phosphate coating was formed on a Mg–Mn–Ce alloy by the plasma electrolytic oxidation (PEO). The antibiotic vancomycin, widely used in the treatment of infections caused by Staphylococcus aureus (S. aureus), was impregnated into the coating. Samples with vancomycin showed high bactericidal activity against S. aureus. The mechanical and electrochemical properties of the formed coatings were studied, as well as in vitro cytotoxicity tests and in vivo tests on mature male rats were performed. According to SEM, EDS, XRD and XPS data, coatings had a developed morphology and contained hydroxyapatite, which indicates high biocompatibility. The analysis of roughness of coatings without and with vancomycin did not reveal any differences, confirming the high roughness of the samples. During electrochemical tests, an increase in corrosion resistance by more than two times after the application of PEO coatings was revealed. According to the results of an in vivo study, after 28 days of the implantation of samples with calcium phosphate PEO coating and vancomycin, no signs of inflammation were observed, while an inflammatory reaction developed in the area of implantation of bare alloy, followed by encapsulation. Antibiotic release tests from the coatings show a sharp decrease in the concentration of the released antibiotic on day 7 and then a gradual decrease until day 28. Throughout the experiment, no significant deviations in the condition and behavior of the animals were observed; clinical tests did not reveal a systemic toxic reaction. [Display omitted] [ABSTRACT FROM AUTHOR]

This study presents a method to prepare hydrogel from Pickering emulsions stabilized with amorphous calcium phosphate (ACP). Pickering emulsion was prepared by utilizing stearic acid (Sa)-modified ACP as the emulsifier, blended oil as the dispersed phase, and aqueous sodium alginate (SA) as the continuous phase. ACP releases calcium ions to crosslink with sodium alginate when the pH decreases, forming a hydrogel. Structural characterization and surface wettability of the modified ACP were assessed through FT-IR, XRD, and contact angle measurements. Droplet sizes in the emulsion were analyzed using optical microscopy, and the release of curcumin from the hydrogel was monitored using ultraviolet spectroscopy. These results demonstrate Sa was grafted onto the surface of ACP. Stabilization of the Pickering emulsion was achieved using 4 wt% Sa-ACP. Moreover, the droplet size exhibited a reduction with heightened particle concentration, oil-water ratio, and pH. The release of curcumin was optimized at 5 wt% SA and 0.75 w/v% Sa-ACP with 53.5% release. The Ca-alginate matrices prevented the release of the curcumin at pH 1.2 and the curcumin was vastly released at pH 7.4, exhibiting pH-responsive release characteristics. These results confirmed the Sa-ACP-stabilized Pickering emulsion hydrogel could be used as an effective delivery system. [ABSTRACT FROM AUTHOR]

In order to evaluate the solubility and oxidation characteristics of different forms of trace elements, four groups of different forms of trace elements were set up, namely, traditional inorganic trace elements (ITE group), glycine trace elements (GTE group), compound amino acid trace elements (CATE group), and coated inorganic trace elements (CITE group). The premix of different groups of trace elements provided the same level of trace elements for eel compound feed. The results showed that the dissolution rate of ITE group, GTE group, and CATE group (except copper and iron) was higher at 0.5 h, and almost all of them were dissolved after 4.0 h. The dissolution rates of Cu, Fe, Mn, and Zn in CITE group increased with time, and were significantly lower than those in ITE group, GTE group, and CATE group (P<0.05). After adding calcium dihydrogen phosphate, the dissolution rates of Cu, Fe, Mn, and Zn in ITE group, GTE group, and CATE group decreased significantly (P<0.05), while the dissolution rates of Cu, Fe, Mn, and Zn in CITE group increased significantly (P<0.05). The peroxide value of eel feed prepared with different forms of trace element premix increased at first and then decreased. At different time points, the peroxide value of ITE group was the highest, followed by the GTE group, CATE group, and CITE group. The study indicates that the dissolution rate of coated inorganic trace elements and compound amino acid trace elements is lower, which can reduce the peroxide value of eel compound feed, and the effect of coated inorganic trace elements is better. [ABSTRACT FROM AUTHOR]

Effective mineralization of biological structures poses a significant challenge in hard tissue engineering as it necessitates overcoming geometric complexities and multistep biomineralization processes. In this regard, we propose "mineral-in-shell nanoarchitectonics", inspired by the nanostructure of matrix vesicles, which can influence multiple mineralization pathways. Our nanostructural design empowers mineral precursors with tailorable properties through encapsulating amorphous calcium phosphate within a multifunctional tannic acid (TA) and silk fibroin (SF) nanoshell. The bioinspired nanosystem facilitates efficient recruitment of mineral precursors throughout the dentin structures, followed by large-scale intradentinal mineralization both in vitro and in vivo, which provides persistent protection against external stimuli. Theoretical simulations combined with experimental studies attribute the success of intradentinal mineralization to the TA-SF nanoshell, which exhibits a strong affinity for the dentin structure, stabilizing amorphous precursors and thereby facilitating concomitant mineral formation. Overall, this bioinspired mineral-in-shell nanoarchitectonics shows a promising prospect for hard tissue repair and serves as a blueprint for next-generation biomineralization-associated materials. [ABSTRACT FROM AUTHOR]

Recently, more and more studies have shown that guanylate cyclase, an enzyme that synthesizes cyclic guanosine monophosphate (cGMP), plays an important role in bone metabolism. Vericiguat (VIT), a novel oral soluble guanylate cyclase stimulator, directly generates cyclic guanosine monophosphate and reduce the death incidence from cardio-vascular causes or hospitalization. Recent studies have shown beneficial effects of VIT in animal models of osteoporosis, but very little is currently known about the effects of VIT on bone defects in the osteoporotic states. Therefore, in this study, β-tricalcium phosphate (β-TCP) was used as a carrier to explore the effect of local VIT administration on the repair of femoral metaphyseal bone defects in ovariectomized (OVX) rats. When MC3T3-E1 was cultured in the presence of H2H2, VIT, similar to Melatonin (MT), therapy could increase the matrix mineralization and ALP, SOD2, SIRT1, and OPG expression, reduce ROS and Mito SOX production, RANKL expression, Promote the recovery of mitochondrial membrane potential. In the OVX rat model, VIT increases the osteogenic effect of β-TCP and better results were obtained at a dose of 5 mg. Local use of VIT can inhibit increased OC, BMP2 and RUNX2 expressions in bone tissue, while decreased SOST and TRAP expressions by RT-PCR and immunohistochemistry. Thereby, VIT stimulates bone regeneration and is a promising candidate for promoting bone repair in osteoporosis. [ABSTRACT FROM AUTHOR]

A calcium phosphate solid formed as an unintended consequence of a novel high-pH orthophosphate lead corrosion control strategy in Providence, RI, resulting in some consumer complaints and clogged plumbing. Investigations were carried out at pH levels of 8.9–10.4, at temperatures of 5–60°C, and with orthophosphate concentrations ranging from 0 to 4.0 mg/L as orthophosphate (PO4) to examine this phenomenon. During field testing, the calcium phosphate initially precipitated at orthophosphate doses above about 2 mg/L as PO4, and the extent of precipitation increased with water age and higher temperature. Laboratory-scale tests confirmed that doses above about 2 mg/L as PO4 were required to form the precipitate in the absence of preexisting calcium phosphate solids and that the solid formed quickly at 60°C (upper range for hot water heaters) and tended to dissolve at lower pH. Solubility studies and solids characterization indicate that the particles are a mixture of noncrystalline compounds containing calcium and phosphate. For water systems currently practicing a high pH/low alkalinity corrosion control strategy, orthophosphate dosing can enhance plumbosolvency control without the risk of pH reduction, but formation of this solid can place an upper limit on the maximum orthophosphate residual level in the distribution system. [ABSTRACT FROM AUTHOR]

The crystal growth of hydroxyapatite (HAp) using a solvothermal method was investigated under various reaction conditions. The purpose of the present study is the synthesis of HAp nanocrystals with multiple facets and the atomic arrangement for various orientations of the crystal was clarified. HAp nanorods were obtained at 200°C after 24 h using a reaction medium of water. The atomic arrangement in HAp nanorods was examined for a characteristic facet in the direction of [21−13−] and [0110−] incidences and crystal orientation along the c‐axis of HAp nanorod was confirmed using electron microscopy. The present study clarifies the HAp crystal growth mechanism, where the adsorption of cations or anions onto the crystal facet determines the HAp crystal shape. The crystals of HAp grew along the c‐axis and became rod‐shaped suggesting that cations were adsorbed predominantly over anions. [ABSTRACT FROM AUTHOR]

BACKGROUND: White spot lesions (WSLs) appear as white, opaque areas on the teeth and are caused by a demineralization of the enamel. OBJECTIVE: The purpose of this systematic review and meta-analysis was to determine whether casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) has beneficial effects on WSLs and provides remineralizing benefits that are superior to those of placebo or no treatment. METHODS: Following a thorough analysis of the literature across major online sources, 103 papers – 54 of which underwent in-depth evaluation – were found. We used inclusion and exclusion criteria to choose research articles that were appropriate for our review. RESULTS: 10 papers met this review's requirements and were subsequently included. As compared to the controls, CPP-ACP demonstrated increased efficacy in treatment of WSLs in terms of remineralisation and other parameters which included microhardness tests and enamel surface roughness. The forest plots present the results of meta-analyses comparing the effect of CPP-ACP versus control/other agents on white spot lesions (WSLs). In terms of odds ratios (OR), CPP-ACP showed a small increase in the odds of WSLs compared to control/other agents. In-vitro studies showed no significant difference in relative risk (RR) between CPP-ACP and control/other agents. Randomized control trials indicated a small increase in the risk of WSLs with CPP-ACP treatment, but the overall effect was not statistically significant. CONCLUSION: There was evidence to support the use of CPP-ACP over other agents for WSL prevention or treatment, but further research is needed to confirm these findings. [ABSTRACT FROM AUTHOR]

Phosphate is the second most essential nutrient for plant growth and development. Although the soil contains abundant phosphorus, only 0.1% is used by plant roots due to the significant amount of calcium carbonate (CaCO3) present in the calcareous soil, which limits the availability of P by reacting calcium ions with phosphate ions. It leads to alkaline reactions by generating insoluble phosphate compounds such as tricalcium phosphate. Here we study to boost phosphate solubilization in PSMs as an alternate strategy. Twenty-one bacterial isolates were selected from two different crops and investigated in vitro for their plant growth potential. All bacteria show capacity for phosphate solubility by producing a clear halo zone beneath and much more around bacterial colonies on Pikovskaya agar. In contrast, on modified Pikovskaya and only seven isolates with 60% reduction in zone formation were revealed to be positive for phosphate solubilization in which SWC5 was the best phosphate solubilizers with 1.25 phosphate solubilization index, respectively. All phosphate solubilizing bacteria showed irregular pattern in lowering the pH ranging from 4.1-6.27, where maximum decreased in pH was shown by SWS10.All bacteria showed phosphate solubilization ability in Pikovskaya broth phosphomolybdate assay ranging from 6.31 to 20.9 µg ml-1 in which the highest efficiency was demonstrated by SWS10. Phosphate solubilization efficiency in the potential isolates was confirmed by the presence of PqqE gene. The presence of the pqqE gene which is involved in phosphate solubilization was found in SWC4, SWC5, SWS10, and SW14 and it was absent in SWS9, SW18, and SW21. All the bacterial isolates were phylogenetically identified by sequencing and analyzing the 16S rRNA gene. The potential isolates Pseudomonas Koreensis, Pantoea dispersa, Pseudomonas sp., Agrobacterium sp. and consortia were selected for controlled condition experiment on Triticum aestivum. The highest plant dry weight was achieved by application of consortia and Pseudomonas Koreensis by increasing 65% and 59%, respectively, compared to control. [ABSTRACT FROM AUTHOR]

The characteristics and suitability of hydroxyapatite (HAP), tricalcium apatite phosphate (PTCa), and octocalcium apatite phosphate (OCPa), which possess similar attributes to those of an ideal adsorbent, were investigated to determine their efficacy in phenol removal. The aim of this paper is to assess the adsorption behavior of phenol on phosphates powders synthesized by the co-precipitation method at ambient temperature. Furthermore, the impact of initial phenol quantities and thermal conditions on the adsorption process was explored. X-ray diffraction analysis revealed the formation of HAP, PTCa, and OCPa structures under room temperature conditions. The sample morphologies were subjected to scrutiny utilizing MEB together with X-ray analysis. Additionally, chemical analysis revealed that Ca/P = 1.6, 1.5, and 1.33 for HAP, PTCa, and OCPa, respectively. The synthesized powders exhibited adsorption abilities of 2.86, 2.74, and 2.52 mg/g for HAP, PTCa, and OCPa, respectively, and reached equilibrium in approximately 80 minutes. The study revealed that the experimental data are appropriately represented by the Langmuir and Freundlich adsorption equations for HAP and PTCa, and Langmuir model in the case of OCPa, as well as by the pseudo-first-order and pseudo-second-order adsorption kinetics. Thermodynamic evaluations, including calculations of ΔG°, ΔH°, and ΔS°, were performed. The results indicated that the adsorption mechanisms exhibited physical characteristics, were thermally absorbing in the case of HAP and exothermic for the other two phosphates, PTCa and OCPa, and occurred spontaneously. [ABSTRACT FROM AUTHOR]

Introduction: This study aimed to investigate the remineralisation effect of combined use of a bioinspired self-assembling peptide (P26) and fluoride varnish on artificial early enamel caries lesions. Methods: Bovine enamel blocks with artificial early enamel caries lesions were prepared. The blocks were randomly allocated to four experimental groups to receive the following treatments: A = P26 + fluoride varnish, B = P26, C = fluoride varnish, and D. distilled water (negative control). The treated blocks were subjected to pH cycling. Enamel blocks were collected at time points of 7 days (d7) and 21 days (d21). The mineral gain, elemental analysis and crystal characteristics of the caries lesion were assessed by micro-computed tomography, scanning electron microscopy with energy dispersive X-ray and X-ray diffraction (XRD), respectively. Results: The mean ± standard deviation of mineral gain of group A to D were 17.4 ± 4.2%, 10.7 ± 2.2%, 10.1 ± 1.2%, and 6.8 ± 0.5% at d7, respectively, and 15.2 ± 2.6%, 8.7 ± 3.1%, 9.7 ± 1.2%, and 7.8 ± 2.3% at d21, respectively. A significant higher mineral gain was observed in group A when compared to other groups at both d7 and d21 (p < 0.05). The calcium-to-phosphate ratio remained consistent across all groups, ranging between 1.2 and 1.4. XRD analysis indicated that crystal composition on the surfaces was apatite for all groups. Conclusion: In conclusion, the present study provided a first indication of better remineralisation effects of the combined use of the bioinspired self-assembling peptide P26 and fluoride varnish compared to the effects of the respective individual uses of P26 or fluoride varnish. [ABSTRACT FROM AUTHOR]