Carbonate Apatite Research Articles

Improved In Vivo Delivery of Small RNA Based on the Calcium Phosphate Method.

In the past few years, we have demonstrated the efficacy of a nanoparticle system, super carbonate apatite (sCA), for the in vivo delivery of siRNA/miRNA. Intravenous injection of sCA loaded with small RNAs results in safe, high tumor delivery in mouse models. To further improve the efficiency of tumor delivery and avoid liver toxicity, we successfully developed an inorganic nanoparticle device (iNaD) via high-frequency ultrasonic pulverization combined with PEG blending during the production of sCA. Compared to sCA loaded with 24 μg of miRNA, systemic administration of iNaD loaded with 0.75 μg of miRNA demonstrated similar delivery efficiency to mouse tumors with little accumulation in the liver. In the mouse therapeutic model, iNaD loaded with 3 μg of the tumor suppressor small RNA MIRTX resulted in an improved anti-tumor effect compared to sCA loaded with 24 μg. Our findings on the bio-distribution and therapeutic effect of iNaD provide new perspectives for future nanomedicine engineering.

Effect of varying phosphate content on the structure and properties of sol-gel derived SiO2-CaO-P2O5 bio-glass

In this work, biocompatible glass (bioglass) particles were prepared by low temperature, acid catalysed sol-gel method. The effect of varying phosphate (P2O5) content (10, 15 and 20 mol %) in the sol-gel derived glass composition were studied. The sol-gel derived bioglass particles were compacted into cylindrical pellets via hydraulic press machine and sintered at 600°C for 3 hours. The bioglass particulates were analysed by x-ray fluorescence (XRF), Fourier Transformed Infrared (FTIR), X-Ray Diffraction (XRD) and nitrogen gas adsorption. Meanwhile, the sintered bioglass pellets were analysed by FTIR, XRD and FESEM-EDX. Furthermore, in vitro bioactivity analysis was performed by immersion in simulated body fluid (SBF) for 14 days. Bioglass particulates with high glassy phase, high surface area and high porosities were obtained for all compositions. Increasing of phosphate content to 20 mol% particularly reduced the porous characteristics of the bioglass particulates. Furthermore, leads to higher bridging oxygen (BO) atoms, higher amorphous silicate networks, lower glass crystallinity and higher number of phosphate crystallites within the amorphous glassy matrix. Increased to 20 mol% of phosphate also reduced the ability of the bioglass surface to induce carbonated apatite formation when immersed in simulated body fluid (SBF) solution.

Quantitative Analysis and Effect of SDF, APF, NaF on Demineralized Human Primary Enamel Using SEM, XRD, and FTIR.

IntroductionTopical fluoride therapy has proven benefits in the prevention of demineralization. Tooth enamel has shown a great potential for remineralization with an application of topical fluorides if administered at an appropriate time. In an effort to find an effective remineralizing agent, a novel fluoride agent silver diamine fluoride (SDF) has emerged as a potent caries arresting as well as caries preventing agent.Aim and objectiveThe present study was aimed at determining the primary tooth enamel resistance to demineralization after topical application of three fluoride agents SDF, APF, and NaF.Materials and methodsEnamel specimens were prepared from 40 caries-free primary molars. These specimens were randomly allocated into three groups of 10 specimens each and they were treated by different topical fluorides namely: Group I–SDF, group II–Acidulated phosphate fluoride (APF), group III–Sodium fluoride. Three enamel specimens from each group were placed on custom-made acrylic blocks with 5 × 5 mm of an exposed window for scanning electron microscope (SEM) evaluation and rest of the specimens were ground into a fine powder for X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) analysis. The tooth blocks and treated samples were subjected to the demineralization process for 168 hours. They were then qualitatively assessed to evaluate their resistance to demineralization using SEM, XRD, and FTIR.Results and conclusionMorphologically, the enamel of all groups specimens was mostly smooth with some groves and microporosities. Chemically, the Ca/P molar ratios of all groups were similar with slight variations. Structurally, the crystalline phases found in enamel by powder XRD were hydroxyapatite and carbonate apatite; and there was a higher amount of incorporated type B carbonate than type A carbonate as evidenced by FTIR. The study concludes that topical application of a 38% SDF solution can inhibit demineralization of enamel.How to cite this articleJabin Z, Nasim I, Vishnu Priya V, et al. Quantitative Analysis and Effect of SDF, APF, NaF on Demineralized Human Primary Enamel Using SEM, XRD, and FTIR. Int J Clin Pediatr Dent 2021;14(4):537–541.

Diamictitic iron formation (DIF) deposits of the Neoproterozoic Nova Aurora Iron District (Macaúbas Group, Southeast Brazil)

The best-known Neoproterozoic glaciation-related iron deposits are the Rapitan-type banded iron formation (BIF) formed dominantly by chemical-sedimentary processes. We present a detailed study on a distinct type of glaciation-related iron deposit: the iron-rich metadiamictites of the Nova Aurora Iron District, comprising over 20 billion tons of iron oxide-rich rocks: the diamictitic iron formations (DIF >15 wt% Fe) and ferruginous metadiamictites (FD: 5–15 wt% Fe). Drill core logging, field mapping and analytical data revealed the protoliths, sediment sources, depositional environment, and ore enrichment processes on the iron district, and were used to discuss differences between the studied DIF and classic Rapitan-type BIF. U–Pb age spectra and Lu–Hf data for detrital zircon grains revealed a wide range of sediment sources and a maximum depositional age around 879 Ma. These data support correlations of the Nova Aurora iron deposits with the Cryogenian Macaúbas rift, a basin filled by glaciomarine successions related to the Sturtian glaciation event. The matrices of prevailing hematite-rich metadiamictites comprise (in vol %): hematite (7–55), quartz (17–57), muscovite (2–40), carbonate (<1–30), biotite (<1–18), chlorite (<1–23), epidote (<1–7), magnetite (1–5), and traces of tourmaline (<3), apatite (<3) and zircon (<1), with hematite, mica and stretched quartz outlining the metamorphic foliation. Clasts are free of iron-rich rocks. Hematite reconcentration (>50 wt% Fe) occurs in local mylonitic shear zones and tightly crenulated bands after gangue minerals removal during deformation. Late hydrothermal alteration formed magnetite-rich metadiamictite in high-strain zones. From base to top, the stratigraphic type-section of the Nova Aurora Iron District shows barren metadiamictite with quartz-rich matrix and graded-bedded quartzite lenses, followed by hematite-rich-matrix metadiamictite, then passing to muscovite-rich-matrix metadiamictite gradually richer in magnetite and sulfide, enclosing metapelite lenses. This section presents a fining-up graded-bedded succession with clasts size decreasing upwards and recurrent load structures, typical of debris flows and turbiditic sedimentation. The hematite/mica, Fe/Al, Fe/Ti and Fe/REE ratios, as well as the biotite/muscovite and silicate/sulfide ratios, which accompany variations in the oxidizing conditions, decrease to the top. Accordingly, the early protoliths were quartz-rich diamictites that passed to iron-rich diamictites and then to clay-rich, and under more reducing conditions, sulfide-bearing diamictites. Sedimentological and geochemical evidences suggest ferrous-iron accumulation followed by iron oxide precipitation from seawater when the conditions changed from anoxic to oxidizing by the input of oxygen-rich waters from deglaciation, followed by increasing reducing conditions accompanying marine transgression. These processes took place in a relatively restricted sector of the glaciomarine basin, probably a graben of the Cryogenian Macaúbas rift. Differences in relation to the classic Rapitan-type iron formations are the coarse-grained (ruditic) texture and the massive structure, the high-energy sedimentary environment, and the absence of true BIF in the Nova Aurora DIF deposits.

Modification of exosomes with carbonate apatite and a glycan polymer improves transduction efficiency and target cell selectivity

Exosomes are secreted from a variety of cells and transmit parental cell-derived biomolecules, such as nucleic acids and proteins, to recipient cells in distant organs. In addition to their important roles in both physiological and pathological conditions, exosomes are expected to serve as natural drug carriers without any cytotoxicity, immunogenicity, or tumorigenicity. However, the use of exosomes as drug delivery tools is limited due to the low uptake efficiency of the target cells, insufficient release of the contents from the endosome to the cytosol, and possible adverse effects caused by the delivery to non-target cells. In the present study, we examined the effects of the modification of exosomes with carbonate apatite or a lactose-carrying polymer. Using newly generated monitoring exosomes that contain either firefly luciferase or fused mCherry/enhanced green fluorescent protein, we demonstrated that the modification of exosomes with carbonate apatite improved their release from the endosome into the cytosol in recipient cells. Meanwhile, the modification of exosomes with a lactose-carrying polymer enhanced the selective delivery to parenchymal hepatocytes. These modified exosomes may provide an efficient strategy for macromolecule therapy for incurable diseases that cannot be treated with conventional small-molecule compounds.

The Chemical Compositon of Urinary Stones at the Military Teaching Hospital of Cotonou

The Chemical composition of urinary stones at the Military Teaching Hospital of Cotonou. Objective: To determine the chemical composition of urinary stones in our patients. Patients and method: We collect surgically removed urinary stones from our patients and send them abroad for infrared spectroscopic analysis. Results: The infrared spectroscopic analysis was performed on urinary stones from 26 patients, i.e. 21 males (80.8%) and 5 females (19.2%). Their mean age was 48 years (range: 21-71). The mean proportions of chemical components in the stones were: 40.8% whewellite (0-97), 29.4% weddellite (0-95), 12.7% uric acid (0-90), 5.4% struvite (0-70), 5.2% carbonate apatite (0-20), 1.9% ammonium urate (0-20), 1.7% silicate (0-45), 1.3% protein (0-10), 1.2% whitlockite (0-10) and 0.1% hydroxyapatite (0-2). All stones were a mixture of 2 or 3 of the identified chemical components. Based on the main component, there were 3 groups of stones: the calcium oxalate stones (77%), the uric acid stones (15.4%) and struvite stones (7.7%). One calcium oxalate stone from a female comprised 45% silicate and 5% protein. There was no stone chemical composition difference between males and females. Conclusion: The stones from the 26 patients were mainly non pure calcium oxalate stones (73%), uric acid stones 8%) and struvite stones (4%).

Staged Sinus Floor Elevation Using Novel Low-Crystalline Carbonate Apatite Granules: Prospective Results after 3-Year Functional Loading.

The aim of this study was to evaluate clinical outcomes of staged sinus floor elevation (SFE) using novel low-crystalline carbonate apatite (CO3Ap) granules. Patients who needed SFE for implant placement were recruited into this clinical trial. A staged procedure (lateral window technique using CO3Ap granules, followed by implant placement after 7 ± 2 months) was employed in 13 patients. Bone-height increase and insertion torque values (ITVs) were assessed along with histological evaluation. The survival and success rates of 3-year functioning implants were also evaluated. Mean of bone-height increase after SFE using CO3Ap granules was 7.2 ± 2.5 mm and this increase allowed implant placement in all cases (17 implants). Mean of ITV was 25.1 ± 13.2 Ncm and primary stability was achieved successfully in all cases. Histological analyses revealed mature new bone formation (36.8 ± 17.3%) and residual CO3Ap granules (16.2 ± 10.1%) in the compartment after SFE. The survival and success rates after 3-year functional loading were 100% and no complications were found. These results clearly indicate the clinical usefulness of CO3Ap granules for SFE.

Honeycomb Scaffold-Guided Bone Reconstruction of Critical-Sized Defects in Rabbit Ulnar Shafts.

Reconstruction of critical-sized defects (CSDs) in bone shafts remains a major challenge in orthopedics. Honeycomb (HC) scaffolds are considered promising as their uniaxial channels bridge the amputation stumps of bones and promote the ingrowth of bone and blood vessels (BV) into the scaffolds. In this study, the ability of the HC scaffolds, composed of the bone mineral or carbonate apatite (CAp), was evaluated by reconstructing 10, 15, and 20 mm segmental defects in the rabbit ulnar shaft. Radiographic and μ-computed tomography evaluations showed that bony calluses were formed around the scaffolds at 4 weeks post-surgery in all defects, whereas no callus bridged in the ulna without scaffolds. At 12 weeks post-surgery, the scaffolds were connected to the host bone in 10 and 15 mm defects, while a slight gap remained between the scaffold and host bone in the 20 mm defect. New bone formation and scaffold resorption progressed over 12 weeks. Histological evaluations showed that mature bones (MB) and BV were already formed at the edges of the scaffolds at 4 weeks post-surgery in 10, 15, and 20 mm defects. In the central region of the scaffold, in the 10 mm defect, MB and BV were formed at 4 weeks post-surgery. In the 15 mm defect, although BV were formed, a few MB were formed. It is concluded that CAp HC scaffolds have good potential value for the reconstruction of CSDs.

Inhibition of Breast Tumour Growth with Intravenously Administered PRKCA siRNA- and PTEN Tumour Suppressor Gene-Loaded Carbonate Apatite Nanoparticles

Gene therapy aims to silence an oncogene through RNA interference, or replace an abnormal tumour suppressor via gene augmentation. In this study, we intended RNA interference for PRKCA oncogene and gene augmentation for PTEN tumour suppressor with a view to reduce tumour growth in a mouse model of breast cancer. Inorganic carbonate apatite nanoparticles (CA NPs) were utilized to deliver the synthetic siRNA and the purified gene-carrying plasmid DNA both in vitro and in vivo. Effects of PRKCA siRNA- and PTEN plasmid-loaded NPs on viability of MCF-7, MDA-MB-231 and 4T1 breast cancer cells were assessed by MTT assay. The cell viability data in MCF-7 cell line demonstrated that combined delivery of PRKCA specific siRNA and PTEN plasmid with CA NPs had an additive effect to significantly decrease cellular growth compared to individual treatments. In addition, we observed a similar pattern of cumulative influence for combined treatment in triple negative MDA-MB-231 breast cancer cell line. Upon treatment with PRKCA siRNA+PTEN plasmid-loaded NPs, a remarkable decrease in the phosphorylated form of AKT protein of PI3K/AKT pathway was observed in Western blot, indicative of diminished proliferative signal. Moreover, in vivo study in MCF-7 xenograft breast cancer mouse model demonstrated that the rate of growth and final tumour volume were reduced significantly in the mouse group that received intravenous treatment of PRKCA siRNA+NPs, and PTEN plasmid+NPs. Our findings demonstrated that PRKCA siRNA and PTEN plasmid loaded into CA NPs attenuated breast tumour growth, suggesting their therapeutic potential in the treatment of breast cancer.

Enhanced Corrosion Resistance and In Vitro Biocompatibility of Mg-Zn Alloys by Carbonate Apatite Coating.

B-type carbonate apatite (CAp) coatings were formed on as-cast and T4-treated Mg-xZn (x = 1, 5, and 7 wt %) alloys containing various sized Zn-rich second phase to improve the corrosion resistance and biocompatibility. The CAp coating grew uniformly on the alloys with a thickness of 1.1-1.3 μm and did not show cracks or pores on 30 μm-sized second-phase particles. The CAp coating retarded corrosion of Mg-Zn substrates for the first 3-5 days in Hanks' solution. Polarization resistance of the CAp-coated alloys was 10-90 and 1-70 times higher than the uncoated and hydroxyapatite (HAp)-coated alloys, respectively. The corrosion rate of CAp-coated alloys was greatly affected by the substrate alloys once the coatings were partly broken. The CAp-coated alloys showed 40-60 and 25-45% lower 14-day average corrosion rates than the uncoated and HAp-coated alloys, respectively, in the immersion test. The CAp coating significantly enhanced the viability of osteoblastic MC3T3-E1 cells on the Mg-Zn alloys for 72 h compared to the uncoated and HAp-coated alloys. The cell densities on CAp-coated alloys were similar for 72 h regardless of substrate alloys. Therefore, the CAp coating can be a superior coating candidate for corrosion-control and biocompatibility improvement for biodegradable Mg alloys.

Replacement Process of Carbonate Apatite by Alveolar Bone in a Rat Extraction Socket.

The objective of this study was to investigate a bone graft substitute containing carbonate apatite (CO3Ap) to analyze bone replacement and the state of bone formation in vitro and in vivo compared with autogenous bone (AB) or control. An osteoclast precursor cell line was cultured with AB or CO3Ap, and morphological analysis using scanning electron microscopy and a tartrate-resistant acid phosphatase activity assay were performed. The right maxillary first and second molars of Wistar rats were extracted and compensated by AB or CO3Ap granules. Following implantation, the bone formation state was evaluated after 3, 5, 7, 14, and 28 days of surgery by micro-computed tomography and immunohistostaining. The osteoclast-like cell morphology was typical with many cell protrusions in the AB and CO3Ap groups. Additionally, the number of osteoclast-like cells formed in the culture increased in each group; however, there was no significant difference between the AB and CO3Ap groups. Five days after tooth extraction, osteoclasts were observed near CO3Ap. The bone thickness in the CO3Ap group was significantly increased than that in the control group and the bone formation in the CO3Ap group increased by the same level as that in the AB group. CO3Ap is gradually absorbed by osteoclasts in the extraction socket and is easily replaced by alveolar bone. The process of bone replacement by osteoclasts is similar to that of autologous bone. By observing the process of bone replacement in more detail, it may be possible to gain a better understanding of the bone formation and control the amount of bone after surgery.

Development of carbonate apatite capsules based on degradable coacervate droplets for bone defect treatment

Development of carbonate apatite capsules based on degradable coacervate droplets for bone defect treatment

A urinary stone from the early medieval site of Riner, Catalonia

ObjectiveThis paper presents the differential diagnosis of a calcified mass found in the pelvic cavity of an adult male dating to the 10th century AD. MaterialsSkeletal remains of an adult male exhumed from the cemetery associated with the early medieval church of Riner (Solsonès, Catalonia). MethodsThe structure and composition of the mass were examined by x-ray imaging, microscopic stereoscopy and Fourier transform infrared spectrometry analysis. ResultsThe examination reveals a light brown kidney-shaped calcification with well-defined margins, irregular hypodense zones, and several thin concentric layers. The obtained spectra showed a mixture of carbonate apatite (with a high level of carbonation) and calcite in all the sections studied. ConclusionThe calcification most likely corresponds to a urinary calculus of infectious origin. SignificanceGiven the insights that urinary calculi can provide towards understanding consequences of infection and environmental conditions, this case will be of interest to other researchers wishing to initiate comparative analyses. LimitationsThe discussion of the etiology of the stone is limited by the lack of preservation of certain elements such as struvite.

Early Osteoconductivity and Degradability of Sintered Porous Bodies of A- and B-Type Carbonated Apatites and Stoichiometric Hydroxyapatite

An artificial bone that mimics the chemical composition of biological apatite is one of the promising implants for the treatment of bone defects and is useful as a scaffold for tissue-engineered bone. There are three types of carbonate substitution in hydroxyapatite (HAp) at hydroxyl groups (A-type), phosphate groups (B-type), and both groups (AB-type). Less is known about the role of A-type carbonate apatite (CAp) in influencing the bone regeneration process and there are no comparative studies of these apatites. The present study aims to elucidate osteoconductivity and degradability of porous sintered bodies of stoichiometric HAp, A-type CAp (A-CAp), and B-type CAp (B-CAp) with a constant carbonate content at 5.0 wt%. Both CAp with 75% porosity showed similar ionic dissolution rates which were faster than HAp with 67% porosity. A-CAp had the largest affinity for albumin from time-dependent adsorption tests. The lowest attachment of MC3T3-E1 cells was observed for A-CAp; however, the proliferation rate was similar of both CAp, which was lower than HAp. Early osteoblastic marker (alkaline phosphatase activity) was significantly upregulated for CAp at day 3 relative to HAp. After two weeks of implantation, A-CAp and HAp showed scarce bone formation encapsulated by fibrous tissue. In contrast, B-CAp showed significant bone ingrowth and closely adjoined to the surrounding bone tissue. The rapid degradation of CAp was attributed to osteoclast activities, in which A-CAp showed better capacity in promoting osteoclast maturation. It is concluded that a specific carbonate substitution type significantly impacts osteoconductivity or degradability of artificial bones.

Enhancement of bone to polylactic acid plate bonding by carbonate apatite coating

Polylactic acid (PLA) has no osteoconductivity, causing the early failure of PLA implants. For obviating this problem, coating, rather than incorporation, of PLA with calcium phosphate is considered to be effective. In this study, PLA plates were coated with granular carbonate apatite (CAp), the inorganic component of bone, using the thermal fusion bonding method. The water contact angles of the CAp-coated PLA (CAp/PLA) plates and PLA were 0.7° ± 0.1° and 90.3° ± 3.9°, respectively. Thus, CAp coating significantly improved the wettability of the PLA surface. Furthermore, the roughness (Ra) of CAp/PLA and PLA was 11.7 ± 2.2 μm and 1.8 ± 0.2 μm, respectively. CAp coating involved two types of micropores (~30–80 μm and ~2 μm). Thus, CAp coating provided a rough surface and micropores to the PLA plate. The CAp/PLA and uncoated PLA plates were fixed onto a rabbit tibial surface to evaluate their bone formation and adhesion abilities. Four weeks after implantation, new bone formed on the surface of the CAp/PLA plates. In contrast, no tissue was present in most of the regions between the uncoated PLA plate and the tibia. The tensile bond strengths of the CAp/PLA and PLA plates to the tibia were 4.0 ± 2.5 and 0 N, respectively. Thus, CAp coating of PLA promoted new bone formation on the plate surface and increased the ability to bond to the bone surface at an early stage. CAp coating of PLA is an effective strategy for achieving rapid and robust bone fixation.

Structural and elemental characterization of glass and ceramic particles for bone surgery

ObjectiveClinically used bioceramics have been characterized previously with different kinds of methods and comparison of results have proven to be difficult due to varieties of the material properties of interest. Therefore, in this study we compared clinically commonly used bioceramics of hydroxyapatite and carbonate apatite, two bioactive glasses 45S5 and S53P4, and alumina with respect of properties which according to the present knowledge are significant for bone biology. MethodsPhysicochemical properties of the materials were characterized by various methods. Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) was used to analyze the material vibrational features. X-ray Power Diffraction (XRD) was used to characterize the material crystal structure and scanning electron microscopy-energy-dispersive x-ray analysis (SEM-EDXA) was used to evaluate the morphology and size of the materials and to calculate their oxide content. The dissolution behavior of the materials, ion release and pH changes in Tris buffer in a continuous flow-through reaction for 24-hours were determined. The change of the surface of the bioactive glasses by interfacial reaction during the Tris immersion was examined and the thickness of the surface reaction layer of the materials was studied. ResultsSEM examination showed that the particle morphology of BG 45S5, BG S53P4 and alumina particle’s surface was smooth. The surface of HAP was porous, but also CAP showed some surface porosity. An increase in the pH of the immersion solution was observed especially for BG 45S5 and BG S53P4. HAP, CAP and alumina caused only a minor increase in pH. BGs 45S5 and S53P4 showed a rapid initial release of sodium and calcium ions, followed by the release of silicon species. Minor release of sodium ions was registered for HAP, CAP and alumina. Calcium ion release was low but constant over the experimental time while only a minor initial dissolution was measured for HAP. SignificanceThe in vitro study showed differences in the materials’ properties, which are considered to be important for biological suitability and in clinical applications, such as materials tomography, ion release and pH changes.

Fabrication of silver-doped apatite powders from silver-substituted octacalcium phosphate powders via solid–solid phase-conversion process

The excellent biocompatibility of apatite (hydroxyapatite, HAp; carbonate apatite, CO3Ap) materials makes them suitable candidates as bone substitutes. However, they have no antibacterial ability. Meanwhile, silver (Ag) exhibits excellent antibacterial properties across a wide antibacterial spectrum. However, soluble Ag salts exhibit cytotoxicity and poor aesthetic properties. We dope Ag into an apatite unit lattice in order for the composite material to exhibit antibacterial contact abilities while simultaneously limiting the release of Ag+, which is the primary cause of the unwanted color changes and cytotoxicity. When a crystal structure in which silver ions are substituted for Ca in octacalcium phosphate (OCP) (Ag-OCP) is immersed in water and/or (NH4)2CO3-containing solutions, Ag-OCP is converted into an apatite containing Ag via a solid–solid phase-transformation process. The Ag contents of the apatite and precursor Ag-OCP are the same. The CO3 content of apatite samples depends on the (NH4)2CO3 concentration of the treated solutions. A single-pot, single-step treatment enables the synthesis of both Ag-containing HAp and CO3Ap. Further, these Ag-containing HAp and CO3Ap samples show little color change from that of the precursor Ag-OCP.

A retrospective study on sex difference in patients with urolithiasis: who is more vulnerable to chronic kidney disease?

BackgroundUrolithiasis is considered a vital public health issue with a substantial burden on kidney function. Additionally, only few reports focused on the gender difference in patients with urolithiasis. Therefore, this study aimed to compare the clinical characteristics of sex difference and their potential risk for chronic kidney disease (CKD) in patients with urolithiasis.MethodsPatients diagnosed with stone disease from 2013 to 2018 were retrospectively reviewed and divided into two groups by gender. Clinical demographic characteristics, stone location, stone composition, urine chemistries, and renal function were investigated. Univariate and multivariate analyses were used to assess the relationship and potential risk of CKD between sex groups.ResultsA total of 1802 patients were included: 1312 from men and 490 from women. Female patients had a higher rate of hypertension, diabetes, and dyslipidemia. Male patients predominantly had calcium-containing stones, especially calcium oxalate stone, uric acid stone, and struvite stone. Carbonate apatite stone was more frequently found in women. Complex surgeries such as percutaneous nephrolithotomy (PCNL) and ureteroscopic lithotripsy (URSL) were more frequently performed in women than that in men. Multivariate analysis confirmed that age > 60 years (odds ratios [ORs] = 6.36; 95% confidence interval [CI], 3.8–10.8), female sex (ORs = 5.31; 95% CI 3.3–8.4), uric acid stone (ORs = 3.55; 95% CI 2.0–6.4), hypertension (OR = 7.20; 95% CI 3.8–13.7), and diabetes (OR = 7.06; 95% CI 3.1–16.2) were independent predictors of poor prognoses in CKD.ConclusionsThe female gender is significantly associated with a higher prevalence of CKD among patients with urolithiasis. Therefore, women with stone disease may need close renal function monitoring during follow-up.

The characterization of hydroxyapatite from blood clam shells and eggs shells: Shyntesis by hydrothermal method

Hydroxyapatite is a bioceramic that can be used as a denture material. Hydroxyapatite can be produced by synthesizing blood clam shells and eggshells as a source of calcium and (NH4) 2HPO4, phosphate through hydrothermal methods. The hydroxyapatite samples were characterized by XRD and FTIR. The results of XRD analysis showed that the hydroxyapatite produced contained calcium carbonate (CaCO3) and apatite carbonate type A. Hydroxyapatite has a hexagonal structure with lattice parameters a = 9.404 Å and c = 6.675 Å the resulting crystal size ranges from 10.19 nm to 57.29 nm. The results of the FTIR spectrum of the hydroxyapatite sample contained functional groups PO4 3-, OH− and CO3 2- which are functional groups of hydroxyapatite.

Fabrication of Hydroxyapatite/Tantalum Composites by Pressureless Sintering in Different Atmosphere.

The effect of sintering atmosphere (air and Ar) and temperature (1100, 1200, 1300 °C) on the microstructure, mechanical properties, and bioactivity of hydroxyapatite/tantalum (HA/Ta) composites were systematically investigated by pressureless sintering of the mixture of HA and Ta powders. It shows that the sintering atmosphere greatly impacts the phase composition and microstructure of the HA/Ta composites. The higher diffusion of atoms promotes shrinkage and causes deeper reaction fusion between the HA matrix and Ta, which improved the interfacial binding of the HA/Ta composites. The refined grain structure and improved interfacial binding obtained within the Ar atmosphere compared to the air atmosphere benefit the mechanical properties. The maximum bending strength and shrinkage observed for the composites sintered at 1300 °C in the Ar atmosphere are 27.24 MPa and 6.65%, respectively. The cell counting kit-8 (CCK-8) method was used to investigate the in vitro cytocompatibility of HA/Ta composites. The results revealed that the HA/Ta composites sintered with different conditions have no cytotoxicity. The simulated body fluid (SBF) soaking results showed that all of the studied composites possess desirable bioactivity, as demonstrated by their ability to form calcium-deficient carbonate apatite layer on the surfaces. For composites sintered at 1300 °C, the surface apatite layer coverage of the composites obtained in the Ar atmosphere was increased by 139.7% than the ones obtained in air, which confirmed an enhanced bioactive mineralization ability. The results indicated that the HA/Ta composites sintered at 1300 °C in Ar possess desirable mechanical properties and bioactivity. This work opens up the new possibility for preparing HA-based composites and is of great value in biomedical applications.