CaCO3 Group Research Articles

Hexanoic acid production and microbial community in anaerobic fermentation: Effects of inorganic carbon addition

Carbon dioxide (CO2) plays a crucial role in carbon chain elongation with ethanol serving as an electron donor. In this study, the impacts of various carbonates on CO2 concentration, hexanoic acid production, and microbial communities during ethanol-butyric acid fermentation were explored. The results showed that the addition of MgCO3 provided sustained inorganic carbon and facilitated interspecific electron transfer, thereby increasing hexanoic acid yield by 58%. MgCO3 and NH4HCO3 inhibited the excessive ethanol oxidation and decreased the yield of acetic acid by 51% and 42%, respectively. The yields of hexanoic acid and acetic acid in the CaCO3 group increased by 19% and 15%, respectively. The NaHCO3 group exhibited high headspace CO2 concentration, promoting acetogenic bacteria enrichment while reducing the abundance of Clostridium_sensu_stricto_12. The batch addition of NaHCO3 accelerated the synthesis of hexanoic acid and increased its production by 26%. The relative abundance of Clostridium_sensus_stricto_12 was positively correlated with hexanoic acid production.

Development of toothpaste formulations containing mineral clays as abrasive agents and their effects on the physical properties of dental enamel.

To assess the physical properties and topographical aspect of dental enamel's surface microhardness (KHN), surface roughness (Ra), and color parameters CIELAB (∆Eab*), CIEDE 2000 (∆E00), and whiteness index for dentistry (∆WID) after toothbrushing with experimental toothpaste formulations with the following mineral clay types: kaolin, Sparclay SGY, and Tersil CGY used as abrasive component. Scanning electron microscopy (SEM) was performed for topographical analyses purposes. A total of 96 bovine incisors were used in the experiment. They were divided into eight experimental groups (n = 12), namely: NC-negative control (no treatment), CT12-Colgate Total 12®, CMP-Colgate® Máxima Proteção Anticáries, K-kaolin experimental toothpaste, SGY-Sparclay SGY experimental toothpaste; CGY-Tersil CGY experimental toothpaste, SD-SiO2 experimental toothpaste, and CC-CaCO3 experimental toothpaste. All samples were subjected to mechanical brushing protocol with 5000 cycles and kept in artificial saliva with daily exchanges. KHN was analyzed through the mixed linear model for repeated measures over time. Ra was analyzed through nonparametric Kruskal Wallis and Dunn tests to compare the groups. Paired Wilcoxon test was run to compare experimental times. ∆WID, ∆Eab*, and ∆E00 were analyzed through Kruskal Wallis and Dunn tests. All analyses were performed in R* software, at 5% significance level. EXP_SGY recorded higher KHN than EXP_SiO2 and EXP_CaCO3, whereas EXP_K showed increased Ra in comparison to CMP (p = 0.0229). ∆Eab and ∆E00 were significantly higher in the CT12, EXP_SiO2, and EXP_CaCO3 groups than in the NC and EXP_K (p < 0.0001). There were no significant changes in ∆WID (p = 0.0852). According to SEM results, toothbrushing with experimental toothpastes added with mineral clay types did not have significant impact on enamel's polishing and smoothness. CLINICAL RELEVANCE: Mineral clays have a broad application in the cosmetic industry, and recently, they have been used in the formulation of vegan toothpaste.

Calcium and Aspirin Supplementation for Prevention of Pre-eclampsia in Moderate to High-Risk Pregnancy: A Randomized Controlled Trial

Background: Pregnancy-induced hypertension is one of the major causes of both maternal and fetal death. Calcium can be prescribed to prevent the development of pre-eclampsia among the population with low calcium intake. However, there are only a few research studies on the effect of calcium alone, the impact of calcium co-administrated with other medications, and the timing of prescription during pregnancy. Materials and Methods: The authors conducted a randomized, single-blind, controlled trial to evaluate the efficacy of high-dose calcium carbonate (CaCO₃) co-administrate with aspirin in women with moderate to high risk of developing pre-eclampsia in reducing the incidence of pre-eclampsia. All pregnant women at 12 to 28 weeks of gestation having a moderate to high risk of developing pre-eclampsia were randomly assigned to receive aspirin with CaCO₃ (3,750 mg/day), or aspirin with standard dose calcium carbonate (1,250 mg/day) until delivery or developed pre-eclampsia. Results: One hundred thirty women underwent randomization with 64 women in the CaCO₃ group and 66 women in the standard dose group. The incidence of pre-eclampsia was six cases in the high-dose group and eight cases in the controlled group (OR 0.8, 95% CI 0.3 to 2.6). The percentage of participants having adverse events related to high-dose and standard dose calcium carbonate did not differ significantly between the groups. Conclusion: The use of CaCO₃ at 3,750 mg/day, co-administrate with low-dose aspirin of 81 mg/day, starting at 12 to 28 weeks of gestation, resulted in a non-significantly difference in the incidence of pre-eclampsia with severe features. Keywords: Calcium carbonate; Pre-eclampsia; Prevention

The effectiveness of polypeptides from phosvitin and eggshell membrane in enhancing the bioavailability of eggshell powder calcium and its accumulation in bones

The low-calcium-specific pathogen-free C57BL/6 (SPF–C57BL/6) mice were used to explore the effectiveness of phosvitin phosphopeptides (PPPs) and eggshell membrane peptides (EMPs) in improving the intestinal calcium absorption and promoting bone deposition of eggshell calcium (ESCa). Intake of ESCa + PPPs + EMPs significantly down regulated the abnormal elevation of serum alkaline phosphatase (ALP) induced by calcium deficiency. The CaCO3 group had lower calcium absorption rate (34.34%) and femur bone mineral density (BMD) (0.13 g/cm3), while the ESCa + PPPs + EMPs treatment significantly improved calcium absorption rate (55.01%) and femur BMD (0.15 g/cm3). The three-dimensional reconstruction images of mice femur showed that the ESCa + PPPs + EMPs group had a more complete, compact, and thicker trabecular structure than the low-calcium, CaCO3, and ESCa groups. These results indicated that the ESCa is a low-cost alternative calcium supplement to achieve adequate calcium intake, and the presence of polypeptides, such as PPPs and EMPs, is more beneficial to calcium absorption and deposition than the ESCa.

De novo transcriptome assembly of Aureobasidium melanogenum CGMCC18996 to analyze the β-poly(L-malic acid) biosynthesis pathway under the CaCO3 addition

β-Poly(L-malic acid) (PMLA) is a water-soluble biopolymer used in food, medicine and other industries. To date, the biosynthesis pathway of PMLA has not been fully elucidated. In this study, we sequenced the transcriptome of strain Aureobasidium melanogenum under 20 g/L CaCO3 addition. The resulting sequencing reads were assembled and annotated for the differentially expressed genes (DEGs) analysis and novel transcripts identification. The result indicated that with the CaCO3 addition, the tricarboxylic cycle (TCA) cycle and glyoxylate pathway were up-regulated, and it also found that a non-ribosomal peptide synthetase (NRPS) like protein was highly expressed. The DEGs analysis showed a high expression level of malate dehydrogenase (MDHC) and phosphoenolpyruvate carboxykinase (PCKA) in the CaCO3 group, which indicated a cytosolic malate activity. We speculated that the malate should be transported to or synthesized in the cytoplasm, which was then polymerized to PMLA by the NRPS-like protein, accompanied by the up-regulated TCA cycle providing ATP for the polymerization. Depending on the analysis, we assumed that an NRPS-like protein, the TCA cycle, and the cytosolic malate together are contributing to the PMLA biosynthesis.

Protective Effect on Bone of Nacre Supplementation in Ovariectomized Rats

ABSTRACTNacre has emerged as a beneficial natural product for bone cells and tissues, but its effect was only studied by gavage in the ovariectomized mouse model. We sought to assess the antiosteoporotic effect of nacre through a nutritional supplementation in the ovariectomized rat model. Sixteen‐week‐old female Wistar rats were either Sham‐operated or bilateral ovariectomized (OVX) and then fed with standard diet (Sham and OVX groups) or standard diet supplemented with either 0.25% CaCO3 or nacre (OVX CaCO3 and OVX Nacre group, respectively) for 28 days (n = 10/group). The bone microarchitecture was assessed at appendicular and axial bones by micro‐computed tomography (μCT). Histomorphometric analysis was performed to determine cellular and dynamic bone parameters. Bone metabolism was also evaluated by biochemical markers and gene expression levels. Nacre‐based diet prevented the OVX‐induced bone loss better than that of the CaCO3 supplement, given the significant changes in trabecular bone volume fraction (BV/TV) both at the femoral distal metaphysis (difference, 35%; p = 0.004) and at the second lumbar spine (difference, 11%; p = 0.01). Trabecular osteoclast surfaces (Oc.S/BS) were also 1.5‐fold lower at the tibial proximal metaphysis in OVX Nacre group compared with OVX CaCO3 group (p = 0.02). By principal component analysis (PCA), OVX Nacre group formed a cluster away from OVX group and with a trend closest to Sham group. These data were consistent with biological measurements demonstrating a positive profile related to nacre supplementation, which blunted an increase in serum CTX level and enhanced serum P1NP secretion 14 days post‐OVX compared with CaCO3 supplementation. Bmp2 mRNA expression in OVX Nacre group was +1.76‐fold (p = 0.004) and +1.30‐fold (p = 0.20) compared with OVX and OVX CaCO3 groups, respectively. We conclude that supplementation with nacre could effectively limit bone loss induced by estrogen deficiency just after OVX in rats by modulating the negative imbalance of bone turnover. © 2022 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Modulating effect of elevated water hardness on growth performance, ammonia dynamics and ion-regulatory capacity in channel catfish (Ictalurus punctatus) following chronic challenge with high environmental ammonia and salinity stress

The aim of this study was to assess whether rearing fish at increased water hardness could assist channel catfish (Ictalurus punctatus) juveniles to efficiently cope with later (sub)lethal ammonia exposure or salinity stress. Fish were subjected to 100, 494 (10% of 96 h-LC50) or 1250 mg/L (25% of 96 h-LC50) CaCO3 water hardness levels for two months. Afterwards, fish were challenged with high environmental ammonia (HEA; 12.2 mg/L total ammonia ~25% of 96 h-LC50 value) or salinity stress (SST;10 ppt) separately for 21 days at their respective water hardness levels. Results show that after two months, weight gain (%), specific growth rate and feed conversion in 1250 mg/L CaCO3 group were markedly worse than 100 and 494 mg/L CaCO3 groups. This finding was accompanied with a down-regulation of hepatic IGF-I and growth hormone receptors (GHR) mRNA levels. During SST, growth was still significantly worse for those at 1250 mg/L CaCO3 (1250SST). However, exposure to HEA inhibited growth for 100HEA and 494HEA relative to 1250HEA. Ammonia excretion rate (Jamm) remained similar at different hardness levels; however, this was strongly inhibited at 100HEA, 494HEA and 100SST. This appeared to align to some degree with high water hardness having a protective effect on the gill histomorphology. In fact, fish at 1250HEA were able to increase Jamm efficiently, which was associated with upregulated branchial expression of ammonia transporters (Rhesus glycoproteins ‘Rhcg’) and Na+/H+ exchanger, as well as augmented gill H+-ATPase activity. These responses prevented a build-up of excess ammonia in plasma. In contrast, both 1250 mg/L CaCO3 and 1250HEA groups displayed inhibited branchial Na+/K+-ATPase activity indicating this unlikely has a major role in ammonia excretion. Gill Ca2+-ATPase activities reduced at the highest hardness (1250 mg/L CaCO3) and 1250HEA groups, likely to prevent hypercalcemia in plasma. No differences among hardness levels were noted for ion-regulation or Ca2+- homeostasis under SST. Overall, findings suggest that although elevated water hardness up to 1250 mg/L CaCO3 adversely affects the growth performance of channel catfish, it can ameliorate the inhibitory growth effects of HEA. This was partly attributed to 1250 mg/L CaCO3 protecting the gills as well as mitigating HEA-induced ammonia excretory and ion-regulatory disruption. However, elevated hardness may not be as effective in alleviating salinity stress in catfish.

The calcium supplementation effect of calcium-binding oligopeptides from bonito (Auxis thazard) hydrolysate in rats

Sixty Ca-deficient male Wistar rats were divided into six groups to investigate the effect of a calcium-binding bonito hydrolysate (PBH-Ca) on calcium bioavailability in rats, including the normal group, the control groups (PBH + CaCO3 group and the CaCO3 group), and three PBH-Ca groups with doses of 2,000 (PBH-Ca-H group), 1,000 (PBH-Ca-M group), and 500 (PBH-Ca-L group) mg/kg body wt/day. Each group was given the corresponding drug by intragastric administration for 4 weeks. The indices measured included the rate of increase in body weight and body length, apparent calcium absorption rate, serum calcium, serum phosphorus, alkaline phosphatase (ALP) activity, bone volume fraction (BV/TV), bone mineral density (BMD), and trabecular microstructure of the rats scanned by micro-computed tomography. The results showed that PBH-Ca promoted the growth of rats, significantly increased the apparent calcium absorption rate and the number of bone trabeculae, stabilized serum calcium and serum phosphorus content in serum, significantly inhibited ALP activity, decreased the separation of bone trabeculae, accelerated bone growth of rats, and raised the BV/TV and femoral BMD in the rats. These results illustrate that PBH-Ca has promising potential in a high-quality calcium diet.

The Effectiveness and Safety of Calcium Carbonate Use in Chronic Kidney Disease Patients with Normophosphatemia

Background: Patients with early and moderate stages of chronic kidney disease (CKD) have normal serum phosphate levels. Increased fibroblast growth factor-23 (FGF23) levels in these patients are responsible for maintaining normophosphatemia status by increasing the excretion of phosphate through urine. However, an increased serum FGF23 level is related to cardiomegaly, vascular calcification, CKD progression, and mortality. This study aimed to examine the effectiveness and safety of calcium carbonate use in stage 3 or 4 CKD patients with normophosphatemia. Methods: This double-blind randomized controlled trial (ClinicalTrials.gov identifier NCT03550534) included stage 3 or 4 CKD patients with normophosphatemia who visited the nephrology or endocrinology clinic at Dr. Cipto Mangunkusumo Hospital. Forty-six subjects were randomized to receive either calcium carbonate or placebo over a 12-weeks period. Urine phosphate, serum phosphate, serum calcium, and serum intact FGF23 levels were measured before and after the intervention. Results: The baseline characteristics of the two groups were similar, except for the higher prevalence of dyslipidemia in the placebo group. The CaCO3 group had shown reduced levels of FGF23 compared to the placebo group, -8.03 vs. 0.15 pg/ml respectively (p = 0.019). The median level of FGF23 showed a significant decrease only in the CaCO3 group. An increase in eGFR and a slightly decrease in urine phosphate were observed in the CaCO3 group; however, the data was found to be statistically not significant. No significant changes were noted in the serum calcium levels in both groups. Conclusion: The administration of calcium carbonate has been shown to be effective and safe for moderate CKD patients with normophosphatemia due to its effect in lowering FGF23 levels without escalating the serum calcium level.

Total flavonoids of Rhizoma Drynariae combined with calcium attenuate osteoporosis by reducing reactive oxygen species generation.

In the present study, the effects of total flavonoids of Rhizoma Drynariae (TFRD) and calcium carbonate (CaCO3) on osteoporosis (OP) were assessed in a rat model of OP. For this purpose, 36 Sprague-Dawley rats, aged 3 months, were randomly divided into a group undergoing sham surgery (sham-operated group), model group (OP group), CaCO3 group (OP + CaCO3 group), TFRD group (OP + TFRD group), TFRD combined with CaCO3 group (OP + TFRD + CaCO3 group) and TFRD and CaCO3 combined with N-acetyl cysteine group (OP + TFRD + CaCO3 + NAC group). The rat model of OP was established by bilateral ovariectomy. The changes in bone mineral density (BMD), bone volume parameters and bone histopathology in the rats from each group were observed. The levels of serum reactive oxygen species, superoxide dismutase (SOD), malondialdehyde, glutathione peroxidase (GSH-Px), interleukin (IL)-6, IL-1β, TNF-α, and the levels of bone tissue runt-related transcription factor 2 (RUNX2), osteoprotegerin (OPG), osteocalcin (BGP), PI3K, p-PI3K, AKT, p-AKT, mammalian target of rapamycin (mTOR) and p-mTOR were measured in the rats of each group. The induction of OP was associated with a marked decrease in BMD, bone mineral content, bone volume fraction and trabecular thickness, and decreased serum levels of SOD and GSH-Px. Moreover, the expressions of RUNX2, OPG, BGP were downregulated and an upregulation of p-PI3K, p-AKT and p-mTOR were observed in osteoporotic rats. However, treatment with TFRD and CaCO3 restored all the aforementioned parameters to almost normal values. Furthermore, the findings on histopathological evaluation were consistent with the biochemical observations. Taken together, the findings of the present study demonstrated that TFRD and CaCO3 significantly increased the antioxidant capacity in rats with OP, increased BMD and reduced bone mineral loss, and may be useful for the prevention and treatment of OP.

Effect of changes in the soil calcium-to-magnesium ratio by calcium application on soybeans, Glycine max (L.) Merr., growth

ABSTRACT There have been few studies in Japan on the effects of the application of lime materials, especially in regard to the soil calcium-to-magnesium ratio (Ca:Mg). The aim of this study was to explore the effects of changes in the soil Ca:Mg on soybean growth via pot and field tests over two growing seasons: 2018–2019. The field tests were conducted in two different fields, one in each year, and the soil for the pot tests in both years was collected from the respective fields used in the field tests. In the pot test from 2018 to 2019, we adjusted the soil Ca:Mg ratio and soil pH using Ca(OH)2 and CaSO4, with three conditions: control (pH = 5.2, Ca:Mg = 1.3), CaMg (pH = 5.0, Ca:Mg = 2.6), and CaMg + pH (pH = 5.7, Ca:Mg = 2.4). Moreover, we added two further conditions for the pot test in 2019: CaCO3 (pH = 5.9, Ca:Mg = 1.8) and dolomite groups (pH = 6.4, Ca:Mg = 1.3). In the field test, we adjusted only the soil Ca:Mg ratio using phosphogypsum and had two conditions: control (pH = 5.0, Ca:Mg = 1.1) and gypsum (pH = 4.7, Ca:Mg = 1.9). In both tests, the application of Ca except for dolomite contributed to the increase in the concentration and uptake of Ca both in the whole plants and some parts of the soybean plants. Likewise, application of Ca except for dolomite contributed to a significant increase in the total number of pods. The weight of seeds and the total dry weight in the CaMg + pH and CaCO3 groups and in the gypsum plot were significantly higher than were those in each control group. Thus, the study suggests that the Ca:Mg ratio in soils with a low Ca:Mg ratio may limit soybean growth to a greater extent than does the soil pH. However, the effect of the interaction between the soil Ca:Mg ratio and soil pH on dry-matter production of soybeans was different between the pot and field tests, and further studies were needed to clarify the discrepancy.

Thrombin-Loaded TA-CaCO3 Microspheres as a Budget, Adaptable, and Highly Efficient Hemostatic

Fast hemostasis, biosecurity, and adaptation of different bleeding sites are the major challenges for hemostatic materials. In this work, an easy-to-make, rapid hemostatic, tannic acid doped calcium carbonate microsphere with a low concentration of thrombin (Thr@TA-CaCO3) was developed. In an in vitro blood clotting assay, the hemostatic effect of Thr@TA-CaCO3 varied with the change of thrombin amount. Furthermore, the average hemostatic time can be reduced from 205 to 20 s as the thrombin levels are elevated. When applied in different hemorrhage models, the Thr@TA-CaCO3-treated group had a lower blood loss than the tannic acid modified CaCO3 (TA-CaCO3) groups. Especially in the rabbit artery injury model, the total bleeding amount in the Thr@TA-CaCO3-treated group was only 11.97% of that in the TA-CaCO3 groups, proving that Thr@TA-CaCO3 had an excellent hemostatic effect even in the case of rapidly flowing blood. Based on the above, Thr@TA-CaCO3 is a promising hemostatic agent and can be applied in more extensive clinical applications.

Effects of Ferric Citrate Hydrate on Calciprotein Particle Levels and Aortic Arch Calcification Progression in Patients on Maintenance Hemodialysis: A Comparison with Calcium Carbonate

Background: Arterial calcification is a predictive marker in patient on hemodialysis (HD), but the relationship between arterial calcification and calciprotein particles (CPPs) is unclear. Methods: We examined the effects of ferric citrate hydrate (JTT-751) on CPP level and evaluated changes in aortic arch calcification (AoAC) grade in patients on maintenance HD (MHD). In total, 70 MHD patients were enrolled in the study and followed for 24 months. We measured serum CPP levels and fibroblast growth factor 23 (FGF 23) among propensity score-matched MHD patients. One group (n = 35) was treated with CaCO3 and the other (n = 35) was treated with ferric citrate hydrate (JTT-751). AoAC was assessed on chest-X rays. Eligible patients continued the same treatment. Results: All 70 patients completed the study. Serum CPP levels reduced in the JTT-751 group, but were not significantly different in the CaCO3 group. Among patients whose baseline AoAC score (AoACS) was ≤ 4 (median), median AoACS increased from 0 (0 - 3) to 3 (2 - 4) (p 3 group, median AoACS increased from 2 (0 - 2) to 3 (0 - 4) (p < 0.05) and Δ% AoACS was 1 (0% - 3%). Conclusion: These results indicate that the administration of JTT-751 decreased serum CPP levels but did not inhibit AoAC progression in patients on MHD.

Biodiesel Production from Reutealis Trisperma Oil Using KOH Impregnated Eggshell as a Heterogeneous Catalyst

This research paper describes the synthesis of a heterogeneous catalyst (Potassium hydroxide (KOH)-impregnated eggshell) from waste chicken eggshell using the wet impregnation technique. In this experiment, the catalyst was derived from eggshell that was calcined at 800 °C for 5 h. It was impregnated with KOH at various KOH concentrations (10%, 15%, 20%, and 25%). The best catalyst was obtained by eggshell impregnated with 20% KOH concentration. This result was supported by the analysis of the catalyst characterization using Fourier-transform infrared spectrometry (FT-IR), which showed that the catalyst contained CaCO3 and CaOH groups. X-ray fluorescence analysis (XRF) was also used to analyze the types of mineral contained in the catalyst, including calcium, potassium, sulfur, and other impurities. It revealed that the optimum minerals were found in the KOH-impregnated eggshell (20%) catalyst of 94.42% calcium, 5.06% potassium, and a small amount of other impurities. These optimum minerals serve as active sites to increase the biodiesel yield. Scanning electron microscopy (SEM) showed that the catalyst samples appear as small, spherical, homogenous, and solid particles. The catalytic activity was investigated by the transesterification of Reutalism trisperma oil in various types of catalyst (KOH-impregnated eggshell, eggshell, and KOH-impregnated CaO), percentages of catalyst loading (weight of 1%, 3%, 5%, 7%, and 10%) and molar ratios (methanol to oil of 6:1, 8:1, 10:1, 12:1, and 15:1) for 60 min at 60 °C. The result indicated the optimum catalyst loading was 5 wt% with an 84.57% biodiesel yield. While the best molar ratio was 12:1 (methanol:oil) with a 97.95% biodiesel yield. The optimum condition was gained using a molar ratio of 12:1, 5 wt% catalyst loading, and KOH-impregnated eggshell with a 94% biodiesel yield.

A pivotal peptide (Val-Ser-Glu-Glu) from duck egg white promotes calcium uptake and structure-activity relationship study

The effects of desalted duck egg white peptides (DPs) and Val-Ser-Glu-Glu (VSEE) on calcium absorption were investigated in calcium-deficient diets rat model. Six-week oral administration results indicated DPs + CaCO3 and VSEE + CaCO3 were significantly higher than CaCO3 group in calcium absorption, serum osteocalcin, bone calcium content and max load, but lower in serum bone alkaline phosphatase level (P < 0.05). Additionally, in the 0.5% calcium diets groups, the rats fed with DPs showed notably increases in calcium absorption, length of tibias and bone max load than those without DPs. The structure-activity relationship results demonstrated the importance of amino acid units like Glu-Glu and Ser-Ser. Homology modeling and molecular docking results provided two possible active sites of TRPV6 in the promotion of calcium uptake by DPs. The present study expands the understanding of the mechanism of calcium uptake in vivo by DPs, as well as highlights the structure-activity relationship and the potential active sites of TRPV6.

Effect of calcium-binding peptide from Pacific cod (Gadus macrocephalus) bone on calcium bioavailability in rats.

Bone collagen peptide with high affinity to Ca was extracted from Pacific cod (Gadus macrocephalus) bone. FTIR spectra of calcium-binding bone collagen peptide showed that band at 3381cm-1 shifted to 3361cm-1, 1455cm-1 moved to 1411cm-1, and amide II became deeper valley, compared with that of bone collagen peptide. This peptide was sequenced by Q-TOF-MS and sequences of Gly-Pro-Glu-Gly, Gly-Glu-Lys, Gly-Pro-Leu-Gly and Gly-Leu-Pro-Gly appeared repeatedly in some peptides. From SEM, after chelated with calcium, the loose and porous structure turned into granular structure. From the animal experiment, Ca apparent absorption rate, Ca retention rate and femur Ca content of calcium-binding bone collagen peptide group were significantly higher than those of model and CaCO3 groups (P<0.05), while serum ALP was significantly lower than model group (P<0.05) and similar to control group. The results suggested that calcium-binding bone collagen peptide could improve bioavailability of Ca and thus prevented Ca deficiency.

Eggshell fractions containing different particle sized affect mineral absorption but not bone mineral retention in growing rats

The purpose of this study was to compare the calcium (Ca) bioavailability from eggshell fractions containing different particle size to purified CaCO3 in male growing rats. Mineral absorption, bone mineral concentration, and biomechanical properties were evaluated. Mean Ca absorption of rats fed with eggshell diets amounted to 56.2% of the ingested Ca, which is considered high. However, we observed lower Ca absorption in large-sized particle eggshell fraction (ES L) and small-sized particle eggshell fraction groups but similar Ca absorption in intermediate-sized particle eggshell fraction (ES M) compared with the CaCO3 group. Rats that received ES M and ES L had higher P and Mg absorption than the CaCO3 group. No changes were observed in the bone mineral deposition, weight or mechanical resistance. We conclude that eggshell Ca is well absorbed by the intestine and retained in bones of growing rats, being a low cost alternative to achieve adequate Ca ingestion.

Dispersion of atmospheric fine particulate matters in simulated lung fluid and their effects on model cell membranes

Atmospheric fine particulate matter (PM2.5) was collected to investigate its dispersion in simulated lung fluid (SLF) and its interaction with model cell membranes. Organic acids, NH4+, SO42− and NO3− were detected in PM2.5 soluble fraction, and heavy metals were detected from the total mass. The insoluble fraction contained kaolinite, CaCO3, aliphatic carbons, aromatic rings, carboxyl and hydroxyl groups reflected by the infrared spectra. Proteins dispersed PM2.5 in SLF, resulted in smaller hydrodynamic diameter (dH) and slower sedimentation rate. Conversely, phospholipids increased dH value and accelerated sedimentation rate. Giant unilamellar vesicles (GUVs) and supported lipid bilayers (SLBs) were used as model cell membranes. PM2.5 adhered on and disrupted the membrane containing positively-charged lipids but not the membrane containing neutrally- and negatively-charged lipids, which was monitored by microscopy and a quartz crystal microbalance with dissipation (QCM-D). The cationic sites on membrane were necessary for PM2.5 adhesion, but membrane should be disrupted by the combined action of electrostatic forces and hydrogen bonds between PM2.5 oxygen containing groups and the lipid phosphate groups. Our results specified the roles of proteins and phospholipids in PM2.5 dispersion and transport, highly suggested that the health hazard of PM2.5 was related to the biomolecules in the lung fluid and the particle surface groups.

Nobel bone regeneration system using carbonate apatite-coated carbonate calcium in vivo

Statement of the Problem: Effective bone regeneration system requires artificial bone substitutes to replace bone. We developed carbonate apatite (CAp) blocks, which is a component of in vivo bone, by using a new procedure. We have already reported that CAp blocks receive absorption by osteoclasts just like in vivo bone and induce effective bone replacement[1]. Here, we further investigated modified CAp granules, which could be controlled with its absorption. Materials and Methods: CAp granules were prepared by using dissolution-precipitation reaction from carbonate calcium (CaCO3) as a precursor[2]. During that reaction, we were able to get the intermediate block, ‘‘carbonate apatite coated carbonate calcium’. The degree of coating with CAp was measured by X-ray diffraction (XRD), then 10% and 30% CAp-coated CaCO3 were prepared. Sixteen rabbits were subjected to bone regeneration assay. We examined 5 groups, 1) Sham group, 2) CaCO3 group, 2) 10% CAp-coated CaCO3 (10% CAp) group, 3) 30% CAp-coated CaCO3 (30% CAp) group, 4) CAp group. Cylindrical bone defects (F5.0 mm 8.0 mm) of rabbit femurwere formedbyusing dental trephinebar. Those rabbits were sacrificed at 4 and 8 weeks after material implantation surgery and analyzed by means of microcomputed tomography (microCT; Latheta LCT-200, ALOKA). Histological observation (MMA embedded; Villanueva-Goldner staining, Toluidine blue staining) was used to quantify new bone volume at the defect site. Methods of Data Analysis: For quantification of the degree of absorption of those granules in rabbit bone defect study (n=3/group), the sacrificed samples at 4 and 8 weeks after operation were scanned by microCT. After standardizing the images, the area of granules was evaluated with Photoshop CS5.1 (Adobe). For quantification of new bone volume, we calculated the area of new bone in five random images/group (40X-magnification) using ImageJ in toluidine blue stained sections. For

Effects of desalted duck egg white peptides and their products on calcium absorption in rats

The effects of desalted duck egg white peptides (DPs), phosphorylated DPs (PDPs) and DPs–calcium complexes (DPs-Ca) on calcium absorption in vivo were investigated. Ninety fast-growing male rats were divided into 10 groups and treated with different dosages of CaCO3, calcium gluconate, DPs-Ca as well as CPPs, DPs and PDPs supplemented with CaCO3. Eight-week oral administration results indicated that the high dosage PDPs+CaCO3 group was significantly higher than the high dosage DPs+CaCO3 group in calcium absorption, bone calcium content, BMD and maximum stress, but lower in ALP activity (P < 0.05). Additionally, the high dosage DPs-Ca group showed higher bone indices than the high dosage DPs+CaCO3, calcium gluconate and CaCO3 groups (P < 0.05). These results suggest that in vivo, phosphorylated DPs are more effective than DPs in improving calcium absorption and bone strength, and DPs–calcium complexes are more beneficial to bone tissues than the DPs and CaCO3 mixture.