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Phosvitin (PV) was treated with high-temperature, mild pressure (HTMP), and enzyme combination, and then phosvitin phosphopeptides-calcium (PPP-Ca) complexes were prepared. The low-calcium specific pathogen free-Kunming (SPF-KM) mice were used to determine the effect of PPP-Ca complexes on intestinal calcium absorption and their utilization for bone formation. The serum calcium content was the highest with the HTMP-Enz-PPP-Ca treatment (2.19 mmol/L), and it significantly down-regulated the abnormal elevation of serum alkaline phosphatase (AKP) caused by calcium deficiency. The low-calcium control group had the lowest calcium deposited to the femur (80.41 mg/g) and the lowest femur bone mineral density (BMD) (0.17 g/cm3), while HTMP-Enz-PPP-Ca significantly improved bone calcium content (94.33 mg/g) and BMD (0.29 g/cm3). The micro-computed tomography (MCT) images showed that the femur with the normal control, PV-Ca, and HTMP-Enz-PPP-Ca treatments had a more compact, complete, and thicker trabecular network than the low-calcium and CaCl2treatments. These results indicated that the organic calcium (HTMP-Enz-PPP-Ca) promoted calcium absorption and bone deposition, and the effect of HTMP-Enz-PPP-Ca was better than the inorganic CaCl2.

Phosvitin (PV) is a highly phosphorylated protein found in egg yolk. PV hydrolysate (PPP) has excellent calcium-binding capacity, although its ability to promote calcium deposition and the underlying mechanism are unclear. This study aimed to explore the calcium deposition capacity and mechanisms of PPP and PPP-Ca. The fraction 3 (PPP3) was isolated by anion-exchange chromatography and exhibited the best calcium-binding activity (98.11 ± 0.91%). To mimic the microenvironment of bone formation, a three-cell co-culture model of intestinal epithelial cells-osteoblasts-osteoclasts (Caco-2/MC3T3-E1/RAW264.7) was established. The alkaline phosphatase results indicated that PPP3 and PPP3-Ca significantly promoted osteoblasts differentiation compared to CaCl2. Correspondingly, PPP3, PPP3-Ca, and CaCl2reduced tartrate resistant acid phosphatase content by 43.84%, 46.92% and 17.21%, respectively, suggesting that PPP3 and PPP3-Ca effectively inhibited osteoclasts differentiation. The molecular mechanism by which PPP3 and PPP3-Ca inhibited osteoclasts bone resorption involved regulating mRNA expression of the OPG/RANKL/RANK pathway. Notably, PPP3-Ca demonstrated higher pro-calcium deposition in co-cultured cells, about 1.70 times higher than CaCl2. PPP3-Ca dependent high phosphorylation exerted a pro-mineralization effect, as analyzed by scanning electron microscopy and energy dispersive spectroscopy. Overall, this study suggested that PPP3-Ca as organic calcium was more effective than CaCl2in promoting calcium deposition.

Phosvitin phosphopeptides (PPP) have a high ability to chelate mineral ions and promote calcium absorption. In this study, The Fe3O4nanospheres were first synthesized by hydrothermal method, then the three magnetic nanoparticles (Fe3O4@PDA@PMAA@PAMAM, Fe3O4@PDA@Ce4+, and Fe3O4@PDA@TiO2) were obtained by layer modification on their surfaces, respectively. The magnetic nanoparticles were characterized by TEM, XRD, VSM, and Zeta potential. TEM analysis revealed that the nanoparticles were spherical and regular in shape. XRD diffraction analysis showed that the modified nanoparticles have a complete crystal structure. Meanwhile, PAMAM, Ce4+, TiO2, and other groups have been successfully modified on the nanoparticles. VSM hysteresis regression line results revealed that the magnetic nanoparticles are superparamagnetic. The three kinds of magnetic nanoparticles still maintained excellent enrichment performance after five times of repeated use. Fe3O4@PDA@TiO2has the best enrichment performance (167 mg g−1). The N/P ratio of the enriched PPP decreased from 1.36 to 0.98, which also showed that it had excellent PPP enrichment performance. Therefore, the modified magnetic nanoparticles could be an optimal PPP enrichment and purification material.

In this paper, the technological progress on Chinese gravity exploration satellites is presented. Novel features such as ultra-stable structure, high accurate thermal control, drag-free and attitude control, micro-thrusters, aerodynamic configuration, the ability to perform micro-vibration analyses, microwave ranging system and mass center trimmer are described.