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221 results on '"Shi, Wanyu"'

20. Direct Immobilization of Folic Acid Molecules on Hydroxyapatite Nanoparticles with Substitution and Coordination Phenomena

Author

Shi, Wanyu, Hatori, Shoma, Noda, Daichi, Yamada, Iori, and Tagaya, Motohiro

Abstract

We successfully synthesized folic acid (FA) immobilized hydroxyapatite (HA) nanoparticles without using a mediative reagent (e.g., silane coupling agent), and the immobilization states were evaluated and discussed. The HA nanoparticles with higher biocompatibility have two different planes, namely, c- and m-planes. These plane surfaces are rich in phosphate groups (P-site) and Ca2+ions (C-site), respectively. We suggested that during the synthesis of the HA nanoparticles, the P-site substitution and C-site coordination with the addition of organic molecules containing -COO–ions can occur. Thus, it is possible to simultaneously immobilize two molecules to one HA nanoparticle. In this study, we successfully synthesized FA-immobilized HA nanoparticles by P-site substitution and C-site coordination reactions, which were named as substitution type and coordination type. In the substitution type, when FA was reacted with HA during the nucleation stage, the PO43–ions of HA decreased as the FA ratio of coverage surface area increased, and the crystalline phase was changed significantly from the Ca deficient HA to the carbonated HA phase. Accordingly, it was indicated that FA was immobilized on HA by the P-site substitution. In the coordination type, since FA was reacted with HA after the completion of crystal growth, the crystalline phase was changed slightly as the FA ratio of coverage surface area increased, indicating that FA was immobilized on HA by the C-site coordination. From the above, we controlled the FA immobilization states on the HA nanoparticles by the P-site substitution and the C-site coordination through the FA addition timing in the synthesis. Since the -COO–ions in FA could be selectively substituted with the P-site in HA, it is possible to directly coordinate the foreign organic molecules to the Ca2+ions in HA. Therefore, the immobilization technique of this study is expected to achieve two different drug molecules with diagnosis and therapy functions (i.e., theranostics) on one nanoparticle.

Published
2024
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23. The Structural Characterization of a Polysaccharide from the Dried Root of Salvia miltiorrhiza and Its Use as a Vaccine Adjuvant to Induce Humoral and Cellular Immune Responses.

Author

Zhu, Yixuan, Yang, Xiaochen, Gu, Pengfei, Wang, Xiao, Bao, Yongzhan, and Shi, Wanyu

Subjects
HUMORAL immunity, SALVIA miltiorrhiza, SUBCUTANEOUS injections, EVIDENCE gaps, LYMPHOCYTE transformation, POLYSACCHARIDES, MONOSACCHARIDES, ROOT growth
Abstract

In order to supplement the research gap concerning Salvia miltiorrhiza polysaccharide extracted from Danshen in NMR analysis, and to clarify its immune enhancement effect as an adjuvant, we isolated and purified SMPD–2, which is composed of nine monosaccharides such as Ara, Gal, and Glc from Danshen. Its weight average molecular weight was 37.30 ± 0.096 KDa. The main chain was mainly composed of →4)-α-D-Galp-(1→, →3,6)-β-D-Glcp-(1→ and a small amount of α-L-Araf-(1→. After the subcutaneous injection of SMPD–2 as an adjuvant to OVA in mice, we found that it enhanced the immune response by activating DCs from lymph nodes, increasing OVA-specific antibody secretion, stimulating spleen lymphocyte activation, and showing good biosafety. In conclusion, SMPD–2 could be a promising candidate for an adjuvant. [ABSTRACT FROM AUTHOR]

Published
2024
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43. Effect of Power on Structural and Mechanical Properties of DC Magnetron Sputtered Cr Coatings.

Author

Shi, Wanyu, Peng, Jian, Xu, Zhigang, Shen, Qiang, and Wang, Chuanbin

Subjects
DC sputtering, SURFACE coatings, SURFACE roughness, WEAR resistance, MAGNETRON sputtering, SURFACE morphology
Abstract

Cr coatings were deposited on the surface of PCrNi1MoA steel by DC magnetron sputtering. The effects of power (100~250 W) on the structure and mechanical properties of the coating were systematically studied. The results show that all Cr coatings have strong (110) preferred orientation and anisotropic surface morphology, and the cross sections are columnar structures. With the increase in power, the deposition rate increases linearly, the surface roughness and grain size increase gradually, and the nanomechanical properties decrease first and then increase slightly. At 100 W, the columnar grain of the coating is compact and continuous, and the wear resistance and plastic deformation resistance are the best, with the highest binding force of 27.04 N. At 200 W, due to grain growth and tensile stress, internal defects increase, and mechanical properties are poor. The combination of coating and substrates is not tight enough, and it is easy to fall off and fail under the action of external force. When the power reaches 250 W, the higher bombardment rate helps the coating release stress, and reduce porosity. [ABSTRACT FROM AUTHOR]

Published
2023
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