Occlusion of Sulfate-Based Diblock Copolymer Nanoparticles within Calcite: Effect of Varying the Surface Density of Anionic Stabilizer Chains.

Polymerization-induced self-assembly (PISA) offers a highly versatile and efficient route to a wide range of organic nanoparticles. In this article, we demonstrate for the first time that poly(ammonium 2-sulfatoethyl methacrylate)-poly(benzyl methacrylate) [PSEM-PBzMA] diblock copolymer nanoparticles can be prepared with either a high or low PSEM stabilizer surface density using either RAFT dispersion polymerization in a 2:1 v/v ethanol/water mixture or RAFT aqueous emulsion polymerization, respectively. We then use these model nanoparticles to gain new insight into a key topic in materials chemistry: the occlusion of organic additives into inorganic crystals. Substantial differences are observed for the extent of occlusion of these two types of anionic nanoparticles into calcite (CaCO3), which serves as a suitable model host crystal. A low PSEM stabilizer surface density leads to uniform nanoparticle occlusion within calcite at up to 7.5% w/w (16% v/v), while minimal occlusion occurs when using nanoparticles with a high PSEM stabilizer surface density. This counter-intuitive observation suggests that an optimum anionic surface density is required for efficient occlusion, which provides a hitherto unexpected design rule for the incorporation of nanoparticles within crystals.

The Crystal Hotel: A Microfluidic Approach to Biomimetic Crystallization.

A "crystal hotel" microfluidic device that allows crystal growth in confined volumes to be studied in situ is used to produce large calcite single crystals with predefined crystallographic orientation, microstructure, and shape by control of the detailed physical environment, flow, and surface chemistry. This general approach can be extended to form technologically important, nanopatterned single crystals.

[Study on change rule of 6 ester-type alkaloids in process of Heishunpian].

To study the variation of six ester-type alkaloids and characteristic fingerprints in the process from Radix Aconite Lateralis to Heishunpian and lay a foundation for the study of the processing principle of Heishunpian, HPLC. analysis was performed on a Phenomenex Gemini C18 (4.6 mm x 250 mm, 5 microm) with acetonitrile and 40 mmol x L(-1) ammonium acetate (adjusted to pH 10 with concentrated ammonia water) as mobile phase. The detection wavelength was set at 235 nm. The flow rate was set at 0.8 mL x min(-1) and the injection volume was 10-20 microL. Six ester-type alkaloids were determined and characteristic fingerprints of the process were established. As the process continues, the contents of diester diterpene alkaloids were decreased step by step, while the contents varia tion of monoester diterpene alkaloids were not obvious. Each sample showed significant difference in characteristic fingerprints. With the exception of 6 known monoester diterpene alkaloids and diester diterpene alkaloids, 13 peaks were marked in the characteristic fingerprints, of which the total change rule of the other 7 unknown peaks were similar with 3 diester diterpene alkaloids. The established method is accurate, reliable and repeatable, and can provide reference for revealing change rule of index components and illuminating processing principle in the process of Heishunpian.

A new precipitation pathway for calcium sulfate dihydrate (gypsum) via amorphous and hemihydrate intermediates.

This work investigates the early stages of precipitation of calcium sulfate from aqueous solution at room temperature and shows for the first time that amorphous calcium sulfate (ACS) and calcium sulfate hemihydrate are sequentially precipitated prior to calcium sulfate dihydrate (gypsum).

[Expression and intracellular localization of FRZB gene in gastric cancer and its significance].

OBJECTIVE: To study the expression and intracellular localization of FRZB gene in gastric cancer tissue, and to explore its significance in gastric cancer. METHODS: The expression of FRZB in tumor tissues from 90 patients with gastric cancer and in normal gastric mucous as control were analyzed by immunohistochemistry in tissue array. FRZB expression in gastric cancer cell lines and immortalized gastric epithelial cell line GES-1 were detected by quantitative real-time PCR(Q-PCR) and Western blot. The intracellular localization of FRZB was observed by immunofluorescence staining. RESULTS: The positive expression rate of FRZB in gastric cancer was 92.2%. FRZB expressed in gastric cancer with well differentiation was higher than that with poor differentiation.The positive rate in normal gastric mucous was 10.0% (one out of ten). By confocal microscope, FRZB localized both in cytoplasma and nucleus, especially on the nuclear membrane. The Q-PCR and Western blot results also showed that the expression of FRZB in gastric cancer cell lines was higher than that in GES-1. CONCLUSIONS: The expression of FRZB in gastric cancer is correlated with tumor cell differentiation and tumor Lauren classification. The nuclear localization of FRZB may contribute to its function in gastric cancer formation and progression.

Over-expression of FRZB in gastric cancer cell suppresses proliferation and induces differentiation.

PURPOSE: Frizzled motif associated with bone development (FRZB) was a member of secreted frizzled related proteins (sFRPs) family. Previous evidences showed that FRZB played role in embryogenesis and diseases such as osteoarthritis and prostate cancer. The purpose of our study is to clarify the role of FRZB in gastric cancer cell proliferation and differentiation. METHODS: The expression of FRZB in gastric cancer tissues were detected by immunohistochemistry. The expression of FRZB in eight gastric cancer cell lines and one immortal gastric epithelial cell GES-1 were detected by western blotting and real-time quantitative PCR. To investigate the role of over-expressed FRZB in gastric cancer cells, FRZB/pcDNA3.1 plasmid was constructed and transfected into gastric cancer cell line SGC7901. The changes of biological features in these stable transfectants were examined. RESULTS: FRZB was highly expressed in gastric cancer (90%), intestinal metaplasia (100%) and gastric dysplasia (90%), but no or just weakly (3/40) expressed in normal gastric mucosa. FRZB staining was stronger in intestinal-type gastric cancer tissues than that in diffuse-type ones and was positive correlated with differentiation grade. The expression of FRZB in eight gastric cancer cell lines was higher than in GES-1. Over-expressed FRZB inhibited cell proliferation in vitro and in vivo which was first caused by prolonged cell division progression in G2/M phase, and second by higher sensitivity to apoptotic inducing factors and spontaneous apoptosis. Our findings gave evidences that FRZB suppressed gastric cancer cell proliferation and modulated the balance between proliferation and differentiation in gastric cancer.

In vitro and in vivo evidence of metallopanstimulin-1 in gastric cancer progression and tumorigenicity.

PURPOSE: The metallopanstimulin-1 (MPS-1) gene is a growth factor-inducible gene, which is highly expressed in many human cancers and may be involved in the progression towards tumor malignancy. However, it is unclear whether MPS-1 plays any role in gastric cancer development or progression. Our studies were designed to clarify the MPS-1 expression pattern and to explore its potential role in gastric cancer. EXPERIMENTAL DESIGN: The expression pattern of MPS-1 was determined in primary gastric cancer specimens and gastric cancer cell lines via immunohistochemistry and Western blotting. To investigate the functional significance of MPS-1 expression, three small interfering RNA (siRNA) expression plasmids were constructed and transfected into gastric cancer cell line SGC7901. The stable cell lines transfected with the siRNA targeting MPS-1 mRNA plasmids were selected and the biological features of these cells were examined. RESULTS: MPS-1 was overexpressed in 86% of the gastric cancer tissues and all gastric cancer cells. In addition, MPS-1 expression was significantly increased and corresponded with the tumor-node-metastasis clinical stage, and was significantly higher in the late stage (P < 0.01). The MPS-1 expression level was significantly decreased in the transfected cells with MPS-1-specific siRNA expression plasmid pRNAT-133. Furthermore, the stable transfected cancer cells exhibited an increase in the incidence of spontaneous apoptosis and a decrease in growth ability and tumorigenicity in nude mice. CONCLUSIONS: These results provide strong evidence that MPS-1 plays an important role in gastric cancer cell proliferation and development, and suggests that MPS-1 is a promising target for gastric cancer treatment.

[Fusion expression of gastric cancer-related gene MPS-1 and preparation of rabbit antibody against GST-MPS-1].

AIM: To express the fusion protein GST-MPS-1 in E.coli and prepare rabbit antibody against GST-MPS-1. METHODS: MPS-1 cDNA was inserted into the vector of pGEX-5X. The recombinant was then transformed into E.coli BL21. After induction with the IPTG, the fusion protein GST-MPS-1 was expressed in E.coli. The purified fusion protein was then used to immunize the New Zealand rabbits to obtain the polyclonal antibody against GST-MPS-1. Specificity of the antibody was tested by Western blot and immunofluorescent staining. RESULTS: The cDNA sequence of MPS-1 in the recombinant was confirmed by restriction endonuclease digestion and sequence analysis. SDS-PAGE result showed that fusion protein was highly expressed in E.coli with a molecular weight of 36 kDa. The titer of the rabbit serum against GST-MPS-1 was as high as 1x10(5) in ELISA analysis. The polyclonal antibody were found to specifically bind to MPS-1 protein in Western blot and immunofluorescent staining. CONCLUSION: The preparation of the polyclonal antibody against MPS-1 lay a foundation for the further study of MPS-1 expression at protein levels and its function.

[Expression and clinical significance of cancer-related gene MPS-1 in gastric cancer].

OBJECTIVE: To investigate the expression of cancer-related gene MPS-1 in gastric cancer and to evaluate its significance in clinical diagnosis and therapy. METHODS: The mRNA expression of MPS-1 was determined by polymerase chain reaction after reverse transcription (RT-PCR) in cancer tissues and adjacent non-cancerous tissues from 42 cases with gastric cancer. The expression levels of MPS-1 in 6 gastric cancer cell lines (AGS, MKN-45, SGC 7901, KATO III, N-87 and SNU-1) were also determined by RT-PCR and Western blot. RESULTS: The MPS-1 mRNA was expressed in all tissues and cell lines. The mRNA expression level of MPS-1 in cancer tissues were 1.37+/- 0.87, significantly higher than 0.99+/- 0.67 in adjacent normal gastric mucous tissues (P< 0.01). The expression of MPS-1 was correlated with TNM stage (P< 0.05), but not with age, gender, tumor size and differentiation. The expression level of MPS-1 mRNA in the primary lesions was hig her in the patients with TNM stages III, IV than those with TNM stages I, II. Meanwhile, RT-PCR and Western blot showed the same results that MPS-1 expression was higher in the six gastric cancer cell lines as compared with that in the normal gastric cell line GES-1. CONCLUSION: The high expression of MPS-1 in gastric cancer indicates that MPS-1 might play an important role in gastric carcinogenesis,which may provide a new target in immunotherapy for gastric cancer.