Effects of hyaluronic acid on differentiation of human amniotic epithelial cells and cell-replacement therapy in type 1 diabetic mice.

Our hypothesis is that hyaluronic acid may regulate the differentiation of human amniotic epithelial cells (hAECs) into insulin-producing cells and help the treatment of type 1 diabetes. Herein, a protocol for the stepwise in vitro differentiation of hAECs into functional insulin-producing cells was developed by mimicking the process of pancreas development. Treatment of hAECs with hyaluronic acid enhanced their differentiation of definitive endoderm and pancreatic progenitors.

Hyaluronic acid promotes osteogenic differentiation of human amniotic mesenchymal stem cells via the TGF-β/Smad signalling pathway.

Aims: This study investigated the effects of hyaluronic acid (HA), a commonly used osteogenic medium referred to as DAG, and the combined administration of HA and DAG (CG) on the osteogenic differentiation of human amniotic mesenchymal stem cells (hAMSCs), and the underlying mechanism.

Main Methods: The phenotype of hAMSCs was detected by flow cytometry and immunocytochemical staining. Alkaline phosphatase (ALP) and calcium deposition assays were employed for evaluating the osteogenic differentiation of hAMSCs.

Synergistic antitumor efficacy of antibacterial helvolic acid from Cordyceps taii and cyclophosphamide in a tumor mouse model.

The antibacterial agent helvolic acid, which was isolated from the active antitumor fraction of Cordyceps taii, showed potent cytotoxicity against different human cancer cells. In the present study, the in vivo antitumor effect of helvolic acid was investigated in murine sarcoma S180 tumor-bearing mice. Doses of 10 and 20 mg/kg/day helvolic acid did not exert significant antitumor activity.

Hyaluronic acid enhances proliferation of human amniotic mesenchymal stem cells through activation of Wnt/β-catenin signaling pathway.

This study investigated the pro-proliferative effect of hyaluronic acid (HA) on human amniotic mesenchymal stem cells (hAMSCs) and the underlying mechanisms. Treatment with HA increased cell population growth in a dose- and time-dependent manner. Analyses by flow cytometry and immunocytochemistry revealed that HA did not change the cytophenotypes of hAMSCs.

Stimuli-responsive metal-organic frameworks gated by pillar[5]arene supramolecular switches.

Spurred on by recent advances in materials chemistry and drug delivery, a new stimuli-responsive theranostic hybrid platform, based on mechanized monodisperse nano metal-organic frameworks (NMOFs) gated by carboxylatopillar[5]arene (CP5) switches with bio-friendly pH-triggered cargo release capabilities, has been constructed for the first time. This nanoscale smart cargo delivery system showed pH- and/or competitive binding agent-triggered controlled cargo release with negligible premature release, large pore sizes for drug encapsulation, low cytotoxicity, good biodegradability and biocompatibility, and potential application in cell imaging, which offers a new tool in targeted drug delivery and the controlled release of therapeutic agents.

Supramolecular assembly-induced yellow emission of 9,10-distyrylanthracene bridged bis(pillar[5]arene)s.

9,10-Distyrylanthracene has been introduced to bridge two pillarenes to form a dimeric host, which can assemble into a linear supramolecular polymer upon cooperatively binding to a neutral guest linker, exhibiting yellow fluorescence emission in solution and solid states.

Stimuli-responsive blue fluorescent supramolecular polymers based on a pillar[5]arene tetramer.

A tetraphenylethene-bridged pillarene tetramer with aggregation-induced emission properties forms an A4/B2-type supramolecular polymer and a gel with a symmetric neutral guest linker, showing a remarkable fluorescence emission enhancement in solution and the solid state and a good responsiveness to temperature and solvent composition.

Mechanized silica nanoparticles based on pillar[5]arenes for on-command cargo release.

Mechanized silica nanoparticles, equipped with pillar[5]arene-[2]pseudorotaxane nanovalves, operate in biological media to trap cargos within their nanopores, but release them when the pH is lowered or a competitive binding agent is added. Although cargo size plays an important role in cargo loading, cargo charge-type does not appear to have any significant influence on the amount of cargo loading or its release. These findings open up the possibility of using pillar[n]arene and its derivatives for the formation of robust and dynamic nanosystems that are capable of performing useful functions.

Viologen-mediated assembly of and sensing with carboxylatopillar[5]arene-modified gold nanoparticles.

Carboxylatopillar[5]arene (CP[5]A), a new water-soluble macrocyclic synthetic receptor, has been employed as a stabilizing ligand for in situ preparation of gold nanoparticles (AuNPs) to gain new insights into supramolecular host-AuNP interactions. CP[5]A-modified AuNPs with good dispersion and narrow size distributions (3.1 ± 0.

[Investigation on spread and hazards of human parasites in Qushui Village, Suixi County, Zhanjiang City].

Objective: To understand the transmission of human parasites in Qushui Village, Yangqing Town, Suixi County, Zhanjing City, Guangdong Province.

Methods: The direct stool smear, floatation, Kato-Katz technique, and hookworm larva culture were used for the parasite infections. The questionnaire survey was applied for the hazards of parasites.

One-pot synthesis of pillar[n]arenes catalyzed by a minimum amount of TfOH and a solution-phase mechanistic study.

A practical and effective trifluoromethanesulfonic acid (TfOH)-catalyzed cyclooligomerization strategy was developed for the synthesis of functionalized pillar[n]arenes and copillar[5]arenes from 1,4-dialkoxybenzenes with paraformaldehyde under mild reaction conditions, and the reaction mechanism of solution-phase catalytic synthesis of pillararenes was investigated by room-temperature X-band ESR spectroscopy, mass spectroscopy, NMR and control experiments, suggesting a free radical process initially and a Friedel-Crafts alkylation process during the consequent coupling and ring-closure stage.

[Study on inducing differentiation of human amniotic epithelial cells into insulin secreting cells in vitro].

Objective: To investigate the differentiation of human amniotic epithelial cells (hAECs) into insulin secreting cells (ISCs) in vitro.

Methods: The hAECs were isolated from human amnion by trypsin digestion, and the phenotype of the isolated cells were identified by flow cytometry and immunocytochemical staining. The hAECs at passage 3 were treated with nicotinamide and N2 supplement to investigate their differentiation into ISCs.

Polysaccharides from the Medicinal Mushroom Cordyceps taii Show Antioxidant and Immunoenhancing Activities in a D-Galactose-Induced Aging Mouse Model.

Cordyceps taii, an edible medicinal mushroom native to south China, is recognized as an unparalleled resource of healthy foods and drug discovery. In the present study, the antioxidant pharmacological properties of C. taii were systematically investigated.

Establishment of a cell-based drug screening model for identifying agonists of human peroxisome proliferator-activated receptor gamma (PPARγ).

Objectives: Peroxisome proliferator-activated receptor gamma (PPARγ) plays a critical role in regulation of diverse biological processes, including lipid metabolism and adipogenesis, cell division and apoptosis, and is involved in variety of disease conditions, such as obesity, atherosclerosis, inflammation and tumour. Developing a cell-based reporter gene model targeting PPARγ would be useful to screen human PPARγ agonists that could be beneficial to patients with these diseases.

Methods: We stably co-transfected human embryonic kidney (HEK) cell line 293T cells with phPPARγ-IRES2-EGFP vector to express human PPARγ (hPPARγ), a reporter vector pPPRE×3-TK-LUC, and control vector pRL-CMV.

[CD133(+) cells derived from human placenta identified as initiating cells for LTC-IC colony formation].

The aim of this study was to evaluate whether human placenta CD133(+) cells have an ability to reconstitute long-term hematopoiesis. Magnetic-activated cell sorting (MACS) was applied to enrich human placental CD133(+) cells. The isolated human placental CD133(+)cells of four different densities were established by limiting-dilution assay and primary fetal bone marrow stromal cells separated from bone marrow as feeder layer cells were co-cultured in long-term culture system so as to observe the incidence of long-term culture initiating-cells (LTC-IC) and their ability of proliferation and differentiation.

[In vitro expansion of megakaryocyte progenitor cells from human placenta CD133+ cells].

Objective: To study the expansion potential of megakaryocyte progenitor cells (MPC) from human placenta tissue CD133+ (PT-CD133+) cells.

Methods: PT-CD133+ cells were purified from mononuclear cells (MNC) by magnetic activated cell sorting (MACS) and seeded in serum-free liquid culture medium supplemented with thrombopoietin (TPO), interleukin-3 (IL-3), and stem cell factor (SCF) to expand MPC. At day 7, 10 and 14, the total cell number was counted and the dynamic changes of CD133, CD34, and CD41 antigens expression during ex-vivo expansion were analyzed by flow cytometry (FCM).

[Epidemiological investigation of Angiostrongylus cantonensis in Jiangmen of Guangdong Province].

Objective: To make an epidemiological survey on Angiostrongylus cantonensis in Jiangmen City of Guangdong Province.

Methods: From October 2006 to November 2007, the characteristics of A. cantonensis infection were investigated in Jiangmen district in various hosts, including the third stage larva infection in the snails Achatina fulica and Pomacea canaliculata by digestion method, and the adult A.

[Construction of gtfB/CAT eukaryotic expression plasmid of Streptococcus mutans in mammalian cells].

Purpose: The study aimed to evaluate the expression of recombinant plasmid pVAX1- gtfB/CAT in mammalian COS-7 cells.

Methods: The eukaryotic plasmid carrying encoding gene of gtfB/CAT of Streptococcus mutans was constructed and introduced into COS-7 cells by lipofectamine reagent. The transient protein expression was detected by immunochemistry technique in COS-7 cells.

[Investigation on antitumor mechanism of polysaccharide from medicinal fungus Penicillium jiangxiense].

Objective: To investigate the possible antitumor mechanism of polysaccharide from medicinal fungus Penicillium jiangxiense.

Methods: The cytotoxic effect was measured by MTT assay, and the cell cycle was analyzed by flow cytometry with Propidium iodide (PI) staining. To apoptotic detections, Hoechst 33258 staining for chromatin, annexin-V FITC/PI double staining for early phase cell apoptosis and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) for late phase cell apoptosis.

[Ex vivo expansion of megakaryocyte progenitor cells for CD133(+) cells derived from human umbilical cord blood].

To study the expansion potentiality of megakaryocyte progenitor cells (MPCs) derived from human umbilical cord blood CD133(+) (UCB-CD133(+)) cells and determine the optimal harvest time. UCB-CD133(+) cells were purified from mononuclear cells (MNCs) by magnetic activated cell sorting (MACS) and seeded in serum-free liquid culture medium supplemented with thrombopoietin (TPO), interleukin-3 (IL-3), and stem cell factor (SCF) to expand MPCs. At day 0, 6, 10 and 14 of culture, the total cell number was counted and the dynamic changes of CD133, CD34, and CD41 antigen expression during ex vivo expansion were analyzed by flow cytometry (FCM).

[Isolation and enrichment of hematopoietic stem/progenitor cells from human placenta tissue].

The aim of this study was to establish the standard protocols for isolating and enriching hematopoietic stem/progenitor cells (HSPC) from human placenta tissue (PT). Single-cell suspension from of human PT was prepared by mechanical method combined with collagenase digestion. Mononucleated cells (MNC) derived from PT were separated by hydroxyethyl starch (6% HES), then the three cell subsets of different immunophenotypes (CD34(-), CD34(+)CD38(-), CD34(+)CD38(+)) contained in MNC were isolated by Magnetic Activated Cell Sorting (MACS).