miR-183 inhibits invasion of gastric cancer by targeting Ezrin

miR-183, a member of an evolutionarily conserved miRNA cluster (miR-96, miR-182, and miR-183), has been demonstrated to act as both a tumor suppressor and oncogene in various type of human cancer. However, the biological role of miR-183 in gastric cancer (GC) still remains unclear. In the present study, miR-183 expression was significantly decreased in gastric cancer tissues compared with its’ adjacent normal tissues, and down-regulation of miR-183 was significantly associated with lymph node metastasis and pathological TNM stage. Furthermore, Erzin, which was reported to be up-regulated in gastric cancer, was identified as an efficient target of miR-183. Overexpression of miR-183 markedly suppressed cells invasion by downregulation of Ezrin expression. However, miR-183 expression didn’t affect cells proliferation and cell cycle distribution of GC. In conclusion, our study demonstrated that miR-183 acts as a tumor suppressor in GC, partially at least via regulation of Ezrin. Therefore, miR-183 may be a potential target for the treatment of gastric cancer.     

Engineering of extensor tendon complex by an ex vivo approach

Engineering of extensor tendon complex remains an unexplored area in tendon engineering research. In addition, less is known about the mechanism of mechanical loading in human tendon development and maturation. In the current study, an ex vivo approach was developed to investigate these issues. Human fetal extensor tenocytes were isolated, expanded and seeded on polyglycolic acid (PGA) fibers that formed a scaffold with a shape mimicking human extensor tendon complex. After in vitro culture for 6 weeks, 7 cell-scaffold constructs were further in vitro cultured with dynamic mechanical loading for another 6 weeks in a bioreactor. The other 14 constructs were in vivo implanted subcutaneously to nude mice for another 14 weeks. Seven of them were implanted without loading, whereas the other 7 were sutured to mouse fascia and animal movement provided a natural dynamic loading in vivo. The results demonstrated that human fetal cells could form an extensor tendon complex structure in vitro and become further matured in vivo by mechanical stimulation. In contrast to in vitro loaded and in vivo non-loaded tendons, in vivo loaded tendons exhibited bigger tissue volume, better aligned collagen fibers, more mature collagen fibril structure with D-band periodicity, and stronger mechanical properties. These findings indicate that an extensor tendon complex like structure is possible to generate by an ex vivo approach and in vivo mechanical loading might be an optimal niche for engineering functional extensor tendon.     

In vitro generation of an osteochondral construct using injectable hydrogel composites encapsulating rabbit marrow mesenchymal stem cells

Injectable, biodegradable hydrogel composites of crosslinked oligo(poly(ethylene glycol) fumarate) (OPF) and gelatin microparticles (MPs) were utilized to fabricate a bilayered osteochondral construct consisting of a chondrogenic layer and an osteogenic layer, and to investigate the differentiation of rabbit marrow mesenchymal stem cells (MSCs) encapsulated in both layers in vitro. The results showed that MSCs in the chondrogenic layer were able to undergo chondrogenic differentiation, especially in the presence of TGF-β1-loaded MPs. In the osteogenic layer, cells maintained their osteoblastic phenotype. Although calcium deposition in the osteogenic layer was limited, cells in the osteogenic layer significantly enhanced chondrogenic differentiation of MSCs in the chondrogenic layer. The greatest effect was observed when MSCs were encapsulated with TGF-β1-loaded MPs and cultured with osteogenic cells in the bilayered constructs. Overall, this study demonstrates the fabrication of bilayered hydrogel composites that mimic the structure and function of osteochondral tissue, along with the application of these composites as cell and growth factor carriers.     

In vitro engineering of fibrocartilage using CDMP1 induced dermal fibroblasts and polyglycolide

This study was designed to explore the feasibility of using cartilage-derived morphogenetic protein-1 (CDMP1) induced dermal fibroblasts (DFs) as seed cells and polyglycolide (PGA) as scaffold for fibrocartilage engineering. DFs isolated from canine were expanded and seeded on PGA scaffold to fabricate cell/scaffold constructs which were cultured with or without CDMP1. Proliferation and differentiation of DFs in different constructs were determined by DNA assay and glycosaminoglycan (GAG) production. Histological and immunohistochemical staining of the constructs after being in vitro cultured for 4 and 6 weeks were carried out to observe the fibrocartilage formation condition. The fibrocartilage-specific gene expression by cells in the constructs was analyzed by real-time PCR. It was shown that in the presence of CDMP1 the proliferation and GAG synthesis of DFs were significantly enhanced compared to those without CDMP1. Fibrocartilage-like tissue was formed in the CDMP1 induced construct after being cultured for 4 weeks, and it became more matured at 6 weeks as stronger staining for GAG and higher gene expression of collagen type II was observed. Since only weak staining for GAG and collagen type II was observed for the construct engineered without CDMP1, the induction effect on the fibrocartilage engineering can be ascertained when using DFs as seed cells. Furthermore, the potential of using DFs as seed cells to engineer fibrocartilage is substantiated and further study on using the engineered tissue to repair fibrocartilage defects is currently ongoing in our group.     

Microwave‐Assisted Synthesis of Poly(L‐lactic acid) via Direct Melt Polycondensation Using Solid Super‐Acids

A microwave‐assisted method of synthesizing high‐molecular‐weight PLA using SSA as green catalyst was developed. Yellowish PLA with above 2.0 × 10⁴ g · mol^?1 was obtained when the reaction was run at 260 °C within 60 min under microwave irradiation with 0.4 wt.‐% SSA. This method used only 10% of the energy consumption necessary for conventional heating, and the catalyst could be used five times without losing catalytic activity. The improvement in and the decrease in the energy consumption under microwave irradiation suggested that selective heating and hot spots effects played a crucial role. The method was shown to be a time‐saving, green and a promising way to lower the cost and spread the application of PLA.

     

A multicentre study assessing the prevalence of sensitizations in patients with asthma and/or rhinitis in China

Background: The prevalence of sensitization in patients with asthma and rhinitis in mainland China remains unclear. Objective: Our aim was to estimate the prevalence of allergy in patients with respiratory allergic diseases such as asthma and/or rhinitis attending respiratory clinics within mainland China. The study also investigated regional and annual differences in the prevalence and pattern of sensitization among the patients in China. Method: A cross‐sectional survey was performed in 6304 patients suffering from asthma and/or rhinitis in 17 cities from 4 regions of China. Patients completed a standardized questionnaire asking for the presence of respiratory and allergic symptoms. They also underwent skin prick tests with 13 common aeroallergens. Results: Among the 6304 patients, 4545 (72.1%) had at least one positive skin prick reaction. The overall prevalence of positive skin prick responses was 59.0% for Dermatophagoides farinae, 57.6% for Dermatophagoides pteronyssinus, 40.7% for Blomia tropicalis, 16.1% for American cockroach, 14.0% for dog, 11.5% for Blatella germanica, 11.3% for Artemisia vulgaris, 10.3% for cat, 6.5% for Ambrosia artemisifolia, 6.3% for mixed mould I, 4.4% for mixed mould IV, 3.5% for mixed grass pollen and 2.2% for mixed tree pollen. Sensitizations to common allergens varied widely between geographical areas and demonstrated unique pattern in patients by stratification with age groups, with asthma and/or rhinitis. Severity of rhinitis and asthma was significantly correlated with skin index of reactivity to Artemisia vulgaris, Ambrosia artemisifolia and to D. pteronyssinus, D. farinae and Blomia tropicalis respectively (P < 0.001). Positive reactivity to the tested allergens and concomitant reactivity to multiple allergens including to house dust mites and Blomia tropicalis was markedly increased in patients with both asthma and rhinitis. Conclusion: House dust mites were the most prevalent allergens in patients with asthma and/or rhinitis in China. There were significant differences in patterns of sensitizations in patients from different geographical areas, age groups as well as asthma and/or rhinitis.     

Abnormal expression of estrogen receptor is associated with thin endometrium

Abstract

This study was conducted to investigate the association of estrogen receptor (ER) and progesterone receptor (PR) expressions with thin endometrium. Patients with endometrial thickness of less than 7?mm were classified as the study group, while the control group was comprised of patients with endometrial thickness of 7 to 14?mm. The expressions of ER and PR were detected with semi-quantitative immunohistochemical analysis, and the differences were compared between the two groups. The expression of ER was significantly decreased (p?<?.05) in the stromal cells of thin endometrium during both proliferative and secretory phases as compared to those of normal endometrium. Likewise, ER expression was found to be lower in the glandular cells of thin endometrium than those of normal endometrium during proliferative phase. However, no significant differences were observed for the expression of PR in both glandular and stromal cells between the two groups. Thin endometrium was associated with reduced expression of ER in stromal cells both during proliferative and secretory phase, but in glandular epithelial cells only during proliferative phase.     

The influence of Gelatin/PCL ratio and 3-D construct shape of electrospun membranes on cartilage regeneration

Scaffolds play an important role in directing three-dimensional (3-D) cartilage regeneration. Our recent study reported the potential advantages of electrospun gelatin/polycaprolactone (GT/PCL) membranes in regenerating 3-D cartilage. However, it is still unknown whether the changes of GT/PCL ratio have significant influence on 3-D cartilage regeneration. To address this issue, the current study prepared three kinds of electrospun membranes with different GT/PCL ratios (70:30, 50:50, 30:70). Adhesion and proliferation of chondrocytes on the membranes were examined to evaluate biocompatibility of the membranes. Cartilage with different 3-D shapes was engineered to further evaluate the influences of GT/PCL ratio on cartilage regeneration. The current results demonstrated that all the membranes with different GT/PCL ratios presented good biocompatibility with chondrocytes. Nevertheless, the high PCL content in the membranes significantly hampered early 3-D cartilage formation at 3 weeks in vivo. Unexpectedly, at 12 weeks, all the cylinder-shaped constructs formed mature cartilage-like tissue with no statistical differences among groups. To our surprise, ear-shaped cartilage regeneration obtained quite different results again: the high PCL content completely disrupted cartilage regeneration even at 12 weeks, and only the least PCL content group formed homogeneous and continuous cartilage with a satisfactory shape and elasticity similar to human ear. All these results indicated that the high PCL content was unfavorable for 3-D cartilage regeneration, especially for the cartilage with a complicated shape, and that GT/PCL 70:30 might be a relatively suitable ratio for ear-shaped cartilage regeneration. The research models established in the current study provide detailed information for cartilage and other tissue regeneration based on electrospun GT/PCL membranes.     

Cellular internalization of doxorubicin loaded star-shaped micelles with hydrophilic zwitterionic sulfobetaine segments

Four arm star-shaped poly(ε-caprolactone)-b-poly((N,N-diethylaminoethyl methacrylate)-r-(N-(3-sulfopropyl)-N-methacryloxyethy-N,N-diethylammoniumbetaine)) (4sPCLDEAS) micelles were loaded with anticancer drug doxorubicin to track their endocytosis in Hela cancer cell line. The effects of mean diameters and surface charges of the drug loaded micelles on the cellular uptake were studied in details. The results demonstrated that the internalization of micelles was both time and energy dependent process. Endocytic pathways including clathrin-mediated endocytosis, caveolae-mediated endocytosis and macropinocytosis were all involved in the internalization; caveolae-mediated endocytosis was the main pathway for the internalization of 4sPCLDEAS micelles. The assays for cell apoptosis and growth inhibition of tumor spheroids identified that these doxorubicin loaded micelles could induce cell apoptosis and inhibit tumor spheroids growth efficiently, which was even equal to free DOX·HCl. This study provided a rational design strategy for fabricating diverse micellar drug delivery systems with high anticancer efficiency.