An in situ mechanical adjustable double crosslinking hyaluronic acid/poly-lysine hydrogel matrix: Fabrication, characterization and cell morphology.

Cell fate and morphologies are influenced by the mechanical property of matrix. However, the relevant works about the dynamic adjustable of matrix mechanical property is rare and most of them need extra stimulation, such as the controllable of the degradation. In this study, double crosslinking (DC) hydrogels are fabricated by sequential covalent crosslinking and electrostatic interactions between hyaluronic acid and poly-lysine. Without any extra stimulation or treatment, the compressive stress of DC-hydrogels increases from 22.4 ± 9.4 kPa to 320.1 ± 6.6 kPa with the elongation of incubation time in DMEM solution. The change of compressive stress of matrix induced the morphology of L929 fibroblast cells adjusted from the distributed round shape to spheroid cell clusters and finally to spread shape. RNA sequence analysis also demonstrated that the differentially gene expression and GO enrichment between the cells seeded on the DC-hydrogel with different incubation time. In addition, by increasing the electrostatic interactions ratio of the hydrogel, the biodegradation, compressive stress and energy dissipation of the DC-hydrogels were also significantly improved. Therefore, our study provides new and critical insights into the design strategy to achieve DC-hydrogels which can in situ alter cells morphology and open up a new avenue for the application of disease therapy.

Fabrication of Multiple-Layered Hydrogel Scaffolds with Elaborate Structure and Good Mechanical Properties via 3D Printing and Ionic Reinforcement.

A major challenge in three-dimensional (3D) printing of hydrogels is the fabrication of stable constructs with high precision and good mechanical properties and biocompatibility. Existing methods typically feature complicated reinforcement steps or use potentially toxic components, such as photocuring polymers and crosslinking reagents. In this study, we used a thermally sensitive hydrogel, hydroxybutyl chitosan (HBC), for 3D-printing applications. For the first time, we demonstrated that this modified polysaccharide is affected by the specific ion effect. As the salt concentration was increased and stronger kosmotropic anions were used, the lower critical solution temperature of the HBC decreased and the storage modulus was improved, indicating a more hydrophobic structure and stronger molecular chain interactions. On the basis of the thermosensitivity and the ion effects of HBC, a 25-layered hydrogel scaffold with strong mechanical properties and an elaborate structure was prepared via a 3D-printing method and one-step ionic post-treatment. In particular, the scaffold treated with 10% NaCl solution exhibited a tunable elastic modulus of 73.2 kPa to 40 MPa and excellent elastic recovery, as well as biodegradability and cytocompatibility, suggesting the potential for its applications to cartilage tissue repair. By simply controlling the temperature and salt concentrations, this novel approach provides a convenient and green route to improving the structural accuracy and regulating the properties of 3D-printed hydrogel constructs.

Archaeosomes with encapsulated antigens for oral vaccine delivery.

Traditional phosphodiester lipid vesicles (liposomes) are not stable and could be easily degraded in the gastrointestinal (GI) tract. We prepared a novel lipid based oral delivery system: archaeosomes, made of the polar lipid fraction E (PLFE) extracted from Sulfolobus acidocaldarius, and tested their immunogenic potentials as oral vaccine delivery vehicles. Our study showed that the archaeosomes had significant superior stability in simulated gastric and intestinal fluids, and would help fluorescent labeled antigens to reside longer time in the GI tract after oral administration. The resulted immune responses against model antigen ovalbumin (OVA) were greatly improved, eliciting substantial IgG response systemically as well as IgA response mucosally. In addition, the archaeosomes also facilitated antigen specific CD8(+) T cell proliferation. These data indicate that archaeosomes may be a potential vaccine carrier and adjuvant for effective oral immunization.

Silencing of heparanase by siRNA inhibits tumor metastasis and angiogenesis of human breast cancer in vitro and in vivo.

Expression of the heparanase gene is associated with invasive, angiogenic and metastatic potential of diverse malignant tumors and cell lines. Here we used RNA interference strategies to evaluate the role of human heparanase in breast malignancy and to explore the therapeutic potential of its specific targeting. The siRNA targeting human heparanase almost completely inhibited the expression of heparanase in human breast carcinoma MDA-MB-435 cells, whereas the mismatched siRNA showed no effect. Cells transfected with heparanase siRNA expressed significantly less heparanase and profoundly reduced invasion and adhesion in vitro. In MDA-MB-435 cell xenograft model, tumors treated with siRNA were less vascularized and less metastatic than those treated with saline and the mismatched controls. The association of reduced levels of heparanase and altered tumorigenic properties in cells with anti-heparanase siRNA indicates that heparanase is important in cancer progress and has potential use as a target for anticancer drug development.

Oligomannurarate sulfate, a novel heparanase inhibitor simultaneously targeting basic fibroblast growth factor, combats tumor angiogenesis and metastasis.

Inhibitors of tumor angiogenesis and metastasis are increasingly emerging as promising agents for cancer therapy. Recently, heparanase inhibitors have offered a new avenue for such work because heparanase is thought to be critically involved in the metastatic and angiogenic potentials of tumor cells. Here, we report that oligomannurarate sulfate (JG3), a novel marine-derived oligosaccharide, acts as a heparanase inhibitor. Our results revealed that JG3 significantly inhibited tumor angiogenesis and metastasis, both in vitro and in vivo, by combating heparanase activity via binding to the KKDC and QPLK domains of the heparanase molecule. The JG3-heparanase interaction was competitively inhibited by low molecular weight heparin (4,000 Da) but not by other glycosaminoglycans. In addition, JG3 abolished heparanase-driven invasion, inhibited the release of heparan sulfate-sequestered basic fibroblast growth factor (bFGF) from the extracellular matrix, and repressed subsequent angiogenesis. Moreover, JG3 inactivated bFGF-induced bFGF receptor and extracellular signal-regulated kinase 1/2 phosphorylation and blocked bFGF-triggered angiogenic events by directly binding to bFGF. Thus, JG3 seems to inhibit both major heparanase activities by simultaneously acting as a substrate mimetic and as a competitive inhibitor of heparan sulfate. These findings suggest that JG3 should be considered as a promising candidate agent for cancer therapy.

Growth arrest induced by C75, A fatty acid synthase inhibitor, was partially modulated by p38 MAPK but not by p53 in human hepatocellular carcinoma.

C75, a well-known fatty acid synthase (FAS) inhibitor, has been shown to possess potent anti-cancer activity in vitro and in vivo. In this study, we reveal that C75 is a cell cycle arrest inducer and explore the potential mechanisms for this effect in hepatocellular carcinoma (HCC) cell lines with abundant FAS expression: HepG2 and SMMC7721 cells with wt-p53, and Hep3B cells with null p53. The results showed FAS protein expression and basal activity levels were higher in HepG2 cells than in the other two HCC cell lines. Treatment with C75 inhibited FAS activity within 30 min of administration and induced G(2) phase arrest accompanied by p53 overexpression in HepG2 and SMMC7721 cells. By contrast, C75 triggered G(1) phase arrest in Hep3B cells, and RNA interference targeting p53 did not attenuate C75-induced G(2) arrest in HepG2 cells. Similarly, p53 overexpression via p53 plasmid transfection did not affect C75-induced G(1) phase arrest in Hep3B cells. However, we observed a clear correlation between p38 MAPK activation triggered by C75 and the induction of cell cycle arrest in all three HCC cells. Furthermore, treatment with the p38 MAPK inhibitor SB203580 reduced p38 MAPK activity and cell cycle arrest, and also partially restored cyclin A, cyclin B1, cyclin D1 and p21 protein levels. Collectively, it was p38 MAPK but not p53 involved in C75-mediated tumor cell growth arrest in HCC cells.

Beta2 adrenergic receptor gene Arg16Gly polymorphism is associated with therapeutic efficacy of benazepril on essential hypertension in Chinese.

BACKGROUND: There is considerable variability in individual response to antihypertensive agents. The reason for this is not known, but may be related to individual genetic variability. This study examined whether the therapeutic efficacy of benazepril on essential hypertension is modified by beta2 adrenergic receptor gene (ADRB2) Arg16Gly (R16G) polymorphism. METHODS AND RESULTS: We conducted a family-based study of 321 and 610 hypertensive subjects from Yuexi and Huoqiu Counties of Anhui, China, respectively. Both systolic and diastolic blood pressures (SBP and DBP) before and after a 15-day benazepril treatment were measured. ADRB2 R16G genotypes were determined for all subjects. ADRB2 G16 allele frequency was found to be 41.0% and. 47.4% in Huoqiu and Yuexi, respectively. In Yuexi family-based association test (FBAT) revealed that the G16 allele was associated with a greater DBP decrease in response to a 15-day benazepril treatment (Z = 2.12, P = 0.03), and the data were consistent with a dominant inheritance model. A similar trend was observed in Huoqiu Chinese, but the magnitudes of effects were smaller and did not reach statistical significance. The FBAT results were further confirmed by using a generalized estimating equation model. CONCLUSION: Our family-based study provided the first evidence that ADRB2 R16G polymorphism may play an important role in DBP response to benazepril treatment, although the magnitude of the effect appears to be modified by other risk factors such as plasma lipid and glucose profiles.

Identification of genes responsive to apoptosis in HL-60 cells.

AIM: To identify genes responsive to apoptosis in HL-60 cells treated by homoharringtonine. METHODS: cDNA microarray technology was used to detect gene expression and the result of microarrays for genes (TIEG and VDUP1) was confirmed by Northern analysis. RESULTS: Seventy-five individual mRNAs whose mass changed significantly were identified. Among these genes (25 were up-regulated and 50 were down-regulated), most are known related to oncogenes and tumor suppressor. Some genes were involved in apoptosis signaling pathways. CONCLUSION: TGF beta and TNF apoptosis signaling pathways were initiated during apoptosis in HL-60 cells. TIEG and VDUP1 play important roles in mediating apoptosis.

[Fatty acid synthase: specific target for cancer therapy].

Fatty acids, the products of fatty acid synthesis, are essential components and forms of energy for cancer growth. Compared to normal human tissues, many common human cancers express elevated levels of fatty acid synthase (FAS), the important enzyme responsible for the synthesis of fatty acid, suggesting FAS can be a specific target for cancer therapy.