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Establishing and maintaining a healthy endothelium on vascular and intravascular devices is crucial for the prevention of thrombosis and stenosis. Generating a biofunctional surface on vascular devices to recruit endothelial progenitor cells (EPCs) and endothelial cells (ECs) has proven efficient in promoting in situ endothelialization. However, molecules conventionally used for EPC/EC capturing generally lack structural stability, capturing specificity, and biological functionalities, which have limited their applications. Discovery of effective, specific, and structurally stable EPC/EC capturing ligands is desperately needed. Using the high-throughput One-Bead One-Compound combinatorial library screening technology, we recently identified a disulfide cyclic octa-peptide LXW7 (cGRGDdvc), which possesses strong binding affinity and functionality to EPCs/ECs, weak binding to platelets, and no binding to inflammatory cells. Because LXW7 is cyclic and 4 out of the 8 amino acids are unnatural D-amino acids, LXW7 is highly proteolytically stable. In this study, we applied LXW7 to modify small diameter vascular grafts using a Click chemistry approach. In vitro studies demonstrated that LXW7-modified grafts significantly improved EPC attachment, proliferation and endothelial differentiation and suppressed platelet attachment. In a rat carotid artery bypass model, LXW7 modification of the small diameter vascular grafts significantly promoted EPC/EC recruitment and rapidly achieved endothelialization. At 6 weeks after implantation, LXW7-modified grafts retained a high patency of 83%, while the untreated grafts had a low patency of 17%. Our results demonstrate that LXW7 is a potent EPC/EC capturing and platelet suppressing ligand and LXW7-modified vascular grafts rapidly generate a healthy and stable endothelial interface between the graft surface and the circulation to reduce thrombosis and improve patency. In this study, One-Bead One-Compound (OBOC) technology has been applied for the first time in discovering bioactive ligands for tissue regeneration applications. Current molecules used to modify artificial vascular grafts generally lack EPC/EC capturing specificity, biological functionalities and structural stability. Using OBOC technology, we identified LXW7, a constitutionally stable disulfide cyclic octa-peptide with strong binding affinity and biological functionality to EPCs/ECs, very weak binding to platelets and no binding to inflammatory cells. These characteristics are crucial for promoting rapid endothelialization to prevent thrombosis and improve patency of vascular grafts. LXW7 coating technology could be applied to a wide range of vascular and intravascular devices, including grafts, stents, cardiac valves, and catheters, where a "living" endothelium and healthy blood interface are needed. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Heparan sulfate (HS) is widely distributed in mammalian tissues in the form of HS proteoglycans, which play essential roles in various physiological and pathological processes. In contrast to the template-guided processes involved in the synthesis of DNA and proteins, HS biosynthesis is not believed to involve a template. However, it appears that the final structure of HS chains was strictly regulated. Herein, we report research based hypothesis that two major steps, namely “coding” and “decoding” steps, are involved in the biosynthesis of HS, which strictly regulate its chemical structure and biological activity. The “coding” process in this context is based on the distribution of sulfate moieties on the amino groups of the glucosamine residues in the HS chains. The sulfation of these amine groups is catalyzed by N -deacetylase/ N -sulfotransferase, which has four isozymes. The composition and distribution of sulfate groups and iduronic acid residues on the glycan chains of HS are determined by several other modification enzymes, which can recognize these coding sequences (i.e., the “decoding” process). The degree and pattern of the sulfation and epimerization in the HS chains determines the extent of their interactions with several different protein factors, which further influences their biological activity. [ABSTRACT FROM AUTHOR]

Compared to conventional progressive cavity pump (PCP), even thickness PCP has numerous advantages such as uniform thermal and swelling expansion, stable operation and high volumetric efficiency. However, adhesive failure occurs on the stator of even thickness PCP more often in actual working conditions, which limits its development and application. In this study, finite element models of conventional PCP and even thickness PCP with the same structural parameters are established and simulated to find the mechanism for adhesive failure. We primarily study the force conditions of adhesive interface which bonds the stator and cylinder sleeve. The results show that shear strain caused by hydraulic pressure difference and interference displacement is quite large around the adhesive interface of even thickness PCP. The too large shear strain around the adhesive interface is the main cause of adhesive failure. Based on this analysis, the relationship between the shear strain and design parameters, such as the rubber adhesion ratio, pressure difference, elastic modulus of stator, magnitude of interference and wall thickness, is investigated. Our results show that the shear strain increases greatly and adhesive failure tends to occur in certain conditions. Furthermore, two new techniques to enhance the adhesive performance are presented and validated with our finite element analysis. Our research can be of great significance for guiding the design and optimization of even thickness PCPs. [ABSTRACT FROM AUTHOR]

A water-soluble polysaccharide named as PRP was isolated from the fruiting bodies of Phellinus ribis by hot water extraction, DEAE-cellulose and Superdex 30 column chromatography. Its structural characteristics were investigated by FT-IR, NMR spectroscopy, GLC-MS, methylation analysis, periodate oxidation and Smith degradation. Based on the data obtained, PRP was found to be a β-d-glucan containing a (1→4), (1→6)-linked backbone, with a single β-d-glucose at the C-3 position of (1→6)-linked glucosyl residue every eight residues, along the main chain. The glucan has a weight-average molecular weight of about 8.59kDa by HPGPC determination using dextran samples as the standards. Preliminary activity tests in vitro revealed that PRP could stimulate the proliferation of spleen lymphocyte. [Copyright &y& Elsevier]

Curdlan have been investigated for a long time. This β (1 → 3)-glucan has distinctive thermal gel-forming character and is edible, which was approved by the Food and Drug Administration (FDA) to be used in food industry. However, curdlan has poor solubility which limit its use and therefore, many researchers concentrate on curdlan modification and as a consequence diverse curdlan derivatives have been prepared. The initial modification purpose was to increase the solubility in water, while with further study, biological activities such as anti-cancer, anti-coagulation, anti-virus and immune-regulation were discovered. Thus curdlan and its derivatives have increasingly wide uses in different areas. In order to give a more comprehensive understanding for curdlan and its derivatives, we summarized recent advances of curdlan and its derivatives, as well as the existing problems need to be solved. [ABSTRACT FROM AUTHOR]

Background: We investigated the effect of the pretransplant administration of recipient''s blood to donor on rat hepatic allograft survival. Methods: Serum levels of interferon (IFN)-γ were determined after transplantation. Immunocompetent cells from the donor were identified with anti-donor class II MHC (RT1Ba) (OX-76) antibodies. The number of donor-derived CD4+ and CD8+ T cells in hepatic allografts or recipient spleen was determined. Results: LEW rats transplanted with hepatic allografts from ACI rats survived a mean of 11.1±2.1 days. Pretreatment intravenous administration of recipient LEW blood did not prolong the survival of hepatic allografts (10.5±1.7 days). In contrast, pretreatment intraportal administration of recipient LEW blood significantly increased the survival of LEW recipients with ACI livers to 31.7±7.6 days (Table 1). The ratio of ox76+CD4+ or ox76+CD8+ T cell to CD4+ or CD8+ cell was significantly greater (25.6% versus 5.7%, 26.6% versus 6.8%) in hepatic allografts pretreated with pretransplant intraportal administration of LEW recipient blood, rather than those cells in recipient spleen (46.2% versus 34.4%, 63.7% versus 71.4%). Conclusions: Pretransplant intraportal administration of recipient LEW blood to ACI donor rats prolonged the survival of hepatic allografts. This may be associated with the regional graft-versus-host reaction. [Copyright &y& Elsevier]

β-glucans, a group of polysaccharides exist in many organism species such as mushrooms, yeasts, oats, barley, seaweed, but not mammalians, have a variety of biological activities and applications in drugs and other healthcare products. In recent years, β-glucans have been studied as adjuvants in anti-infection vaccines as well as immunomodulators in anti-cancer immunotherapy. β-glucans can regulate immune responses when administered alone and can connect innate and adaptive immunity to improve immunogenicity of vaccines. When β-glucans act as immunostimulants or adjuvants, a set of receptors have been revealed to recognize β-glucans, including dectin-1, complement receptor 3 (CR3), CD5, lactosylceramide, and so on. Therefore, this review is mainly focused on the application of β-glucans as immune adjuvants, the receptors of β-glucans, as well as their structure and activity relationship which will benefit future research of β-glucans. [ABSTRACT FROM AUTHOR]

Sepiella maindroni ink polysaccharide (SIP) from the ink of cuttlefish Sepiella maindroni and its sulfated derivative (SIP-SII) have been demonstrated to possess diverse biological activities. But little is known about low molecular weight squid ink polysaccharides (LMWSIPs). In this study, LMWSIPs were prepared by acidolysis, and the fragments with molecular weight (M w) distribution in the ranges of 7 kDa to 9 kDa, 5 kDa to 7 kDa and 3 kDa to 5 kDa were grouped and named as LMWSIP-1, LMWSIP-2 and LMWSIP-3, respectively. The structural features of LMWSIPs were elucidated, and their anti-tumor, antioxidant and immunomodulatory activities were also studied. The results showed that with the exception of LMWSIP-3, the main structures of LMWSIP-1 and LMWSIP-2 did not change compared with SIP. Though there were no significant differences in the antioxidant capacity between LMWSIPs and SIP, the anti-tumor and immunomodulatory activities of SIP were enhanced to a certain extent after degradation. It is particularly noteworthy that the activities of LMWSIP-2 in anti-proliferation, promoting apoptosis and inhibiting migration of tumor cells as well as promoting the proliferation of spleen lymphocytes were significantly higher than those of SIP and the other degradation products, which is promising in the anti-tumor pharmaceutical field. • Sepiella maindroni ink polysaccharide (SIP) was degraded by acidolysis to prepare low molecular weight SIPs (LMWSIPs). • The main structures of LMWSIP-1 and LMWSIP-2, except for LMWSIP-3, were not changed compared with SIP. • Compared with SIP and other derivatives, LMWSIP-2 showed the strongest anti-tumor and immunomodulatory activities. • The antioxidant activity of SIP was not altered after degradation. [ABSTRACT FROM AUTHOR]

Abstract: Surface-driven progressive cavity pump (PCP) has been widely used as an effective artificial lift equipment in various oilfield productions. During the operation of PCPs, the problem of internal slip, which defines the pump performance in terms of volumetric efficiency and lifting capacity, always occurs. However, due to the complex geometrical structure and coupling interactions between the stator and the oil lifted, it is difficult to solve the volumetric efficiency analytically. In this study, we established a new finite element model of PCP, which consists of the stator, the rotor, the lifted fluid and the fluid–solid interaction. The controlling equations of solid deformation and fluid dynamics are solved using different solvers for solid domain and fluid domain respectively, and their results are exchanged through the fluid–solid interface. Partitioned solution algorithm is employed to tackle the problem of this two-way fluid–solid interaction. From our numerical simulation results, we found two leakage mechanisms: longitudinal slippage and transversal slippage. We took GLB500 PCP as a benchmark to validate our model and simulation method. Our computed volumetric efficiency of PCP with specified design parameters is consistent with experimental result of laboratory test. Furthermore, the model with fluid–structure interaction was used to compare the hydraulic characteristic curves of conventional and even-thickness PCPs and study the influence of different material and structure parameters on internal slip of PCP. The interference and stator thickness are found to be the two main factors influencing the volumetric efficiency, which can be used to optimize the design of PCP for specified purpose. [Copyright &y& Elsevier]

[Display omitted] • Different classes and assembled mechanisms of amphipathic peptides are described. • Several strategies to design and stabilize amphiphilic peptides are summarized. • Several strategies to realize functional transformation are elaborated. • Several delivery systems of amphiphilic peptides are outlined. Amphiphilic self-assembling peptides are widely used in tissue and cell engineering, antimicrobials, drug-delivery systems and other biomedical fields due to their good biocompatibility, functionality, flexibility of design and synthesis, and tremendous potential as delivery carriers for drugs. Currently, the design and study of amphipathic peptides by a bottom-up method to develop new biomedical materials have become a hot topic. However, defined rules have not been established for the design and development of self-assembled peptides. Therefore, the focus of this review is to summarize and provide several rational strategies for the design and study of amphiphilic self-assembly peptides. In addition, this paper also describes the types and general self-assembling mechanism of amphipathic peptides, and outlines their applications in the delivery of hydrophobic drugs, nucleic acid drugs, peptide drugs and vaccines. Amphiphilic self-assembled peptides are expected to exploit new functional materials for drug delivery and other applications. [ABSTRACT FROM AUTHOR]

Abstract: Heparin and heparosan have been confirmed to be effective blockers in inhibiting adhesion of pathogens in vitro. However, their effects on gut microbiota in vivo remain unknown. Here we have studied the effects of oral administration of heparin or heparosan on gut microbiota in rats by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). Results showed that the predominant bacterial communities in the feces of heparin- or heparosan-treated animals were different from those of the saline-treated animals, with increased Lactobacillus spp. and decreased Enterococcus sp. Different DGGE banding patterns were also observed for the subpopulations of Lactobacillus and Bacteroides groups. In conclusion, heparin or heparosan may be used as an effective gut microbiota modulator by increasing the subpopulation of Lactobacillus. [Copyright &y& Elsevier]

Abstract: Taking into account the rising trend of the incidence of cancers of various organs, effective therapies are urgently needed to control human malignancies. However, almost all of the chemotherapy drugs currently on the market cause serious side effects. Fortunately, several previous studies have shown that some non-toxic biological macromolecules, including polysaccharides and polysaccharide–protein complexes, possess anti-cancer activities or can increase the efficacy of conventional chemotherapy drugs. Based on these encouraging observations, a great deal of effort has been focused on discovering anti-cancer polysaccharides and complexes for the development of effective therapeutics for various human cancers. This review focuses on the advancements in the anti-cancer efficacy of various natural polysaccharides and polysaccharide complexes in the past 5 years. Most polysaccharides were tested using model systems, while several involved clinical trials. [Copyright &y& Elsevier]

Abstract: In this study, the effects of heparin–superoxide dismutase conjugate (heparin–SOD) on bleomycin-induced pulmonary fibrosis in vivo and on inflammatory cytokine expression in vitro were evaluated. To investigate the effects of heparin–SOD on pulmonary fibrosis, heparin–SOD was administered to bleomycin (BLM)-treated mice by intraperitoneal injection once a day and the hydroxyproline content in lung was determined per 7days. The degree of fibrosis was assessed quantitatively using histopathologic features. The results showed that heparin–SOD inhibited BLM-induced lung fibrotic lesions as reflected by the decrease of lung hydroxyproline content and lung fibrosis grade 28days after BLM instillation. The in vitro effects on the cytokine level expressed by irradiated 3T3 fibroblasts showed that heparin–SOD significantly lowered the levels of transforming growth factor-β1 and interleukin-1β. These results strongly demonstrated that heparin–SOD might be useful in the prevention and treatment of pulmonary fibrosis. [Copyright &y& Elsevier]

Abstract: SIP-SII is the sulfated S. maindroni ink polysaccharide (SIP) isolated from cuttlefish Sepiella maindroni. SIP-SII weakly inhibited tumor cell growth without cytotoxicity in vitro assay. Herein, we examined the effects of SIP-SII on the expression of matrix metalloproteinase MMP-2 and MMP-9 as well as tumor cell invasion and migration. SIP-SII (0.8–500μg/ml) significantly decreased the expression of MMP-2 activity in human ovarian carcinoma cells SKOV3 as evidenced by the gelatin zymography analysis. No significant decrease of MMP-9 was detected in the cell line after SIP-SII treatment. The expression of MMP-2 was also evaluated using Western blot analysis. The results showed that SIP-SII inhibited the expression of MMP-2 in SKOV3 and human umbilical vein vascular endothelial cells ECV304 after 24h incubation. Furthermore, the activity of invasion and migration of SKOV3 and ECV304 cells were measured. SIP-SII displayed an inhibitory effect on the penetration of SKOV3 cells through Matrigel-coated membrane in transwell chamber. A significant inhibition of ECV304 cell migration was observed in the presence of SIP-SII. These results suggest that SIP-SII might suppress invasion and migration of carcinoma cells via inhibition of MMP-2 proteolytic activity. [Copyright &y& Elsevier]

The content of pullulan and melanin in 500 mutants of Aureobasidum pullulans obtained by ultraviolet mutagenesis were examined and statistically analyzed, and a strong positive correlation was found between them. The result was further confirmed by culturing wild type strain As3.3984 in different media. Then we constructed melanin-deletion mutant As- Δalb1 and pullulan-deletion mutant As- Δpul. As- Δalb1 was a melanin-free strain with the yield of pullulan decreased by 41.01%. The supplementation of melanin in the culture of As- Δalb1 increased the production of pullulan. As- Δpul synthesized neither pullulan nor melanin and recovered melanin synthesis by adding pullulan to the medium. The results suggested that high concentration- of pullulan induced morphological transformation and synthesis of melanin, and melanin promoted the synthesis of pullulan. The pullulan biosynthetic genes, upt , pgm , ugp , and pul , were down-regulated, while the negative regulatory gene of pullulan synthesis, creA , was up-regulated by melanin deficiency. • The synergistic correlation exists between the synthesis of pullulan and melanin. • High concentrations of pullulan induced the synthesis of melanin. • Melanin promotes the synthesis of pullulan. [ABSTRACT FROM AUTHOR]

Dendritic cell (DC) vaccine immunotherapy applies tumor antigens or tumor cell lysate (TCL)-pulsed DCs to induce an antigen-specific immune response to attack cancer cells. However, tumor antigen alone has limited immunostimulatory effects, and so immunostimulants are needed to prepare mature DCs. In our previous study, curdlan sulfate (CS) showed potent adjuvant properties with the HBV vaccine; therefore, we attempted to use CS to mature TCL-pulsed DCs. We first prepared four CSs (CS1-CS4) with different sulfation (S) degrees and molecular weights (MWs), then studied the structure-activity relationship of CS in vitro and finally screened CS3 (14.316% S content and 30.66 kDa MW) as the DC vaccine adjuvant. An in vivo study showed that a DC vaccine adjuvanted with CS3 significantly prolonged the survival of tumor-bearing mice, reduced tumor burden and inhibited tumor growth. The CS3-adjuvanted DC vaccine increased CD80, MHC-I and MHC-II expression, promoted CD8+ T cell infiltration, upregulated TNF-α and IFN-γ transcription, and downregulated TGF-β transcription in tumor tissues. A preliminary mechanism study showed that CS activated DCs mainly via the TLR4 and TLR2 signalling pathways. Based on these results, we concluded that CS3 is a potential adjuvant for DC vaccines and is worth studying for tumor immunotherapy. [ABSTRACT FROM AUTHOR]

Neovascularization is crucial to the occurrence and progression of tumors, and the development of antiangiogenic drugs has essential theoretical value and clinical significance. However, antiangiogenesis therapy alone cannot meet the needs of tumor therapy. Meanwhile, polysaccharides are ideal drug carriers with promising applications in drug modification and delivery. In this research, we developed a novel redox and acid sensitive nanodrug (CDDP-CS-Cys-EA, CCEA) composed of chondroitin sulfate (CS), antiangiogenic peptide (endostatin2-alft1, EA) and chemotherapeutic drug (cisplatin, CDDP). CCEA exhibited redox and acid responsiveness, better blood hemocompatibility (hemolysis rate < 5 %), the ability to target tumors (CD44-mediated endocytosis), and strong antiangiogenesis and antitumor characteristics in vitro. Moreover, CCEA showed excellent antitumor activity and low toxicity in B16 xenograft mice. It also has been confirmed that CCEA induced tumor cell apoptosis through promoting the expression of Bax, suppressing the expression of Bcl-2, decreasing mitochondrial membrane potential, releasing cytochrome C (Cyto C), and enhancing the activities of Caspase 9 and Caspase 3. The results of this paper provided a theoretical basis and insight for the development of antitumor drugs. [ABSTRACT FROM AUTHOR]

Highlights • Nanoparticles enter macrophages and escape from lysosomes effectively. • Nanoparticles upregulate phenotypic and functional maturation of dendritic cells. • Nanoparticles induce activation of type Ⅰ interferons in dendritic cells. • Nanoparticles promote production of cytokines in immunocytes. • Nanoparticles induce lymphocytes proliferation. Abstract Nasal immunization to prevent and treat diseases caused by infection through the respiratory tract cannot be actualized because of the lack of effective adjuvants. We have proven that compared with antigens loaded on CS or O -HTCC alone in nasal vaccination, antigens loaded on the nanoparticles of curdlan sulfate/ O -(2-hydroxyl) propyl-3-trimethyl ammonium chitosan chloride (CS/ O -HTCC) can induce stronger systemic and mucosal immune responses. In this study, we evaluated the immunostimulatory activity and mechanisms of CS/ O -HTCC nanoparticles. The results showed that CS/ O -HTCC nanoparticles can improve the activation of antigen-presenting cells, upregulate the production of inflammatory factors and cytokines, induce cross-presentation, and simultaneously activate type I interferon-related genes. CS/ O -HTCC nanoparticles also activated the PI3K/AKT and MAPK pathways and significantly promoted IL-2 transcription to induce the proliferation of lymphocytes. The results revealed that CS/ O- HTCC nanoparticles as a type of multifunctional adjuvant can improve multiple arms of immune responses. [ABSTRACT FROM AUTHOR]

Highlights • HTCOSC-ES2 displayed improved anti-angiogenesis activity and prolonged halflife. • HTCOSC-ES2 displayed significant anti-tumor activity in B16-tumor bearing C57 mice. • HTCOSC-ES2 has good potential in angiogenesis related tumor treatment. Abstract Most solid tumors require neovascularization during their growth. In our previous study, ES2 (IVRRADRAAVP) was covalently conjugated to soluble chitooligosaccharide chloride (HTCOSC) to form one novel HTCOSC-ES2 conjugate, which displayed better anti-angiogenic activity. In this work, the intracellular distribution and endocytosis of the conjugate in endothelial cells, as well effects on endothelial cell cycle and apoptosis were investigated. In addition, pharmacokinetic and antitumor studies were conducted. HTCOSC-ES2 entered the cell via clathrin and lipid valve pathway and was transported to the nucleus via lysosomal transport mechanism. Unlike ES2, HTCOSC-ES2 effectively inhibited the growth of endothelial cells and promoted apoptosis; thus, it could inhibit tumor angiogenesis, resulting in strong anti-tumor activity in vivo. The half-life of HTCOSC-ES2 was also prolonged, and its clearance was delayed. Immunohistochemistry assays showed that HTCOSC-ES2 obviously reduced the microvessel density, decreased the expression of VEGF, and increased the expression of caspase-3. [ABSTRACT FROM AUTHOR]

Highlights • The carboxyl group of the GSHP was linked to the amino group of the ES2 C-terminal. • The GSHP-ES2 displayed no significant anticoagulant activity. • Improved heat stability and higher P-selectin affinity was obtained through the conjugation of GSHP to ES2. • Better bioactivities of GSHP-ES2 were obtained both in vitro and in vivo. • GSHP has good potential as protein/peptide modifier. Abstract Endostatin (ES) has attracted considerable attention for the treatment of anti-angiogenesis-related disorders. An 11-amino-acid peptide (ES2, IVRRADRAAVP) from the amino terminal of ES is of interest because it is the main active fragment of ES. However, both ES and ES2 have a poor stability and a short half-life, and other disadvantages need to be further resolved. Thus, we conjugated ES2 to glycol-split heparin derivatives (GSHPs) to yield the polymer-peptide conjugate, GSHP-ES2. This study showed that GSHP-ES2 exhibited increased stability, a wider pH activity range, better inhibition of endothelial cell proliferation, migration and tube formation in vitro, better anti-angiogenic activity and a longer half-life in vivo compared with ES2. These results also indicate that GSHP-ES2 has good potential for the treatment of angiogenesis-related diseases, either alone or in combination with other chemicals. [ABSTRACT FROM AUTHOR]

We have previously reported an application of lower range of molecular weight of xanthan gum (LRWXG) for inhibiting cartilage matrix destruction and preventing mitochondrial damage in rabbit osteoarthritis (OA) model. However, whether LRWXG exerts its anti-OA activity through intrinsic bax-mitochondria cytochrome c-caspase signaling pathway in OA still requires further study. To address this problem, the OA model was induced by anterior cruciate ligament transection (ACLT) in rabbit and then treated with LRWXG. The results showed that LRWXG could inhibit the loss of collagen in cartilage matrix, protect trabecular bone in subchondral, decrease the apoptosis of chondrocytes, down-regulate the expressions of active caspase-9, active caspase-3 and bax, and up-regulate the expression of bcl-2. In addition, LRWXG could up-regulate the expression of cyt-c in mitochondria, while down-regulate the expression of cyt-c in cytoplasm. These findings show that LRWXG inhibits cartilage degradation via an intrinsic bax-mitochondria cytochrome c-caspase pathway in OA. [ABSTRACT FROM AUTHOR]

Chitin is a natural polymeric polysaccharide extracted from marine crustaceans, and chitosan is obtained by removing part of the acetyl group (usually more than 60 %) in chitin's structure. Chitosan has attracted wide attention from researchers worldwide due to its good biodegradability, biocompatibility, hypoallergenic and biological activities (antibacterial, immune and antitumor activities). However, research has shown that chitosan does not melt or dissolve in water, alkaline solutions and general organic solvents, which greatly limits its application range. Therefore, researchers have carried out extensive and in-depth chemical modification of chitosan and prepared a variety of chitosan derivatives, which have expanded the application field of chitosan. Among them, the most extensive research has been conducted in the pharmaceutical field. This paper summarizes the application of chitosan and chitosan derivatives in medical materials over the past five years. [Display omitted] [ABSTRACT FROM AUTHOR]

Previous studies demonstrated that SIP-SII, a sulfated derivative of SIP that is isolated from the ink of Sepiella maindroni , showed significant inhibition of tumor growth and metastasis. In this study, the effects of SIP-SII on the migration, invasion and molecular mechanism in ovarian cancer cell line, SKOV-3 cells, were investigated. The flow cytometry, confocal microscope observation, western blot and RT-PCR results indicated that SIP-SII located on cell membrane and inhibited the expression and activation of epidermal growth factor receptor (EGFR). Moreover, the binding capacity of SIP-SII with EGFR was confirmed by surface plasmon resonance (SPR) analysis and co-localization of EGFR and SIP-SII. Accordingly, SIP-SII was proved to attenuate the EGF-induced EGFR phosphorylation and migration by western blot and wound healing assay, respectively. Additionally, SIP-SII inhibited p38/MAPK and PI3K/Akt/mTOR signaling pathways in SKOV-3 cells significantly. What is more, SIP-SII showed amplified inhibitory activity on migration, invasion, and MMP-2 expression in combination with p38-specific inhibitor, PI3K-specific inhibitor or mTOR-specific inhibitor in SKOV-3 cells. Therefore, the mechanism that SIP-SII suppressed EGFR-mediated p38/MAPK and PI3K/Akt/mTOR signaling pathways to inhibit migration and invasion of SKOV-3 cells was demonstrated. These findings suggested that SIP-SII might be used as a potential inhibitor against tumor metastasis. [ABSTRACT FROM AUTHOR]

SIP-SII, the sulfated Sepiella maindroni ink polysaccharide (SIP), has been manifested to possess anti-tumor and anti-metastasis activity in vivo and in vitro . In the present study, we evaluated its inhibitory effect on the epidermal growth factor (EGF)-induced migration and invasion of human epidermoid carcinoma cell (KB cell line) as well as the related signaling pathways. The results of MTT assay indicated that SIP-SII inhibited the proliferation of KB cells in a concentration and time dependent manner. Notably, the attenuation of cell growth by SIP-SII was enlarged in the presence of EGF. The wound healing assay and transwell invasion assay were used to evaluate the effect of SIP-SII on the EGF-induced migration and invasion of KB cells and the results showed that SIP-SII markedly attenuated the EGF-induced migration and invasion. Besides, the EGF-induced matrix metalloproteinase-2 (MMP-2) expression was also suppressed by SIP-SII. However, SIP-SII showed no significant inhibition of the EGF-induced matrix metalloproteinase-9 (MMP-9) expression. Further research revealed that SIP-SII decreased the EGF-induced phosphorylation of epidermal growth factor receptor (EGFR), Akt and p38, but no significant suppression on EGF-induced phosphorylation of extracellular signal-regulated kinase 1 and 2 (Erk1/2) and c-Jun N-terminal kinases (JNK) by SIP-SII treatment was observed. The involvement of EGFR/Akt/p38 pathway was confirmed by evidence that SIP-SII would enlarge the inhibitory effect of the specific signal pathway inhibitors. These results indicate that SIP-SII has the potential to be used as the inhibitor of tumor metastasis especially for cancers characterized by over-activation of EGF/EGFR signaling. [ABSTRACT FROM AUTHOR]

The polysaccharides used in the treatment of osteoarthritis (OA) mainly include sodium hyaluronate, chondroitin sulfate, chitosan, xanthan gum, Low molecular weight heparin, alginate and other polysaccharides. This review summarizes the recent advances in the chemistry and biological activities of polysaccharides for the treatment of OA. [ABSTRACT FROM AUTHOR]

An insightful investigation into specificity of bacterial heparinase III has been intriguingly difficult due to heterogeneity of polymeric substrates. Herein, we chemoenzymatically synthesized a tailored library of HS oligosaccharides as substrates. A ∼15-fold reactivity difference to heparinase III was found between trisaccharides bearing different primary cleavage sites. Variable glucosamine modification decreased reactivity of trisaccharides by >20-fold compared with their counterpart primary substrates, while iduronate-containing secondary linkage showed slightly less sensitivity. The 2-sulfated iduronate residue extremely reduced reactivity to its adjacent primary site at reducing end of oligosaccharides, but showed marginal influence on the non-reducing site. Moreover, oligosaccharide susceptibility to digestion was size-dependent and had an obvious preference for the internal linkages over those near to non-reducing/reducing ends. Surface plasmon resonance revealed cleavage promiscuity attributed to different affinities or incorrect binding of substrates to the enzyme. The attractive information on heparinase III will be valuable in characterizing heparin and HS. [ABSTRACT FROM AUTHOR]

Exosomes are small membrane vesicles secreted by most cell types, and widely exist in cell supernatants and various body fluids. They can transmit numerous bioactive elements, such as proteins, nucleic acids, and lipids, to affect the gene expression and function of recipient cells. Mesenchymal stem cells (MSCs) have been confirmed to be a potentially promising therapy for tissue repair and regeneration. Accumulating studies demonstrated that the predominant regenerative paradigm of MSCs transplantation was the paracrine effect but not the differentiation effect. Exosomes secreted by MSCs also showed similar therapeutic effects as their parent cells and were considered to be used for cell-free regenerative medicine. However, the inefficient and limited production has hampered their development for clinical translation. In this review, we summarize potential methods to efficiently promote the yield of exosomes. We mainly focus on engineering the process of exosome biogenesis and secretion, altering the cell culture conditions, cell expansion through 3D dynamic culture and the isolation of exosomes. In addition, we also discuss the application of MSCs-derived exosomes as therapeutics in disease treatment. [Display omitted] [ABSTRACT FROM AUTHOR]

We have previously reported the application of low molecular weight XG(LM-XG), with molecular weights ranging from 1 × 10 6 Da to 1.5 × 10 6 Da for treating osteoarthritis. In this study, we investigated the anti-apoptotic activity of LM-XG under oxidative stress conditions, activated by hydrogen peroxide (H 2 O 2 )-treated chondrocytes in vitro . Chondrocytes were pretreated with various doses of LM-XG (0, 10, 100, 500, or 1000 μg/mL) or 1000 μg/mL sodium hyaluronate for 12 h, and then exposed to 0.5 mmol/L H 2 O 2 for another 12 h. After treatment, chondrocyte viability was evaluated using a cell counting kit-8; DNA fragmentation was detected using Hoechst33258 staining; the percentage of DNA fragmentation was evaluated using the diphenylamine DNA assay kit; the apoptosis rate was evaluated using flow cytometry; chondrocyte ultra-microscopic morphology was observed using transmission electron microscopy; intracellular reactive oxygen species levels were observed and quantified using 2,7-dichlorofuorescin diacetate, mitochondrial permeability transition analysis was performed using MitoTracker Red CMXRos and 4′,6-diamidino-2-phenylindole staining; and finally, caspase-3 activity was detected by western blot. The results showed that, compared with H 2 O 2 -treated chondrocytes, LM-XG improved cell viability, decreased the percentage of DNA fragmentation, reduced the apoptosis rate, decreased the levels of intracellular reactive oxygen species and mitochondrial permeability transition, reverted the morphological damage, and downregulated cleaved caspase-3 levels. These results demonstrate that LM-XG has anti-apoptotic activity in H 2 O 2 -treated chondrocytes. [ABSTRACT FROM AUTHOR]

In this study, we evaluated the immunomodulatory effects of xanthan gum (XG) in RAW264.7 macrophages and the underlying molecular mechanisms. We used scanning electron microscopy (SEM) to analyze the morphology of XG-treated RAW264.7 cells with and without lipopolysaccharide (LPS) stimulation and investigated the subsequent effects on nitric oxide (NO), interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor (TNF-α), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) levels in LPS-activated mouse RAW264.7 macrophages. We also analyzed the binding affinity of XG to Toll-like receptor 4 (TLR4) with surface plasmon resonance (SPR) analysis and observed that XG decreased NO, IL-6 and TNF-α secretion into the culture medium and iNOS and COX-2 protein levels induced by LPS. This study reveals a two-way immunomodulatory effect of XG on inflammatory mediators in RAW264.7 macrophages that may involve the TLR4 signal pathway, providing a pharmacological basis for the use of XG in the control of inflammatory disorders. [ABSTRACT FROM AUTHOR]

Osteoarthritis (OA) is one of the most common chronic diseases and characterized by degradation of articular cartilage. We have previously reported xanthan gum (XG) injection preparation with high molecular weights ( Mw ) in ranging from 3 × 10 6 Da to 5 × 10 6 Da (HM-XG) could enhance the viscosity of synovial fluid, protect joint cartilage in rabbit, and the therapeutical effect has no significance difference with an existing clinical medication (sodium hyaluronate, SH) at the same injection frequency (once weekly for 5 weeks). Herein, we prepared a XG injection preparation with a low M w (LM-XG) in ranging from 1 × 10 6 Da to 1.5 × 10 6 Da, and evaluated the therapeutical effect for OA therapy at once every 2 weeks for 5 weeks with an SH at once weekly for 5 weeks as reference. The model of OA was induced using anterior cruciate ligament transection (ACLT) in a rabbit in vivo and also using sodium nitroprusside (SNP) in cell culture in vitro . The results showed that LW-XG could also protect cartilage from damage, decrease the concentration of nitric oxide (NO) in synovial fluid and reverse the amplification of the knee joint width similar to HM-XG as our previously reported. At the cellular level, LW-XG promotes proliferation while decreases apoptosis of chondrocytes. Mechanistically at the molecular level, these effects are elicited via down-regulation of the protein levels of caspase-3 and bax and up-regulation of the protein levels of bcl-2 in cartilage in both in vivo and in vitro. These results showed that LW-XG maybe become an excellent candidate long-acting drug for treating OA. [ABSTRACT FROM AUTHOR]

The enzymatic synthesis of biologically important and structurally unique human P1PK blood group type P1 pentasaccharide antigen is described. This synthesis features a three-step sequential one-pot multienzyme (OPME) glycosylation for the stepwise enzymatic chain elongation of readily available lactoside acceptor with cheap and commercially available galactose and N -acetylglucosamine as donor precursors. This enzymatic synthesis provides an operationally simple approach to access P1 pentasaccharide and its structurally related Gb3 and P1 trisaccharide epitopes. [ABSTRACT FROM AUTHOR]

Uncovering the biological roles of heparosan oligosaccharides requires a simple and robust method for their separation and identification. We reported on systematic investigations of the retention behaviors of synthetic heparosan oligosaccharides on porous graphitic carbon (PGC) column by HPLC with charged aerosol detection. Oligosaccharides were strongly retained by PGC material in water-acetonitrile mobile phase, and eluted by trifluoroacetic acid occurring as narrow peaks. Addition of small fraction of methanol led to better selectivity of PGC to oligosaccharides than acetonitrile modifier alone, presumably, resulting from displacement of methanol to give different chemical environment at the PGC surface. Van’t-Hoff plots demonstrated that retention behaviors highly depended on the column temperature and oligosaccharide moieties. By implementing the optimal MeOH content and temperature, a novel isocratic elution method was successfully developed for baseline resolution and identification of seven heparosan oligosaccharides using PGC-HPLC–CAD/MS. This approach allows for rapid analysis of heparosan oligosaccharides from various sources. [ABSTRACT FROM AUTHOR]

Methods 8-week-age male ApoE −/− mice were fed with the atherogenic diet together with or without tested compounds (rosuvastatin calcium, α-LNA-LMWCS, LMWCS and α-LNA) for 16 weeks. When the animals were killed, blood plasma was isolated to test the level of TC, LDL-C, TNF-α, IL-6 and CRP by biochemistry analysis and ELISA method. The whole aorta and aortic root sections were also collected to study atherogenesis level and reveal the possible mechanism by histological examination, real-time PCR and Western blot analysis. Results The level of TC, LDL-C, TNF-α, IL-6 and CRP in plasma in H-LNA-LMWCS group were significantly lower than those of the control group (rosuvastatin calcium). Plaques in H-LNA-LMWCS group showed higher content of smooth muscle cells, lower content of lipid and macrophages, and lower mRNA levels of TNF-α, IL-6, CRP, MCP-1, VCAM-1 and ICAM-1 than those in the control group. In addition, α-LNA-LMWCS could reduce the nuclear translocation of NF-κB, inhibit expressions of p-ERK1/2, p-p38, MCP-1, VCAM-1 and ICAM-1 in mice aorta. Conclusion α-LNA-LMWCS exhibited anti-atherosclerosis effect through regulating the lipid metabolism and diminishing the synthesis of pro-inflammatory cytokines. The possible mechanism may be that α-LNA-LMWCS could influence MAPK/ NF-κB related signal pathway. General Significance The results may provide significant suggestions for the application of α-LNA-LMWCS in anti-atherosclerosis. [ABSTRACT FROM AUTHOR]

Background Diabetic retinopathy is a leading cause of blindness. The objective was to design a novel fusion protein, Tat PTD-Endostatin-RGD, to treat retinal neovascularization via eye drops instead of traditional intravitreal injection trepapeutical methods. Method The anti-angiogenesis ability was evaluated in vitro by chick embryo chorioallantoic membrane assay, wound healing assay and tube formation assay. Corneal barrier and blood-retina barrier were constructed in vitro to investigate the penetration ability of Tat PTD-Endostatin-RGD. Western blot was used to detect the integrin α v β 3 expression level in rat retina microvascular endothelial cells which was stimulated by S -nitroso- N -acetylpenicillamine. The binding affinity of Tat PTD-Endostatin-RGD to integrin α v β 3 was investigated by evaluating the penetration ability on blood-retina barriers treated with S -nitroso- N -acetylpenicillamine. The pharmacodynamics and efficacy analysis were further carried out in the oxygen-induced retinopathy model in vivo . In addition, the pharmacokinetic profile via eye drops was studied on a C57BL/6 mice model. Result Tat PTD-Endostatin-RGD showed high anti-angiogenesis activity and high ability to penetrate these two barriers in vitro . The Western blot results indicated S -nitroso- N -acetylpenicillamine upregulated the expression level of integrin α v β 3 in a dose-dependent manner. Tat PTD-Endostatin-RGD showed a high affinity to rat retina microvascular endothelial cells treated with S -nitroso- N -acetylpenicillamine. The results showed that Tat PTD-Endostatin-RGD could inhibit abnormal angiogenesis in retina via eye drops. Conclusion Tat PTD-Endostatin-RGD showed high penetration ability through ocular barriers, bound specifically to integrin α v β 3 and effectively inhibited the abnormal angiogenesis. General significance Tat PTD-Endostatin-RGD represents a potent novel drug applied via eye drops for fundus oculi neovascularization diseases. [ABSTRACT FROM AUTHOR]

This study reports the use of diethylenetriamine as background electrolyte for the simultaneous separation of hyaluronan acid, chondroitin sulfate, dermatan sulfate and heparin. The analytes were baseline separated by using an uncoated fused silica capillary at 37 °C with a run time of 23 min. The migration order, with hyaluronan acid at first and heparin at last, was related to the sulfation degree. The effect of salt concentration on resolution and migration order was also investigated. The developed method was applied to the simultaneous determination of hyaluronan acid and chondroitin sulfate in mouse plasma. Interferences in plasma were removed by protein precipitation and glycosaminoglycans were further purified by ethanol precipitation. The method was validated over the concentration range from 50 to 600 μg/mL for hyaluronan acid and 500 to 6000 μg/mL for chondroitin sulfate in mouse plasma. Results from assay validations showed that the method was selective and robust. [ABSTRACT FROM AUTHOR]

Background Currently marketed chondroitin sulfate isolated from animal sources and structurally quite heterogeneous. Synthesis of structurally defined chondroitin sulfate is highly desired. The capsular polysaccharide from Escherichia coli strain K4 is similar to chondroitin, and its biosynthesis requires a chondroitin polymerase (KfoC). The essential step toward de novo enzymatic synthesis of chondroitin sulfate, synthesis of chondroitin, could be achieved by employing this enzyme. Methods Structurally defined acceptors and donor-sugars were prepared by chemoenzymatic approaches. In addition, surface plasmon resonance was employed to determine the binding affinities of individual substrates and donor–acceptor pairs for KfoC. Results KfoC has broad donor substrate specificity and acceptor promiscuity, making it an attractive tool enzyme for use in structurally-defined chimeric glycosaminoglycan oligosaccharide synthesis in vitro . In addition, the binding of donor substrate molecules regulated the affinity of KfoC for acceptors, then influenced the glycosyl transferase reaction catalyzed by this chondroitin polymerase. Conclusion and general significance These results assist in the development of enzymatic synthesis approaches toward chimeric glycosaminoglycan oligosaccharides and designing future strategies for directed evolution of KfoC in order to create mutants toward user-defined goals. [ABSTRACT FROM AUTHOR]