Endothelial progenitor cells (EPCs) and endothelial cells (ECs) play a vital role in endothelialization and vascularization for tissue regeneration. Various EPC/EC targeting biomolecules have been investigated to improve tissue regeneration with limited success often due to their limited functional specificity and structural stability. One-bead one-compound (OBOC) combinatorial technology is an ultrahigh throughput chemical library synthesis and screening method suitable for ligand discovery against a wide range of biological targets, such as integrins. In this study, using primary human EPCs/ECs as living probes, we identified an αvβ3 integrin ligand LXW7 discovered by OBOC combinatorial technology as a potent and specific EPC/EC targeting ligand. LXW7 overcomes the major barriers of other functional biomolecules that have previously been used to improve vascularization for tissue regeneration and possesses optimal stability, EPC/EC specificity, and functionality. LXW7 is a disulfide cyclic octa-peptide (cGRGDdvc) containing unnatural amino acids flanking both sides of the main functional motif; therefore it will be more resistant to proteolysis and more stable in vivo compared to linear peptides and peptides consisting of only natural amino acids. Compared with the conventional αvβ3 integrin ligand GRGD peptide, LXW7 showed stronger binding affinity to primary EPCs/ECs but weaker binding to platelets and no binding to THP-1 monocytes. In addition, ECs bound to the LXW7 treated culture surface exhibited enhanced biological functions such as proliferation, likely due to increased phosphorylation of VEGF receptor 2 (VEGF-R2) and activation of mitogen-activated protein kinase (MAPK) ERK1/2. Surface modification of electrospun microfibrous PLLA/PCL biomaterial scaffolds with LXW7 via Click chemistry resulted in significantly improved endothelial coverage. LXW7 and its derivatives hold great promise for EPC/EC recruitment and delivery and can be widely applied to functionalize various biological and medical materials to improve endothelialization and vascularization for tissue regeneration applications.

•Biologically active polysaccharides for the treatment of osteoarthritis.•The efficacy of polysaccharides for the treatment of osteoarthritis in the clinical.•The potential polysaccharides for the treatment of osteoarthritis in the pre-clinical.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.This review aims to summarize the recent advances in the chemistry and biological activities of polysaccharides for the treatment of osteoarthritis.Download high-res image (210KB)Download full-size image

•Immunomodulatory effects of xanthan gum (XG) in macrophages were evaluated.•XG ameliorates morphological alteration of LPS-stimulated RAW264.7 macrophages.•XG inhibits inflammatory mediators stimulated by LPS at the mRNA and protein levels.•XG has a high binding affinity to TLR4 as assessed using SPR analysis.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.

•LWXG improves cell viability and decrease apoptosis rates following H2O2 treatment.•LWXG decreases H2O2-generated DNA fragmentation.•LWXG down-regulates the level of intracellular reactive oxygen species and mitochondrial permeability transition.•LWXG reverts reactive oxygen species-associated morphological changes.•LWXG represses the H2O2-induced cleavage of caspase-3 in chondrocytes.We have previously reported the application of low molecular weight XG(LM-XG), with molecular weights ranging from 1 × 106 Da to 1.5 × 106 Da for treating osteoarthritis. In this study, we investigated the anti-apoptotic activity of LM-XG under oxidative stress conditions, activated by hydrogen peroxide (H2O2)-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 H2O2 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 H2O2-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 H2O2-treated chondrocytes.Download high-res image (254KB)Download full-size image

Cancer cells can be distinguished from normal cells by displaying aberrant levels and types of carbohydrate structures on their surfaces. These carbohydrate structures are known as tumor-associated carbohydrate antigens (TACAs). TACAs were considered as promising targets for the design of anticancer vaccines. Unfortunately, carbohydrates alone can only evoke poor immunogenicity because they are unable to induce T-cell-dependent immune responses, which is critical for cancer therapy. Moreover, immunotolerance and immunosuppression are easily induced by using natural occurring TACAs as antigens due to their endogenous property. This review summarizes the recent strategies to overcome these obstacles: (1) covalently coupling TACAs to proper carriers to improve immunogenicity, including clustered or multivalent conjugate vaccines, (2) coupling TACAs to T-cell peptide epitopes or the built-in adjuvant to form multicomponent glycoconjugate vaccines, and (3) developing vaccines based on chemically modified TACAs, which is combined with metabolic engineering of cancer cells.

•HA, CS, DS and heparin were separated.•A new buffer system was employed.•A fast and steady plasma GAGs extraction method was established.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.

•Two major steps, “coding” and “decoding”, are involved in the biosynthesis of HS.•“Coding” is based on the distribution of sulfate moieties on the glucosamine.•“Code” is created by N-deacetylase/N-sulfotransferase, which has four isozymes.•C5-epimerase and O-sulfotransferases recognized the “Code”.•This mechanism regulates chemical structure and biological activity of HS.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.

The diversity-oriented chemoenzymatic synthesis of α-dystroglycan (α-DG) core M1 O-mannose glycans has been achieved via a three-step sequential one-pot multienzyme (OPME) glycosylation of a chemically prepared disaccharyl serine intermediate. The high flexibility and efficiency of this chemoenzymatic strategy was demonstrated for the synthesis of three more complex core M1 O-mannose glycans for the first time along with three previously reported core M1 structures.

Lacto-N-neotetraose and its sialyl and fucosyl derivatives including Lewis x (Lex) pentasaccharide, sialyl Lewis x (sLex) hexasaccharide and internally sialylated derivatives were enzymatically synthesized from readily available lactoside, commercially available uridine 5′-diphosphate-glucose (UDP-Glc) and the corresponding monosaccharides using a highly efficient sequential one-pot multienzyme (OPME) strategy. The OPME strategy which combines bacterial glycosyltransferases and sugar nucleotide generation enzymes provides easy access to the biologically important complex oligosaccharides at preparative scale. Moreover, the same OPME strategy can be used for the regioselective introduction of sialic acid to the internal galactose unit of LNnT in a designed glycosylation route by simply changing the glycosylation sequence.

•Functional and specific analytical methods for complement system were reviewed;•The roles of glycosaminoglycans played in complement system were reviewed.•Glycosaminoglycans have great potential as complement inhibitor in complement system.Complement system is composed of over 30 proteins and it plays important roles in self-defence and inflammation. There are three activation pathways, including classical pathway, alternative pathway and lectin pathway, in complement system, and they are associated with many diseases such as osteoarthritis and age-related macular degeneration. Modulation of the complement system may be a promising strategy in the treatment of related diseases. Glycosaminoglycans are anionic linear polysaccharides without branches. They are one kind of multi-functional macromolecules which have great potential in regulating complement system. This review is organized around two aspects between the introduction of complement system and the interaction of glycosaminoglycans with complement system. Three complement activation pathways and the biological significance were introduced first. Then functional analysis methods were compared to provide a strategy for potential glycosaminoglycans screen. Finally, the roles of glycosaminoglycans played in the complement system were summed up.

•SIP-S showed anti-tumor activity in vivo.•SIP-S could improve the thymus and spleen indices of S180-bearing mice and the mice treated with cyclophosphamide.•SIP-S could induced apoptosis in SKOV3 cells by regulating apoptotic protein expression in vitro.Our previous studies demonstrated that SIP-S had anti-metastatic activity and inhibited the growth of metastatic foci. Here we report the anti-tumor and immunoregulatory potential of SIP-S.SIP-S could significantly inhibit tumor growth in S180-bearing mice, and the inhibition rates was 43.7% at 30 mg/kg d. Besides, SIP-S could improve the thymus and spleen indices of S180-bearing mice and the mice treated with CTX. The combination of SIP-S (15 mg/kg d) with CTX (12.5 mg/kg d) showed higher anti-tumor potency than CTX (25 mg/kg d) alone. These results indicated that SIP-S had immunoenhancing and anticancer activity, and the immunoenhancing activity might be one mechanism for its anti-tumor activity.Flow cytometry results showed that SIP-S could induce tumor cells apoptosis. Western blot analysis indicated that SIP-S could upregulate the expression of pro-apoptotic proteins, caspase-3, -8, -9 and Bax, and downregulate the expression of anti-apoptotic protein PARP-1 in tumor cells in a dose-dependent manner.In summary, SIP-S has anti-tumor activity, which may be associated with its immunostimulating and pro-apoptotic activity.

•A new polysaccharide named PRG was obtained from Phellinus ribis.•Monosaccharide composition analysis confirmed that PRG consisted of glucose only.•PRG was defined to be a (1→3), (1→6)-β-D-glucan.•PRG promoted the neurite outgrowth of the nerve growth factor-stimulated PC12 cells.A new polysaccharide named PRG was isolated from the fruiting bodies of Phellinus ribis by hot water extraction, ethanol precipitation, anion-exchange and gel-filtration chromatography. PRG was homogeneous, with a molecular weight of 5.16 × 103 Da, as determined by high-performance size-exclusion chromatography–multiangle laser light scattering analysis. Its structural characteristics were investigated and elucidated by methylation analysis, partial acid hydrolysis, gas–liquid chromatography mass spectrometry, Fourier transform infrared and nuclear magnetic resonance spectroscopy. Based on obtained data, PRG was found to be a β-d-glucan containing a (1 → 3)-linked backbone, with a branch of two (1 → 6)-linked and one terminal glucoses substituting at the C-6 position every three residues, along the main chain. PRG exhibited neurotrophic activity, which significantly promoted the neurite outgrowth of the nerve growth factor-stimulated PC12 cells, suggesting that it might be a potential candidate for the treatment of neurodegenerative diseases.

•A molecular weight determination model of XG was built based on NIR spectroscopy.•Fiber-optic probe module was compared with integrating sphere module.•Several validation characteristics of the established method were evaluated.•The moisture content of the samples had significant influence on the method.A practical molecular weight determination model of xanthan gum (XG), based on near-infrared (NIR) spectroscopy, was built in this study. Two sample measurement modules, integrating sphere module and fiber-optic probe module, were compared, and the best partial least square (PLS) regression model was based on fiber-optic probe module. The values of coefficient of determination in calibration (R2c), coefficient of determination in prediction (R2p), residual predictive deviation (RPD) and root mean square error of prediction (RMSEP) were 0.967, 0.975, 6.028 and 0.250 × 106 Da, respectively. The molecular weight range, linearity, accuracy and precision of the established method were also validated. Furthermore, influence factors on this method were discussed in order to establish an appropriate measurement protocol. Results showed that the proposed NIR method may be suitable for practical applications in manufacturing plants and probably be accepted as a good alternative approach for fast determination of molecular weight of XG in production process.

An electrophoretically mediated microanalysis (EMMA) protocol for the determination of different chondroitin sulfate (CS) origins based on the difference in the content of unsaturated disaccharides produced by degradation with chondroitinase ABC was developed. Separations were performed in an uncoated fused silica capillary (total length: 60.2 cm, effective length: 50 cm, 50 μm i.d.) at 20 kV and 37 °C. The influences of various parameters, such as different kinds of separation buffers, substrate concentration and incubation time, on separation were investigated. The optimum conditions were as follows: separation buffer, 25 mM tetraborate buffer (pH 9.5); incubation buffer, 50 mM Tris-60 mM acetate buffer (pH 8.0); sample injection, 5 s at 0.5 psi; CS concentration, 500 μg mL−1; incubation time, 8 min. Nonsulfated, monosulfated, disulfated and trisulfated Δ-disaccharides were separated well under the above optimal conditions. The developed method was used to determine the amounts of disaccharides in CS from different sources and the results were compared with those obtained by offline analysis. The results indicated that the developed method could successfully distinguish CS with minor differences and could obtain good coherence results compared with the traditional method.

•Chemical synthesis of unsymmetrical 3,6-branched Man5 oligosaccharide.•One-pot sequential glycosylation is superior to stepwise synthesis.•Three-component convergent synthesis.An expeditious three-component, one-pot sequential glycosylation protocol has been developed for the preparation of 3,6-branched unsymmetrical mannopentaose (Man5), employing a mannose trisaccharide donor, a mannose monosaccharide donor and a mannose monosaccharide acceptor. The high efficiency of this one-pot procedure was demonstrated by comparison study with a stepwise synthesis using the same three building blocks.

A novel chemoenzymatic approach for the synthesis of disialyl tetrasaccharide epitopes found as the terminal oligosaccharides of GD1α, GT1aα, and GQ1bα is described. It relies on chemical manipulation of enzymatically generated trisaccharides as conformationally constrained acceptors for regioselective enzymatic α2–6-sialylation. This strategy provides a new route for easy access to disialyl tetrasaccharide epitopes and their derivatives.

•The paper reported preparation of the sulfated derivatives of a β-glucan, which was isolated from Phellinus ribis for the first time.•The sulfated derivatives had high antitumor activities in vivo, without producing any overt signs of general toxicity.•The derivatives showed antiangiogenic activities in zebrafishes, as well as in H22 hepatoma in mice.•It is possible to expect that the antitumoral effects of the sulfated derivatives are mediated via their antiangiogenic properties.Two sulfated derivatives (PRP-S1 and PRP-S2) of a β-glucan from Phellinus ribis with different degrees of substitution were obtained by chlorosulfonic acid method. The derivatives could block formation of new vessels in zebrafish and inhibit the proliferation of human umbilical vein endothelial cells (HUVECs). The two sulfated derivatives had remarkably high antitumor activities in vivo (in BALB/c mice inoculated with H22 hepatocellular carcinoma) as well as in vitro (against human ovary cancer SKOV-3 cells), without producing any overt signs of general toxicity. The results of immunohistochemistry assay indicated that the derivatives significantly reduced the average number of microvessel density (MVD) and inhibited the expression of vascular endothelial growth factor (VEGF) in tumor. Thus, these derivatives exhibit pronounced antiangiogenic and antitumoral properties. Except for cytotoxic effects on tumor cells, it is reasonable to expect that the antitumoral effects of PRP-S1 and PRP-S2 are mediated via their antiangiogenic properties.

•Raman and NIR are fast, accurate and precise compared to conventional method.•Correlation coefficient method was used for identifying the counterfeits.•iPCA method was used for distinguishing tablets from different factories.Vibrational spectroscopy including Raman and near-infrared (NIR) spectroscopy has become an attractive tool for pharmaceutical analysis. In this study, effective calibration models for the identification of anisodamine tablet and its counterfeit and the distinguishment of manufacturing plants, based on Raman and NIR spectroscopy, were built, respectively. Anisodamine counterfeit tablets were identified by Raman spectroscopy with correlation coefficient method, and the results showed that the predictive accuracy was 100%. The genuine anisodamine tablets from 5 different manufacturing plants were distinguished by NIR spectroscopy using partial least squares discriminant analysis (PLS-DA) models based on interval principal component analysis (iPCA) method. And the results showed the recognition rate and rejection rate were 100% respectively. In conclusion, Raman spectroscopy and NIR spectroscopy combined with chemometrics are feasible and potential tools for rapid pharmaceutical tablet discrimination.Graphical abstract

A reliable and cost-efficient protein synthesis system is the prerequisite for both structural and functional proteomic studies. The last decades saw the great technological improvement in the development of different protein synthesis systems. The cell-free protein synthesis system, especially Escherichia coli-based cell-free protein synthesis system, has emerged as one of the most robust protocols which can meet the growing demand of protein synthesis. E. coli-based cell-free protein synthesis system has become a more complete system for protein synthesis over the last two decades. Here, we review the main development and modifications of the E. coli-based cell-free protein synthesis system.

Fluorinated Thomsen–Friedenreich (T) antigens were synthesized efficiently from chemically produced fluorinated monosaccharides using a highly efficient one-pot two-enzyme chemoenzymatic approach containing a galactokinase and a D-galactosyl-β1–3-N-acetyl-D-hexosamine phosphorylase. These fluorinated T-antigens were further sialylated to form fluorinated ST-antigens using a one-pot two-enzyme system containing a CMP-sialic acid synthetase and an α-2–3-sialyltransferase.

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.Highlights► Heparin and heparosan increased Lactobacillus spp. in rat gut microbiota. ► Heparin and heparosan decreased Enterococcus sp. in rat gut microbiota. ► Heparin or heparosan can be an effective gut microbiota modulator.

A previous study demonstrated that SIP-SII, a sulfated Sepiella maindroni ink polysaccharide, suppressed the invasion and migration of cancer cells via the inhibition of the proteolytic activity of matrix metalloproteinase-2 (MMP-2). Therefore, this study investigated the anti-metastatic effect of SIP-SII in vivo. SIP-SII (15 and 30 mg/kg d) markedly decreased B16F10 pulmonary metastasis in mice models by 85.9% and 88.0%, respectively. Immunohistochemistry showed that SIP-SII decreased the expression of the intercellular adhesion molecule 1 (ICAM-1) and basic fibroblast growth factor (bFGF) in lung metastasis nodules. In addition, SIP-SII inhibited neovascularization in chick chorioallantoic membrane assay at 0.08–2 mg/mL. In the in vitro experiments, SIP-SII (0.8–500 μg/mL) significantly decreased the protein and mRNA expression of ICAM-1 and bFGF in SKOV3 and EA.hy926 cells, respectively. These results suggested that SIP-SII might suppress melanoma metastasis via the inhibition of the tumor adhesion mediated by ICAM-1 and the angiogenesis mediated by bFGF, as well as resulting in depression of the invasion and migration of carcinoma cells.Highlights► Previous study demonstrated that SIP-SII had antimetastatic activity in vitro. ► SIP-SII significantly inhibited melanoma metastasis in vivo. ► SIP-SII inhibited angiogenesis in chick chorioallantoic membrane assay. ► SIP-SII inhibited the expression of ICAM-1 and bFGF both in vitro and in vivo.

Ion-exchange chromatography is a widely used purification technology in the heparin manufacturing process. To improve the efficiency and understand the process directly, a rapid and equally precise method needs to be developed to measure heparin concentration in chromatography process. Here, two robust partial least squares regression (PLS-R) models were established for quantification of heparin based on the near-infrared (NIR) spectroscopy with 80 samples of adsorption process and 76 samples of elution process. Several variables selection algorithms, including correlation coefficient method, successive projection algorithm (SPA) and interval partial least squares (iPLSs), were performed to remove non-informative variables. The results showed that the correlation coefficient of validation (Rp) and the residual predictive deviation (RPD) corresponded to 0.957 and 3.4472 for adsorption process, 0.968 and 3.9849 for elution process, respectively. The approach was found considerable potential for real-time monitoring the heparin concentration of chromatography process.Graphical abstractHighlights► Firstly apply of NIR spectroscopy to monitoring crude heparin purification. ► Great potential to real-time monitor and understand heparin chromatography process. ► Referable methods to in-line monitor chromatography process of glycosaminoglycan.

We have previously shown that intra-articular injection of xanthan gum (XG) could protect the joint cartilage and reduce osteoarthritis progression. In this study, we investigated the preliminary cytotoxicity of XG on chondrocytes, evaluated the effects of XG on the proliferation and the protein expression of matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinase-1 (TIMP-1) in interleukin-1β (IL-1β)-induced rabbit chondrocytes. Primary rabbit chondrocytes were cultured. After treatment with various concentrations of XG with or without 10 ng/mL IL-1β, the proliferation of chondrocytes was evaluated using the MTT assay and the expression levels of MMPs and TIMP-1 were evaluated using ELISA. The results showed that XG alone displayed no adverse effects on cell viability and reversed significantly IL-1β-reduced cell proliferation in a dose-dependent manner. Furthermore, XG showed a dose-dependent inhibition in the IL-1β-induced release of MMPs while increasing TIMP-1 expression. These results strongly suggest that XG affords protection on IL-1β induced rabbit chondrocytes.Highlights► Xanthan gum displayed no adverse effects on chondrocytes viability. ► Xanthan gum showed no marked modulation in the basal levels of MMPs and TIMP-1. ► Xanthan gum reversed interleukin-1β-reduced chondrocytes proliferation. ► Xanthan gum inhibited interleukin-1β-induced release of MMPs. ► Xanthan gum reversed interleukin-1β-reduced TIMP-1 production.

The object of this study was to explore the feasibility of support vector machine (SVM) to identify the origin of chondroitin sulfate (CS) by near infrared spectroscopy. 96 batches CS from three different origins were collected in this research, 66 batches of which were chosen for training set by Kennard–Stone (KS) method and the rest were used for testing. Through the comparison of pretreatment methods of standard normal variate transformation (SNV), multiplicative scatter correction (MSC), Savitzky-Golay (SG) smoothing and derivative with SG smoothing, a SVM discrimination model was constructed, of which the prediction result is 100% accurate with the pretreatment of first derivative and SG smoothing with 15 points. The result indicated that it had great potential using SVM to identify the origin of CS.

With a population of 1.3 billion people and a rapidly expanding economy, China has recently risen to become the third largest pharmaceutical market globally, and it has been predicted that this market will grow by 25–27% to a value of more than US$50 billion in 2011 (Ref. 1). Although many of the drugs in the current market are either generic versions or developed outside China, several multinational pharmaceutical companies have now located research and development (R&D) centres in China, and Chinese pharmaceutical companies are increasingly focusing on innovative drug R&D. Furthermore, the Chinese government implemented a special drug R&D funding programme in which $2.7 billion was invested from 2008 to 2010, with another $6 billion to follow in the next 5 years.However, information on the output of innovative drug R&D in China is limited. With the aim of addressing this issue, we have collected and analysed information from the Chinese State Food and Drug Administration (SFDA) and the Center for Drug Evaluation of the SFDA (CDE) for all novel pharmaceuticals for which new drug applications (NDAs) and investigational new drug applications (INDs) were approved in China between 2003 and 2010. The novel pharmaceuticals discussed in this article only include chemical drugs in classes 1.1 and 1.2 and biological drugs in class 1, which are defined by the SFDA as not being previously approved for marketing as a drug anywhere else in the world. Thus, the scope of novel drugs in this article is narrower than that of the new chemical entities (NCEs) used by the US Food and Drug Administration (FDA). For example, if a drug was first approved by the FDA or the European Medicines Agency, it would not be qualified as a class 1 new drug by the SFDA when its approval is later sought in China. Multinational pharmaceutical companies usually market their drugs in developed countries first, and in our survey, all the innovative drugs approved as class 1 by the SFDA are from domestic Chinese pharmaceutical companies. Consequently, the class 1 approvals by the SFDA reflect the status of innovative drug development solely in domestic Chinese pharmaceutical companies. Additionally, traditional Chinese medicine and vaccines are not discussed here.In the period analysed, ~25 drug candidates were approved for entry into clinical trials (that is, an IND was granted) and an average of four drugs were approved for marketing per year (Fig. 1). However, there was a significant reduction in the number of drugs approved for marketing since 2006, with less than two approvals per year in comparison with the preceding years that ended with 11 approvals in 2005. This is primarily due to the introduction by the SFDA in 2007 of much more stringent rules and regulations regarding new drug approval and registration.A total of 187 novel therapeutics are currently in clinical trials. Nearly two-thirds of the therapeutics are in Phase I trials, with those in Phase II and III trials accounting for 19% and 22%, respectively (Fig. 2a). As shown in Fig. 2b, oncology is the most common therapeutic area (32% of therapeutics analysed), followed by infectious diseases (17%) and cardiovascular diseases (10%).Bearing in mind the importance of patent protection in drug R&D as well as the evolution of Chinese patent law in recent years, we also analysed the patenting of the investigational therapeutics in China. Patents for pharmaceuticals are divided into two categories: compound patents and secondary patents, which include preparation, detection, pharmaceutical composition and usage. Out of 187 investigational drugs, 70 have compound patent protection in China, whereas 23 have compound patent protection in the United States and 16 in Europe (Fig. 2c). We also investigated the characteristics of those novel therapeutics that had patent protection in either the United States or Europe, which are presented in Table 1.The increased investment by the Chinese government and multinational pharmaceutical companies, as well as other improvements (discussed below), are creating a stronger environment for innovative drug R&D in China. First, in the past two decades, the Chinese regulatory system has undergone a systematic transformation to adapt to the emergence of more INDs. The first drug administration law in China was enacted in 1985, and there have been four major amendments since, with the latest one enacted in 2007. As mentioned above, the SFDA (which itself was founded in 2003) has introduced more robust regulations regarding new drug approval and registration, and to improve transparency and efficiency, which could pave the way for the emergence of more innovative drugs in the long term. For example, the registration status of an IND or NDA is publicly available, and applicants have easy access to all information regarding the approval process for their drugs. Local agencies of the SFDA are authorized to conduct preliminary approval procedures to increase efficiency. Companies that provide false information or samples will be penalized and barred from submitting NDAs for up to 3 years.Patent protection is a second factor that is essential in innovative drug development. The current Chinese patent law was enacted in 1984, but until it was amended in 1992, pharmaceutical compositions were not patentable. Now, the patent system has evolved to provide greater protection for innovative drugs. The final judgment from the Beijing High People's Court in 2007 on the patent dispute over sildenafil (Viagra; Pfizer) is one example. The judgment rejected the patent challenge from 12 domestic generics companies, effectively providing patent protection for sildenafil until 2014. Interestingly, the patent that was under dispute is a method-of-use patent, which is more vulnerable to challenges from generics companies than compound patents.Third, to improve investment, ChiNext, China's 'NASDAQ', was launched in 2009, focusing on innovative enterprises and other fledgling venture enterprises. ChiNext provides an important exit for investment, such as venture capital in the field of innovative R&D. Fourth, China initiated a health-care reform plan in 2009, which will create a demand for innovative pharmaceutical products in the years to come. Finally, with regard to talent, the current wave of returnees to China includes many experienced professionals from pharmaceutical and biotechnology companies elsewhere in the world.In conclusion, although the innovative pharmaceutical industry in China is still in the early stages of development, it has progressed rapidly in the past decade. Moreover, China has made considerable improvements and continues to improve the key factors — regulatory systems, patent protection, basic research, investment, talent and market incentives — for the creation of a first-class environment for innovative drug R&D.

The paper reports the preparation, characterization and potential biological activities of a chemically sulfated polysaccharide isolated from Phellinus ribis. Four sulfated derivatives (PRP-SI–IV) with variable degrees of substitution were obtained by the chlorosulfonic acid method, without degradation of the polysaccharide (PRP). The sulfate groups were not regularly distributed along the polysaccharide chain with a multiple substitution pattern as determined by 13C NMR. The sulfated derivatives except for PRP-SI showed significant inhibition effects on HepG2 cells in comparison with the native non-sulfated polysaccharide (PRP). All sulfated derivatives could block new angiogenic vessel formation in zebrafish assay, however, the effects were less than PRP.

•An low molecular weight of xanthan gum (1 × 106 to 1.5 × 106 Da) injection preparation maybe become an excellent candidate long-acting drug for treating osteoarthritis.•The effectiveness treatment of low molecular weight of xanthan gum in osteoarthritis outperforms an existing clinical medication-sodium hyaluronate.•The potential mechanism of low molecular weight of xanthan gum for the anti-osteoarthritis effect is attributed to regulate the protein levels of caspase-3, bax, and bcl-2.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 × 106 Da to 5 × 106 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 Mw (LM-XG) in ranging from 1 × 106 Da to 1.5 × 106 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.

•Tα1–TP5 (305 μg/kg) alleviated immunosuppression induced by hydrocortisone (HC).•Tα1–TP5 (305 μg/kg) combined with cyclophosphamide (CY) had a better tumor growth inhibitory effect than CY alone.•Tα1–TP5 could bind to toll-like receptor 2 (TLR2), and Tα1–TP5 had a higher affinity to TLR2 than that of Tα1.In the present study, the immunomodulatory and synergistic anti-tumor activity of thymosin α1–thymopentin fusion peptide (Tα1–TP5) was investigated in vivo. In addition, the potential receptor of Tα1–TP5 was investigated by surface plasmon resonance (SPR) binding studies. It was found that Tα1–TP5 (305 μg/kg) alleviated immunosuppression induced by hydrocortisone (HC). Tα1–TP5 (305 μg/kg) combined with cyclophosphamide (CY) had a better tumor growth inhibitory effect than CY alone. Furthermore, Tα1–TP5 had a higher affinity (KD = 6.84 μmol/L) to toll-like receptor 2 (TLR2) than Tα1 (KD = 35.4 μmol/L), but its affinity was not significantly different from that of TP5. The results of our present work indicate that Tα1–TP5 can possibly be developed as a new immunomodulatory agent.

Lacto-N-neotetraose and its sialyl and fucosyl derivatives including Lewis x (Lex) pentasaccharide, sialyl Lewis x (sLex) hexasaccharide and internally sialylated derivatives were enzymatically synthesized from readily available lactoside, commercially available uridine 5′-diphosphate-glucose (UDP-Glc) and the corresponding monosaccharides using a highly efficient sequential one-pot multienzyme (OPME) strategy. The OPME strategy which combines bacterial glycosyltransferases and sugar nucleotide generation enzymes provides easy access to the biologically important complex oligosaccharides at preparative scale. Moreover, the same OPME strategy can be used for the regioselective introduction of sialic acid to the internal galactose unit of LNnT in a designed glycosylation route by simply changing the glycosylation sequence.

The diversity-oriented chemoenzymatic synthesis of α-dystroglycan (α-DG) core M1 O-mannose glycans has been achieved via a three-step sequential one-pot multienzyme (OPME) glycosylation of a chemically prepared disaccharyl serine intermediate. The high flexibility and efficiency of this chemoenzymatic strategy was demonstrated for the synthesis of three more complex core M1 O-mannose glycans for the first time along with three previously reported core M1 structures.

Fluorinated Thomsen–Friedenreich (T) antigens were synthesized efficiently from chemically produced fluorinated monosaccharides using a highly efficient one-pot two-enzyme chemoenzymatic approach containing a galactokinase and a D-galactosyl-β1–3-N-acetyl-D-hexosamine phosphorylase. These fluorinated T-antigens were further sialylated to form fluorinated ST-antigens using a one-pot two-enzyme system containing a CMP-sialic acid synthetase and an α-2–3-sialyltransferase.