Acylated chitosan sulfate (ChS1), a sulfated polysaccharide with high anticoagulant activity, was chemically synthesized and structurally characterized using FT-IR analysis. The beneficial structural ...properties and high availability of the sulfate group in ChS1 led to greater anticoagulant activity through both the intrinsic and common pathways with antithrombin III (AT III)-mediated inhibition, particularly involving coagulation factors FXa and FIIa. The analysis of the binding affinities using surface plasma resonance found that the equilibrium dissociation constant (KD) of ChS1 for FXa and FIIa in the presence of AT III was 67.4 nM and 112.6 nM, respectively, indicating the stronger interaction of the AT III/ChS1 complex with the ligands and the inhibition of activated FX and FII. The results of amidolytic assays further demonstrated the stronger inhibition of the proteolytic conversion of factor X by the intrinsic FXase complex and of FII by the prothrombinase complex. Molecular docking analysis further validated the protein-ligand interactions of ChS1 with AT III and their binding affinity.
Chitosan sulfates (CHS) were prepared with chlorosulfonic acid homogeneously and non-homogeneously. The total degrees of substitution (DS) ascribed to sulfate groups (DSS) were determined with ...elemental analysis and the partial DS at 6-O-position was estimated via 13C NMR. CHS with diverse total DSS and sulfation patterns were obtained according to the analysis. The effects of selected reaction parameters that can influence the distribution of sulfate groups were examined. The structure of CHS was then characterized with various NMR techniques, i.e. one- (1D-) and two-dimensional (2D-) NMR, and FT Raman spectroscopy. It was found that the primary hydroxyl groups were always predominantly sulfated for CHS prepared under homogeneous or non-homogeneous conditions and no sulfate groups at 2-N-position could be detected. Finally, the feasibility of using FT Raman spectroscopy as another alternative for determining the total DSS of CHS was presented.
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Tissue engineering has a major emphasis in creating tissue specific extracellular ambiance by altering chemical functionalities of scaffold materials. Heterogeneity of osteochondral tissue ...necessitates tailorable bone and cartilage specific extracellular environment. Carboxylate- and sulfate-functionalized glycosaminoglycans (GAGs) in cartilage extracellular matrix (ECM) create an acidic ambience to support chondrogenic activity, whereas phosphate-rich environment in bone enables chelation of calcium leading to the formation of mineralized matrix along with an alkaline environment to support osteogenesis. In this study, chitosan, a naturally occurring GAGs, was functionalized with phosphate/sulfate groups analogous to bone/cartilage ECM and incorporated in thermogelling agarose hydrogel for delivery to osteochondral defects. In vitro studies revealed significantly higher adhesion and proliferation of adipose derived mesenchymal stem cells (ADMSCs) with blended hydrogels as compared to that of native agarose. Cell differentiation and RT-PCR studies of the phosphorylated hydrogels revealed higher osteogenic potential, while sulfated hydrogels demonstrated enhanced chondrogenic activity in comparison to agarose. Recovery of osteochondral defects after delivery of the thermoresponsive agarose-based hydrogels decorated with phosphorylated derivatives showed significantly higher bone formation. On the other hand, cartilage formation was significant with chitosan sulfate decorated hydrogels. The study highlights the role of chitosan derivatives in osteochondral defect healing, especially phosphorylated ones as bone promoter, whereas sulfated ones act as cartilage enhancer, which was quantitatively distinguished through micro-CT-based noninvasive imaging and analysis.
Chitosan sulfates (CHS) exhibiting various total degrees of substitution ascribed to sulfate groups (DS
S) were synthesized. The sulfation could be under homogeneous or non-homogeneous conditions. ...The obtained CHS were characterized and total DS
S of up to 1.73 were determined. Using chlorosulfonic acid as sulfating agent, CS with total DS
S between 0.86 and 1.67 were obtained and the total DS
S can be regulated by varying the sulfation parameters. Using other sulfating agents, CS with distinct total DS
S of up to 1.73 were prepared. By means of FT Raman spectroscopy, marker bands at 1070
cm
−1 or 1014
cm
−1 attributed to vibrations of sulfation groups can be applied for quantifying the total DS
S of CHS. Calibration curves with correlation coefficients of more than 0.95 were established, suggesting the feasibility of Raman spectroscopy for quantifying the total DS
S of CHS. Finally, the capacity of CHS to improve the osteogenic activity of bone morphogenetic protein-2 (BMP-2) was presented.
Chitosan, carboxymethyl chitosan (CMCS) and chitosan sulfates (CSS) with different molecular weight were modified by reacting with 4-hydroxyl-5-chloride-1,3-benzene-disulfo-chloride or ...2-hydroxyl-5-chloride-1,3-benzene-disulfo-chloride to give 12 kinds of new hydroxylbenzenesulfonailides derivatives of them. The preparation conditions of the derivatives were discussed in this paper, and their structures were characterized by FT-IR and
13C NMR spectroscopy. The solubility of the derivatives was measured in the experiment. In addition, their antimicrobial activities against four bacteria and five crop-threatening pathogenic fungi were tested in the experiment. Besides, the rule and mechanism of their antibacterial activities were discussed in this paper.
The adsorption behavior of human serum albumin (HSA) on differently modified poly(ethylene terephthalate) (PET) model film surfaces was studied using the quartz crystal microbalance (QCM), X-ray ...photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) techniques. The aim was to evaluate the influence of different modifications of PET surfaces with selected polysaccharides (chitosan, fucoidan, chitosan sulfate) on HSA adsorption.
As a first step, PET hydrophilicity was increased by alkaline hydrolysis. From these foils model PET films were prepared by the spin coating technique on a quartz crystal. Selected polysaccharides (chitosan, fucoidan and chitosan sulfate) were adsorbed from aqueous solutions on the PET surfaces. Adsorption of HSA on the films was monitored with QCM-D. The surface composition and morphology of the HSA covered PET films was analyzed using XPS and AFM.
It was found that due to steric repulsion the chitosan, fucoidan and chitosan sulfate adlayers reduced HSA adsorption, especially in case of chitosan/fucoidan and chitosan/chitosan sulfate covered films.
► Water-soluble CMCS was prepared by CMC and sulfating agent N(SO3Na)3. ► The effects of CMCS on proliferation of fibroblasts were studied upon MTT method. ► CMCS exhibited good abilities for ...promoting proliferation of skin fibroblasts.
Carboxymethyl chitosan (CMC) was chemically modified by sulfating agent N(SO3Na)3. The product carboxymethyl chitosan sulfate (CMCS) was characterized by Fourier transform infrared spectroscopy (FT-IR) and carbon-13 nuclear magnetic resonance spectroscopy (13C NMR). And the optimal reaction conditions were also studied by means of single factor experiment. MTT method was applied to evaluate the effects of CMCS on proliferation of skin fibroblasts. The results revealed the CMCS with sulfate content of 26.26% at the concentration of 100μg/ml best promoted the proliferation of skin fibroblasts.
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