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In this study, a sulfonation approach using chlorosulfonic acid (CSA) to prepare cellulose sulfate nanofibers (CSNFs) from raw jute fibers is demonstrated. Both elemental sulfur content and zeta potential in the CSNFs are found to increase with increasing CSA content used. However, the corresponding crystallinity in the CSNFs decreases with the increasing amount of CSA used due to degradation of cellulose chains under harsh acidic conditions. The ammonium adsorption results from the CSNFs with varying degrees of sulfonation were analyzed using the Langmuir isotherm model, and the analysis showed a very high maximum ammonium adsorption capacity (41.1 mg/g) under neutral pH, comparable to the best value from a synthetic hydrogel in the literature. The high ammonium adsorption capacity of the CSNFs was found to be maintained in a broad acidic range (pH = 2.5 to 6.5).

Since 1980 after introducing the concept of live cell encapsulation by Lim et al. , this technology has received enormous attention. Several studies have been conducted to improve this technique; different polymers, either natural or synthetic, have been used as microcapsules` making materials and different substances as coating layers. Literature review leads us to the conclusion that alginate (Alg) multilayer microcapsules and, in particular, alginate-poly l-lysine (PLL)-alginate (APA) are the most used structures for live cell encapsulation. Although, disadvantages of PLL ( e.g ., weak mechanical strength and low biocompatibility) made researchers work on other cationic polymers to find an alternative. This review aims to discuss more popularly suggested cationic polymers such as poly l-ornithine (PLO), chitosan, etc . As alternatives for PLL and, more importantly, we want to take a closer look to see which one of these systems are closer to clinical applications.

In this study, cellulose sulfate was synthesized through sulfonation of cotton, and polypyrrole was coated on the surface of fibers. Then, the optimum ratio of pyrrole to cellulose sulfate was evaluated, and the physical, chemical, and morphological properties of the composite were assessed by using FESEM, EDS, FTIR, BET, and TGA analysis. Furthermore, adsorption of hexavalent chromium using the composite adsorbent was studied by the results of designed experiments with the Box-Behnken technique to assess the effect of pH, contact time, adsorbent dose and the initial concentration of hexavalent chromium and optimize the adsorption process. The removal percentage was 99.9% under the optimum conditions (adsorbent dose, 4 g L-1; initial concentration of Cr(VI), 200 mg L-1; pH value, 2; contact time, 200 min). The results of adsorption isotherms illustrated that the adsorption process followed Redlich-Peterson, Freundlich, Radke-Prausnitz, and UT models, and the calculated maximum adsorption capacity by the Langmuir model was 198 mg g-1. Based on the kinetic and thermodynamic studies, the adsorption process followed the intraparticle diffusion model and showed the endothermic and spontaneous adsorption with an increase in entropy on the adsorbent surface. The presence of copper, nickel and zinc cations had no adverse effect on the removal percentage of hexavalent chromium significantly. The adsorbent was reused successfully in four sequential treatments. Consequently, the synthesized adsorbent is efficient due to the high efficiency of hexavalent chromium removal percentage from electroplating effluent (99.87%)., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Articular cartilage has limited healing and self-repair capability. Damage to articular cartilage becomes irreversible leading to osteoarthritis, which can impact a person's quality of life. Approximately, 5-10% of cartilage tissue is made up of sulfated glycosaminoglycans (GAGs), which sequester growth factors as well as provide structural integrity to the native cartilage tissue. This study evaluated the chondrogenic differentiation of human mesenchymal stem cells (MSCs) on gelatin-based scaffolds containing partially sulfated cellulose (pSC), a GAG mimetic derived from cellulose, in comparison to native GAGs, chondroitin sulfate-A (CS-A) and chondroitin sulfate-C (CS-C), where pSC has similarity to CS-C in terms of degree and pattern of sulfation. Scaffolds were prepared by electrospinning gelatin with pSC or the native GAGs. All scaffolds consist of fibers having average diameters of approximately 3 μm and inter-fiber spacing of approximately 30 μm and were hydrolytically stable throughout the culture. MSCs cultured on pSC containing scaffolds showed early production of sulfated GAGs and higher collagen type II to type I ratio than native GAGs. Among the native GAGs, chondrogenesis was promoted to a greater extent for CS-C in comparison to CS-A containing scaffolds, which suggests the pattern of sulfation impacts chondrogenesis. Partially sulfated cellulose could be used as a potential GAG mimic for cartilage tissue engineering applications.

The deposition of polyelectrolyte (PEL) multilayers (PEMs) of poly(l-lysine)/cellulose sulfate (PLL/CS) onto germanium (Ge) substrates depending on salt concentration (c S ) and deposition step z at constant PEL concentration c PEL = 0.01 M and pH = 7.0 was studied. In situ ATR-FTIR spectroscopy was used for the quantitative determination of alternate PLL/CS deposition profiles (adsorbed amount versus z) and total deposited PEM amount. By varying c S from 0 M to 1.0 M, a maximum of deposited amount was obtained at 0.1 M, so that both no salinity (0 M) and high salinity (1.0 M) revealed deposited amounts that were far lower than for mean salinity (0.1 M). Furthermore, in situ ATR-FTIR allowed to determine the detailed modulation of the PEL composition during the consecutive PEM deposition, which was interpreted as being due to both diffusion of given PEL from the PEM interior towards the outermost region and release of the PEM upon contact with the bulk oppositely charged PEL solution. Finally, ex situ ATR-FTIR measurements on the PEL solutions after deposition of PEM-20 revealed the distinct release of PEL from the PEM solely for c S = 1.0 M, due to the highest mobility of PEL under high salt conditions. These studies help to prepare functional PEM coatings with defined thicknesses and morphologies for the passivation and activation of material surfaces in the biomedical and food field.

Spinal cord injury can lead to severe dysfunction as a result of limited nerve regeneration that is due to an inhibitory environment created at the site of injury. Neural tissue engineering using materials that closely mimic the extracellular matrix (ECM) during neural development could enhance neural regeneration. Glycosaminoglycans (GAGs), which are sulfated polysaccharides, have been shown to modulate axonal outgrowth in neural tissue depending upon the position and degree of sulfation. Cellulose sulfate (CelS), which is a GAG mimetic, was evaluated for its use in promoting neurite extension. Aligned fibrous scaffolds containing gelatin blended with 0.25% partially sulfated cellulose sulfate (pCelS), having sulfate predominantly at the 6-carbon position of the glucose monomer unit, and fully sulfated cellulose sulfate (fCelS), which is sulfated at the 2-, 3-, and 6-carbon positions of the glucose monomer unit, were fabricated using the electrospinning method. Comparisons were made with scaffolds containing native GAGs, chondroitin sulfate-A (CS-A) and chondroitin sulfate-C (CS-C), which were obtained from commercial sources. CS-A and CS-C are present in neural tissue ECM. The degree of sulfation and position of sulfate groups was determined using elemental analysis, Fourier-transform infrared spectroscopy (FTIR), Raman microspectroscopy, and 13 C nuclear magnetic resonance (NMR). In vitro studies examined both nerve growth factor (NGF) binding on scaffolds and neurite extension by dorsal root ganglion (DRG) neurons. NGF binding was highest on scaffolds containing pCelS and fCelS. Neurite extension was greatest for scaffolds containing fCelS followed by pCelS, with the lowest outgrowth on the CS-A containing scaffolds, suggesting that the degree and position of sulfation of CelS was permissible for neurite outgrowth. This study demonstrated that cellulose sulfate, as a GAG mimetic, could be used for future neural tissue regeneration application. STATEMENT OF SIGNFICANCE: Scaffolds that closely mimic the native extracellular matrix (ECM) during development may be a promising approach to enhance neural regeneration. Here, we reported a glycosaminoglycan (GAG) mimetic derived from cellulose that promotes neurite extension over native GAGs, chondroitin sulfate-A (CS-A) and chondroitin sulfate-C (CS-C), which are present in neural ECM. Depending upon the degree and position of sulfation, the GAG mimetic can impact nerve growth factor binding and permissive neurite outgrowth., (Copyright © 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

Polyphosphates are important polyanionic electrolytes that play a major role in stabilization and consolidation of colloids surface and interior microstructures. In this study, the polyelectrolyte complexes (PEC) microcapsules (sodium cellulose sulfate-chitosan hydrochloride, sample 1), and the patched ones via sodium tripolyphosphate (sample 2), sodium pyrophosphate (sample 3) and sodium hexametaphosphate (sample 4) were fabricated under mild conditions. The effects of polyphosphates on the formation of the PEC microcapsules were investigated systematically. Scanning electron microscope (SEM) and confocal laser scanning microscope (CLSM) observation showed that both of the sample 2 and sample 3 had more compact interior microstructures with higher fluorescence intensity, compared with the sample 4 with macroporous ones and sample 1 with irregular ones. Fourier transform-infrared spectroscopy (FT-IR) and thermogravimetric analysis (TGA) showed the electrostatic interactions occurred among the -NH 3 + groups, -SO 3 - groups, HP 3 O 10 4- groups, P 2 O 7 4- groups and H 2 PO 4 - groups, and the sample 2 and sample 3 had a more thermal stability comparatively. The sample microcapsules showed good capacity of drug loading and encapsulation efficiency (max. 66.9 ± 4.6% and 74.2 ± 5.1%). In the in vitro release studies showed that the sample 2 and sample 3 had a larger accumulative drug release rate of 5-aminosalicylic acid (5-ASA) at the same time point and released completely at 12 h; the drug release mechanisms analysis indicated that the sample 1 and sample 3 were mainly diffusion controlled, while the sample 2 and sample 4 were followed the mechanism of non-Fickian transport. Under the polyphosphate's consolidation, the PEC microcapsules fabricated with sustained drug release profiles could be used as the promising drug vehicles., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Angiogenesis plays an important role in both soft and hard tissue regeneration, which can be modulated by therapeutic drugs. If nanoparticles (NP) are used as vectors for drug delivery, they have to encounter endothelial cells (EC) lining the vascular lumen, if applied intravenously. Herein the interaction of unloaded polyelectrolyte complex nanoparticles (PECNP) composed of cationic poly(l-lysine) (PLL) and various anionic polysaccharides with human vascular endothelial cells (HUVEC) was analyzed. In particular PECNP were tested for their cell adhesive properties, their cellular uptake and intracellular localization considering composition and net charge. PECNP may form a platform for both cell coating and drug delivery. PECNP, composed of PLL in combination with the polysaccharides dextran sulfate (DS), cellulose sulfate (CS) or heparin (HEP), either unlabeled or labeled with fluorescein isothiocyanate (FITC) and either with positive or negative net charge were prepared. PECNP were applied to human umbilical cord vein endothelial cells (HUVEC) in both, the volume phase and immobilized phase at model substrates like tissue culture dishes. The attachment of PECNP to the cell surface, their intracellular uptake, and effects on cell proliferation and growth behavior were determined. Immobilized PECNP reduced attachment of HUVEC, most prominently the systems PLL/HEP and PLL/DS. A small percentage of immobilized PECNP was taken up by cells during adhesion. PECNP in the volume phase showed no effect of the net charge sign and only minor effects of the composition on the binding and uptake of PECNP at HUVEC. PECNP were stored in endosomal vesicles in a cumulative manner without apparent further processing. During mitosis, internalized PECNP were almost equally distributed among the dividing cells. Both, in the volume phase and immobilized at the surface, PECNP composed of PLL/HEP and PLL/DS clearly reduced cell proliferation of HUVEC, however without an apparent cytotoxic effect, while PLL/CS composition showed minor impairment. PECNP have an anti-adhesive effect on HUVEC and are taken up by endothelial cells which may negatively influence the proliferation rate of HUVEC. The negative effects were less obvious with the composition PLL/CS. Since uptake and binding for PLL/HEP was more efficient than for PLL/DS, PECNP of PLL/HEP may be used to deliver growth factors to endothelial cells during vascularization of bone reconstitution material, whereas those of PLL/CS may have an advantage for substituting biomimetic bone scaffold material.

Cellulose nanofibrils (CNF) were sulfonated and the dispersion quality was compared to unfunctionalized and 2,2,6,6-tetramethylpiperdine-1-oxyl radical (TEMPO) post-oxidation treatment of existing CNF (mechanically fibrillated pulp). A post-sulfonation treatment on existing CNF in chlorosulfonic acid and dimethylformamide (DMF) resulted in sulfonated CNF that retained a fibril-like morphology. There was a small decrease in the cellulose crystallinity index for the sulfonated CNF, but this was much lower than the reported regioselective oxidative bisulfite pretreatment method used to make sulfonated CNF. The current approach was extremely quick, and 5min of reaction time was sufficient to result in significant improvements in dispersibility compared to unfunctionalized CNF. The sulfonated CNF and TEMPO oxidized CNF had better dispersibility compared to the unfunctionalized CNF when dispersed in DMF and water, and in many cases the sulfonated CNF had better dispersibility than the TEMPO CNF. It was found that when CNF was dispersed in DMF the TEMPO CNF formed carboxyl dimethylammonium groups, while the sulfonated CNF formed formate groups., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Articular cartilage has a limited capacity to heal and, currently, no treatment exists that can restore normal hyaline cartilage. Creating tissue engineering scaffolds that more closely mimic the native extracellular matrix may be an attractive approach. Glycosaminoglycans, which are present in native cartilage tissue, provide signalling and structural cues to cells. This study evaluated the use of a glycosaminoglycan mimetic, derived from cellulose, as a potential scaffold for cartilage repair applications. Fully sulfated sodium cellulose sulfate (NaCS) was initially evaluated in soluble form as an additive to cell culture media. Human mesenchymal stem cell (MSC) chondrogenesis in pellet culture was enhanced with 0.01% NaCS added to induction media as demonstrated by significantly higher gene expression for type II collagen and aggrecan. NaCS was combined with gelatine to form fibrous scaffolds using the electrospinning technique. Scaffolds were characterized for fibre morphology, overall hydrolytic stability, protein/growth factor interaction and for supporting MSC chondrogenesis in vitro. Scaffolds immersed in phosphate buffered saline for up to 56 days had no changes in swelling and no dissolution of NaCS as compared to day 0. Increasing concentrations of the model protein lysozyme and transforming growth factor-β3 were detected on scaffolds with increasing concentrations of NaCS (p < 0.05). MSC chondrogenesis was enhanced on the scaffold with the lowest NaCS concentration as seen with the highest collagen type II production, collagen type II immunostaining, and expression of cartilage-specific genes. These studies demonstrate the feasibility of cellulose sulfate as a scaffolding material for cartilage tissue engineering. Copyright © 2016 John Wiley & Sons, Ltd., (Copyright © 2016 John Wiley & Sons, Ltd.)

Articular cartilage has a limited capacity to heal after damage from injury or degenerative disease. Tissue engineering constructs that more closely mimic the native cartilage microenvironment can be utilized to promote repair. Glycosaminoglycans (GAGs), a major component of the cartilage extracellular matrix, have the ability to sequester growth factors due to their level and spatial distribution of sulfate groups. This study evaluated the use of a GAG mimetic, cellulose sulfate, as a scaffolding material for cartilage tissue engineering. Cellulose sulfate can be synthesized to have a similar level and spatial distribution of sulfates as chondroitin sulfate C (CSC), the naturally occurring GAG. This partially sulfated cellulose (pSC) was incorporated into a fibrous gelatin construct by the electrospinning process. Scaffolds were characterized for fiber morphology and overall stability over time in an aqueous environment, growth factor interaction, and for supporting mesenchymal stem cell (MSC) chondrogenesis in vitro. All scaffold groups had micron-sized fibers and maintained overall stability in aqueous environments. Increasing concentrations of the transforming growth factor-beta 3 (TGF-β3) were detected on scaffolds with increasing pSC. MSC chondrogenesis was enhanced on the scaffold with the highest pSC concentration as seen with the highest collagen type II production, collagen type II immunostaining, expression of cartilage-specific genes, and ratio of collagen type II to collagen type I production. These studies demonstrated the potential of pSC sulfate as a scaffolding material for cartilage tissue engineering.

Experiments on rabbits showed that increasing the dose of intravenously administered cellulose sulfate from wheat straw (dynamic viscosity 3.4 cP, sulfur content 14.1%) increased plasma clotting time in some coagulation tests and plasma anticoagulant activity. When cellulose sulfate was administered in the dose of 1 mg/kg, plasma clotting time in the presence of the anticoagulant (5 min after administration) was ~3-fold higher than after saline administration.

Polysaccharide sulfates are naturally existing chemicals that show important biological activities in living organisms. Cellulose sulfate is a semi-synthesized polysaccharide sulfate with a relatively simple chain structure and unique biological properties and its biological applications have been explored in research and clinical trials. With the advance of cellulose derivatization and characterization, cellulose sulfate molecules with tailored structures have been developed to fulfill individual requirements. This review aims to provide a summary of recent development of cellulose sulfate in biomedical applications. Its synthesis pathways were discussed with structure-property relationship elucidated. The application of cellulose sulfate in drug delivery and microbe/cell immobilization were summarized with emphasis given on its polyelectrolyte complex formation processes., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Here, we report fabrication of polyelectrolyte multilayers by blending a natural glycosaminoglycan (heparin) with semisynthetic cellulose sulfates as polyanions paired with polycation chitosan. Two types of polyanionic blends were prepared by mixing heparin with either cellulose sulfates (CS) of high (CS2.6) or intermediate (CS1.6) sulfation degree in equal mass ratios. Multilayer growth was monitored by surface plasmon resonance (SPR) and quartz crystal micro balance with dissipation monitoring (QCM-D) where as surface wettability was measured by water contact angle measurements (WCA). Both SPR and QCM-D showed differences in biomolecular mass adsorption and dissipation values for different multilayers and also helped in estimating the hydration levels of layers. WCA indicated arrangement of polyanion and polycation layers within the multilayer systems, weather distinct layers, or more intermingled multilayers were established. Overall physico-chemical characterization data suggested a dominating incorporation of heparin over CS in blend multilayer systems. Biological interactions of these blend multilayers investigated with C2C12 cells also indicated a leading contribution of heparin in the blend systems. This current study suggested that heparin was preferentially incorporated over CS that are highly sulfated and points towards the dominance of carboxylic groups over sulfate groups in interacting with amino groups of chitosan., (© 2014 Wiley Periodicals, Inc.)

Multilayer coatings of polycationic chitosan paired with polyanionic semi-synthetic cellulose sulfates or heparin were prepared by the layer-by-layer method. Two different cellulose sulfates (CS) with high (CS2.6) and intermediate (CS1.6) sulfation degree were prepared by sulfation of cellulose. Multilayers were fabricated at pH 4 and the resulting films were characterized by several methods. The multilayer 'optical' mass, measured by surface plasmon resonance, showed little differences in the total mass adsorbed irrespective of which polyanion was used. In contrast, 'acoustic' mass, calculated from quartz crystal micro balance with dissipation monitoring, showed the lowest mass and dissipation values for CS2.6 (highest sulfation degree) multilayers indicating formation of stiffer layers compared to heparin and CS1.6 layers which led to higher mass and dissipation values. Water contact angle and zeta potential measurements indicated formation of more distinct layers with using heparin as polyanion, while use of CS1.6 and CS2.6 resulted into more fuzzy intermingled multilayers. CS1.6 multilayers significantly supported adhesion and growth of C2C12 cells where as only few cells attached and started to spread initially on CS2.6 layers but favoured long term cell growth. Contrastingly cells adhered and grew poorly on to the layers of heparin. This present study shows that cellulose sulfates are attractive candidates for multilayer formation as potential substratum for controlled cell adhesion. Since a peculiar interaction of cellulose sulfates with growth factors was found during previous studies, immobilization of cellulose sulfate in multilayer systems might be of great interest for tissue engineering applications., (Copyright © 2013 Elsevier B.V. All rights reserved.)