MALDI-TOF Mass Spectrometric Detection of SARS-CoV-2 Using Cellulose Sulfate Ester Enrichment and Hot Acid Treatment.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes the ongoing coronavirus disease 2019 (COVID-19) pandemic. Here we report a novel strategy for the rapid detection of SARS-CoV-2 based on an enrichment approach exploiting the affinity between the virus and cellulose sulfate ester functional groups, hot acid hydrolysis, and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS). Virus samples were enriched using cellulose sulfate ester microcolumns. Virus peptides were prepared using the hot acid aspartate-selective hydrolysis and characterized by MALDI-TOF MS. Collected spectra were processed with a peptide fingerprint algorithm, and searching parameters were optimized for the detection of SARS-CoV-2. These peptides provide high sequence coverage for nucleocapsid (N protein) and allow confident identification of SARS-CoV-2. Peptide markers contributing to the detection were rigorously identified using bottom-up proteomics. The approach demonstrated in this study holds the potential for developing a rapid assay for COVID-19 diagnosis and detecting virus variants from a variety of sources, such as sewage and nasal swabs.

Efficient removal of hexavalent chromium from electroplating wastewater using polypyrrole coated on cellulose sulfate fibers.

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%).

Anomalous Influence of Salt Concentration on Deposition of Poly(l-Lysine)/Cellulose Sulfate Multilayers Evidenced by In Situ ATR-FTIR.

The deposition of polyelectrolyte (PEL) multilayers (PEMs) of poly(l-lysine)/cellulose sulfate (PLL/CS) onto germanium (Ge) substrates depending on salt concentration (cS) and deposition step z at constant PEL concentration cPEL = 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 cS 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 cS = 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.

Dose Dependence of the Anticoagulant Effect of Intravenously Administered Cellulose Sulfate.

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.

Hydrogels Based on Oxidized Cellulose Sulfates and Carboxymethyl Chitosan: Studies on Intrinsic Gel Properties, Stability, and Biocompatibility.

Cellulose and chitosan are excellent components for the fabrication of bioactive scaffolds, as they are biocompatible and abundantly available. Their derivatives Ocarboxymethyl chitosan (CMChi) and oxidized cellulose sulfate (oxCS) can form in situ gelling, bioactive hydrogels, due to the formation of imine bonds for crosslinking. Here the influence of the degrees of sulfation (DS), oxidation (DO), and the molecular weight of oxCS on intrinsic and rheological properties of such hydrogels and their ability to support the survival and growth of human-adipose-derived stem cells (hADSC) is investigated. It is found that the pH of the hydrogels is generally slightly acidic, while their network density and E-modulus are found to be dependent on the DS and DO, which makes the properties of hydrogels tunable. Extensive studies show that hydrogels can be stable for up to 14 days and that their stability is largely dependent on the DO, molecular weight, and the components mixing ratio. Cytotoxicity studies of the hydrogel with hADSCs show biocompatible gels in dependence on the molecular weight and degree of oxidation with viable cells up to 14 days. These findings can help to develop specifically tailored hydrogels for tissue engineering applications to replace different types of connective tissue.

Conformational and rheological properties of bacterial cellulose sulfate.

In this study, a water-soluble bacterial cellulose sulfate (BCS) was prepared with sulfur trioxide pyridine complex (SO3· Py) in a lithium chloride (LiCl)/dimethylacetamide (DMAc) homogeneous solution system using bacterial cellulose (BC). The structural study showed that the value for the degrees of substitution of BCS was 1.23. After modification, the C-6 hydroxyl group of BC was completely substituted and the C-2 and C-3 hydroxyl groups were partially substituted. In an aqueous solution, the BCS existed as a linear polymer with irregular coil conformation, which was consistent with the findings observed using atomic force microscopy. The steady-state shear flow and dynamic viscoelasticity were systematically determined over a range of BCS concentrations (1 %-4 %, w/v) and temperature (5 °C-50 °C). Steady-state flow experiments revealed that BCS exhibited shear thinning behavior, which increased with an increase in concentration and a decrease in temperature. These observations were quantitatively demonstrated using the cross model. Moreover, based on the dynamical viscoelastic properties, we confirmed that BCS was a temperature-sensitive and weak elastic gel, which was somewhere between a dilute solution and an elastic gel. Therefore, considering the special synthetic strategy and rheological behavior, BCS might be used as a renewable material in the field of biological tissue engineering, especially in the manufacture of injectable hydrogels, cell scaffolds, and as a drug carrier.

Comparative Study of Electrospun Scaffolds Containing Native GAGs and a GAG Mimetic for Human Mesenchymal Stem Cell Chondrogenesis.

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.

Investigation of glycosaminoglycan mimetic scaffolds for neurite growth.

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 13C 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.

Fabrication of the polyphosphates patched cellulose sulfate-chitosan hydrochloride microcapsules and as vehicles for sustained drug release.

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 -NH3+ groups, -SO3- groups, HP3O104- groups, P2O74- groups and H2PO4- 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 ±â€¯4.6% and 74.2 ±â€¯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.

Preparation and anticoagulant properties of heparin-like electrospun membranes from carboxymethyl chitosan and bacterial cellulose sulfate.

Heparin-like membranes (CPBS) with nanofibers (approximate diameters of 100-500 nm) were prepared through electrospinning of a blended solution of carboxymethyl chitosan nanoparticle (CMCN, diameters 483 nm) and poly (vinyl alcohol) (CMCN/PVA) onto the surface of modified bacterial cellulose sulfate (BCS) membranes. SEM images confirmed that the CMCN were stretched to nanofibers during electrospinning. The presence of BCS on the collector of electrospinning machine increased the spinnability of CMCN/PVA solution. FTIR and XPS measurement revealed that there were SO3-, COO-, and OH groups on the surface of CPBS membrane, expressing structural similarity to heparin. CPBS membranes maintained hydrophilicity and the glutaraldehyde crosslinked CPBS membrane was stable in water. The clotting time and platelet adhesion experiments expressed the anticoagulant properties of CPBS. The APTT, TT and PT of CPBS increased up to 116.0%, 189.8%, and 50% than those of the plasma, (67.4 s, 16.2 s, and 48.4 s, respectively). No platelets adhered onto the surface of CPBS. An inflammatory response was determined according to activation of the macrophages seeded onto the membranes.

Investigating cellulose derived glycosaminoglycan mimetic scaffolds for cartilage tissue engineering applications.

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-ß3 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.

Bioactive bacterial cellulose sulfate electrospun nanofibers for tissue engineering applications.

Cellulosic materials have been of tremendous importance to mankind since its discovery due to its superior properties and its abundance in nature. Recently, an increase in demand for alternate green materials has rekindled the interest for cellulosic materials. Here, bacterial cellulose has been functionalized with sulfate groups through acetosulfation to gain solubility in aqueous media, which provides access to several applications. The cell viability, antioxidant, and hemocompatibility assays have verified the biocompatible and antioxidant characteristics of bacterial cellulose sulfate (BCS) in both in vitro and ex vivo conditions. Further, novel BCS/polyvinyl alcohol nanofibers were fabricated by simple electrospinning route to engineer ultrafine nanoscale fibers. The biological evaluation of BCS/polyvinyl alcohol nanofiber scaffolds was done using L929 mouse fibroblast cells, which confirmed that these nanofibers are excellent matrices for cell adhesion and proliferation.

* Gelatin Scaffolds Containing Partially Sulfated Cellulose Promote Mesenchymal Stem Cell Chondrogenesis.

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-ß3) 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.

Synthesis and characterization of novel cellulose ether sulfates.

The synthesis and characterization of novel cellulose sulfate derivatives was reported. Various cellulose ethers were prepared in a homogeneous reaction with common sulfating agents. The received product possess different properties in dependence on the reaction conditions like sulfating agent, solvent, reaction time and reaction temperature. The cellulose ether sulfates are all soluble in water, they rheological behavior could be determined by viscosity measurements and the determination of the sulfur content by elemental analysis lead to a resulting degree of substitution ascribed to sulfate groups (DSSul) of the product. A wide range of products from DSSul 0.1 to DSSul 2.7 will be obtained. Furthermore the cellulose sulfate ethers could be characterized by Raman spectroscopy.

Effect of the cross-linking agent on performances of NaCS-CS/WSC microcapsules.

Based on the properties of oppositely charged natural polysaccharides, the polyelectrolyte complexes (PECs) prepared with chitosan-related polycationic polyelectrolytes and cellulose-related polyanionic polyelectrolytes have been widely concerned for their potential applications as micro-drug-carriers for colon. However, the poor mechanical property of the PECs becomes the obstacle encountered in practical applications. This study investigated the effect of the cross-linking agent (sodium polyphosphate, PPS) on the performances of sodium cellulose sulfate -chitosan/water soluble chitosan (NaCS-CS/WSC) microcapsules. The results revealed that PPS could penetrate through the PEC film and form tighter interior structures compared with the microcapsules without the addition of cross-linking agent. The NaCS-CS microcapsules and NaCS-WSC microcapsules with or without PPS had distinct microstructures, which could be ascribed to the different physicochemical properties of CS and WSC. During the formation process, CS can be dissolved in water under acidic conditions, while WSC can be directly dissolved and protonated in acid-free aqueous providing NH3(+) groups quickly, which resulted in the microstructure's difference. Further analysis showed the NaCS-CS-PPS microcapsules and NaCS-WSC-PPS microcapsules had lower swelling ratios due to their tighter interior microstructures that formed. The cross-linking agent had important effect on the total mass of PECs that produced; moreover, the decline of zeta potential of NaCS-CS-PPS microcapsules was lower than that of NaCS-CS microcapsules, similar trend was found in the NaCS-WSC-PPS microcapsules compared with NaCS-WSC microcapsules, indicating the PPS participated in the interactions and played a role in the microcapsules' formation process.

Fabrication and formation studies on single-walled CA/NaCS-WSC microcapsules.

The micron-sized calcium alginate/sodium cellulose sulfate-water soluble chitosan (CA/NaCS-WSC) microcapsules were prepared by membrane emulsification method using sodium alginate (NaAlg), NaCS and WSC as raw materials. The CA/NaCS microspheres prepared dispersed well and held spherical shape with an emulsifier volume ratio of 7:3 (Span 80:Tween 80) and a concentration of cross-linking agent of 1.5% (w/v) calcium chloride and 5% (w/v) sodium chloride. The CA/NaCS-WSC microcapsules had a spherical shape with average diameter of 62.36±13.87µm. A fluorescent ring could be seen obviously on the surface of CA/NaCS-WSC microcapsules under confocal microscope, when WSC was labeled by fluorescein isothiocyanate. The discussion on the formation studies implied that Ca(2+) could diffuse into the droplets of NaAlg/NaCS forming CA/NaCS microspheres, while NaCS could react with WSC forming a polyelectrolyte complexes film. The microcapsules prepared with typical wall-capsule/core structure could be used to develop micron-sized drug delivery carriers.

Review on biomedical and bioengineering applications of cellulose sulfate.

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.

Study on multilayer structures prepared from heparin and semi-synthetic cellulose sulfates as polyanions and their influence on cellular response.

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.

Multilayer films by blending heparin with semisynthetic cellulose sulfates: Physico-chemical characterization and cell responses.

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.

Characterization of novel lactoferrin loaded capsules prepared with polyelectrolyte complexes.

Novel capsules loaded with lactoferrin (LF) were prepared using polyelectrolyte complexes that were formed by water soluble chitosan (WSC), sodium cellulose sulfate (NaCS) and sodium polyphosphate (PPS). Normal chitosan (soluble in acidic conditions) was chosen as a control to prepare similar capsules with NaCS and PPS. (1)H NMR and FTIR spectra analysis showed that WSC was in a form of chitosan hydrochloride which can be directly dissolved and protonated in acid-free water. SEM results showed that the capsules had a typical wall-capsule structure with a regular spherical shape and an average diameter of 1.97 mm. TGA studies revealed that the thermal stability of the capsules were enhanced and the moisture content of the drug-free/loaded capsules were 6.3% and 3.2%. SDS-PAGE results showed that the primary structures of the processed LF in the capsules were unchanged. Drug loading (LE%) and encapsulation efficiency (EE%) analysis showed that the capsules had a higher LE% (45.6%) and EE% (70.7%) than that of the control. In vitro release studies showed that the capsules had a regular and sustainable release profiles in simulated colonic fluid. All of these results indicated that the capsules prepared could be used as a candidate protein drug carrier for colon.