Search

The preparation and characterization of natural polymer-based hydrogels that contain 50-nm diameter magnetite (i.e., FeO:Fe(2)O(3)) nanoparticles are described herein. Fourier-transform infrared spectroscopy (FTIR) analysis confirmed the efficiency of the polysaccharide-modifying process. Thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and compressive moduli demostrate that the presence of magnetite improves thermal and mechanical resistance. Transient diffusion of water in magnetic hydrogels was analyzed via boundary layer mass transfer across an expaning interface, and the degree of swelling of these polysaccharide hydrogels decreases in the presence of magnetite, with no variation in the binary diffusion mechanism. The absence of hysteresis loops and coercivity observed via magnetometry suggests that magnetic hydrogels are useful for remote-controlled drug release, as demonstrated by magnetic-field-induced release of curcumin. Experiments reveal that magnetic hydrogels with greater magnetic susceptibility have the potential to release larger concentrations of drugs from the hydrogel network., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Polyelectrolyte multilayers using the polycations chitosan and N,N,N-trimethyl chitosan and the polyanions hyaluronan, chondroitin sulfate, and heparin are studied. Chitosan and hyaluronan behave as a weak polycation and weak polyanion, respectively, whereas N,N,N-trimethyl chitosan, chondroitin sulfate, and heparin behave as strong polyelectrolytes. Hydrophilicity is determined by water contact angle measurements and by comparing wet and dry film thickness measurements. Wet thickness is obtained using Fourier transform surface plasmon resonance, whereas dry thickness is obtained through ellipsometry. For the very thin PEMs studied here, the surface hydrophilicity and swelling in water are highly correlated. The multilayer chemistry is assessed by FT-IR and X-ray photoelectron spectroscopy (XPS). FT-IR and XPS provide information about the composition, degree of ionization, and by inference, the ion pairing. We find that hydrophilicity and swelling are reduced when one polyelectrolyte is strong and the other is weak, whereas ion pairing is increased. By this combination of techniques, we are able to compose a unified description of how the PEM swelling is dictated by the ion pairing in thin polysaccharide-based PEMs.

Polysaccharides offer a wealth of biochemical and biomechanical functionality that can be used to develop new biomaterials. In mammalian tissues, polysaccharides often exhibit a hierarchy of structure, which includes assembly at the nanometer length scale. Furthermore, their biochemical function is determined by their nanoscale organization. These biological nanostructures provide the inspiration for developing techniques to tune the assembly of polysaccharides at the nanoscale. These new polysaccharide nanostructures are being used for the stabilization and delivery of drugs, proteins, and genes, the engineering of cells and tissues, and as new platforms on which to study biochemistry. In biological systems polysaccharide nanostructures are assembled via bottom-up processes. Many biologically derived polysaccharides behave as polyelectrolytes, and their polyelectrolyte nature can be used to tune their bottom-up assembly. New techniques designed to tune the structure and composition of polysaccharides at the nanoscale are enabling researchers to study in detail the emergent biological properties that arise from the nanoassembly of these important biological macromolecules.

Nanoscale chemical and topographical features have been demonstrated to influence a variety of significant responses of mammalian cells to biomaterials surfaces. Thus, an important goal for biomaterials scientists is the ability to engineer the nanoscale surface features of biologically active materials. The goal of the current work is to demonstrate that polyelectrolyte complex nanoparticles (PCNs) in polyelectrolyte multilayers (PEMs) can be combined to create surfaces with controlled nanoscale surface topography and nanoscale presentation of surface chemistry. The polysaccharides used in this work are the biomedically relevant chitosan, heparin, and hyaluronan. Nanostructured surface coatings were characterized on both modified gold substrates and tissue-culture polystyrene surfaces. PCNs were adsorbed to oppositely charged PEMs, and were also embedded within PEMs. The construction of the surface coatings was characterized by quartz crystal microbalance with dissipation (QCM-D). The surface morphology was characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The chemistry of the coatings was confirmed by both X-ray photoelectron spectroscopy (XPS) and polarization modulation infra-red reflection absorption spectroscopy (PM-IRRAS). Morphologically, we found that PCNs were colloidally stable and homogeneously distributed when adsorbed on or in the PEMs. Chemical analysis confirms that the PCNs adsorbed to PEMs significantly altered the surface chemistry, indicating significant surface coverage. Furthermore, the position of the PCNs normal to the surface can be adjusted by adding PEMs on top of adsorbed PCNs. Thus, PCNs can be used to introduce discrete nanoscale surface topographical features and varying surface chemistry into PEM surface coatings in a controlled way., (2010 Elsevier B.V. All rights reserved.)

The formation of polyelectrolyte complex nanoparticles (PCN) was investigated at different charge mixing ratios for the chitosan-heparin (chi-hep) and chitosan-hyaluronan (chi-ha) polycation-polyanion pairs. The range of 0.08-19.2 for charge mixing ratio (n(+)/n(-)) was examined. The one-shot addition of polycation and polyanion solutions used for the formation of the PCN permitted formation of both cationic and anionic particles from both polysaccharide pairs. The influence of the charge mixing ratio on the size and zeta potential of the particles was investigated. The morphology and stability of the particles when adsorbed to surfaces was studied by scanning electron microscopy (SEM). For most conditions studied, colloidally stable, nonstoichiometric PCN were formed in solution. However, PCN formation was inhibited by flocculation at charge mixing ratios near 1. When adsorbed to surfaces and dried, some formulations resulted in discrete nanoparticles, while others partially or completely aggregated or coalesced, leading to different surface morphologies.

Blood vessels present a dense, non-uniform, polysaccharide-rich layer, called the endothelial glycocalyx. The polysaccharides in the glycocalyx include polyanionic glycosaminoglycans (GAGs). This polysaccharide-rich surface has excellent and unique blood compatibility. We report new methods for preparing and characterizing dense GAG surfaces that can serve as models of the vascular endothelial glycocalyx. The GAG-rich surfaces are prepared by adsorbing heparin or chondroitin sulfate-containing polyelectrolyte complex nanoparticles (PCNs) to chitosan-hyaluronan polyelectrolyte multilayers (PEMs). The surfaces are characterized by PeakForce tapping atomic force microscopy, both in air and in aqueous pH 7.4 buffer, and by PeakForce quantitative nanomechanics (PF-QNM) mode with high spatial resolution. These new surfaces provide access to heparin-rich or chondroitin sulfate-rich coatings that mimic both composition and nanoscale structural features of the vascular endothelial glycocalyx. [ABSTRACT FROM AUTHOR]

Abstract: Here we present a novel matrix-mimetic nanoassembly based on polysaccharides. Chitosan electrospun fiber networks are decorated with heparin-containing polyelectrolyte complex nanoparticles (PCNs) that present basic fibroblast growth factor (FGF-2), both stably adsorbed to the surfaces and released into solution. These FGF-2/PCN complexes can be released from the fibers with zero-order kinetics over a period of 30days. Further modification of fibers with a single bilayer of polyelectrolyte multilayer (PEM) composed of N,N,N-trimethyl chitosan and heparin completely prevent release, and the FGF-2/PCN complexes are retained on the fibers for the duration of the release experiment (30days). We also compare the mitogenic activity of these FGF-2/PCN complexes delivered in two different states: adsorbed to a surface and dissolved in solution. FGF-2/PCN complexes exhibit mitogenic activity with respect to ovine bone marrow-derived mesenchymal stem cells, even after being preconditioned by incubating for 27days at 37°C in solution. However, when the FGF-2/PCN complexes are adsorbed to chitosan and coated with PEMs, the mitogenic activity of the FGF-2 steadily decreases with increasing preconditioning time. This work demonstrates a new system for stabilizing and controlling the delivery of heparin-binding growth factors, using polysaccharide-based matrix-mimetic nanomaterials. This work also contributes to our understanding of the preferred mode of growth factor delivery from porous scaffolds. [Copyright &y& Elsevier]

Polysaccharide-based materials created by physical processes have received considerable attention for biomedical applications. These structures are often made by associating charged polyelectrolytes in aqueous solutions, avoiding toxic chemistries (crosslinking agents). We review the principal polysaccharides (glycosaminoglycans, marine polysaccharides, and derivatives) containing ionizable groups in their structures and cellulose (neutral polysaccharide). Physical materials with high stability in aqueous media can be developed depending on the selected strategy. We review strategies, including coacervation, ionotropic gelation, electrospinning, layer-by-layer coating, gelation of polymer blends, solvent evaporation, and freezing–thawing methods, that create polysaccharide-based assemblies via in situ (one-step) methods for biomedical applications. We focus on materials used for growth factor (GFs) delivery, scaffolds, antimicrobial coatings, and wound dressings. [ABSTRACT FROM AUTHOR]

• Chitosan/alginate and N,N- dimethyl chitosan/alginate-based adsorbents are prepared. • An ionic liquid is used to carry out the polysaccharide-based adsorbents. • Adsorbents are produced by precipitating of blends performed in an ionic liquid. • The ionic liquid is recovered and reused to create new adsorbents. • The adsorbents have high capacity for removing Pb(II) ions from aqueous systems. Alginate/chitosan (ALG/CHT) and alginate/ N , N -dimethyl chitosan (ALG/DMC) polyelectrolyte complex (PEC)-based adsorbents with high capacities for removing Pb(II) from aqueous systems are produced in [1-hydrogen-3-methylimidazolium hydrogen sulfate ionic liquid ([Hmim][HSO 4 ―]). The [Hmim][HSO 4 ―] is recovered, characterized by 1H NMR and reused to yield novel polysaccharide-based adsorbents. As-obtained PEC materials are characterized through infrared spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy and Zeta potential measurements. Kinetic and equilibrium adsorption studies reveal that the pseudo-second-order Kinetic, as well as the Redlich-Peterson isotherm, provide the best fits for the experimental data, respectively. CHT/ALG and DMC/ALG adsorbents promoted maximum adsorption capacities (q m) of 529.4 mg g−1 and 560.2 mg g−1, respectively. After adsorption, the materials are characterized by infrared spectroscopy and X-ray photoelectron spectroscopy, confirming that the chemisorption prevails upon Pb(II) removal. Also, PECs produced in the recovered [Hmim][HSO 4 ―] have good capacities for removing Pb(II) ions from aqueous systems as well. This study showed that the [Hmim][HSO 4 ―] is an alternative solvent to prepare novel and eco-friendly PEC-based adsorbents. [ABSTRACT FROM AUTHOR]

In this work free-standing gels formed from gellan gum (GG) by solvent evaporation are coated with polysaccharide-based polyelectrolyte multilayers, using the layer-by-layer approach. We show that PEMs composed of iota -carrageenan (CAR) and three different natural polycationic polymers have composition-dependent antimicrobial properties, and support mammalian cell growth. Cationic polymers (chitosan (CHT), N , N , N -trimethyl chitosan (TMC), and an amino-functionalized tannin derivative (TN)) are individually assembled with the anionic iota -carrageenan (CAR) at pH 5.0. PEMs (15-layers) are alternately deposited on the GG film. The GG film and coated GG films with PEMs are characterized by infrared spectroscopy with attenuated total reflectance (FTIR-ATR), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and water contact angle (WCA) measurements. The TN/CAR coating provides a hydrophobic (WCA = 127°) and rough surface (R q = 243 ± 48 nm), and the TMC/CAR coating provides a hydrophilic surface (WCA = 78°) with the lowest roughness (R q = 97 ± 12 nm). Polymer coatings promote stability and durability of the GG film, and introduce antimicrobial properties against Gram-negative (Salmonella enteritidis) and Gram-positive (Staphylococcus aureus) bacteria. The films are also cytocompatible. Therefore, they have properties that can be further developed as wound dressings and food packaging. • A commercial gellan gum is characterized, supporting stable films due to the metallic ions presence in its composition. • The solvent evaporation method provides a stiffer gellan gum film. • The film is coated with polyelectrolyte multilayers due to the carboxylate moieties on the gellan gum. • Chitosan/ iota -carrageenan and N , N , N -trimethyl chitosan/ iota -carrageenan coatings support antimicrobial activities. • The coated films can be applied in the food and biomedical fields. [ABSTRACT FROM AUTHOR]

Carboxymethylcellulose (CMC) and keratin nanoparticle (KNP) hydrogels were obtained, characterized, and applied as drug delivery systems (DDSs) for the first time. Lyophilized CMC/KNP mixtures containing 10, 25, and 50 wt% of KNPs were kept at 170 °C for 90 min to crosslink CMC chains through a solid-state reaction with the KNPs. The hydrogels were characterized by infrared spectroscopy, thermal analyses, X-ray diffraction, mechanical measurements, and scanning electron microscopy. The infrared spectra indicated the formation of ester and amide linkages between crosslinked CMC and KNPs. The elastic modulus of the hydrogel containing 10 wt% KNPs was 2-fold higher than that of the hydrogel containing 50 wt% KNPs. The mechanical properties influenced the hydrogel stability and water uptake. The anti-inflammatory prednisolone (PRED) drug was incorporated into the hydrogels, and the release mechanism was investigated. The hydrogels supported PRED release by drug desorption for approximately 360 h. A sustained release mechanism was achieved. The CMC/KNP and CMC/KNP/PRED hydrogels were cytocompatible toward mammalian cells. The CMC/KNP/PRED set imparted the highest cell viability after 7 days of incubation. This study showed a straightforward procedure to create DDSs (chemically crosslinked) based on polysaccharides and proteins for efficient PRED delivery. [ABSTRACT FROM AUTHOR]

Processing water-soluble polysaccharides, like pectin (PT), into materials with desirable stability and mechanical properties has been challenging. Here we report a new method to create water stable and mechanical resistant polyelectrolyte complex (PEC) membranes from PT and chitosan (CS) assemblies, without covalent crosslinking. This new method overcomes challenges of obtaining stable and durable complexes, by performing the complexation at low pH, enabling complex formation even when using an excess of PT, and when using PT with high degree of O- methoxylation. By performing the complexation at low pH, the complexes form with a high degree of intermolecular association, instead of forming by electrostatic complexation. This method avoids precipitation, and overcomes the aqueous instability typical of PT/CS complexes. After neutralization, the PEC membranes display features characteristic of a high degree of intermolecular association because of the self-assembling of polymer chains. The PT/CS ratio can be tuned to enhance the mechanical strength (σ = 39 MPa) of the membranes. These polysaccharide-based materials can demonstrate advantages over synthetic materials for technological applications. [ABSTRACT FROM AUTHOR]

Chitosan/alginate (CHT/ALG) and magnetic CHT/ALG/Fe 3 O 4 @SiO 2 composites were successfully prepared and used as adsorbent materials to remove Pb(II) from aqueous systems. New hydrogel beads were yielded through an unpublished methodology, examining the ionic strength of the chitosan (CHT) solutions. Polyvalent cations and toxic cross-linking agents such as glutaraldehyde and epichlorohydrin, frequently used to prepare CHT/ALG-based materials were not used in this study. The samples were characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, thermal analysis (TAG/DSC), and zeta potential measurements. The addition of Fe 3 O 4 @SiO 2 (8 ± 3 nm) significantly modified the surface morphology of the composites. The CHT/ALG/Fe 3 O 4 @SiO 2 (8) hydrogel comprising the highest Fe 3 O 4 @SiO 2 content (8.0 wt%), displayed magnetic feature and zeta potential of −76.8 mV at pH 6.0. Kinetic and equilibrium adsorption studies reveal that Elovich and Redlich-Peterson mathematical models provide the best fits for the experimental data, respectively. The magnetic composite CHT/ALG/Fe 3 O 4 @SiO 2 (8) had maximum adsorption capacity (q m ) of 234.77 mg g −1 and adsorption/desorption cycles designed its reuse performance. The CHT/ALG/Fe 3 O 4 @SiO 2 (8) hydrogel was applied to treat battery effluent, achieving 99.04% Pb(II) removal, and diminishing the turbidity from 73 to 3.0 NTU. Wastewater and battery effluents contaminated with Pb(II) may be treated using an eco-friendly magnetic hybrid material based on CHT/ALG/Fe 3 O 4 @SiO 2 as the adsorbent. [ABSTRACT FROM AUTHOR]

Proteoglycans have vital biochemical and biomechanical functions. Their proteolytic degradation results in loss of these functions. We have previously reported nonprotein proteoglycan-mimetic graft copolymers that stabilize and deliver growth factors and are not subject to proteases. Here we expand our investigation of these proteoglycan mimics by also investigating their effects on hydrogel mechanical properties. Four polysaccharide side chains, chondroitin sulfate, heparin, dextran, and dextran sulfate, are each grafted to a hyaluronan backbone. The polysaccharides and graft copolymers are added to agarose hydrogels. Cyclic compression and stress relaxation tests reveal how the addition of the polysaccharides and graft copolymers influence hydrogel modulus. Cells encapsulated in agarose hydrogels containing chondroitin sulfate and the chondroitin sulfate graft copolymer have decreased cell viability and metabolic activity compared to cells in unmodified agarose hydrogels. These multifunctional additives can be used to improve both the biochemistry and biomechanics of materials, warranting further optimization to overcome the potentially negative effects these may have on cell viability and activity. [ABSTRACT FROM AUTHOR]

Ideal wound dressings should be biocompatible, exhibit high antibacterial activity, and promote blood coagulation. To impart these imperative functions, carboxymethyl-kappa-carrageenan was incorporated into poly(vinyl alcohol) nanofibers (PVA-CMKC). The antibacterial activity of the nanofibers was evaluated. Adsorption of two important blood proteins, fibrinogen and albumin, was also assessed. The adhesion and activation of platelets, and the clotting of whole blood were evaluated to characterize the ability of the nanofibers to promote hemostasis. Adhesion and morphology of both Staphylococcus aureus and Pseudomonas aeruginosa were evaluated using fluorescence microscopy and scanning electron microscopy. CMKC-containing nanofibers demonstrated significant increases in platelet adhesion and activation, percentage of coagulation in whole blood clotting test and fibrinogen adsorption, compared to PVA nanofibers, showing blood coagulation activity. Incorporating CMKC also reduces adhesion and viability of S. aureus and P. aeruginosa bacteria after 24 h of incubation. PVA-CMKC nanofibers show potential application as dressings for wound healing applications. [Display omitted] • Carboxymethyl kappa-carrageenan and poly(vinyl alcohol) blends can be electrospun. • Adding CMKC enhances fibrinogen adsorption, platelet activation, and blood clotting. • Adding CMKC increases antimicrobial activity toward S. aureus and P. aeruginosa. • New bioactive CMKC-containing nanofibers show promise as wound dressings. • CMKC is an alternative to using hazardous sulfation and sulfonation chemistries. [ABSTRACT FROM AUTHOR]

• Fluorescent Eu3+ complexes are proposed as selective transition metal ion sensors with visible-light excitation. • The lifetime decay and quantum yield of complex particles are 442.53 μs and 59.12 %, respectively. • The complexes with polysaccharides enable compatibilization with aqueous samples. • The fluorescent complexes have good cytocompatibility and cell membrane permeability enabling intracellular ion detection. Fluorescent lanthanide complexes have favorable features for fluorescence-based sensors compared to organic fluorophores and quantum dots. They exhibit very long fluorescence lifetimes, sharp emission bands, and stability with respect to photo-bleaching, without blinking. However, these complexes are usually hydrophobic, and many are excited by UV light, making them hazardous and incompatible with aqueous environments and biological samples. In this work, the strong fluorescent Eu3+-induced aggregates of polysaccharides (EIAP) was used to improve their aqueous solubility, and to tune the appropriate excitation wavelength in the visible range for avoiding toxicity of UV light in biological applications. The complexes exhibit bright fluorescence with an excitation maximum in the visible range, near 405 nm. EIAP 3 also exhibit rapid quenching response in the presence of transition metal ions. This enables the detection of Cu2+ and Fe3+ below 1 ppm. The reverse of quenching response of copper by the addition of a chelating agent makes it possible to recover the fluorescence property. Successfully, the EIAP exhibit cytocompatibility with mammalian cells. Thus, these new polysaccharide-based complexes have the potential for rapid, sensitive and selective metal ion sensors for the environmental systems. [ABSTRACT FROM AUTHOR]

• Polyelectrolyte multilayers based on chitosan/ iota -carrageenan and chitosan/pectin are produced. • The polyelectrolyte multilayers have antimicrobial and antiadhesive activities. • The polyelectrolyte multilayers support the attachment and proliferation of bone cells. • The polyelectrolyte multilayers promote cytocompatibility of surfaces. It has been a challenge to develop durable and cytocompatible antibacterial coatings with antiadhesive and antimicrobial activities. To overcome the problems caused by bacteria contamination on biomedical devices, we are proposing layer-by-layer films based on iota -carrageenan/chitosan, and pectin/chitosan polyelectrolyte multilayers (PEMs) assembled in an acetic acid/acetate buffer solution at pH 5.0. PEMs with 5 and 15 layers are established with chitosan-terminated layers. As compared to pectin, the iota -carrageenan promotes a PEM with a more wettable surface (water contact angle of 25°) and a low roughness. The PEMs have strong antiadhesive and bactericidal activities against Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus). For P. aeruginosa , the effect is seen after 6 h and for S. aureus the effect is seen after 24 h. The antibacterial test in-vitro indicates that PEMs can kill and avoid the attachment of bacteria effectively. To confirm the biomedical potential of these PEMs to act as coatings for tissue scaffolds and implants, adhesion and proliferation of bone marrow-derived stem cells (BMSCs) is demonstrated after 4 and 7 days of incubation. The iota -carrageenan/chitosan PEM supports the BMSCs adhesion, proliferation and spreading, inhibits the attachment and growth of bacteria and promotes cytocompatibility of surfaces. [ABSTRACT FROM AUTHOR]

Here, we have demonstrated the production and characterization of hydrogel scaffolds based on chitosan/gellan gum (CS/GG) assemblies, without any covalent and metallic crosslinking agents, conventionally used to yield non-soluble polysaccharide-based materials. The polyelectrolyte complexes (physical hydrogels called as PECs) are characterized by Fourier-transform infrared spectroscopy, wide-angle X-ray scattering, and scanning electron microscopy. Hydrogels containing chitosan (CS) excesses (ranging from 60 to 80 wt%) were created. Durable polysaccharide-based scaffolds with structural homogeneity and interconnecting pore networks are developed by modulating the CS/GG weight ratio. The CS/GG hydrogel prepared at 80/20 CS/GG weight ratio (sample CS/GG80-20) is cytocompatible, supporting the attachment, growth, and spreading of bone marrow mesenchymal stem cells (BMSCs) after nine days of cell culture. The cytocompatibility is correlated to the swelling capacity of the PEC in PBS buffer (pH 7.4). By controlling the CS content, we can tune the water uptake of the material, enhancing the capacity to serve as a three-dimensional cell scaffold for BMSCs. This work presents for the first time that CS/GG hydrogels can be applied as scaffolds for tissue engineering purposes. Image 1 • Durable chitosan/gellan gum scaffold assemblies are developed. • Chitosan/gellan gum hydrogels are cytocompatible. • The hydrogel promotes growth and spreading of bone mesenchymal stem cells. • Scaffolding behavior is achieved by increasing the chitosan content into the hydrogel. [ABSTRACT FROM AUTHOR]

Curcumin (CUR) is a hydrophobic drug which has been loaded into polymeric carrier matrices by using experimental strategies with many steps, as well as by using conventional and volatile organic solvents. For the first time, this study reports the use of an ionic liquid ([Hmim][HSO 4 −]) to solubilize polycation-polyanion polymer pairs and hydrophobic CUR in the same system. By using the [Hmim][HSO 4 −] as an appropriated solvent, CUR (ca. 10% wt) is loaded into a polyelectrolyte complex (PEC) based on chitosan and commercial iota -carrageenan, following a straightforward method (in-situ approach). A solution containing chitosan, iota -carrageenan, and CUR is produced in [Hmim][HSO 4 −] and subsequently precipitated in an ice-water bath to form the CUR-loaded PEC. The ionic liquid is synthesized following a straightforward experimental route, and after PEC production, it is recovered and reused. X-ray photoelectron spectroscopy analysis shows that chitosan and iota -carrageenan are principally interacting by coulombic forces. Also, X-ray photoelectron spectroscopy and infrared spectroscopy analyses confirm that CUR is loaded into the PEC structure. Wide-angle X-ray scattering, scanning electron microscopy, and differential scanning calorimetry also confirm that CUR loaded PEC (ca. 105 mg g−1) comprise a more disorganized structure when compared to the pristine drug. The CUR is released in simulated gastric fluid (SGF, pH 1.2) because the PEC material increases 3.3-fold its solubility in SGF when compared to the raw curcumin. The ionic liquid can remain in the PEC structure, potentially imparting cytotoxicity. A simple aqueous washing step is sufficient to remove the residual [Hmim][HSO 4 −] and promote cytocompatibility. Cell viability assay performed on bone marrow-derived stem cells demonstrates that CUR significantly increases the cell viability promoted by the PEC. • Chitosan/carrageenan polyelectrolyte complexes are prepared. • A polyelectrolyte complex/curcumin-based material is created by precipitation of a miscible mixture. • A strategy in-situ is developed to load curcumin into the polyelectrolyte complex. • An aqueous washing step removes the residual ionic liquid into the material structure. • The loaded curcumin improves the cytocompatibility and cell viability on mesenchymal stem cells. [ABSTRACT FROM AUTHOR]