Polyelectrolyte Complexes Research Articles

Alginate/Chitosan Complex Fibers Reinforcement and Their Mechanical Transition Continuum With Water Uptake Increasing.

Living tissues span a remarkable spectrum of modulus ranging from the level of Pa to GPa in a water-rich environment. Constructing soft and hard materials that match the mechanics of tissues and researching mechanical transition in water, are beneficial for their biological applications. Here, using polyelectrolyte complex fiber as a model system and reinforcing the fiber by stepwisely introducing additional coordination and covalent bonds, this investigated that the water effect on mechanical transition behaviors. Alginate/chitosan fiber (AC fiber) has a single electrostatic bond and shows continuous mechanical transition containing a glassy state, rubbery state, and terminal relaxation (initial modulus lower than 10MPa) in aqueous solution. Alginate/chitosan/calcium fiber (ACC fiber) has both electrostatic and coordination bonds, which shows the behavior of hard rubber (initial modulus 100MPa) when water reaches equilibrium. Alginate/chitosan/calcium/polydopamine fiber (ACCP fiber) with triple bonds, including electrostatic, coordination, and covalent bonds, exhibits the behavior like ductile plastics in aqueous solution (initial modulus 1000MPa). This work not only provides important insight into the toughening mechanism of polyelectrolyte complexes in water but also contributes to the preparation of tissue adaptive implantations.

The Effect of Kappa Carrageenan Composition on the Characteristics of Chitosan-Kappa Carrageenan Hydrogel Film

Chitosan-Kappa Carrageenan (Chit-KC) hydrogel films have been made using a casting method with different compositions. This research aimed to investigate the effects of different compositions on the chemical, physical, and mechanical characteristics of the Chit-KC hydrogel films. The compositions of the kappa carrageenan in the Chit-KC films were 0%, 16.67%, 33.33%, 50.0%, and 100.0%. The films were characterized using FTIR, SEM, DTA-TGA, and XRD instruments to analyze their functional groups, morphology, thermal properties, and crystallinity. They were also tested for their solubility, swelling, water vapor permeability (WVP), and mechanical characteristics. The results revealed that the addition of kappa-carrageenan induced the formation of a polyelectrolyte complex. The polyelectrolyte complex caused an increase in swelling, crystallinity, and WVP values and a decrease in solubility, tensile strength, elongation, and elasticity. It also caused the formation of film layers and granules on the surface of the hydrogel film. The IR spectra exhibited that the Chit-KC hydrogel films contained O-H, C-H, C=O, S=O, C-O, and C-O-C groups. The DTA-TGA test results revealed that the film began decomposing at around 200°C and re-decomposing at 300°C.

Evaporation Induced Flame Retardant Polyelectrolyte Complex for Cotton

Evaporation Induced Flame Retardant Polyelectrolyte Complex for Cotton

Preparation of hydrophilic PVDF membranes through in situ assembly of phytate-polyethyleneimine-Fe3+ for efficient separation of herbal volatile oil from oily water.

In the realm of oil-water separation technologies, membrane-based separation emerges as an efficacious approach. Nevertheless, crafting a hydrophilic membrane capable of effectively segregating herbal volatile oil remains a formidable challenge. Our study introduces a facile in situ assembly strategy for fabricating a double-crosslinked composite coating comprising phytate (PA)-polyethyleneimine (PEI) polyelectrolyte complexes and PA-Fe3⁺ assemblies. The PA within the PA-PEI/Fe3⁺ coatings form a double cross-linking layer through interactions with amine groups and metal ions, thereby enhancing interfacial interactions and structural integrity of the membranes. Consequently, the resultant PVDF/PA-PEI/Fe3⁺ membranes exhibit improved coating stability, pronounced hydrophilicity, and exceptional antifouling capabilities, rendering them highly suitable for the separation of diverse herbal volatile oil-in-water emulsions. Furthermore, they possess the capability for reuse with an average retention ratio exceeding 90% and a pure water flux reaching up to 3200 L·m⁻2·h⁻1. Additionally, they demonstrate long-term stability and resistance to corrosion. With a simplistic yet efficient preparation process, the PVDF/PA-PEI/Fe3⁺ membrane holds significant potential for the extraction of oils from herbal volatile oil-in-water emulsions.

Tragacanth Gum/Trimethyl Chitosan‐Derived Polyelectrolyte Complex as Potential Carriers in Drug Delivery Applications

ABSTRACTA three‐step procedure described in the literature has been used to create N,N,N‐trimethyl Ct a chitosan derivative that is extremely soluble in water. By combining two polymers in aqueous media, this derivative and tragacanth gum were able to form a new polyelectrolyte complex. The TGA, FTIR, and DSC analysis established the development of TMC/XG‐PEC. SEM was used to describe the TMC/TG‐PEC's surface morphology. The features of diffusion and swelling, such as the theoretical equilibrium ratio, initial swelling rate constant, and the process of water transportation into TMC/TG‐PEC, were established. The TMC/TG‐PEC swelling is seen to be pH‐dependent. It swells in the subsequent order: pH 7.4 > 6.8 > 1.2. At pH 1.2, 6.8, and 7.4, the TMC/TG‐PEC swelling ratio was found to be 6.5, 7.7, and 9.6 g/g, respectively. The second‐order kinetics of the swelling process is indicated by the linearity of the plot “t/SR” versus “t”. The TMC/TG‐PEC's n values under various pH circumstances ranged from 0.12 to 0.16, suggesting the Fickian water transport mechanism. The utility of complex as a matrix for KP formulations for sustained‐release tablets was investigated. It was discovered that 90.5% of KP was loaded into PEC. There is evidence that pH influences how much medicine is released. When the medium's pH was altered from acidic to neutral, the KP release was considerably boosted. The TMC/TG‐PEC demonstrated a maximum drug release of 7% in a pH 1.2 medium and between 85% and 90% in a pH 7.4 medium, demonstrating the TMC/TG‐PEC's potential as a matrix substance for the drug's prolonged release formulations of KP. The Fickian drug transport mechanism was indicated by the release exponent n, which was less than 0.5.

The effect of sulfonated reduced graphene oxide on the properties of ionic strength sensitive PEC film comprising protein/polysaccharides combined system

In the current study, sulfonated reduced graphene oxide (SRGO) at different amounts (0.0 %, 0.015 %, 0.030 %, 0.050 % w/v) was incorporated into the polyelectrolyte complex (PEC) which was produced by using protein/polysaccharides combined system composed of gelatin (Gel)/carboxymethyl cellulose (CMC) and hyaluronic acid (HA) not only to enhance mechanical and conductive properties but also to investigate the effect of sulfonyl groups on the ionic strength response of the produced PEC films. While FT-IR, SEM and zeta potential analyses were confirmed the character of produced samples, their mechanical and conductivity tests showed that the introduction of SRGO enhanced both mechanical performance and conductive feature of PEC films. Swelling and 5- fluorouracil (5-FU), a chemotherapeutic agent, release tests carried out in the solution with a varying ionic strength at a pH: 1.2 to simulate acidic stomach environment demonstrated that while pure PEC film has anti-polyelectrolyte behavior, SRGO based PEC films exhibited polyelectrolyte character due to sulfonyl groups with an increasing ionic strength of medium. It could be emphasized from all these results that the produced SRGO based PEC films with enhanced mechanical and conductive properties could be utilized as an ionic strength sensitive drug carrier which ensures controlled and targeted release for cancer treatments.

Mucoadhesive polyelectrolyte complexes of fucoidan and chitin nanowhiskers to prolong the antiprotozoal activity of metronidazole

The improvement of the specific pharmacological activity of agents with antimicrobial and antiprotozoal properties (e.g. metronidazole, MET) is of interest for clinical applications in the treatment of bacterial infections. In this work, we prepared the polyelectrolyte complexes (PEC) based on chitin nanowhiskers (CNW) and fucoidan (FUC) with hydrodynamic diameters of 244 and 816 nm, a ζ-potential of about −22 mV and good mucoadhesive properties. The incorporation of MET into PEC particles promoted the sustained release of MET for 10 h and maintained the antiprotozoal activity against clinical isolates of Trichomonas vaginalis for up to 10 h. At concentrations of 1–3 mg/mL (HeLa cell line), the CWN-FUC-MET particles showed no cytotoxicity. The sustained drug release rate, combined with pronounced mucoadhesive properties, improved pharmacological activity, and non-cytotoxicity makes the developed biopolymer delivery systems promising candidates for further clinical trials.

Performance of delaying release and reducing adsorption of polyethyleneimine/poly(vinyl sulfonate) polyelectrolyte complex nanoparticles in polyacrylamide/polyethyleneimine gel system

Polyacrylamide/Polyethyleneimine (HPAM/PEI) is an environmentally friendly and promising gel system. However, inadequate gelation time and retention of the cross-linker (polyethyleneimine, PEI) during migration pose significant challenges for effective water control treatment in deep reservoirs. Polyelectrolyte complex nanoparticles (PECs) have demonstrated the ability to efficiently encapsulate PEI, facilitating for its gradual release. To achieve this, a cost-effective polyanionic complex, poly(vinyl sulfonate) (PVS), was employed to form PECs with PEI. By adjusting the mixing ratio of PEI and PVS, stable PECs suspensions with varying charges were successfully produced. These stable PECs exhibited spherical shapes with a particle size distribution ranging from 127.3–442.71 nm, and an average particle size of approximately 200 nm. The encapsulation efficiency of PEI by PECs varied from 64.56 % to 86.14 %. Under different conditions, 55.12 % to 90.26 % of PEI could be released from PECs. Increased temperatures, higher ionic strengths, and greater deviations in pH from the initial state of the PECs suspension all facilitated the release of PEI. The most stable PECs delayed the gelation time of the HPAM/PEI system to 9.5 days, which is twice the base gelation time of 4.5 days. The strength of mature HPAM/PEI (PECs) gels increased by 8.95 Pa in storage modulus (G′) compared to HPAM/PEI at the same concentration, albeit with a reduced linear viscoelastic region. And, the PECs-based delayed crosslinking method does not negatively affect the mechanical strength of the HPAM/PEI gel system, and thus its water control ability, under reservoir conditions. On the other hand, the static adsorption of PEI encapsulated by anionic PECs on sand decreased to one-fourth of that of free PEI (PEI solution). Additionally, the breakthrough of PEI encapsulated in anionic PECs in fractured sandstone cores was significantly advanced compared to free PEI.

Rifampicin‐Loaded Nano‐in‐Microparticles (Trojan Particles) as a Pulmonary Delivery System for Tuberculosis Treatment

AbstractThe oral rifampicin (RIF) dosage forms possess various side effects and limited efficacy for tuberculosis treatment. Thus, this work developed the nano‐in‐microparticles containing RIF (trojan nRIF) as a novel pulmonary delivery system. The RIF‐loaded nanoparticles (nRIF) were prepared by self‐assembly polyelectrolyte complexation between lecithin and chitosan, whereas the trojan nRIF were formulated by spray‐drying method of nRIF and mannitol/maltodextrin. The nRIF had a spherical shape with sizes of 86–126 nm, zeta potentials of 24–39 mV, entrapment efficiencies of 44–80 %, and drug loading capacities of 13–42 %. The RIF release from nRIF occurred in two stages, the initially rapid release stage and the controlled release stage upto 96 h, followed the Higuchi model. The trojan nRIF possessed the mass median aerodynamic diameter of 3.7–4.6 μm, fine particle fraction of 34–40 %, and alveolar fraction of 17–21 %. Compared to mannitol, maltodextrin was a superior carrier for nRIF, which yielded better aerodynamic properties and RIF was mainly stayed in the amorphous form. Moreover, using the scanning electron microscopy, the nano‐in‐microparticles were clearly observed with hollow structure. Finally, the trojan nRIF could preserve the physical properties of the encapsulated nRIF. In summary, the trojan nRIF could become a potential inhalation anti‐tuberculosis product.

PH-driven fabrication of a caseinate–pectin polyelectrolyte complex as a promising carrier for lutein and zeaxanthin delivery: Microencapsulation, stability, and sustained release properties

In this study, caseinate–pectin polyelectrolyte complexes and co-solutions were successfully fabricated at pH 3.0 and 7.0, respectively, to encapsulate bioactive molecules. During the fabrication process, the effect of the sequence in which each component was added on lutein/zeaxanthin (Lut/Zx) complexation with sodium caseinate (NaCas) was investigated. The protective effect of the polyelectrolyte complex and co-solution for Lut/Zx in liquid formulations was compared with that of a binary system containing only caseinate and Lut/Zx. Compared with the binary system, the polyelectrolyte complex at pH 3.0 further enhanced the chemical stability of Lut/Zx during storage, whereas the co-solution at pH 7.0 did not exhibit this ability. Unexpectedly, NaCas−Lut/Zx − pectin (NC-L/Z-P) with a theoretically sandwich structure did not exhibit better protection than NaCas−pectin−Lut/Zx (NC-P-L/Z). Fluorescence quenching spectra revealed that the addition of NaCas to Lut/Zx and ultimately to pectin resulted in the formation of a sandwich structure, which was soon followed by structural rebalancing. Finally, freshly prepared NC-L/Z-P complexes were lyophilized to stabilize their sandwich structure, resulting in improved encapsulation and sustained-release properties compared with those of the dried NC-P-L/Z. These results suggest that protein-polysaccharide complexes, combined with timely dehydration, enhance the combination of Lut/Zx with caseinate, leading to heightened protective effects.

Delivery system for dexamethasone phosphate based on a Zn2+-crosslinked polyelectrolyte complex of diethylaminoethyl chitosan and chondroitin sulfate

Hybrid nano- and microparticles based on metal ion crosslinked biopolymers are promising carriers for the development of drug delivery systems with improved biopharmaceutical properties. In this work, dexamethasone phosphate-containing particles based on chondroitin sulfate and chitosan or diethylaminoethyl chitosan additionally crosslinked with Zn2+ were prepared. Depending on the polycation/polyanion ratio in the system, anionic and cationic polyelectrolyte complexes (PECs) were obtained. The anionic Zn2+-containing and Zn2+-free PECs had sizes of 154 and 180 nm and ζ-potentials of −22.4 and −27.5 mV, respectively. The cationic Zn2+-containing and Zn2+-free PECs had sizes of 242 and 362 nm and ζ-potentials of 22.4 and 24.7 mV, respectively. The presence of Zn2+ in the system significantly prolonged the release of dexamethasone phosphate from the hybrid polyelectrolyte particle. The resulting release profiles of dexamethasone phosphate were in agreement with the Peppas-Sahlin kinetic model, which considers the combined effects of Fickian diffusion and polymer chain relaxation on the drug release rate. It was shown that the prolongation of drug release was mainly due to swelling and relaxation of the Zn2+ crosslinked polymers. The developed particles exhibited good mucoadhesive properties and pronounced anti-inflammatory activity, making them attractive candidates for biomedical applications.

PH-Responsive Alginate/Chitosan Gel Films: An Alternative for Removing Cadmium and Lead from Water.

Biosorption, a non-expensive and easy method for removing potentially toxic metal ions from water, has been the subject of extensive research. In this context, this study introduces a novel approach using sodium alginate and chitosan, versatile biopolymers that have shown excellent results as biosorbents. The challenge of maintaining high efficiencies and reuse is addressed by developing alginate/chitosan-based films. These films, prepared using solvent casting and crosslinking methods, form a hydrogel network. The alginate/chitosan-based films, obtained using the eco-friendly polyelectrolyte complex method, were characterized by FTIR, SEM, TGA, and DSC. The study of their swelling pH response, adsorption, and desorption behavior revealed promising results. The adsorption of Pb was significantly enhanced by the presence of both biopolymers (98%) in a shorter time (15 min) at pH = 6.5. The adsorption of both ions followed a pseudo-second-order kinetic and the Langmuir isotherm model. The desorption efficiencies for Cd and Pb were 98.8% and 77.6% after five adsorption/desorption cycles, respectively. In conclusion, the alginate/chitosan-based films present a highly effective and novel approach for removing Cd and Pb from water, with a promising potential for reuse, demonstrating their strong potential in potentially toxic metal removal.

Sustainable polyelectrolyte complexes of pectin and chitosan as adsorbents for heavy metal ions from surface water

Sustainable polyelectrolyte complexes of pectin and chitosan as adsorbents for heavy metal ions from surface water

Fine-tuning the cytotoxicity profile of N,N,N-trimethyl chitosan through trimethylation, molecular weight, and polyelectrolyte complex nanoparticles

N,N,N-trimethyl chitosan (TMC) is a promising biopolymer for pharmaceutical applications due to its enhanced solubility and bioadhesive properties, though its cytotoxic limitations necessitate careful modification to ensure safety and efficacy. This study sought to investigate whether nanoparticle (NP) formation could reduce the anticipated cytotoxic effects of TMC, thus improving its applicability across a wider spectrum of pharmaceutical uses. TMC's capability to form NPs with anionic polyelectrolytes led to the application of chondroitin sulfate (ChS) in this study. Five TMC samples, varying in degree of trimethylation (DTM 23, 32, 46, 50 and 99 %) and molecular weight (Mw, 66–290 kDa) were synthesized, and their biocompatibility with human umbilical vein endothelial cells (HUVECs) was assessed. The results revealed a discernible impact of both DTM and Mw on cell viability, with higher DTM and lower Mw correlating with increased toxicity. Cytotoxicity studies against ovarian cancer cell lines SKOV-3 and OVISE showed a clear indication of a higher cytotoxic effect of TMC samples against cancer cells compared to healthy cells (HUVEC). The cytotoxicity against cancer cells also indicated an optimal DTM for maximum efficacy, deviating from a linear trend. The effects of Mw were cell-dependent, introducing complexity to the observed relationship. Additionally, TMC-ChS NPs were successfully prepared, demonstrating a substantial reduction in cytotoxicity compared to TMC alone in all tested cells. This promising outcome suggests the potential of NP formation to fine-tune the cytotoxicity profile of TMC, paving the way for the development of safer and more effective pharmaceutical formulations.

Highly Asymmetric Lamellar Structure in Blends of Polystyrene-b-Poly(acrylic acid) Block Copolymers and Poly(4-vinylpyridine) Homopolymers Facilitated by Polyelectrolyte Complexation

Highly Asymmetric Lamellar Structure in Blends of Polystyrene-<i>b</i>-Poly(acrylic acid) Block Copolymers and Poly(4-vinylpyridine) Homopolymers Facilitated by Polyelectrolyte Complexation

Study of the influence of the composition and pH of the solution on the structure and morphology of particle dispersions of a (bio)polyelectrolyte complex between chitosan and gelatin

Study of the influence of the composition and pH of the solution on the structure and morphology of particle dispersions of a (bio)polyelectrolyte complex between chitosan and gelatin

Methods to Enhance Mechanical Strength of 3D Printed Chitosan Scaffolds for Jawbone Regeneration

Current jaw reconstruction methods using autografts and allografts have limitations such as donor site morbidity, limited bone volume, and immunological rejection. As opposed to surgical methods synthetic biomaterials are used however they often fall short in providing the optimal combination of biocompatibility, mechanical strength, and customizable design required for effective jawbone reconstruction. 3D-printed chitosan scaffolds offer a promising alternative due to their biocompatibility, ease of customization, and potential for improved mechanical strength. This review explores strategies to optimize 3D-printed chitosan scaffolds for jaw reconstruction. We examine ways to increase their mechanical strength without compromising biocompatibility, with a particular emphasis on chemical modifications such as hydroxyapatite (HA) and beta-tricalcium phosphate (β-TCP) cross-linking and chitosan polyelectrolyte complex formation. We also discuss the critical roles that 3D printing processes (FDM and SLA) and intrinsic chitosan qualities (degree of deacetylation) play in making an ink printable. Optimizing 3D printing methods for chitosan-ceramic composites and exploring biocompatible additives to enhance printability are identified as key areas for further research. By addressing these challenges, 3D-printed chitosan scaffolds have the potential to become next-generation biomaterials for jaw reconstruction, revolutionizing the field through precise anatomical adaptation, enhanced osteoconductivity, controlled biodegradation, and the capacity for incorporating bioactive molecules, ultimately leading to accelerated bone regeneration and improved functional and aesthetic outcomes.

Development of keratin-based fibers fabricated by interfacial polyelectrolyte complexation for suture applications

Interfacial Polyelectrolyte Complexation (IPC) is a convenient way to produce composite, micro-scale fibers. In this paper, we report the successful development of novel keratin-based IPC fibers and also demonstrate the feasibility of using these fibers as sutures through a proof-of-concept in vivo study. Two composite fibers were produced: chitosan-keratin (CK) and keratin-keratin (KK). These fibers were evaluated for their physico-chemical, mechanical and biochemical properties. In the dry state, the CK fiber had a greater Young's modulus of about 2 GPa while the KK fiber registered a longer strain-at-break of about 100 % due to the strain-stiffening effect. Notably, the keratins were found to assemble into amyloids within the composite fibers based on Congo red staining and Wide-Angle X-Ray Scattering. Functionally, both fibers were malleable could be weaved, braided and knotted. When used as sutures to close incisional wounds in mice over 21 days, these fibers were found to elicit minimal host tissue response and were partially degraded over the duration. Interestingly, the KK fiber evoked a lower extent of immune cell response and fibrous capsule encapsulation that was comparable to commercial, non-absorbable Dafilon® sutures. This work demonstrated the possibility of producing keratin-based IPC fibers which may find practicality as medical sutures.

Spontaneous Formation of Solid Shell Polymeric Multicompartments at All-Aqueous Interfaces.

Multicompartmental capsules have demonstrated value in fields ranging from drug release, mimetics of artificial cells, to energy conversion and storage. However, the fabrication of devices with different compartments usually requires the use of toxic solvents, and/or the adaptation of technically demanding methods, including precision microfluidics and multistep processes. The spontaneous formation of multi-core capsules resulting from polyelectrolyte complexation at the interface of a prototypic all-aqueous two-phase system is described here. The variation of polyelectrolyte concentration and complexation time are described as simple working parameters capable of driving the formation of compartments at different yields, as well as tailoring their morphology. The mild processing technology enables the encapsulation of animal cells, which are capable of invading capsule walls for specific processing conditions.

Development of chitosan/sodium carboxymethyl cellulose-based polyelectrolyte complex of dexamethasone for treatment of anterior uveitis

Anterior uveitis is one of the most prevalent forms of ocular inflammation caused by infections, trauma, and other idiopathic conditions if not treated properly, it can cause complete blindness. Therefore, this study aimed to formulate and evaluate dexamethasone sodium phosphate (DSP) loaded polyelectrolyte complex (PEC) nanoparticles (NPs) for the treatment of anterior uveitis. DSP-loaded PEC-NPs were formed through complex coacervation by mixing low molecular weight chitosan and the anionic polymer carboxy methyl cellulose (CMC). The formulations were optimized using Box-Behnken design and evaluated the effect of independent variables: Chitosan concentration, CMC concentration, and pH of chitosan solution on the dependent variables: particle size (PS), Polydispersity Index (PDI), pH of the formulation, and % entrapment efficacy (%EE). The PS, PDI, zeta potential, and pH of the optimized formulation were found 451 ± 82.0995 nm, 0.3807 ± 0.1862, +20.33 ± 1.04 mV and 6.8367 ± 0.0737 respectively. The %EE and drug loading of formulation were 61.66 ± 4.2914% and 21.442 ± 1.814% respectively.In vitrodrug release studies of optimized formulation showed the prolonged release up to 12 h whereas, the marketed formulation showed the burst release 85.625 ± 4.3062% in 1 h and 98.1462 ± 3.0921% at 6 h, respectively. Fourier transform infrared studies suggested the effective incorporation of the drug into the PEC-NPs formulation whereas differential scanning calorimetry and x-ray diffraction studies showed the amorphized nature of the drug in the formulation. Transmission electron microscopy study showed self-assembled, nearly spherical, core-shell nanostructures. The corneal permeation study showed higher permeation of the drug from PEC-NPs compared to the marketed formulation. Hen's Eggs test-Chorioallantoic Membrane test of the optimized formulation revealed non-irritant and safe for ocular administration. Therefore, DSP-loaded PEC-NPs are an effective substitute for conventional eye drops due to their ability to increase bioavailability through longer precorneal retention duration and sustained drug release.