Polyelectrolyte Complexes Research Articles

Preparation of biobased guar gum polyelectrolyte complex coatings by sol‐gel method for improving the flame retardancy of ramie fabrics

AbstractIn this study, to improve the flame‐retardant properties of ramie fabrics (RFs), a polyelectrolyte complex (PEC) was prepared in a one‐step process using biobased guar gum (GG), polyethyleneimine (PEI), and ammonium polyphosphate (APP) and deposited on the surface of the RF to construct an intumescent flame‐retardant coating. Fabrics treated with PEC coatings exhibited excellent flame‐retardant properties. Specifically, the cone calorimeter test results revealed that an increase in sample weight of only 13.23 wt% resulted in significant reductions in the peak heat release rate (pHRR), total heat release (THR), and fire growth rate (FGR) of 91.37%, 65.12%, and 95.28%, respectively. Additionally, the limiting oxygen index (LOI) increased from 19.4% to 33.5%, and the fabrics self‐extinguished immediately after the ignition source was removed during the UL‐94 test. Scanning electron microscopy (SEM) of the char residue revealed expansion bubbles on the surface, suggesting that the PEC coating provides flame retardancy through a synergistic effect involving both the gas phase and the condensed phase. This study provides a simple and convenient solution for realizing green and efficient flame‐retardant coatings on RF.

Isolation of Na-alginate from Brown Seaweed (Padina sp.) and Synthesis of Na-alginate-chitosan Polyelectrolytecomplex (PEC) Film as Methylene Blue Adsorbent

Isolation of Na-alginate from Brown Seaweed (Padina sp.) and Synthesis of Na-alginate-chitosan Polyelectrolytecomplex (PEC) Film as Methylene Blue Adsorbent

Immunomodulatory hydrogel orchestrates pro-regenerative response of macrophages and angiogenesis for chronic wound healing

Chronic wound healing often encounters challenges characterized by prolonged inflammation and impaired angiogenesis. While the immune response plays a pivotal role in orchestrating the intricate process of wound healing, excessive inflammation can hinder tissue repair. In this study, a bilayer alginate hydrogel system encapsulating polyelectrolyte complex nanoparticles (PCNs) loaded with anti-inflammatory cytokines and angiogenic growth factors is developed to address the challenges of chronic wound healing. The alginate hydrogel is designed using two distinct crosslinking methods to achieve differential degradation, thereby enabling precise spatial and temporal controlled release of PCNs. Initially, interleukin-10 (IL-10) is released to mitigate inflammation, while unsaturated PCNs bind and remove accumulated pro-inflammatory cytokines at the wound site. Subsequently, angiogenic growth factors, including vascular endothelial growth factor and platelet-derived growth factor, are released to promote vascularization and vessel maturation. Our results demonstrate that the bilayer hydrogel exhibits distinct degradation kinetics between the two layers, facilitating the staged release of multiple signaling molecules. In vitro experiments reveal that IL-10 can activate the Jak1/STAT3 pathway, thereby suppressing pro-inflammatory cytokines and chemokines while down-regulating inflammation-related genes. In vivo studies demonstrate that application of the hydrogel in chronic wounds using diabetic murine model promotes healing by positively modulating multiple integral reparative mechanisms. These include reducing inflammation, promoting macrophage polarization towards a pro-regenerative phenotype, enhancing keratinocyte migration, stimulating angiogenesis, and expediting wound closure. In conclusion, our hydrogel system effectively mitigates inflammatory responses and provides essential physiological cues by inducing a synergistic angiogenic effect, thus offering a promising approach for the treatment of chronic wounds.

Polyelectrolyte Complex Coated Cotton Fabrics with Hydrophobicity, Antibacterial Activity, and Flame Retardancy

AbstractCotton fabrics with the main constituent of cellulose, which is hydrophilic, bacterial infected, and flammable, are in urgent need of functionalization as a kind of widely applied material. To address these issues, in this work, modified polyelectrolyte complex (MPEC) coatings with polyethylenimine (PEI), polyphosphate (APP), and perfluorodecyltrichlorosilane modified PEI (PFTS‐PEI) are prepared to construct multi‐functionally gradient MPEC coatings on cotton fabrics. Stability and synergistic effects on hydrophobicity, antibacterial activity, and flame retardancy in this system have been studied. Notably, PFTS‐PEI with fluorine and silicone elements are confirmed to provide hydrophobicity and durability for MPEC coatings, which not only has no negative effect on other functions but also makes some improvement in antibacterial activity. This MPEC‐treated cotton fabric finally has an antibacterial rate against S. aureus and E. coli of 99.9% and 96.9%, limiting oxygen index of 28.5% and water contact angle of 118°, which can be almost maintained after 20 times washing. The modified PEC will provide an efficient strategy to achieve durable multi‐functions on cellulose‐based fabrics.

Formamide as a Robust Alternative to Water for Plasticizing Polyelectrolyte Complexes

Formamide as a Robust Alternative to Water for Plasticizing Polyelectrolyte Complexes

Molecular Information Processing in a Chemical Reaction Network Using Surface‐Mediated Polyelectrolyte Complexation

AbstractBiochemical communication is ubiquitous in life. Biology uses chemical reaction networks to regulate concentrations of myriad signaling molecules. Recent advances in supramolecular and systems chemistry demonstrate that feedback mechanisms of such networks can be rationally designed but strategies to transmit and process information encoded in molecules are still in their infancy. Here, we designed a polyelectrolyte reaction network maintained under out‐of‐equilibrium conditions using pH gradients in flow. The network comprises two weak polyelectrolytes (polyallylamine, PAH, and polyacrylic acid, PAA) in solution and one immobilized on the surface (poly‐l‐lysine, PLL). We chose PAH and PAA as their complexation process is known to be history‐dependent (i. e., the preceding state of the system can determine the next state). Surprisingly, we found that the hysteresis diminished as the PLL‐coated surface supported rather than perturbed the formation of the complex. PLL‐coated surfaces are further exploited to establish that reversible switching between the assembled and disassembled state of polyelectrolytes can process signals encoded in the frequency and duration of pH pulses. We envision that the strategy employed to modulate information in this polyelectrolyte reaction network could open novel routes to transmit and process molecular information in biologically relevant processes.

Remarkable Dielectric Breakdown Strength of Printable Polyelectrolyte Photopolymer Complexes.

Polymer-based dielectrics are struggling to keep pace with the increasing demands of modern electronics. This lag in dielectric performance has spurred significant interest in the production of advanced dielectrics via novel chemistries and processing techniques. Polyelectrolyte complexes (PECs) have recently shown great promise as dielectric insulation, but processing challenges presented by these ionically bound networks limit their use to conformal thin films. Recent advances have enabled the additive manufacturing of PECs with vat photopolymerization, allowing the creation of a polyelectrolyte complex of arbitrary shape. Herein, multiple polyelectrolyte resin formulations, comprised of polyethylenimine and methacrylic acid (with varying amounts of 2-hydroxyethyl methacrylate and/or N,N-dimethylacrylamide), are investigated for the production of additively manufactured dielectric insulators. These dielectrics not only possess high dielectric breakdown strengths (>300 kV/mm), but their dielectric behavior can also be readily tailored through resin formulation and post-processing conditions. The presented vat photopolymerization of PECs allows for the creation of bulk dielectrics with arbitrary geometry, while the novel chemistry provides a practical route forward to produce dielectrics with precisely tailored properties for specific applications.

Optimization, physicochemical stability and in vivo study of alginate-chitosan composites as nanocarriers for low molecular weight angiotensin I-converting enzyme (ACE)-inhibitory peptide.

Chitosan and alginate, are non-toxic and biodegradable polymers used to enhance the stability of biotherapeutics by loading them into nanocarriers. In this study, the stone fish-derived low molecular weight peptide (Ala-Leu-Gly-Pro-Gln-Phe-Tyr), exhibited an in vitro ACE-inhibitory activity of 94.43 ± 2.05% and an IC50 of 0.012 ± 0.001 mM. The peptide was encapsulated via ionic gelation with alginate followed by polyelectrolyte complexation with chitosan. The resulting ACE-inhibitory peptide-loaded alginate-chitosan nanoparticles (ACE-I-ALG-CS NPs) were optimized to achieve small particle size (212.60 nm) and high encapsulation efficiency (EE, 74.48%). This was based on an optimum chitosan concentration (0.420%w/v), homogenization speed (6000 rpm), and homogenization time (30 min) using Box Behnken experimental design (BBED). Characterization of the ACE-I-ALG-CS NPs revealed a spherical, monodispersed morphology with high physicochemical stability during storage at 2 °C, 7 °C, and 12 °C for 12 weeks. Moreover, the in vivo study conducted on spontaneously hypertensive rats (SHRs) demonstrated a significantly higher (p < 0.05) systolic blood pressure (SBP)-lowering effect of the ACE-I-ALG-CS NPs compared to captopril and unencapsulated peptide. Hence, alginate and chitosan can be used as biocompatible coating materials to enhance the stability and in vivo anti-hypertensive effect of Ala-Leu-Gly-Pro-Gln-Phe-Tyr through encapsulation, thereby making it potentially valuable for various applications in pharmaceuticals and food industry.

Controlling Bicontinuous Polyelectrolyte Complexation for Membrane Selectivity: Redox‐Mediated Electrochemical Separation of Volatile Fatty Acids

Controlling Bicontinuous Polyelectrolyte Complexation for Membrane Selectivity: Redox‐Mediated Electrochemical Separation of Volatile Fatty Acids

Bio-based flame retardant coatings for polyester/cotton fabrics with high physical properties using ammonium vinyl phosphonate-grafted chitosan complexes

Polyester/cotton (T/C) blended fabrics are widely utilized in textile due to the dimensional stability and high elasticity provided by polyester, combined with the comfort and moisture absorption offered by cotton. However, simultaneously enhancing the flame retardancy and maintaining the physical properties of T/C blended fabrics for clothing and furniture applications remains a big challenge. This study introduces a bio-based flame-retardant coating using polyelectrolyte complexes (PEC) composed of ammonium vinyl phosphonate-grafted chitosan (AMVP-g-CS). The protonation degree of the PEC coating is controlled by adjusting the pH to solidify and stabilize the complex structure, preparing bio-based PEC flame retardant T/C blended fabric. Flame retardant analysis reveals that the coated fabrics achieved a limiting oxygen index of 30.5 % and a char length of 11 mm, indicating significantly improved flame retardancy. The combustible volatile substances are significantly reduced for the coated fabrics, achieving a gas-phase flame retardant effect, and forming an expansive char layer with thermal insulation and oxygen blocking properties. Importantly, physical analysis proves that the PEC deposition improved mechanical properties, satisfactory whiteness index and hand feeling of the fabrics. This work opens up a pragmatic and industrially feasible strategy for the development of CSs in the field of flame retardant coating.

Eco‐Friendly Food Packaging Barrier Coatings Comprised of Ball‐Milled Polysaccharide Polyelectrolyte Complexes

ABSTRACTIncreasing demand for packaging has motivated research into sustainable materials to prevent continued plastic pollution. Materials based on polysaccharide polyelectrolyte complexes (PPCs) are emerging as a viable solution for packaging applications. We employed ball milling, a well‐established technology, for the preparation of PPC materials to create an innovative one‐step process capable of producing highly concentrated and homogeneous PPC particle precursor dispersions. We fabricated carboxymethyl cellulose (CMC) and chitosan (CS)–based PPC solutions exhibiting high‐solid loading and investigated the potential of PPC solutions made from ball milling as alternative barriers for packaging. PPC‐coated paperboard exhibited improved Cobb test performance and outstanding grease resistance as compared to pristine paper. The results certified that a single‐step process via ball milling can produce high‐solid content PPC solutions useful for creating bio‐based coatings with excellent barrier performance.

Electroplating of zinc onto polyelectrolyte complex membranes as anode for aqueous zinc-ion batteries

Conventionally, the anode of a primary Aqueous zinc-ion batteries (ZIBs) is metallic and rigid, which made it difficult to integrate into flexible designs. In this research, a composite polyelectrolyte complex (PEC) with cationic poly(diallyldimethylammonium chloride), anionic poly(sodium-4-styrenesulfonate) and carbon black (CB) as conductive filler (PEC-CB) was developed as an anode substrate for zinc deposition via electroplating technique. The Zinc-electroplated PEC-CB (Zn-PEC-CB) anode was characterized using electron microscopy and X-Ray diffraction analysis to verify the successful zinc coating. The Zn-PEC-CB was then assembled with PEC-CB-MnO cathodes in an ZIB setup. The results demonstrated the potential of PEC-based electrodes as a promising alternative to conventional materials in ZIBs, encouraging further exploration in energy storage applications.

Development of fucoidan/polyethyleneimine based sorafenib-loaded self-assembled nanoparticles with machine learning and DoE-ANN implementation: Optimization, characterization, and in-vitro assessment for the anticancer drug delivery

This study aims to develop sorafenib-loaded self-assembled nanoparticles (SFB-SANPs) using the combined approach of artificial neural network and design of experiments (ANN-DoE) and to compare it with other machine learning (ML) models. The central composite design (CCD) and ML algorithms were used to screen the effects of concentrations of both the polymers (polyethyleneimine and fucoidan) on the outcome responses, i.e., particle size and entrapment efficiency with defined constraints. The prediction from different ML models (bootstrap forest, K-nearest neighbors, artificial neural network, generalized regression-lasso and support vector machines) were compared with ANN-DoE model. The ANN-DoE model showed better accuracy and predictability and outperformed all the other models. This depicted that the concept of using ANN and DoE combination approach provided the best, uncomplicated and cost-effective way to optimized the nanoformulations. The optimized formulation generated from the ANN-DoE combined model was further evaluated for characterization and anticancer activity. The optimized SFB-SANPs were prepared using the polyelectrolyte complexation method with Polyethyleneimine (PEI) as a cationic polymer and fucoidan (FCD) as an anionic. The SFB-SANPs were nanometric in size (280.4 ± 0.089 nm) and slightly anionic in nature (zeta potential = −6.03 ± 0.92 mV) with an encapsulation efficiency of 95.56 ± 0.30 %. The drug release from SFB-SANPs was controlled and sustained in the cancer microenvironment (pH 5.0). The SFB-SANPs were compatible with red blood cells (RBCs), and the % hemolysis was found to be <5.0 %. The anticancer activity of the SFB-SANPs exhibited an IC50 at 2.017 ± 0.516 μM against MDMB-231 cells, showing a significantly high inhibitory effect on breast cancer cell lines. Therefore, the nanocarriers developed using various ML tools inherit a huge promise in anticancer drug delivery.

Tuning the Properties of Xylan/Chitosan-Based Films by Temperature and Citric Acid Crosslinking Agent.

Petroleum-based food packaging causes environmental problems such as waste accumulation and microplastic generation. In this work, biobased films from stable polyelectrolyte complex suspensions (PECs) of xylan and chitosan (70 Xyl/30 Ch wt% mass ratio), at different concentrations of citric acid (CA) (0, 2.5, 5, 7.5 wt%), were prepared and characterized. Films were treated at two temperatures (135 °C, 155 °C) and times (30 min, 60 min) to promote covalent crosslinking. Esterification and amidation reactions were confirmed by Fourier Transform Infrared Spectroscopy and Confocal Raman Microscopy. Water resistance and dry and wet stress-strain results were markedly increased by thermal treatment, mainly at 155 °C. The presence of 5 wt% CA tended to increase dry and wet stress-strain values further, up to 88 MPa-10% (155 °C for 60 min), and 5.6 MPa-40% (155 °C for 30 min), respectively. The UV-blocking performance of the films was improved by all treatments, as was thermal stability (up to Tonset: 230 °C). Contact angle values were between 73 and 84°, indicating partly wettable surfaces. Thus, thermal treatment at low CA concentrations represents a good alternative for improving the performance of Xyl/Ch films.

Enhancing vitamin A stability using saponin-chitosan polyelectrolytes coating: Optimization, characterization, and controlled release.

Microencapsulation has the potential to address the stability issues associated with vitamin A. This study examined the effectiveness of emulsifying a saponin-chitosan polyelectrolyte complex to encapsulate vitamin A. Utilizing response surface methodology (RSM), the effects of the chitosan, saponin, and vitamin A contents on various response variables were measured to optimize the formulation. The optimized emulsion was characterized through fluorescence microscopy, Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), storage stability, and release profile. Fluorescence microscopy showed that vitamin A was evenly distributed throughout the optimized emulsion. The polyelectrolyte complex and vitamin A were shown to interact hydrophobically and electrostatically by FTIR analysis. The DSC results verified the effective encapsulation and showed that vitamin A heat stability had been enhanced. Study on storage stability demonstrated that during a 2-month storage period, the encapsulated vitamin A remained stable. Moreover, vitamin A was significantly released from the encapsulated form at pH 1.2, based on release assays. In conclusion, saponin-chitosan polyelectrolyte coating proved to be a potentially useful new material for the stability and applications of vitamin A in a range of formulations.

Recent Advancements of Hyaluronic Acid Nanoscaffolds in Arthritis Management

AbstractArthritis is a significant health concern affecting over 528 million people globally, reducing quality of life. The chronic nature of arthritis, coupled with insufficient therapeutic effectiveness, recurrence, and adverse side effects, complicates its management. Hyaluronic acid (HA) has emerged as a promising solution due to its biocompatibility, non‐toxicity, and targeted drug delivery capabilities, being a key component of the cartilage extracellular matrix widely used in managing arthritis. HA's inherent viscoelastic property and ability to target CD44 have spurred interest in developing HA‐based systems for delivering drugs to manage arthritis. Hyaluronic acid nanoscaffolds (HA‐NSCfs) show improved outcomes over treatments, including enhanced drug uptake through receptor‐mediated targeting, prolonged retention in the synovium, reduced proinflammatory mediator expression, enhanced cartilage regeneration, reduced drug toxicity due to sustained release, and more cost‐effective treatments. This review highlights the rationale for using HA‐NSCfs for the management and advanced drug delivery systems in arthritis, emphasizing preclinical and clinical results. It discusses various solid‐lipid nanoparticles, hydroxyapatite nanoparticles, polyelectrolyte complexes, liposomes, bilosomes, drug‐polymer conjugates, hydrogels, inorganic nanoparticles, and polymer nanoparticles, etc reported for arthritis management. Additionally, the review identifies key challenges and offers suggestions to address them, ultimately highlighting the potential of HA‐NSCfs as a topical treatment for arthritis.

A novel macroporous carboxymethyl chitosan/sodium alginate sponge dressing capable of rapid hemostasis and drug delivery

Carboxymethyl chitosan (CMCS) and sodium alginate (SA), which are excellent polysaccharide-based hemostatic agents, are capable of forming polyelectrolyte complexes (PEC) through electrostatic interactions. However, CMCS/SA PEC sponges prepared by the conventional sol-gel process exhibited slow liquid absorption rate and poor mechanical properties post-swelling. In this work, a novel strategy involving freeze casting followed by acetic acid vapor treatment to induce electrostatic interactions was developed to fabricate novel PEC sponges with varying CMCS/SA mass ratios. Compared to sol-gel process sponge, the novel sponge exhibited a higher density of electrostatic interactions, resulting in denser pore walls that resist re-gelation and swelling according to FTIR, XRD, and SEM analyses. Additionally, the liquid absorption kinetics, as well as compression and tension tests, demonstrated that the novel sponge had significantly improved rapid blood absorption capacity and mechanical properties. Furthermore, in vitro coagulation and drug release studies showed that the novel sponge had a lower blood clotting index and clotting time, along with a slower drug release rate after loading with berberine hydrochloride, showcasing its potential as a rapid hemostatic dressing with controlled drug release capabilities.

Sustained release of MAPK14-targeting siRNA from polyelectrolyte complex hydrogels mitigates MSC osteogenesis in vitro with potential application in growth plate injury.

The growth plate is a cartilage structure at the end of long bones which mediates growth in children. When fractured, the formation of bony repair tissue known as a "bony bar" can occur and cause limb deformities. There are currently no effective clinical solutions for the prevention of the bony bar formation or regeneration of healthy growth plate cartilage after a fracture. This study employs previously developed alginate/chitosan polyelectrolyte complex (PEC) hydrogels as a sustained release vehicle for the delivery of short-interfering RNA (siRNA). Specifically, the siRNA targets the p38-MAPK pathway in mesenchymal stem cells (MSCs) to prevent their osteogenic differentiation. In vitro experimental findings show sustained release of siRNA from the hydrogels for 6 months. Flow cytometry and confocal imaging indicate that the hydrogels release siRNA to effectively knockdown GFP expression over a sustained period. MAPK-14 targeting siRNA was used to knockdown the expression of MAPK-14 and correspondingly decrease the expression of other osteogenic genes in MSCs in vitro over the span of 21 days. These hydrogels were used in a rat model of growth plate injury to determine whether siMAPK-14 released from the gels could inhibit bony bar formation. No significant reduction of bony bar formation was seen in vivo at the one concentration of siRNA examined. This PEC hydrogel represents a significant advancement for siRNA sustained delivery, and presents an interesting potential therapeutic delivery system for growth plate injuries and other regenerative medicine applications.

Lidocaine HCl-Loaded Polyelectrolyte Complex -Poloxamer Thermoresponsive Hydrogel: In Vitro- In Vivo Anesthetic Evaluations for Tooth Socket Wound Delivery.

Local anesthesia is essential in dental practices, particularly for managing pain in tooth socket wounds, yet improving drug delivery systems remains a significant challenge. This study explored the physicochemical characteristics of lidocaine hydrochloride (LH) incorporated into a polyelectrolyte complex and poloxamer thermosensitivity hydrogel, assessing its local anesthetic efficacy in mouse models and its onset and duration of action as topical anesthetics in clinical trials. The thermoresponsive hydrogel exhibited a rapid phase transition within 1-3minutes and demonstrated pseudo-plastic flow behavior. Its release kinetics followed Korsmeyer-Peppas, with 50% of biodegradation occurring over 48h. In mouse models, certain thermogels showed superior anesthetic effects, with rapid onset and prolonged action, as evidenced by heat tolerance in tail-flick and hot plate models. In clinical trials, the LH-loaded thermoresponsive hydrogel provided rapid numbness onset, with anesthesia (Ton) beginning at an average of 46.5 ± 22.5seconds and lasting effectively (Teff) for 202.5 ± 41.0seconds, ranging from 120 to 240seconds, indicating sustained release. These results highlight the promising properties of these formulations: rapid onset, prolonged duration, mucoadhesion, biodegradability, and high anesthesia effectiveness. This study demonstrates the potential for advancing local anesthesia across various medical fields, emphasizing the synergy between material science and clinical applications to improve patient care and safety.

A Jacobian-free pseudo-arclength continuation method for phase transitions in inhomogeneous thermodynamic systems.

Developing phase diagrams for inhomogeneous systems in thermodynamics is difficult, in part, due to the large phase space and the possibility of unstable and metastable solutions arising from first-order phase transitions. Pseudo-arclength continuation (PAC) is a method that allows one to trace out stable and unstable solutions of nonlinear systems. Typically, PAC utilizes the Jacobian in order to implement Newton (or quasi-Newton) steps. In this work, we present a Jacobian-free PAC method that is amenable to the usual workflows in inhomogeneous thermodynamics. We demonstrate our method in systems that have first-order phase transitions, including a novel example of polyelectrolyte complex coacervation in confinement, where multiple surface phase transitions occur and can overlap with one another.