Semi-interpenetrating Network Hydrogels Research Articles

Facile synthesis of an acrylic acid-co-2-acrylamide-2-methylpropanesulfonic acid copolymer / polyvinylpyrrolidone semi-IPN hydrogel with excellent swelling and anti-leakage properties

Water scarcity becomes an increasingly serious problem for humankind due to climate change and population growth, especially the water leakage in arid and semi-arid areas. Hydrogel polymers show increasingly important roles on water resources utilization. A novel hydrogel copolymer, acrylic acid-co-2-acrylamide-2-methylpropanesulfonic acid copolymer / polyvinylpyrrolidone (P(AA-co-AMPS)/PVP) semi-interpenetrating network (semi-IPN) hydrogel, was designed and successfully synthesized via a facile one-pot free radical copolymerization method. The main parameters during the synthesis process were optimized, including relative contents of polymer monomers, cross-linking agent, initiator and neutralization agent. Physical characterizations demonstrate that, P(AA-co-AMPS)/PVP hydrogel shows porous three-dimensional network structure, including a crosslinked network structure in P(AA-co-AMPS) copolymers and their intermolecular hydrogen bonding interactions with linear PVP. The as-synthesized P(AA-co-AMPS)/PVP hydrogel not only can deliver superior water absorbing capability (up to 1689.95 g g−1) and good reswelling performance, but also shows excellent water anti-leakage performance when being composed with red clay, demonstrating its multi-role applications in future sustainable agriculture.

Transparent injectable sericin-honey hydrogel with antioxidant and antibacterial activities combined with feeding sericin accelerates diabetic wound healing.

Wound healing in diabetics is often impaired or delayed due to the presence of high reactive oxygen species and low antioxidant levels. Here, a sericin-honey semi-interpenetrating network hydrogel with excellent antioxidant activity was prepared. Besides, the sericin-honey hydrogel is transparent, injectable, sticky, highly porous, and has good swelling properties, antibacterial activity, and cell compatibility. Based on its good performance in vitro, sericin-honey hydrogel achieved effective in vivo treatment on a mouse diabetic wound model, significantly accelerating the wound healing process. Furthermore, the combined effect of feeding sericin solution played a positive role in strengthening the effect of diabetic wound repair.

An anti-fouling wearable molecular imprinting sensor based on semi-interpenetrating network hydrogel for the detection of tryptophan in sweat

The challenge of heavy biofouling in complex sweat environments limits the potential of electrochemical sweat sensors for noninvasive physiological assessment. In this study, a novel semi-interpenetrating hydrogel of PSBMA/PEDOT:PSS was engineered by interlacing PEDOT:PSS conductive polymer with zwitterionic PSBMA network. This versatile hydrogel served as the foundation for developing an anti-fouling wearable molecular imprinting sensor capable of sensitive and robust detection of tryptophan (Trp) in complex sweat. The incorporation of PEDOT:PSS conductive polymer into the semi-interpenetrating hydrogel introduced diverse physical crosslinks, including hydrogen bonding, electrostatic interactions, and chain entanglement. This incorporation considerably boosted the hydrogel's mechanical robustness and imparted commendable self-healing property. At the same time, the synergistic coupling between the well-balanced charge of the zwitterionic network and the high conductivity of the PEDOT:PSS polymer facilitated efficient charge transfer. The formation of the desired molecular imprinting membrane of semi-interpenetrating hydrogel was triggered by self-polymerization of dopamine (DA) in the presence of Trp. The designed biosensor demonstrated good sensitivity, selectivity and stability in detecting the target Trp. Notably, it also exhibited exceptional anti-fouling abilities, allowing for accurate Trp detection in complex real sweat samples, yielding results comparable to commercial enzyme-linked immunoassay (ELISA).

Interpenetrating and semi-interpenetrating network superabsorbent hydrogels based on sodium alginate and cellulose nanocrystals: A biodegradable and high-performance solution for adult incontinence pads

Superabsorbent hydrogels (SAHs) are essential in various applications, including hygienic products like adult incontinence pads. However, synthetic-based super absorbent polymers (SAPs) dominate the market despite being non-biodegradable. Alternatively, bio-based hydrogels, such as sodium alginate (SA)-based hydrogels, offer biodegradable alternatives. In this study, we aimed to enhance the practical applied properties of SA-based hydrogels by grafting SA with acrylic acid (AA) and incorporating cellulose nanocrystals (CNCs). Specifically, we investigated the potential of interpenetrating network (IPN) and semi-interpenetrating network (S-IPN) hydrogels as absorbent materials in adult incontinence pads. The fabricated SAHs were characterized by Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM). They were also evaluated for absorption and rheological properties. The results showed that in IPN/SAHs, the addition of CNCs decreased pore sizes, while in S-IPN/SAHs, CNC incorporation increased pore sizes. The S-IPN/SAHs exhibited a significantly higher free swelling capacity (FSC) with CNCs loading, reaching 142.29 g/g in 0.9 % NaCl solution and 817.4 g/g in distilled water. On the other hand, IPN/SAHs showed a higher storage modulus and lower loss modulus compared to S-IPN/SAHs. Notably, the superior samples from this study showed a 33 % reduction in SAP consumption compared to commercial SAPs, making them more cost-effective for adult incontinence pad manufacturers. Overall, our research demonstrates the potential of interpenetrating and semi-interpenetrating network superabsorbent hydrogels as high-performance absorbent materials. The results offer improved absorbency and cost savings for producers of adult incontinence pads, and bio-based hydrogels like SA-based hydrogels are promising biodegradable alternatives to synthetic-based SAPs.

MXene-Induced Flexible, Water-Retention, Semi-Interpenetrating Network Hydrogel for Ultra-Stable Strain Sensors with Real-Time Gesture Recognition.

As water-saturated polymer networks, hydrogels are a growing family of soft materials that have recently become promising candidates for flexible electronics application. However, it remains still difficult for hydrogel-based strain sensors to achieve the organic unity of mechanical properties, electrical conductivity, and water retention. To address this challenge, based on the template, the excellent properties of MXene nanoflakes (rich surface functional groups, high specific surface area, hydrophilicity, and conductivity) are fully utilized in this study to prepare the P(AA-co-AM)/MXene@PDADMAC semi-interpenetrating network (semi-IPN) hydrogel. The proposed hydrogel continues to exhibit excellent strain response and flexibility after 30 days of storage at room temperature, and its performance do not decrease after 1100 cycles. Considering these characteristics, a hydrogel-based device for converting sign language into Chinese characters is successfully developed and optimized using machine learning. Therefore, this study provides novel insight and application directions for hydrogel families.

Preparation of a controlled drug release system from semi-interpenetrating polymeric network hydrogel of NaAlg-g-poly(NaA)/PVP

Preparation of a controlled drug release system from semi-interpenetrating polymeric network hydrogel of NaAlg-g-poly(NaA)/PVP

Photocuring and Gelatin-Based Antibacterial Hydrogel for Skin Care.

The development of moisturizing, antibacterial, and biocompatible multifunctional hydrogels is essential to protect skin and promote skin defects recovery. Gelatin has admired potential to be applied for skin care as a hydrogel in virtue of its hydrophilic biocompatible and biodegradable properties. In this study, triclosan-grafted gelatin and photo-cross-linkable methacrylated gelatin were synthesized and then combined to construct the semi-interpenetrating network and antibacterial hydrogels with the aid of a visible blue light. The antimicrobial test demonstrated that the resulting hydrogel obtained excellent inactivation capacity against E. coli, S. aureus, T. rubrum, and C. albicans with sterilizing rates of 99.998%, 99.998%, 99.19%, and 99.64%, respectively. In addition, the cytotoxicity, hemolysis, skin irritation, and rat skin wound healing experiments proved the good biocompatibility of the hydrogel. Therefore, this investigation sheds light on the development of multifunctional hydrogels in skin care.

Highly expandable edible hydrogels for the prevention and treatment of obesity through dietary intervention

Long treatment periods, high risk of operation, and large side effects of drugs are the main factors, affecting obesity treatment. Obesity prevention or treatment through dietary intervention for obese patients has become an emerging method to lose weight. In this study, two types of high-swelling hydrogels were designed using cheap and safe food-grade raw materials. The appearance of the ester base infrared peak and scanning electron microscope macropore structure confirmed the successful cross-linking between citric acid (CA) and sodium carboxymethylcellulose (CMC). The semi-interpenetrating network hydrogels produced by the addition of hyaluronic acid (HA) exhibited high swelling, large pore structures, strong mechanical properties, and non-degradation characteristics. The in vivo imaging experiments of mice suggested that the hydrogel entered the body and mainly existed in the digestive system. In the mouse intervention groups, hydrogels effectively slowed down the weight gain and reduced liver fat accumulation, lipid levels, and inflammatory responses. The treatment of obese mice with hydrogels reduced their body weight and obesity-related symptoms. These results indicated that the high-swelling edible hydrogels prepared in this study might have great potential for the prevention and treatment of obesity.

Characterization of semi-interpenetrating hydrogel based on Artemisia sphaerocephala Krasch Polysaccharide and cellulose nanocrystals crosslinked by ferric ions

Hydrogels are important bionic materials that can be used in a wide variety of biomedical applications. Artemisia sphaerocephala Krasch polysaccharide (ASKP) has been demonstrated to be crosslinked by ferric ions to form three-dimensional network. Here, a semi-interpenetrating network (semi-IPN) hydrogel based on ASKP and cellulose nanocrystals (CNC) crosslinked by ferric ions was fabricated and the effect of specific rod-like CNC was evaluated. It was found that the network of ASKP-Fe3+ hydrogel incorporated by CNC became denser along with the decreased pore diameter and the thickened pore wall. ASKP/CNC-Fe3+ hydrogel displayed an enhanced gel strength and water holding capacity. The dominant interaction of ASKP and CNC was hydrogen bonds proved by FTIR and QCM-D. Additionally, the elasticity of the semi-IPN hydrogel significantly increased along with the decrease of platform height in MSD curves based on particles tracking. These results may be caused by the fact that the rod-shaped CNC can be entangled with ASKP and prone to induce the orderly extension of ASKP chains, resulting in more hydroxyl and carboxyl groups exposed to be crosslinked with ferric ions. What's more, the stiff CNC located on the pore wall of ASKP-Fe3+ hydrogel can also strengthen the rigidity of network. Thus, this study suggests a new strategy to improve the properties of ASKP based hydrogel, and can be developed as a carrier to deliver iron ions.

Application of poly (dimethyl diallyl ammonium chloride)−reinforced multifunctional poly (vinyl alcohol)/ polyaniline hydrogels as flexible sensor materials

The design of multifunctional hydrogel sensor materials with comprehensive properties such as frost resistance, good reusability, adhesion, and flexibility needs to be developed to meet the demands of complex environments. Herein, a conductive, semi-interpenetrating network hydrogel was constructed from poly (vinyl alcohol), polyaniline (PANI), and poly (dimethyl diallyl ammonium chloride) (PDDA), and the process assisted by the Hofmeister effect. A double conductive pathway hydrogel with types of PDDA and PANI polymers was formed simultaneously to provide excellent conductivity (1.217 S/m−1) for the hydrogel. With the increase in the concentration of PDDA from 0 to 16 wt%, the mechanical strength increased from 0.066 MPa to 0.34 MPa, and the modulus of elasticity and toughness increased by 684.9% and 748.8%, respectively. The hydrogel can be efficiently generated as a strain sensor material with excellent sensitivities of GF= 2.337 and S= 3.229%/KPa under tension and compression, respectively. The hydrogel could be used as an electronic skin and be used for the monitoring of even small strains in the skin caused by pulse beats. In addition, the hydrogel has excellent temperature sensitivity (1.575%/℃), frost resistance (−53.45 ℃), self-healing capability, and reusability. Data AvailabilityData will be made available on request.

Preparation of pH/temperature-sensitive semi-interpenetrating network hydrogel adsorbents from sodium alginate via photopolymerization for removing methylene blue

Preparation of pH/temperature-sensitive semi-interpenetrating network hydrogel adsorbents from sodium alginate via photopolymerization for removing methylene blue

Quarternized chitosan/quercetin/polyacrylamide semi-interpenetrating network hydrogel with recoverability, toughness and antibacterial properties for wound healing

Antibiotic abuse has posed enormous burdens on patients and healthcare systems. Hence, the design and development of non-antibiotic wound dressings to meet clinical demand are urgently desired. However, there remains one of the impediments to hydrogel wound dressings that integrated with good recoverability, toughness, and excellent antibacterial properties. Herein, a series of semi-interpenetrating network (semi-IPN) hydrogels with exceptional mechanical performance and remarkable antibacterial activity based on quaternized chitosan (QCS) and polyacrylamide (PAM) were developed using a one-pot method. Additionally, the antibacterial activity of semi-IPN hydrogel against S. aureus and E. coli was enhanced by integrating it with quercetin (QT). The semi-IPN hydrogels also exhibited high recoverability and toughness, outstanding liquid absorbability (the swelling ratio reached 565 ± 12 %), and a satisfying water vapor transmission rate. Moreover, the semi-IPN hydrogels presented ideal hemocompatibility and cytocompatibility. These high-elastic hydrogels are promising candidates for potential applications in wound dressing, tissue repair, chronic wound care, as well as other biomedical fields.

Silk fibroin based interpenetrating network hydrogel for corneal stromal regeneration

There is a need to develop tissue engineering based approaches to address the shortage of donor corneas worldwide for transplantation. To do this a novel approach to fabricate three-dimensional hydrogels using free-radical polymerization was investigated to generate constructs for corneal stromal tissue regeneration. Different ratios of silk fibroin (SF) to polyacrylamide (PA) were used to fabricate semi-interpenetrating hydrogels. Scanning electron micrograph displayed the interconnectivity of pores within the fabricated hydrogels. Pore sizes ranged from 25 to 66 μm. Scaffolds with increasing concentration of SF had enhanced β-sheet structure (verified by Fourier transform infrared spectroscopy). The biological response of human corneal stromal cells to these hydrogels was examined using cellular adhesion, proliferation, cytoskeleton organization, gene expression and immunocytochemical analysis. The fabricated hydrogels possess rapid gelation (∼3 min) at 37 °C, 84 % porosity facilitating keratocyte migration during healing, improved cellular adhesion and no cytotoxicity, indicating their efficiency for in-situ corneal tissue regeneration. Presence of SF in semi-interpenetrating network hydrogel enhanced cellular proliferation, elevated GAG deposition, and increased expression of keratocyte genes, normally associated with healthy corneal stromal tissue. This study acts as an initial step towards fabricating SF based semi-interpenetrating network hydrogels for developing clinically applicable ocular implants.

An injectable and self-healing cellulose nanofiber-reinforced alginate hydrogel for bone repair

Biomedical materials are in high demand for transplantation in cases of diseased or damaged bone tissue. Hydrogels are potential candidates for bone defect repair; however, traditional hydrogels lack the necessary strength and multiple functions. Herein, we effectively synthesized a cellulose nanofiber (CNF)-reinforced oxidized alginate (OSA)/gelatin (Gel) semi-interpenetrating network hydrogel through a facile one-step approach without a cross-linker by using the synergistic effects of dynamic imine bonds and hydrogen bonds. The OSA/Gel/CNF sample showed a notable compressive modulus (up to 361.3 KPa). The gelation time (~150 s) ensured excellent injectability. Self-healing exhibited a high efficiency of up to 92 %, which would enable minimally invasive, dynamic adjustments and personalized therapies. Furthermore, the OSA/Gel/CNF hydrogel showed excellent biomineralization (Ca/P ratio ~ 1.69) and enhanced preosteoblast cell (MC3T3-E1) viability (over 96 %), proliferation, and osteogenic differentiation. Thus, this multifunctional hydrogel has promising potential for using in the bone tissue repairs.

A Biomass Based Photonic Crystal Hydrogel Made of Bletilla striata Polysaccharide.

Bletilla striata is an herb with a good medicinal value whose main active ingredient is Bletilla striata polysaccharide (BSP) in the tuber of Bletilla striata. In this study, a polysaccharide-based semi-interpenetrating network hydrogel was constructed by introducing BSP into polyacrylamide (PAM) hydrogel. The introduction of the BSP chain no only maintains the excellent mechanical properties of PAM, but also endows it with good biocompatibility. By implanting the colloidal crystal array into the above hydrogels, we obtained a novel biomass-based photonic crystal with good stimulus responsiveness that is sensitive to volatile organic compounds (VOCs), especially alcohol vapor. In addition, due to the scavenging ability of BSP to hydroxyl radicals, the photonic crystal hydrogel also has a good response to hydrogen peroxide ().

Antimicrobial effects of hydroxyapatite mosaicked polyvinyl alcohol-alginate semi-interpenetrating hydrogel-loaded with ethanolic extract of Glycyrrhiza glabra against oral pathogens.

Glycyrrhiza glabra (GG) elicits protective effects against periodontal diseases. However, the sustained bioavailability of GG extract at therapeutic concentration warrants ideal delivery vehicles. Present study has focused on the design, fabrication, and evaluations of ethanolic-crude extract of GG-loaded semi-interpenetrating network (semi-IPN) hydrogel (HAAPS-GG) using alginic acid and polyvinyl alcohol (PVA) hydrogel mosaicked with HA for periodontal regeneration. The study has examined the performance of the hydrogel against the selected oral pathogens S. mutans, E. faecalis, L. acidophilus and C. albicans. HAAPS-GG was successfully fabricated and the surface functional groups were confirmed by attenuated total reflectance-infrared (ATR-IR) spectroscopy. HAAPS-GG displayed interconnecting pores, hydrophilicity and excellent water profile contributing to the biocompatibility as evident from direct contact and MTT assay in L929 fibroblasts. The hydrogel was mechanically stable and was immunocompatible owing to the relatively decreased levels of pro-inflammatory mediators COX2, 5LPO, iNOS and MPO in RAW 264.7 macrophages. In addition, the transcript analysis on RAW 264.7 revealed the down-regulation of inflammatory transcription factor NF-κβ and the pro-inflammatory cytokine TNF-α. Importantly, HAAPS-GG arrested the progression of periodontal pathogens predominantly S. mutans, and C. albicans as evident by disc diffusion assay, MTT assay and confocal microscopy. Overall, the HAAPS-GG system offers promising translational avenues in periodontal regeneration.

Graphene oxide incorporated chitosan/acrylamide/itaconic acid semi-interpenetrating network hydrogel bio-adsorbents for highly efficient and selective removal of cationic dyes

In recent years, polymeric bio-adsorbents offers high removal efficiency, superior adsorption capacity and selectivity against various pollutants in aqueous medium. While designing these adsorbents, their environmental friendliness, sustainability, renewability, easy accessibility, and cost-effectiveness should be considered. In this study, GO incorporated semi-interpenetrating network (semi-IPN) nanocomposite hydrogels (CS/AAm/IA/GO) were obtained by free radical copolymerization of acrylamide (AAm) and itaconic acid (IA) in the presence of chitosan (CS) as an environmentally friendly bio-adsorbent. GO significantly improved the thermal stability, compressive strength, and percentage swelling of the hydrogel. The selective adsorption studies demonstrated that methylene blue (MB) was the most efficiently removed dye from both individual and mixed dye systems with 99.8 % removal efficiency. The adsorption capacity was found to be 247.47 mg g−1 using 0.025 g hydrogel adsorbent containing 0.5 wt% of GO and an initial MB concentration of 5 mg L−1 at pH 8 over 90 min at room temperature. The kinetic and isotherm studies revealed that the adsorption process followed the pseudo-second-order kinetic model and Langmuir adsorption isotherm. Thermodynamic studies suggested the spontaneous and endothermic nature of MB adsorption. Also, the MB removal efficiency above 96 % was obtained after 7 consecutive adsorption-desorption cycles while maintaining the structural stability of the bio-adsorbent.

Synthesis and characterisation of high resilience collagen-polyacrylamide semi-interpenetrating network hydrogel

Collagen-polyacrylamide (Collagen-PAm) semi-interpenetrating network composite hydrogels were prepared by in-situ free radical polymerization. This collagen - polyacrylamide hydrogel has good tensile and compression repair properties, collagen can improve the mechanical properties of PAm. Composite hydrogels have regular pore structure. Collagen/polyacrylamide (g/g) ratio of 6.0:100 hydrogel pore size range 75–95 µm, conducive to cell migration and growth. The study of swelling kinetics showed that the water diffusion in hydrogel was Fick diffusion, which was beneficial to the fixation of cells and drugs. The pH sensitivity study showed that complex hydrogels have good environmental stability under acidic, neutral and weakly alkaline conditions. The addition of collagen can improve the thermal stability of the composite hydrogel because of the strong hydrogen bond between collagen and polyacrylamide in the semi-interpenetrating network. DMA results show that the E ' of Collagen-PAm is 6 ~ 8KPa, E 'of Collagen-PAm is 12 ~ 35KPa, which is 2–4 times higher than PAm, and the deformation reversibility and formability are good. Therefore, as a new tissue engineering material, collagen-polyacrylamide composite hydrogel has a good application prospect.

Environment-adaptable PAM/PVA Semi-IPN hydrogels reinforced by GO for high electromagnetic shielding performance

In this work, one type of mechanically robust, lithium chloride (LiCl)-containing semi-interpenetrating network (IPN) hydrogel consisting of crosslinked polyacrylamide (PAM) and linear polyvinyl alcohol (PVA) chains and reinforced with graphene oxide (GO) was fabricated, which had excellent anti-dehydration, anti-icing and electromagnetic interference (EMI) shielding performance. The experimental results showed PAM/PVA/GO/LiCl hydrogels had excellent cyclic compression recovery performance. The compressive strength of PAM/PVA (6 wt%)/GO (0.1 wt%)/LiCl (12 mol/1000 g PVA/GO solution) (PAM/PVA 6 /GO 0.1 /LiCl 12 ) hydrogel was almost unchanged after 10 compression cycles at a compressive strain of 70%. The water retention rate of PAM/PVA 6 /GO 0.1 /LiCl 12 hydrogels was nearly 100% under the conditions of 25 °C and 30% RH for 30 h. In addition, the hydrogels had good flexibility even at −50 °C, demonstrating excellent anti-icing properties. The hydrogels exhibited excellent electrical conductivity and EMI shielding performance whose shielding effectiveness was beyond 37.2 dB, showing potential applications in wearable devices, sensors or telecommunications. • Mechanically robust semi-interpenetrating network hydrogels were fabricated. • Excellent anti-dehydration and anti-icing properties of hydrogels were achieved. • PAM/PVA/GO/LiCl hydrogel exhibited excellent EMI shielding performance.

Drug-free contact lens based on quaternized chitosan and tannic acid for bacterial keratitis therapy and corneal repair

Bacterial keratitis (BK) and related inflammatory diseases causes irreversible damage to the corneal tissue. In this study, a novel polyacrylamide semi-interpenetrating network hydrogel including quaternized chitosan and tannic acid (PAM-QCS-TA) were used to construct a novel antibacterial and antioxidant contact lens. The obtained hydrogels showed high water content (>85%), swelling resistance, light transmittance (>90%) and adjustable mechanical property. Both quantitative and qualitative antibacterial experiments against Staphylococcus aureus and Escherichia coli (E. coli) indicated excellent sterilization function especially against E. coli (almost 100%). Due to the presence of tannin acid, it showed obvious antioxidant properties, which relieved oxidative stress and protect cells from reactive oxygen species-induced cytotoxicity. Animal experiments also indicated the shortened treatment time of BK (only 3 days) as well as the protection of eye tissue structure. Therefore, such drug-free antibacterial and antioxidant contact lens avoiding the development of drug resistance is a potential candidate in ocular infectious and inflammatory diseases treatment.