Strong Hydrogels Research Articles

Highly sensitive, anti-freeze, repairable, and conductive double-network organohydrogel for flexible pressure sensors

Flexible strain sensors based on double network conductive hydrogels have attracted much attention due to their great potential for human motion health and smart detection. However, the development of conductive hydrogels with high sensitivity and anti-freezing properties for a wide range of use environments is still a challenge. Herein, a novel organohydrogel-based PVA-P-TA-MWCNTs (PPTME) double network capable of pressure and strain sensing was reported with high ambient stability, excellent anti-freezing capability, smart reparability and superior sensitivity. The multiple interactions within the PPTME organohydrogel have been substantiated through Density Functional Theory (DFT) analysis. The organohydrogel utilizing strong hydrogel bonds, crystalline microphases, and chain entanglement of PTA/PVA exhibited good mechanical properties (374%) and excellent cycling performance. Meanwhile, owing to the addition of H2O/EG (ethylene glycol) binary solvent, this organohydrogel exhibited long-term water retention (15 days), anti-freezing properties (−61.9 °C), greatly improving the applications at low temperatures. Furthermore, the assembled pressure sensors showed ultrahigh sensitivity (1.88 kPa−1) in wide detection range (0–266.2 kPa). Based on these excellent properties, a flexible organohydrogel sensor was prepared, demonstrating its enormous potential in the field of human motor behavior detection and wearable.

Enhanced Strength for Double Network Hydrogel Adhesive Through Cohesion‐Adhesion Balance

AbstractHydrogel adhesives exhibit great potential in various biomedical fields such as tissue sealing and soft robotics. However, the high‐water content and defective network structures of these hydrogel adhesives result in low intrinsic mechanical strength, severely impeding their application. In this study, it is reported that the strong hydrogel adhesive strength can be achieved when a balance is established between adhesive forces and cohesive forces. Based on this principle, a new double network (DN) design is created to combine an adhesive polyvinyl alcohol (PVA) as the first network with a flexible sodium alginate (SA) as the second network. A delicate balance is achieved between cohesion and adhesion by adjusting the ratio between the first rigid adhesive network and the second flexible network. As a result, this balanced DN hydrogel adhesive exhibits a strong tissue adhesion strength, approximately three times higher than that in the non‐balance situation.

Preparation of strong and tough conductive hydrogel based on Grafting, Fe3+-Catechol complexations and salting out for triboelectric nanogenerators

The development of a strong and tough conductive hydrogel capable of meeting the strict requirements of the electrode of a hydrogel-based triboelectric nanogenerator (H-TENG) remains an enormous challenge. Herein, a robust conductive polyvinyl alcohol (PVA) hydrogel is designed via a three-step method: (1) grafting with 3,4-dihydroxy benzaldehyde, (2) metal complexation using ferric chloride (FeCl3) and (3) salting-out using sodium citrate. The hydrogel contains robust crystalline PVA domains and reversible/high-density non-covalent interactions, such as hydrogen bonding, π–π interactions and Fe3+-catechol complexations. Benefiting from the crystalline domains, the hydrogel can resist external forces to the hydrogel network; meanwhile, the reversible/high-density of non-covalent interactions can impart gradual and persistent energy dissipation during deformation. The hydrogel possesses multiple cross-linked networks, with 6.47 MPa tensile stress, 1000 % strain, 35.24 MJ/m3 toughness and 37.59 kJ/m2 fracture energy. Furthermore, the inter-connected porous hydrogel has an ideal structure for ionic-conducing channels. The hydrogel is assembled into an H-TENG, which can generate open circuit voltage of ∼ 150 V, short-circuit current of ∼ 3.0 μA, with superb damage immunity. Subsequently, road traffic monitoring systems are innovatively developed and demonstrated by using the H-TENG. This study provides a novel strategy to prepare superiorly strong and tough hydrogels that can meet the high demand for H-TENGs.

Strong and anti-freezing alginate-based hydrogel with humidity response and wide-temperature-range strain sensing ability

To get strong and anti-freezing hydrogel with multiple contact and non-contact sensing performance, a facial method is proposed in this work using multiple physical bonding crosslinking and glycerol (GL) immersing strategy. The obtained hydrogels show a tensile stress at break of 5.4 MPa, an elongation at break of 1420 %, and a compression strength of 12.2 MPa at 80 % strain. Additionally, benefiting from the GL immersing the hydrogel shows superior anti-freezing (no ice formation at −60 °C) and water retention ability (water loss less than 17 % after storing at 50 °C for 7 h). Furthermore, the volume resistance of hydrogels exhibits excellent responses against humidity, temperature, strain, and stress. The variation of the resistance against temperature can be well described by the Arrhenius equation with an activation energy of 501.3 meV, verifying a band-gap dominated diffusion hopping conductive mechanism of the hydrogel. The sufficient humidity and temperature responses make the hydrogel applicable as a non-contact sensor, and the wide temperature strain sensing (−40 to 50 °C) and stress sensing capability ensures that the hydrogel can be used as a contact sensor, ensuring that the hydrogel can be used as perfect flexible sensor for monitoring human motion and physiological signals.

Stiff, strong, and tear-resistant physical hydrogels with widely tunable toughness by post-treatments

Abstract Synthetic polymeric hydrogel is a potential substitute for soft biological tissues. However, the poor mechanical properties of traditional synthetic hydrogels limit their applications in biological fields. Herein, a series of tough physical hydrogels have been prepared by micellar polymerization, in the existence of sodium bromide (NaBr), using methacrylic acid (MA) and stearyl acrylate (SA) as monomers, cetyltrimethyl ammonium bromide (CTAB) as cationic surfactant. The hydrogels exhibit excellent mechanical properties: modulus, toughness, and tearing fracture energy up to 7.8 MPa, 34 MJ m−3, and 16,600 J m−2, respectively. Moreover, it was found that the toughness of the hydrogels can be modulated in a very wide range by different post-treatments, e.g., dried/reswelling, freezing/thawing, or heated treatments. After post-treatments, the elastic physical hydrogels even turn into brittle plastics: modulus and toughness vary by 3 and 4 orders of magnitude, respectively. The mechanism for this wide tunability is attributed to the change of electrostatic attraction, crystallization, and phase separation during post-treatments.

MXene sheets surface constructed a strong hydrogel coating for sustainable oily wastewater separation

Membrane separation technology can effectively address the issues of high energy consumption and low efficiency encountered in traditional separation processes. However, oil fouling hinders the widespread adoption of membrane technology in the field of oil-water separation. Therefore, preventing membrane fouling is crucial for overcoming this bottleneck. Titanium carbide (Ti3C2Tx, MXene), a recent addition to the two-dimensional material family, has garnered significant interest in the domain of water treatment owing to its controllable surface groups, hydrophilic nature, antimicrobial properties, and high electrical conductivity. Hence, we proposed a strategy to construct hydrogel coatings on carboxylated MXene surfaces. Moreover, the rigidity of the hydrogel framework was further improved by introducing CaCO3 nanoparticles. A stronger hydrogel layer ensured that the hydration layer is difficult to contaminate with oil and the fastness of the membrane material. Naturally, the as-prepared membrane showed excellent separation performance for a wide range of emulsions, maintaining high levels (3979.5 L m–2 h−1 bar−1 and 99.96 %) after 5 consecutive separation cycles of 200 min. Additionally, the membrane separated emulsions containing acids, salts, or alkali with a permeability of 2982.8 L m–2 h−1 bar−1 after 40 min; it also treated actual oily wastewater achieving a permeability of 238.9 L m–2 h−1 bar−1 and showed high removal efficiency (>99.9 %) for several heavy metals (Cu, Li, Pb, Se, and V), as well as antimicrobial (92.5 %) properties that enhance its potential for industrial applications. This study offers a new idea for designing anti-oil-fouling MXene oil-water separation membranes.

Superwettable calcium ion exchanged carboxymethyl cellulose powder with self-gelation, tissue adhesion and bioabsorption for effective hemorrhage control

Water-soluble polymers can be used to develop self-gelling hemostatic powders, and powder wettability potentially plays the key role in determining their hemostatic efficacy. Herein, a superwettable calcium ion exchanged carboxymethyl cellulose (Ca-ex-CMC) powder is reported for effective hemorrhage control. Despite being water-soluble, Ca-ex-CMC powder can form a physically crosslinked hydrogel upon contact with water (self-gelation), and the rate of water permeating the hydrogel to achieve dissolution is extremely slow. With increased calcium content, Ca-ex-CMC powder shows not only improved procoagulant activity, but enhanced wettability which can facilitate the fusion of the powders with water, resulting in promoted water uptake and in-situ formation of strong hydrogel barriers with enhanced tissue adhesion. Applying Ca-ex-CMC powder to non-compressible (liver and tail) and massive (artery) hemorrhage wounds in rat and rabbit models can stanch bleeding instantly, because of complete sealing of the bleeding sites by enhanced in-situ self-gelation. Moreover, owing to water-solubility, Ca-ex-CMC powder shows outstanding bioabsorbability and histocompatibility after implantation into rabbit liver and gluteus. These findings not only support Ca-ex-CMC powder as a promising hemostatic agent for extensive application but identify the critical role of wettability in promoting hemostasis for self-gelling powders.

Strong, tough and conductive single-network hydrogels based on deswelling and the salting-out effect.

In recent years, the continuous attention given to increasing the fracture toughness and Young's modulus of polymeric gels has gradually shifted from toughening strategies on double-network (DN) gels to single-network (SN) gels. The salt-soaking method has been adopted to realize the toughening of SN gels through the salting-out effect and deswelling, constructing dense network structures with simultaneously precipitated polymer chains and cross-links. By comparing the mechanical properties between salt-treated hydrogels and air-dried hydrogels, the increased polymer chain concentration is proved to promote energy transfer by enlarging the dissipation region size due to the unwinding and slippage of coiled chains during stretching. The newly formed cross-link points in salt-treated hydrogels are considered to consume more deformation energy during stretching. The synergistic effect in energy transfer and dissipation arising from increases in polymer fraction and cross-linking plays an indispensable role in toughening SN hydrogels. In addition, the soaking process introduces abundant free ions to endow hydrogels with prominent conductivity. Thus, this salt-soaking method provides a general approach to synthesize strong, tough and conductive hydrogels with applications in flexible electrical devices.

Strong, tough and anisotropic bioinspired hydrogels.

Soft materials are widely used in tissue engineering, soft robots, wearable electronics, etc. However, it remains a challenge to fabricate soft materials, such as hydrogels, with both high strength and toughness that are comparable to biological tissues. Inspired by the anisotropic structure of biological tissues, a novel solvent-exchange-assisted wet-stretching strategy is proposed to prepare anisotropic polyvinyl alcohol (PVA) hydrogels by tuning the macromolecular chain movement and optimizing the polymer network. The reinforcing and toughening mechanisms are found to be "macromolecule crystallization and nanofibril formation". These hydrogels exhibit excellent mechanical properties, such as extremely high fracture stress (12.8 ± 0.7 MPa) and fracture strain (1719 ± 77%), excellent modulus (4.51 ± 0.76 MPa), high work of fracture (134.47 ± 9.29 MJ m-3), and fracture toughness (305.04 kJ m-2) compared with other strong hydrogels and even natural tendons. In addition, excellent conductivity, strain sensing capability, water retention, freezing resistance, swelling resistance, and biocompatibility can also be achieved. This work provides a new and effective method to fabricate multifunctional anisotropic hydrogels with high tunable strength and toughness with potential applications in the fields of regenerative medicine, flexible sensors, and soft robotics.

Strong and anti-swelling nanofibrous hydrogel composites inspired by biological tissue for amphibious motion sensors.

Conductive hydrogel-based sensors are increasingly favored for flexible electronics due to their skin-like characteristics. However, conventional hydrogels suffer from significant swelling in humid environments and poor mechanical properties which largely restrict their applications in wearable electronic devices, especially for underwater sensing. Herein, drawing inspiration from the extracellular matrix (ECM) structure, a TPU-PVAc@AgNPs/MXene nanofibrous hydrogel composite (TPAMH) with excellent mechanical robustness and anti-swelling properties is developed. The TPAMH nanofibrous hydrogel composite is created by integrating the silver nanoparticles (AgNPs) and MXene nanosheets into an interwoven network comprising of stiff TPU nanofibers as the fibril scaffold and formic acid-crosslinked PVA hydrogel fibers as the elastic matrix (PVAc). Benefiting from the unique ECM structure, the obtained nanofibrous hydrogel composites exhibit exceptional tensile strength (4.47 MPa), remarkable elongation at break (621%), excellent anti-swelling properties, and high detection sensitivity (maximum gauge factor = 105.02), which are sufficient to monitor body motions in both air and water environments effectively. They can detect large strain movements of fingers, elbows, wrists, and knees, as well as small strain physiological signals such as frown, smile, and pulse beats, with high accuracy. Particularly noteworthy is their ability to accurately identify underwater multidirectional motions and facilitate underwater smart alarms using Morse code.

Highly transparent and strong nanohesive hydrogel patch for tissue adhesion

This research aimed to design and fabricate a biocompatible dual-layer chitosan hydrogel adhesive patch with exceptional mechanical properties by employing a nanoadhesive strategy to assess its tissue adhesion performance. The design involves physical cross-linking to construct a robust chitosan hydrogel as a backing membrane, followed by in situ photocuring to create the adhesive hydrogel layer, resulting in an integrated chitosan hydrogel adhesive patch. To facilitate adhesion between the hydrogel patch and biological tissue, surface-activated silica nanoparticles serve as interfacial connectors, analogous to nanoglue, promoting binding of the hydrogel to the substrate. Characterization of the patch reveals an adhesive energy of 282 J/m<sup>2</sup> to biological tissues in vitro and a burst pressure of 450 mmHg (1 mmHg=0.133 kPa). The patch exhibits outstanding mechanical properties, with a tensile strength of 4.3 MPa, an elongation rate of 65%, and a fracture toughness of 3.82 kJ/m<sup>2</sup>. Additionally, the nanohesion-based chitosan hydrogel adhesive patch is highly transparent and demonstrates excellent biocompatibility. It holds promise for applications in various biomedical fields, including tissue repair and drug delivery, thereby providing a robust material foundation for advancements in clinical surgery.

Strong, tough, and elastic poly(vinyl alcohol)/polyacrylamide DN hydrogels based on the Hofmeister effect for articular cartilage replacement.

Traditional hydrogels are usually weak and brittle, which limit their application in articular cartilage replacement because cartilage is generally strong, tough, and elastic in nature. Therefore, it is highly desirable to construct hydrogels to mimic the mechanical properties of the native articular cartilage. Herein, in this work, poly(vinyl alcohol)/polyacrylamide (PVA/PAM) DN hydrogels were prepared by in situ polymerization, which were then treated with Hofmeister series ions (Cit3-, SO42-, and Cl-) to achieve H-PVA/PAM DN hydrogels. Among the three Hofmeister ions, the DN hydrogel treated with Cit3- (named PVA/PAM-Cit) showed the densest microstructure and the highest crystallinity degree. In this context, PVA/PAM-Cit exhibited a tensile strength of 18.9 ± 1.6 MPa, a compressive strength of 102.3 ± 7.9 MPa, a tensile modulus of 10.6 ± 2.1 MPa, a compressive modulus of 8.9 ± 0.8 MPa, and a roughness of 66.2 ± 4.2 MJ m-3, respectively, which were the highest strength and modulus, and the second highest toughness when compared with those of the reported PVA and PVA based DN hydrogels so far. It also showed an extreme high elasticity, which could maintain a stress of 99.2% after 500 cycles of fatigue testing. Additionally, PVA/PAM-Cit can promote the adhesion, spreading and proliferation of chondrocytes. These results verify that such a strong, tough, and elastic hydrogel could be a novel candidate material for articular cartilage replacement.

Elastic and conductive gellan gum/polyvinyl alcohol physical hydrogels with low swelling potential for sustainable flexible electronics

Conductive hydrogels are considered to be promising materials for flexible electronics, but those nondegradable are bound to produce substantial undesirable electronic wastes once widely applied, inconsistent with the long-term sustainable development goals. To develop biodegradable conductive hydrogels for sustainable flexible electronics, a green chemical reaction-free strategy was developed to manufacture a novel type of composite hydrogels, exploiting biodegradable gellan gum and polyvinyl alcohol as the matrices and natural-derived tannic acid as the crosslinking agent. The technique involves successive cool-induced sol−gel transition, freeze-thawing and Na2SO4 solution treatment. A universal electronic testing machine, scanning electronic microscope, X-ray diffractometer, thermogravimetric analyzer, and electrochemical work station were employed to study the mechanics, structure and morphology, swelling and conductivity of the hydrogels. The results indicate strong, elastic and tough hydrogels were achieved owing to the multi-crosslinked multiple-network structure. The maximum compressive stress (90% strain), tensile strength, breakage elongation and fracture energy reach 10.7 MPa, 1.2 MPa, 890% and 480 kJ/m3 respectively. The stress recovery rate still remains 86% after 10 consecutive loading-unloading under 200% strain. The highest conductivity reaches 3.27 S/m, which along with the excellent mechanics confers them good strain-sensing behavior. Moreover, the final hydrogels show low swelling in both water (the equilibrium swelling ratio (ESR) < 300%) and physiological saline (ESR < 90%). The excellent mechanical performance, high conductivity and good strain sensing, low swelling and inherent biodegradability as well as the ecofriendly manufacturing process imply potential prospect in sustainable flexible electronics.

Biomimicking natural wood to fabricate isotropically super-strong, tough, and transparent hydrogels for strain sensor and triboelectric nanogenerator applications

We describe an efficient wood-inspired biomimicking strategy integrating multiscale structures to synthesize isotropically strong, tough, conductive, and transparent hydrogels as strain sensors and self-powered triboelectric nanogenerators.

Anti‐Swelling, High‐Strength, Anisotropic Conductive Hydrogel with Excellent Biocompatibility for Implantable Electronic Tendon

AbstractAs hydrogels rapidly advance for diverse technologies, their practical applications as implantable artificial tendon becomes promising, yet challenging. It requires similar anisotropic fibril structures, matching water content, high mechanical strength, good biocompatibility, and stable performance under physiological conditions. Furthermore, the capabilities of real‐time joint motion monitoring and implant condition are extremely important for the precise assessment of rehabilitation processes. However, it is challenging to realize all these properties simultaneously. Herein, this work reports an intelligent implantable artificial tendon based on strong and conductive anisotropic hydrogel, by coupling prestretching‐induced ordered structure with drying‐enabled strengthening. The fiber structure fixed during drying/rehydration produces a dense and stable network with a hierarchically anisotropic structure. The resulting anisotropic hydrogel presents excellent anti‐swelling ability (&lt;3%), high tensile strength (3.71 MPa), and toughness (9.86 MJ m−3) upon hydration, at a tendon‐matching water content of 72.5 wt%. The in vitro and in vivo tests demonstrate its excellent biocompatibility with significant protein resistance. With reliable strain sensing, the hydrogel can act as an intelligent artificial tendon to restore and real‐time monitor joint motion in an in vitro model. The SD rats with tendon defects display restored motor function after implantation of the hydrogel as tendon substitutes, facilitating malfunction tissue therapeutics and rehabilitation.

Сорбционно-структурные свойства аэрогельных материалов на основе биополимеров

Nowadays aerogel materials (AM) are successfully used as entero- and applicative sorbents to eliminate excessive amounts of heavy metals and toxins from living organisms. Natural biopolymers alginate and chitosan, as well as various lignin derivatives are an inexhaustible raw material base for the creation of AM. A significant number of sorption materials and wound coatings of various types have been developed on their basis, which is associated not only with a wide range of physicochemical properties of these polymers and their already proven biomedical activity, but also with the prevalence and renewability of raw material sources for the production of these polymers, ease of extraction, the possibility of achieving a high degree of purification and relatively low price. The key stage in the AM synthesis is the formation of a strong hydrogel which is the AM framework. One of the technological methods is to obtain interpolyelectrolyte solid hydrogel. The paper proposes two different packaging models for the formation of the structure of interpolyelectrolyte complexes (IPEC) based on biopolymers pairs: sodium alginate (ALNa)–chitosan (CT) and sodium lignosulfonate (LSNa)–CT. The first model is a block model, in which the structure is formed due to ionic bonds between the carboxyl groups of ALNa and amino groups of CT, as well as a cooperative system of hydrogen bonds and dispersion interactions. The second model is an aggregation-tubular model, the structure of which is formed through ionic bonds between sulfogroups (within the rod-shaped supramolecular structures of LSNa) and amino groups of CT, as well as hydrogen bonds and dispersion interactions. Upon the process of IPEC drying under supercritical (SC-) conditions, strong phase contacts are formed, and the changes in the gel structure become irreversible. As a result, hydrophobic micro- and mesoporous two-component AMs differing in internal structure were obtained. AM ALNa–CT are characterized by fibrillar structure, and LSNa–CT – by structural elements of spherical shape. The obtained AM ALNa–CT and LSNa–CT have high sorption activity towards water and a wide range of heavy metals and low molecular weight toxins. The purpose of the work is to study the structural and sorption properties of AM based on biopolymers of various structural organization. A significant increase in the sorption activity of AM ALNa–CT in comparison with LSNa–CT is apparently due to their different supramolecular structure. There is a combination of several sorption mechanisms such as wetting, absorption, diffusion, osmotic phenomena and chemical interaction due to the highly porous structure of AM and the presence of sorption-active centers. For citation: Brovko O.S., Palamarchuk I.A., Gorshkova N.A., Bogdanovich N.I., Ivakhnov A.D. Sorption and Structural Properties of Aerogel Materials Based on Biopolymers. Lesnoy Zhurnal = Russian Forestry Journal, 2023, no. 6, pp. 190–203. (In Russ.). https://doi.org/10.37482/0536-1036-2023-6-190-203

Synthesis and Characterization of pH Triggered Imine Functional Low Molecular Weight Hydrogel

AbstractA C‐3 symmetric imine functional nonpolymeric low molecular weight gelator is prepared using microwave assisted Schiff base reaction. The synthesized molecule forms a hydrogel at 5 wt% under slightly acidic pH. The material was characterized using an inversion tube test, thermogravimetric analysis (TGA), powder X‐ray diffraction (PXRD) and FT‐IR spectroscopy. Rheological studies show the material forms a strong hydrogel with formation of nanofibrils supported by field‐emission scanning electron microscopy (FE‐SEM). To the best of our knowledge this is the first example of imine based trigonal low molecular weight hydrogelator reported.

Exceptionally Fast Temperature-Responsive, Mechanically Strong and Extensible Monolithic Non-Porous Hydrogels: Poly(N-isopropylacrylamide) Intercalated with Hydroxypropyl Methylcellulose.

Exceptionally fast temperature-responsive, mechanically strong, tough and extensible monolithic non-porous hydrogels were synthesized. They are based on divinyl-crosslinked poly(N-isopropyl-acrylamide) (PNIPAm) intercalated by hydroxypropyl methylcellulose (HPMC). HPMC was largely extracted after polymerization, thus yielding a 'template-modified' PNIPAm network intercalated with a modest residue of HPMC. High contents of divinyl crosslinker and of HPMC caused a varying degree of micro-phase-separation in some products, but without detriment to mechanical or tensile properties. After extraction of non-fixed HPMC, the micro-phase-separated products combine superior mechanical properties with ultra-fast T-response (in 30 s). Their PNIPAm network was highly regular and extensible (intercalation effect), toughened by hydrogen bonds to HPMC, and interpenetrated by a network of nano-channels (left behind by extracted HPMC), which ensured the water transport rates needed for ultra-fast deswelling. Moreover, the T-response rate could be widely tuned by the degree of heterogeneity during synthesis. The fastest-responsive among our hydrogels could be of practical interest as soft actuators with very good mechanical properties (soft robotics), while the slower ones offer applications in drug delivery systems (as tested on the example of Theophylline), or in related biomedical engineering applications.

Biomimetic 3D Color-Changing Hydrogel Actuators Constructed Based on Soft Permeable Photonic Crystals.

The integration of photonic crystals and self-shaping actuators is a promising method for constructing powerful biomimetic color-changing actuators. The major barrier is that common photonic crystals generally block the transfer/orientation of monomers/fillers and hence hinder the formation of heterogeneous structures for programmed 3D deformations as well as degrade the deformation capacity and mechanical properties of actuators. Herein, we present the construction of complex and strong 3D color-changing hydrogel actuators by asymmetric photolithography based on soft, permeable photonic crystals. The soft permeable photonic crystals are assembled by hydrogel microspheres with an ultralow volume fraction. During the asymmetric photolithography, the monomers in precursor solutions can thus transfer freely to generate heterogeneous microstructures, spatially patterned internal stresses, and interpenetrating networks for programming the deformation trajectories and initial 3D configurations and enhancing mechanical properties of actuators. Various 3D color-changing hydrogel actuators (e.g., flower and scroll painting) are constructed for applications such as information encryption and display.

Preparation and properties of chitosan/dialdehyde sodium alginate/dopamine magnetic drug-delivery hydrogels

The proportion of individuals with bladder cancer has drastically increased, thereby rendering bladder cancer a focus of social concern and great challenge for human health management. Hydrogels with three-dimensional network structures have attracted considerable attention in the field of drug delivery for tumor therapy. Therefore, exploring hydrogel drug-delivery systems with excellent biocompatibility and targeting ability is a current research hotspot. Herein, a chitosan/dialdehyde sodium alginate/magnetic dopamine hydrogel was investigated for this purpose. The hydrogel was prepared from chitosan using sodium dialdehyde alginate and dopamine via grafting, crosslinking, and compounding. Furthermore, characterization of the product structure, targeted adhesion, and evaluation of drug delivery properties were performed. The prepared wall-adherent hydrogel materials exhibited excellent targeted drug-delivery and controlled-release properties. In addition, the effect of dopamine dosage on the performance of drug-loaded hydrogels was examined. In conclusion, the drug-delivery materials exhibited strong organ-wall adhesion, hydrogel properties, targeting ability, antibacterial and antimicrobial abilities (98%), and biocompatibility (99%). Based on these excellent properties, the constructed targeted hydrogels demonstrate considerable potential for drug delivery and bladder cancer treatment.