Good Self-healing Properties Research Articles

A robust bio-based polyurethane employed as surgical suture with help to promote skin wound healing

Designing bio-based polyurethane materials with excellent mechanical, biocompatibility, and self-healing properties simultaneously is currently a significant challenge due to the increasing demands for high-performance materials. In this study, we propose an asymmetric backbone strategy utilizing bio-based polycarbonate as the soft segment, equimolar ratios of lysine diisocyanate and isophorone diisocyanate as asymmetric hard segments, and isophorone diamine as the chain extender. The resulting polyurethane elastomers exhibit excellent mechanical properties, including high tensile stress (46.1 MPa), toughness (213.9 MJ/m3), and fracture energy (98.47 kJ/m3). The polyurethane elastomers demonstrate good self-healing and recyclable properties under simple heat treatment. Furthermore, biological experiments confirm the degradability and bio-safety of the bio-based polyurethane elastomers, which have shown potential in accelerating wound healing in mice when used as surgical sutures. These findings highlight the promising prospects of the obtained polyurethane elastomers in various applications, including biomedicine, flexible sensing, and electronic components.

Novel Supramolecular Hydrogel for Infected Diabetic Foot Ulcer Treatment.

Multifunctional responsive hydrogels hold significant promise for diabetic foot ulcer (DFU) treatment, though their complex design and manufacturing present challenges. This study introduces a novel supramolecular guanosine-phenylboronic-chlorogenic acid (GBC) hydrogel developed using a dynamic covalent strategy. The hydrogel forms through guanosine quadruplex assembly in the presence of potassium ions and chlorogenic acid (CA) linkage via dynamic borate bonds. GBC hydrogels exhibit pH and glucose responsiveness, releasing more chlorogenic acid under acidic and high glucose conditions due to borate bond dissociation and G-quadruplex (G4)hydrogel disintegration. Experimental results indicate that GBC hydrogels exhibit good self-healing, shear-thinning, injectability, and swelling properties. Both in vitro and in vivo studies demonstrate the GBC hydrogel's good biocompatibility, ability to eliminate bacteria and reactive oxygen species (ROS), facilitate macrophage polarization from the M1 phenotype to the M2 phenotype (decreasing CD86 expression and increasing CD206 expression), exhibit anti-inflammatory effects (reducing TNF-α expression and increasing IL-10 expression), and promote angiogenesis (increasing VEGF, CD31, and α-SMA expression). Thus, GBC hydrogels accelerate DFU healing and enhance tissue remodeling and collagen deposition. This work provides a new approach to developing responsive hydrogels to expedite DFU healing.

Ultratough Supramolecular Polyurethane Featuring an Interwoven Network with Recyclability, Ideal Self-Healing and Editable Shape Memory Properties.

Developing multifunctional polymers with excellent mechanical properties, outstanding shape memory characteristics, and good self-healing properties is a formidable challenge. Inspired by the woven cross-linking strategy, a series of supramolecular polyurethane (PU) with an interwoven network structure composed of covalent and supramolecular cross-linking nodes have been successfully synthesized by introducing the ureido-pyrimidinone (UPy) motifs into the PU skeleton. The best-performing sample exhibited ultrahigh strength (∼77.2 MPa) and toughness (∼312.7 MJ m-3), along with an ideal self-healing efficiency (up to 90.8% for 6 h) and satisfactory temperature-responsive shape memory effect (shape recovery rates up to 96.9%). Furthermore, it ensured recyclability. These favorable properties are mainly ascribed to the effective dissipation of strain energy due to the disassembly and reconfiguration of supramolecular nodes (i.e., quadruple hydrogen bonds (H-bonds) between UPy units), as well as the covalent cross-linking nodes that maintain the integrity of the polymer network structure. Thus, our work provides a universal strategy that breaks through the traditional contradictions and paves the way for the commercialization of high-performance multifunctional PU elastomers.

Nanomotor-hydrogel Delivery System with Enhanced Antibacterial Performance for Wound Treatment.

In this study, we present a novel system consisting of nanomotors and a hydrogel. Calcium carbonate nanomotors are prepared using layer-by-layer self-assembly technology with calcium carbonate nanoparticles as the core and catalase (CAT) and polydopamine (PDA) as the shell. Calcium carbonate nanomotors were loaded into a Schiff base hydrogel to synthesize the CaCO3@NM-hydrogel system. A nanomotor is a device that works on the nanoscale to convert some form of energy to mechanical energy. The motion speed of the system in 5.0 mM H2O2 aqueous solution under near-infrared light (NIR) irradiation with a power density of 1.8 W/cm2 is 13.6 μm/s. The addition of CaCO3@NM further promotes gelation and improves the mechanical properties. The energy storage modulus increases to 4.0 × 103 Pa, which is 50 times higher. Schiff base hydrogels form dynamic reversible chemical bonds due to inter- and intramolecular hydrogen bonding. They also have good self-healing properties, as observed by measuring the energy storage modulus versus the loss modulus at 1 versus 10 kHz. The results show that the system significantly inhibited the growth of both Gram-positive bacteria, Staphylococcus aureus, and Gram-negative bacteria, Escherichia coli, after 48 h, with an inhibition rate of nearly 95%. These findings provide a basis for further research and potential applications of the system in wound dressings.

Enhanced thermal and water stability of halide perovskite MAPbBr3 by double-coated hydrogen-bonded polymer network

MAPbX3 (X = Br, I, Cl) type lead halide perovskite has great potential for light-emitting devices due to its excellent optical properties; however, their degradation under the influence of heat and atmospheric moisture severely limited their applications. To address this issue, we used a dynamic hydrogen bonding network constructed by amino-terminated hyperbranched aminoglycoside polymer (AHP) and thermoplastic polyurethane (PUIP) to double-coat MAPbBr3. The thermal and water degradation of MAPbBr3 was greatly alleviated upon formation of the MAPbBr3@AHP@PUIP composite. The structures of AHP, PUIP, MAPbBr3@AHP, and MAPbBr3@AHP@PUIP films were characterized by various techniques. The double-coated MAPbBr3@AHP@PUIP film exhibited high quantum efficiency and excellent luminescence stability at room temperature, with quantum yields remained above 90 % of the original value even after 20 days in air. Moreover, the polymer film still maintains high fluorescence emission after 72 h in the water phase, and can achieve fluorescence recovery transformation at a specific temperature, and has a good self-healing property at room temperature. This inexpensive and convenient method not only greatly enhanced PL efficiency, increased water stability, but also demonstrated excellent flexibility and elasticity, suggesting broad prospects for the commercial application of inorganic perovskite materials in flexible electronics.

Injectable exosome-loaded quaternized chitosan/oxidized sodium alginate hydrogel with self-healing, bioadhesive, and antibacterial properties for treating combined radiation-wound injury

The management of combined radiation-wound injury (CRWI) is a major clinical challenge owing to the delayed and prolonged wound-healing process. Moreover, the mechanisms underlying the healing of CRWI are complex, and chronic wounds can increase vulnerability to multidrug-resistant bacterial infections, vascular disease, and other adverse conditions. Although exosomes from iPSC-derived mesenchymal stem cells (iMSCs) can promote injury repair, the feasibility of encapsulating them within polysaccharide-based hydrogels to treat CRWI remains to be explored. Here, iMSC-derived exosomes were encapsulated within an injectable hydrogel (HACC/OSA) consisting of quaternized chitosan (HACC) and oxidized sodium alginate (OSA). The HACC/OSA hydrogel exhibited good self-healing properties, excellent injectability, and good biocompatibility. In mouse models of CRWI, the HACC/OSA hydrogel could form a protective barrier covering the wound. Due to the presence of quaternary ammonium salts, the hydrogel could provide long-term antimicrobial protection to the wound, which was favorable for wound healing. In addition, the hydrogel could also promote CRWI repair by stabilizing exosome release. The exosome-loaded hydrogel (HACC/OSA@Exos) significantly inhibited bacterial growth and promoted the repair of CRWI, as indicated by enhanced wound healing efficiency, rapid re-epithelialization, favorable collagen deposition, and abundant angiogenesis at the wound site. Together, the in vivo and in vitro results indicated that the exosome-loaded polysaccharide-based hydrogel (HACC/OSA@Exos) can promote the healing of CRWI and potentially serve as a valuable clinical agent for CRWI management.

Exosomes-carried curcumin based on polysaccharide hydrogel promote flap survival

Flap grafting is a common technique used to repair skin defects in orthopedics and plastic and reconstructive surgeries. However, oxidative stress injury caused by ischemia and ischemia-reperfusion injury at the distal end of the skin flap can cause flap necrosis. Curcumin is a natural compound with anti-inflammatory and antioxidant properties that tackle oxidative stress. However, its applicability is limited by its poor water solubility. Exosomes are membranous vesicles that can be loaded with hydrophobic drugs. They are widely studied in drug delivery applications and can be investigated to augment curcumin efficiency. In this study, a self-healing oxidized pullulan polysaccharide-carboxymethylated chitosan composite hydrogel was used as a curcumin-loaded exosome delivery system to evaluate its impact on the viability of skin flaps. The hydrogel exhibited good self-healing properties that allowed the continuous and stable release of drugs. It had anti-inflammatory and antioxidant properties that could reduce oxidative stress damage due to early ischemia and hypoxia of the skin flap in vitro. Moreover, this composite hydrogel attenuated inflammatory responses, promoted angiogenesis, and reduced the distal necrosis of the flap in vivo. Therefore, our hydrogel provides a novel strategy for skin flap graft protection with reduced necrosis and the potential for broad clinical applications.

Light- and heat-induced shape deformation polyurethane actuators that combine self-healing capabilities

Materials commonly experience physical damage during regular usage, and the implementation of self-healing materials can effectively repair this damage, thereby prolonging the lifespan of the materials. We have successfully synthesized a polyurethane material, S-PU, by introducing azobenzene and reversible disulfide bonds through co-polymerization. The S-PU film not only exhibits light-induced bending, heat-induced recovery ability, but also good self-healing properties. The disulfide bonds in S-PU accelerate the dynamic exchange as the polymer chains flow under heated conditions, enabling self-repairing without affecting the mechanical properties of the material. S-PU is a self-repairing material that can repair damage in a variety of ways. By combining dual-stimulus response characteristics with self-healing properties, this work provides a new idea for self-healing materials and opens more directions for the practical application of the material.

Cellulose-based eutectogel electrolyte with high ionic conductivity for solid-state lithium-ion batteries

It is known that the low ionic conductivity of solid-state polymer electrolytes at room temperature (RT) has severely restricted their practical application in lithium-ion batteries. Although eutectogel (ETG) electrolytes could solve this problem to some extent, highly compatible deep eutectic solvent (DES)/polymer systems are desirable to further enhance ion conduction. Herein, we designed cellulose-based ETG (CETG) with dual channels through “hopping” and “vehicle” mechanisms by hydroxyethyl cellulose (HEC) molecular chains and N-methylacetamide (NMA)/LiTFSI-derived DES, respectively. Thanks to the strong molecular interactions between HEC and DES, the highest DES content in the ETG could achieve 90 %, which endowed the CETG with an excellent ionic conductivity of 2.04 × 10–3 S cm−1 at 30 °C. Additionally, our designed CETG displayed good self-healing and fire retardant properties. The assembled Li/LiFePO4 cell showed a capacity retention of 91.8 % after 200 cycles at 0.2 C under RT with an initial discharge capacity of 156.2 mAh g−1. In particular, the capacity retention rates of the assembled batteries reached 95.2 % and 92.1 %, respectively, after 100 cycles at 0.2 C under 60 °C and 50 cycles at 0.2 C under 100 °C. Our fabrication strategy would provide a novel idea for the design of green, safe and efficient solid-state polymer electrolytes for lithium-ion batteries.

Biomimetic dually cross-linked injectable poly(l-glutamic acid) based nanofiber composite hydrogels with self-healing, osteogenic and angiogenic properties for bone regeneration

Biomimetic hydrogels with satisfactory mechanical properties and osteogenic/angiogenic abilities have attracted extensive attention in recent years. Injectable hydrogels with the advantages of minimally invasive implantation and adaptability to irregular defects exhibit superior application potential in the field of bone regeneration. However, poor mechanical properties and limited self-healing ability hinder their potential as supporting materials. Furthermore, the absence of osteogenic and angiogenic properties significantly affect their application in bone regeneration. For injectable hydrogels, simulating natural bone tissue ECM presents an opportunity for developing innovative materials for bone repair. In this work, a strategy to prepare biomimetic nanofiber-reinforced dually cross-linked (DC) injectable hydrogels with self-healing, osteogenic and angiogenic properties was proposed. The PLGA/MDex/CaP@PBLG nanofiber hydrogels were crosslinked through two reversible dynamic interactions including Schiff base reaction and physical chelation, thereby demonstrating good self-healing property. Meanwhile, the incorporation of CaP@PBLG mineralized nanofibers and alendronate sodium (BP) grafted on PLGA could endow the hydrogels with favorable osteogenic function. Moreover, the introduction of antioxidant ferulic acid (FA) could significantly stimulate angiogenic activity of the hydrogels. The successful regeneration of cranial defects in rats demonstrated a potential application of PLGA/MDex/CaP@PBLG nanofiber hydrogels in the field of bone regeneration.

A High-Stretching, Rapid-Self-Healing, and Printable Composite Hydrogel Based on Poly(Vinyl Alcohol), Nanocellulose, and Sodium Alginate.

Hydrogels with excellent flexibility, conductivity, and controllable mechanical properties are the current research hotspots in the field of biomaterial sensors. However, it is difficult for hydrogel sensors to regain their original function after being damaged, which limits their practical applications. Herein, a composite hydrogel (named SPBC) of poly(vinyl alcohol) (PVA)/sodium alginate (SA)/cellulose nanofibers (CNFs)/sodium borate tetrahydrate was synthesized, which has good self-healing, electrical conductivity, and excellent mechanical properties. The SPBC0.3 hydrogel demonstrates rapid self-healing (<30 s) and achieves mechanical properties of 33.92 kPa. Additionally, it exhibits high tensile strain performance (4000%). The abundant internal ions and functional groups of SPBC hydrogels provide support for the good electrical conductivity (0.62 S/cm) and electrical response properties. In addition, the SPBC hydrogel can be attached to surfaces such as fingers and wrists to monitor human movements in real time, and its good rheological property supports three-dimensional (3D) printing molding methods. In summary, this study successfully prepared a self-healing, conductive, printable, and mechanically superior SPBC hydrogel. Its suitability for 3D-printing personalized fabrication and outstanding sensor properties makes it a useful reference for hydrogels in wearable devices and human motion monitoring.

Silver sulfide anchored bismuth molybdate p-n heterojunction nano-coating with excellent photo-thermal self-healing performance

In this research, a self-healing nano-coating with excellent photo-thermal response to near-infrared (NIR) laser is prepared. This coating incorporates silver sulfide anchored bismuth molybdate (Ag2S@Bi2MoO6) into a shape memory epoxy resin to achieve for a good photo-thermal conversion capability. The Ag2S@Bi2MoO6 p-n heterojunction could photo-generate more electron-holes pairs under the NIR laser irradiation. Also, it shows a wider absorption range of visible light, leading to effectively absorb the light energy, generate enough heat to induce the shape memory recovery in the coating, and seal the scratch. The results indicate that the temperature of EP-1 % Ag2S@Bi2MoO6 coating has reached about 88 °C, while good self-healing and anti-corrosion properties with a self-healing rate of 88.41 % have been achieved. Furthermore, calculations based on Density Functional Theory and Finite Element Method pointed out that the formation of p-n heterojunction effectively has enhanced the photo-thermal effect. This research opens a new way for developing self-healing coatings with an ultra-fast response time and high self-healing efficiency.

An interface-integrated hydrogel for all-in-one flexible supercapacitor with excellent wide-temperature and self-healing properties

With the rapid development of flexible energy storage devices, the abilities to withstand various of mechanical deformation and maintain stable electrochemical performance at different temperatures are two decisive factors that stand out in their applications. Herein, aniline containing 2-acrylamido-2methylpropane sulfonic acid sodium is polymerized in-situ on hydrogels with double cross-linked networks constructed by polyacrylamide, polyvinyl alcohol and quaternary ammonium salt of chitosan through electrostatic interaction, so as to obtain the PPHP-Na hydrogels for the construction of the all-in-one flexible supercapacitors. The PPHP-Na hydrogels can withstand a maximum of 544% tensile strain at tensile stress up to 601 kPa, and can maintain stable dissipation during stress-strain tensile cycles and recover quickly after cycling, exhibiting excellent mechanical properties. In addition, the optimal PPHP-Na hydrogel shows a high ionic conductivity of 65.6 mS cm−1. More importantly, as an all-in-one flexible energy storage device, the PPHP-Na supercapacitor shows high area capacitance of 250.75 mF cm−2, and can maintain relatively stable electrochemical performance at -40-80 °C and good self-healing property. This interface-integrated strategy of all-in-one flexible supercapacitors with excellent and stable electrochemical performance constructed provides meaningful ideas for the development of flexible electronic devices.

Multifunctional self-healing peptide hydrogel for wound healing

The complete healing of wounds remains a challenge in clinical care. In addition, various complications such as inflammation and infection that may occur during skin wound healing can impede the healing process. Here, we constructed a multifunctional self-repairing hydrogel by utilizing Schiff base bonds. This hydrogel exhibited good self-healing properties and could cope with destructive external influences. The self-healing hydrogel was injectable, ensuring that the hydrogel dressing adhered to the wound. Carboxymethyl chitosan and oxidized chondroitin sulfate demonstrated good biocompatibility and multiple bioactivities and were successfully used to prepare self-healing hydrogels. Meanwhile, the SIKVAV biopeptide was less expensive and more morphologically stable than vascular endothelial growth factor and had a high pro-angiogenic activity. Thus, the SIKVAV biopeptide was cross-linked to the oxidized chondroitin sulfate of the hydrogel through covalent bonding to avoid rapid biopeptide degradation, achieving a slow release of the drug. This peptide hydrogel exhibited good biocompatibility and antimicrobial properties; moreover, experiments conducted on mice revealed that it could effectively promote angiogenesis and skin tissue repair. These findings suggest that the injectable self-repairing peptide hydrogel may facilitate skin wound healing and other applications.

Fabrication of anti-freezing and self-healing nanocomposite hydrogels based on phytic acid and cellulose nanocrystals for high strain sensing applications.

For hydrogel-based flexible sensors, it is a challenge to enhance the stability at sub-zero temperatures while maintaining good self-healing properties. Herein, an anti-freezing nanocomposite hydrogel with self-healing properties and conductivity was designed by introducing cellulose nanocrystals (CNCs) and phytic acid (PA). The CNCs were grafted with polypyrrole (PPy) by chemical oxidation, which were used as the nanoparticle reinforcement phase to reinforce the mechanical strength of hydrogels (851.8%). PA as a biomass material could form strong hydrogen bond interactions with H2O molecules, endowing hydrogels with prominent anti-freezing properties. Based on the non-covalent interactions, the self-healing rate of the hydrogels reached 92.9% at -15 °C as the content of PA was 40.0 wt%. Hydrogel-based strain sensors displayed high sensitivity (GF = 0.75), rapid response time (350 ms), good conductivity (3.1 S m-1) and stability at -15 °C. Various human movements could be detected by using them, including small (smile and frown) and large changes (elbow and knee bending). This work provides a promising method for the development of flexible wearable sensors that work stably in frigid environments.

Antibacterial conductive self-healing hydrogel wound dressing with dual dynamic bonds promotes infected wound healing.

In clinical applications, there is a lack of wound dressings that combine efficient resistance to drug-resistant bacteria with good self-healing properties. In this study, a series of adhesive self-healing conductive antibacterial hydrogel dressings based on oxidized sodium alginate-grafted dopamine/carboxymethyl chitosan/Fe3+ (OSD/CMC/Fe hydrogel)/polydopamine-encapsulated poly(thiophene-3-acetic acid) (OSD/CMC/Fe/PA hydrogel) were prepared for the repair of infected wound. The Schiff base and Fe3+ coordination bonds of the hydrogel structure are dynamic bonds that can be repaired automatically after the hydrogel network is disrupted. Macroscopically, the hydrogel exhibits self-healing properties, allowing the hydrogel dressing to adapt to complex wound surfaces. The OSD/CMC/Fe/PA hydrogel showed good conductivity and photothermal antibacterial properties under near-infrared (NIR) light irradiation. In addition, the hydrogels exhibit tunable rheological properties, suitable mechanical properties, antioxidant properties, tissue adhesion properties and hemostatic properties. Furthermore, all hydrogel dressings improved wound healing in the infected full-thickness defect skin wound repair test in mice. The wound size repaired by OSD/CMC/Fe/PA3 hydrogel+NIR was much smaller (12%) than the control group treated with Tegaderm™ film after 14 days. In conclusion, the hydrogels have high antibacterial efficiency, suitable conductivity, great self-healing properties, good biocompatibility, hemostasis and antioxidant properties, making them promising candidates for wound healing dressings for the treatment of infected skin wounds.

Self-healing poly(oxime–carbamate) films with tunable mechanical properties derived from rosin

Thermoset polymers with superior dimensional stability and creep resistance have been widely used in various electronic and energy devices. However, they are difficult to reprocess and recycle, and with the gradual decrease in nonrenewable resources, there is an urgent need for new sustainable materials as alternatives to thermoset polymers. Polymer materials with self-healing properties can provide high durability and sustainability for devices. In this work, we prepared a series of rosin-based poly(oxime–carbamate) films by reacting rosin acrylate/glycidyl methacrylate ester with toluene 2, 4-diisocyanate using dimethylglyoxime as the chain extender and triethanolamine as the crosslinking agent. The introduction of rosin with a rigid tricyclic phenanthrene structure in the prepared films resulted in excellent tensile strength (4.9 ± 0.03 MPa) while maintaining high elongation at break (973.2 % ± 4.8 %) and toughness (20.9 ± 0.1 MJ m−3). The good self-healing properties of the prepared films (90.6 % ± 1.5 %, 60 °C for 3 h) were attributed to the introduction of dynamic oxime–carbamate bonds. In particular, the tunable mechanical and self-healing properties of the films can be achieved by varying the molar ratio of rosin acrylate/glycidyl methacrylate ester to dimethylglyoxime. Furthermore, the prepared rosin-based films exhibited good adhesion, welding, and anticorrosion properties. Considering the reversible exchange mechanism of dynamic oxime–carbamate bonds and their use in self-healing and recycling applications, a new strategy for developing sustainable high-performance biobased self-healing coatings is presented.

Recastable assemblies of carbon dots into mechanically robust macroscopic materials

Assembly of nanoparticles into macroscopic materials with mechanical robustness, green processability, and recastable ability is an important and challenging task in materials science and nanotechnology. As an emerging nanoparticle with superior properties, macroscopic materials assembled from carbon dots will inherit their properties and further offer collective properties; however, macroscopic materials assembled from carbon dots solely remain unexplored. Here we report macroscopic films assembled from carbon dots modified by ureido pyrimidinone. These films show tunable fluorescence inherited from carbon dots. More importantly, these films exhibit collective properties including self-healing, re-castability, and superior mechanical properties, with Young’s modulus over 490 MPa and breaking strength over 30 MPa. The macroscopic films maintain original mechanical properties after several cycles of recasting. Through scratch healing and welding experiments, these films show good self-healing properties under mild conditions. Moreover, the molecular dynamics simulation reveals that the interplay of interparticle and intraparticle hydrogen bonding controls mechanical properties of macroscopic films. Notably, these films are processed into diverse shapes by an eco-friendly hydrosetting method. The methodology and results in this work shed light on the exploration of functional macroscopic materials assembled from nanoparticles and will accelerate innovative developments of nanomaterials in practical applications.

Realization of dual crosslinked network robust, high toughness self-healing polyurethane elastomers for electronics applications

Currently, research into self-healing polyurethane materials has progressed significantly; however, ensuring that the materials exhibit excellent mechanical properties and good healing efficiency is an urgent problem. In this study, a self-healing polyurethane elastomer exhibiting the synergistic enhancement effect of a double-crosslinked network is prepared by introducing a hydrogen-bond functional monomer and the Diels-Alder reaction. Consequently, the resulting elastomer shows a high fracture strength of 72.5 MPa, an elongation at break of 1241.0 %, an ultrahigh toughness of 235.7 MJ/m3, and a fracture energy of 219.4 KJ/m2. Dynamic covalent crosslinking and reversible hydrogen bonding dual networks endow the elastomers with good self-healing properties and multiple repair capabilities, thus allowing them to achieve up to 86 % self-healing efficiency. In addition, we prepare self-healing capacitive electronic devices using a liquid metal blended and compounded with a dual dynamic bonded polymer system, which exhibit stable electrochemical properties, excellent mechanical properties, excellent self-healing properties, and two-component recyclable properties after mechanical training. The self-repairing device can be reused, thus significantly reducing material waste and pollution, and benefits environmental and resource conservation.

Double Cross-Linked Chitosan/Bacterial Cellulose Dressing with Self-Healable Ability.

Self-healing hydrogel products have attracted a great deal of interest in wound healing due to their ability to repair their own structural damage. Herein, an all-natural self-healing hydrogel based on methacrylated chitosan (CSMA) and dialdehyde bacterial cellulose (DABC) is developed. MA is used to modify CS and obtain water-soluble biomaterial-based CSMA with photo crosslinking effects. BC is modified through a simple oxidation method to gain dialdehyde on the polymer chain. The success of the modification is confirmed via FTIR. Hydrogels are formed within 11 min through the establishment of a Schiff base between the amino of CSMA and the aldehyde of DABC. A dynamically reversible Schiff base bond endows hydrogel with good self-healing properties through macroscopic and microscopic observations. We observe the uniform and porous structure in the hydrogel using SEM images, and DABC nanofibers are found to be well distributed in the hydrogel. The compressive strength of the hydrogel is more than 20 kPa and the swelling rate sees over a 10-fold increase. In addition, the CSMA/DABC hydrogel has good cytocompatibility, with cell viability exceeding 90%. These results indicate that the all-natural self-healable CSMA/DABC hydrogel demonstrates strong application potential in wound healing and tissue repair.