Showing papers on "Self-healing hydrogels published in 2022"
TL;DR: Adhesion-enhanced self-healing multifunctional PC/GO/Met hydrogels with stimuli-responsive metformin release ability and easy removability have shown a promoting effect on the healing of chronic athletic diabetic wounds and provide a local-specific drug dual-response release strategy for the treatment of type II diabetic feet.
Abstract: In view of the lack of a specific drug-sustained release system that is responsive to chronic wounds of the type II diabetic foot, and the demands for frequent movement at the foot wound, pH/glucose dual-responsive metformin-released adhesion-enhanced self-healing easy-removable antibacterial antioxidant conductive hemostasis multifunctional phenylboronic acid and benzaldehyde bifunctional polyethylene glycol-co-poly(glycerol sebacic acid)/dihydrocaffeic acid and l-arginine cografted chitosan (PEGS-PBA-BA/CS-DA-LAG, denoted as PC) hydrogel dressings were constructed based on the double dynamic bond of the Schiff-base and phenylboronate ester. It was further demonstrated that the PC hydrogel promotes wound healing by reducing inflammation and enhancing angiogenesis in a rat type II diabetic foot model. In addition, the addition of metformin (Met) and graphene oxide (GO), as well as their synergy, were confirmed to better promote wound repair in vivo. In summary, adhesion-enhanced self-healing multifunctional PC/GO/Met hydrogels with stimuli-responsive metformin release ability and easy removability have shown a promoting effect on the healing of chronic athletic diabetic wounds and provide a local-specific drug dual-response release strategy for the treatment of type II diabetic feet.
235 citations
TL;DR: Results indicate that these multifunctional antibacterial adhesive hemostatic hydrogels have better healing effects than commercially available Tegaderm™ Film, revealing that they have become promising alternative in the healing of infected wounds.
216 citations
TL;DR: Wang et al. as mentioned in this paper developed photo-crosslinked multifunctional antibacterial adhesive anti-oxidant hemostatic hydrogel dressings based on polyethylene glycol monomethyl ether modified glycidyl methacrylate functionalized chitosan (CSG-PEG) for disinfection of drug-resistant bacteria and promoting wound healing.
191 citations
TL;DR: This review is expected to offer comparative views and critical insights to inspire more advanced studies on supramolecular adhesive hydrogels and pave the way for different fields even beyond tissue engineering applications.
Abstract: Tissue engineering is a promising and revolutionary strategy to treat patients who suffer the loss or failure of an organ or tissue, with the aim to restore the dysfunctional tissues and enhance life expectancy. Supramolecular adhesive hydrogels are emerging as appealing materials for tissue engineering applications owing to their favorable attributes such as tailorable structure, inherent flexibility, excellent biocompatibility, near-physiological environment, dynamic mechanical strength, and particularly attractive self-adhesiveness. In this review, the key design principles and various supramolecular strategies to construct adhesive hydrogels are comprehensively summarized. Thereafter, the recent research progress regarding their tissue engineering applications, including primarily dermal tissue repair, muscle tissue repair, bone tissue repair, neural tissue repair, vascular tissue repair, oral tissue repair, corneal tissue repair, cardiac tissue repair, fetal membrane repair, hepatic tissue repair, and gastric tissue repair, is systematically highlighted. Finally, the scientific challenges and the remaining opportunities are underlined to show a full picture of the supramolecular adhesive hydrogels. This review is expected to offer comparative views and critical insights to inspire more advanced studies on supramolecular adhesive hydrogels and pave the way for different fields even beyond tissue engineering applications.
124 citations
TL;DR: Recent efforts in nanomaterials-combined GelMA hydrogels that are considered as next-generation multifunctional platforms for tissue therapeutics are systematically reviewed.
112 citations
TL;DR: In this article , a self-powered sweat sensor is fabricated from a cellulose-based conductive hydrogel to quantify Na+, K+, and Ca2+ contents in perspiration, to sensitivities of 0.039, 0.082, and 0.069 mmol-1, respectively.
Abstract: Though visualizing perspiration constituents is crucial for physiological evaluation, inadequate material healing and unreliable power supply methods restrict its applications. Herein, a fully flexible self‐powered sweat sensor is fabricated from a cellulose‐based conductive hydrogel to address these issues. The hydrogel electrode is composed of a cellulose nanocomposite polymerized in situ with polyaniline and cross‐linked with polyvinyl alcohol/borax. The cellulose nanocomposites furnish the sweat sensor with tensile and electrical self‐healing efficiencies exceeding 95% within 10 s, a stretchability of 1530%, and conductivity of 0.6 S m−1. The sweat sensor quantitatively analyzes Na+, K+, and Ca2+ contents in perspiration, to sensitivities of 0.039, 0.082, and 0.069 mmol–1, respectively, in real time via triboelectric effect and wirelessly transmits the results to a user interface. This fabricated sweat sensor with high flexibility, stability, and analytical sensitivity and selectivity provides new opportunities for self‐powered health monitoring.
108 citations
TL;DR: In the PA-infected burn wound model, the QCS/OD/TOB/PPY@PDA9 hydrogel more effectively controlled wound inflammation levels and promoted collagen deposition, vascular generation, and earlier wound closure compared to Tegaderm dressings.
Abstract: Burns are a common health problem worldwide and are highly susceptible to bacterial infections that are difficult to handle with ordinary wound dressings. Therefore, burn wound repair is extremely challenging in clinical practice. Herein, a series of self-healing hydrogels (QCS/OD/TOB/PPY@PDA) with good electrical conductivity and antioxidant activity were prepared on the basis of quaternized chitosan (QCS), oxidized dextran (OD), tobramycin (TOB), and polydopamine-coated polypyrrole nanowires (PPY@PDA NWs). These Schiff base cross-links between the aminoglycoside antibiotic TOB and OD enable TOB to be slowly released and responsive to pH. Interestingly, the acidic substances during the bacteria growth process can induce the on-demand release of TOB, avoiding the abuse of antibiotics. The antibacterial results showed that the QCS/OD/TOB/PPY@PDA9 hydrogel could kill high concentrations of Pseudomonas aeruginosa (PA), Staphylococcus aureus, and Escherichia coli in a short time and showed a bactericidal effect for up to 11 days in an agar plate diffusion experiment, while showing good in vivo antibacterial activity. Excellent and long-lasting antibacterial properties make it suitable for severely infected wounds. Furthermore, the incorporation of PPY@PDA endowed the hydrogel with near-infrared (NIR) irradiation assisted bactericidal activity of drug-resistant bacteria, conductivity, and antioxidant activity. Most importantly, in the PA-infected burn wound model, the QCS/OD/TOB/PPY@PDA9 hydrogel more effectively controlled wound inflammation levels and promoted collagen deposition, vascular generation, and earlier wound closure compared to Tegaderm dressings. Therefore, the TOB smart release hydrogels with on-demand delivery are extremely advantageous for bacterial-infected burn wound healing.
107 citations
TL;DR: In this article , a conducting polymer hydrogel strain sensor exhibiting both ultimate strain (300%) and negligible hysteresis (<1.5%) is presented. This is achieved through a unique microphase semiseparated network design by compositing poly(3,4−ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) nanofibers with poly(vinyl alcohol) (PVA) and facile fabrication by combining 3D printing and successive freeze-thawing.
Abstract: Highly stretchable strain sensors based on conducting polymer hydrogel are rapidly emerging as a promising candidate toward diverse wearable skins and sensing devices for soft machines. However, due to the intrinsic limitations of low stretchability and large hysteresis, existing strain sensors cannot fully exploit their potential when used in wearable or robotic systems. Here, a conducting polymer hydrogel strain sensor exhibiting both ultimate strain (300%) and negligible hysteresis (<1.5%) is presented. This is achieved through a unique microphase semiseparated network design by compositing poly(3,4‐ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) nanofibers with poly(vinyl alcohol) (PVA) and facile fabrication by combining 3D printing and successive freeze‐thawing. The overall superior performances of the strain sensor including stretchability, linearity, cyclic stability, and robustness against mechanical twisting and pressing are systematically characterized. The integration and application of such strain sensor with electronic skins are further demonstrated to measure various physiological signals, identify hand gestures, enable a soft gripper for objection recognition, and remote control of an industrial robot. This work may offer both promising conducting polymer hydrogels with enhanced sensing functionalities and technical platforms toward stretchable electronic skins and intelligent robotic systems.
106 citations
TL;DR: In this article , the authors presented a review of the use of biomimetic hydrogels in bone tissue engineering, and some key factors that can determine the therapy effect for bone tissue regeneration were also mentioned.
104 citations
TL;DR: In this article , a review of nanomaterials-combined GelMA hydrogels that are considered as next-generation multifunctional platforms for tissue therapeutics is presented.
98 citations
TL;DR: A light‐controlled oxidative stress amplifier system is designed by co‐encapsulating Pd‐C SAzymes and camptothecin in agarose hydrogel, which exhibits enhanced synergistic antitumor activity by self‐producing H2O2 and transforming “cold” tumors.
Abstract: Single‐atom nanozyme (SAzyme) with peroxidase‐like activity can alter cellular redox balance and shows promising potential for tumor therapy. However, the “cold” immune microenvironment and limited amount of hydrogen peroxide (H2O2) in solid tumors severely restrict its efficacy. Herein, a light‐controlled oxidative stress amplifier system is designed by co‐encapsulating Pd‐C SAzymes and camptothecin in agarose hydrogel, which exhibits enhanced synergistic antitumor activity by self‐producing H2O2 and transforming “cold” tumors. In this nanozyme hydrogel system, the Pd‐C SAzyme converts near‐infrared laser into heat, resulting in agarose degradation and consequent camptothecin release. The camptothecin increases H2O2 level in tumors by activating nicotinamide adenine dinucleotide phosphate oxidase, improving the catalytic performance of SAzymes with peroxidase‐like activity. Moreover, the combination of photothermal therapy, chemotherapy, and nanozyme‐based catalytic therapy further facilitates tumor immunogenic death and enhanced antitumor immunity. The results reveal the synergistic antitumor potential of the novel SAzyme/chemotherapeutics‐based hydrogel system.
TL;DR: A novel glycyrrhizic acid (GA)‐based hybrid hydrogel dressing with intrinsic immunoregulatory properties is developed to promote rapid diabetic wound healing and serve as a promising dressing for the management of diabetic wounds.
Abstract: M1 macrophage accumulation and excessive inflammation are commonly encountered issues in diabetic wounds and can fail in the healing process. Hence, hydrogel dressings with immunoregulatory capacity have great promise in the clinical practice of diabetic wound healing. However, current immunoregulatory hydrogels are always needed for complex interventions and high‐cost treatments, such as cytokines and cell therapies. In this study, a novel glycyrrhizic acid (GA)‐based hybrid hydrogel dressing with intrinsic immunoregulatory properties is developed to promote rapid diabetic wound healing. This hybrid hydrogel consists of interpenetrating polymer networks composed of inorganic Zn2+‐induced self‐assembled GA and photo‐crosslinked methyl acrylated silk fibroin (SF), realizing both excellent injectability and mechanical strength. Notably, the SF/GA/Zn hybrid hydrogel can regulate macrophage responses in the inflammatory microenvironment, circumventing the use of any additives. The immunomodulatory properties of the hydrogel can be harnessed for safe and efficient therapeutics that accelerate the three phases of wound repair and serve as a promising dressing for the management of diabetic wounds.
TL;DR: In in vivo normal and infected full-thickness skin defect motion wound models, the hydrogel dressings significantly prevented wound infections and promoted wound healing with milder inflammation, higher granulation tissue thickness and collagen disposition, indicating their great potential in motion wound treatment in clinics.
TL;DR: The characterization, synthesis, and performance validation of biopolymer-based hydrogel electrolytes are summarized, analyzed, and discussed in this paper , where the remaining challenges of using biopolymers-based electrolytes for advanced energy storage and conversion devices are also presented.
TL;DR: The MoS2@TA/Fe nanozyme-anchored multifunctional hydrogel showed high potential for bacteria-infected wound healing and demonstrated fast self-healing and rapid shape adaptability.
TL;DR: In this paper , a series of injectable adhesive self-healing photothermal dual dynamic Schiff base network hydrogels were developed based on adipic dihydrazide modified hyaluronic acid, benzaldehyde group functionalized poly(ethylene glycol)-co-poly(glycerol sebacate) and cuttlefish melanin nanoparticles, and their excellent tissue adhesion, stretchability and selfhealing properties enable them to adapt to the frequent movement of motion wounds.
TL;DR: Results indicate the hydrogel is promising in synchronously noninvasive wound closure and enhanced wound healing.
Abstract: Conventional wound closure and dressing are two crucial, time‐consuming but isolated principles in wound care. Even though tissue adhesive opens a new era for wound closure, the method and biomaterial that can simultaneously achieve noninvasive wound closure and promote wound healing are highly appreciated. Herein, a novel supramolecular poly(N‐isopropylacrylamide) hybrid hydrogel dressing composed of quaternized chitosan‐graft‐β‐cyclodextrin, adenine, and polypyrrole nanotubes via host–guest interaction and hydrogen bonds is developed. The hydrogel demonstrates thermal contraction of 47% remaining area after 2 h at 37 ℃ and tissue adhesion of 5.74 kPa, which are essential for noninvasive wound closure, and multiple mechanical and biological properties including suitable mechanical properties, self‐healing, on‐demand removal, antioxidant, hemostasis, and photothermal/intrinsic antibacterial activity (higher 99% killing ratio within 5 min after irradiation). In both full‐thickness skin incision and excision wound models, the hydrogel reveals significant wound closure after 24 h post‐surgery. In acute and methicillin‐resistant Staphylococcus aureus‐infected wound and photothermal/intrinsic antibacterial activity assays, wounds treated with the hydrogel demonstrate enhanced wound healing with rapid wound closure rate, mild inflammatory response, advanced angiogenesis, and well‐arranged collagen fibers. Altogether, the results indicate the hydrogel is promising in synchronously noninvasive wound closure and enhanced wound healing.
TL;DR: In this paper , a tannic acid-chelated Fe-decorated molybdenum disulfide nanosheets (MoS2@TA/Fe NSs) with dual enzyme activities were developed and anchored to a multifunctional hydrogel.
TL;DR: Wang et al. as discussed by the authors constructed a novel hydrogel dressing with excellent reactive oxygen species scavenging property and outstanding antibacterial performance by introducing tannic acid (TA) into quaternized chitosan (QCS) matrix.
TL;DR: In this paper, a carrageenan and itaconic acid-based superadsorbent hydrogel having appreciable swelling properties and adsorption capacity towards Methylene blue (MB), Crystal violet (CV), and Methyl Red (MR) was synthesized by suspension polymerization technique.
TL;DR: In this article , a semi-interpenetrating network of carboxymethyl cellulose (CMC) molecules grafted to polyacrylic acid (PAA) was used as an eco-friendly and non-toxic polymer with numerous carboxyl and hydroxyl functional groups.
TL;DR: In this article, a semi-interpenetrating network of carboxymethyl cellulose (CMC) molecules grafted to polyacrylic acid (PAA) was used as an eco-friendly and non-toxic polymer with numerous carboxyl and hydroxyl functional groups.
TL;DR: In this paper , a carrageenan and itaconic acid-based superadsorbent hydrogel having appreciable swelling properties and adsorption capacity towards Methylene blue (MB), Crystal violet (CV), and Methyl Red (MR) was synthesized by suspension polymerization technique.
TL;DR: In this article , the authors proposed a double network hydrogel to balance electrical conductivity and mechanical stretchability in soft bioelectronics, which achieved high-quality physiological signal recording and reliable, low-voltage electrical stimulation based on an in vivo rat model.
Abstract: Conducting polymer hydrogels are promising materials in soft bioelectronics because of their tissue‐like mechanical properties and the capability of electrical interaction with tissues. However, it is challenging to balance electrical conductivity and mechanical stretchability: pure conducting polymer hydrogels are highly conductive, but they are brittle; while incorporating the conducting network with a soft network to form a double network can improve the stretchability, its electrical conductivity significantly decreases. Here, the problem is addressed by concentrating a poorly crosslinked precursor hydrogel with a high content ratio of the conducting polymer to achieve a densified double‐network hydrogel (5.5 wt% conducting polymer), exhibiting both high electrical conductivity (≈10 S cm–1) and a large fracture strain (≈150%), in addition to high biocompatibility, tissue‐like softness, low swelling ratio, and desired electrochemical properties for bioelectronics. A surface grafting method is further used to form an adhesive layer on the conducting hydrogel, enabling robust and rapid bonding on the tissues. Furthermore, the proposed hydrogel is applied to show high‐quality physiological signal recording and reliable, low‐voltage electrical stimulation based on an in vivo rat model. This method provides an ideal strategy for rapid and reliable tissue‐device integration with high‐quality electrical communications.
TL;DR: In this paper , a review of different types of smart/stimuli-responsive hydrogels with emphasis on their synthesis scheme is presented, and the mechanisms of their responsiveness to different stimuli are elaborated.
Abstract: Recently, biomedicine and tissue regeneration have emerged as great advances that impacted the spectrum of healthcare. This left the door open for further improvement of their applications to revitalize the impaired tissues. Hence, restoring their functions. The implementation of therapeutic protocols that merge biomimetic scaffolds, bioactive molecules, and cells plays a pivotal role in this track. Smart/stimuli-responsive hydrogels are remarkable three-dimensional (3D) bioscaffolds intended for tissue engineering and other biomedical purposes. They can simulate the physicochemical, mechanical, and biological characters of the innate tissues. Also, they provide the aqueous conditions for cell growth, support 3D conformation, provide mechanical stability for the cells, and serve as potent delivery matrices for bioactive molecules. Many natural and artificial polymers were broadly utilized to design these intelligent platforms with novel advanced characteristics and tailored functionalities that fit such applications. In the present review, we highlighted the different types of smart/stimuli-responsive hydrogels with emphasis on their synthesis scheme. Besides, the mechanisms of their responsiveness to different stimuli were elaborated. Their potential for tissue engineering applications was discussed. Furthermore, their exploitation in other biomedical applications as targeted drug delivery, smart biosensors, actuators, 3D and 4D printing, and 3D cell culture were outlined. In addition, we threw light on smart self-healing hydrogels and their applications in biomedicine. Eventually, we presented their future perceptions in biomedical and tissue regeneration applications. Conclusively, current progress in the design of smart/stimuli-responsive hydrogels enhances their prospective to function as intelligent, and sophisticated systems in different biomedical applications.
TL;DR: In this paper , a series of self-healing, adhesive, and antibacterial hydrogels based on gelatin methacrylate (GelMA), acrylated adenine (AA), and CuCl2 were designed through covalent bonding, coordination complexation of Cu2+ and carboxyl groups and hydrogen bonding to promote diabetic wound healing.
TL;DR: Jiang et al. as discussed by the authors used turgor pressure and electroosmosis to realize a strong and fast hydrogel-based actuator, which can break a brick and construct underwater structures within a few minutes.
Abstract: Hydrogels are promising as materials for soft actuators because of qualities such as softness, transparency, and responsiveness to stimuli. However, weak and slow actuations remain challenging as a result of low modulus and osmosis-driven slow water diffusion, respectively. We used turgor pressure and electroosmosis to realize a strong and fast hydrogel-based actuator. A turgor actuator fabricated with a gel confined by a selectively permeable membrane can retain a high osmotic pressure that drives gel swelling; thus, our actuator exerts large stress [0.73 megapascals (MPa) in 96 minutes (min)] with a 1.16 cubic centimeters of hydrogel. With the accelerated water transport caused by electroosmosis, the gel swells rapidly, enhancing the actuation speed (0.79 MPa in 9 min). Our strategies enable a soft hydrogel to break a brick and construct underwater structures within a few minutes. Description Wrap it up Conventional stimuli-responsive hydrogel actuators generally suffer from weak actuation force and slow response speed because of the osmotic-driven actuation mechanism. They are also limited in how much pressure they can endure and will collapse or shatter if pushed too hard. Na et al. significantly increased the actuation stress of a hydrogel wrapping the gel in a relatively stiff but flexible semipermeable membrane, which confined the transverse deformation (see the Perspective by Jiang and Song). This effect is similar to the turgor pressure seen in biological cells. The actuation speed can also be enhanced by adding the electrolyte into the water solution and applying an electric field, which reduces the actuation time from hours to minutes. —MSL A selectively permeable membrane can enhance the strength and actuation speed of a hydrogel actuator.
TL;DR: This study introduces the volumetric bioprinting of complex organoid‐laden constructs, which capture key functions of the human liver and opens up new possibilities for regenerative medicine and personalized drug testing.
Abstract: Organ‐ and tissue‐level biological functions are intimately linked to microscale cell–cell interactions and to the overarching tissue architecture. Together, biofabrication and organoid technologies offer the unique potential to engineer multi‐scale living constructs, with cellular microenvironments formed by stem cell self‐assembled structures embedded in customizable bioprinted geometries. This study introduces the volumetric bioprinting of complex organoid‐laden constructs, which capture key functions of the human liver. Volumetric bioprinting via optical tomography shapes organoid‐laden gelatin hydrogels into complex centimeter‐scale 3D structures in under 20 s. Optically tuned bioresins enable refractive index matching of specific intracellular structures, countering the disruptive impact of cell‐mediated light scattering on printing resolution. This layerless, nozzle‐free technique poses no harmful mechanical stresses on organoids, resulting in superior viability and morphology preservation post‐printing. Bioprinted organoids undergo hepatocytic differentiation showing albumin synthesis, liver‐specific enzyme activity, and remarkably acquired native‐like polarization. Organoids embedded within low stiffness gelatins (<2 kPa) are bioprinted into mathematically defined lattices with varying degrees of pore network tortuosity, and cultured under perfusion. These structures act as metabolic biofactories in which liver‐specific ammonia detoxification can be enhanced by the architectural profile of the constructs. This technology opens up new possibilities for regenerative medicine and personalized drug testing.
TL;DR: A new efficient synthetic strategy to prepare cationic hydrogels (PHCI) with intrinsically efficient antimicrobial properties by chemically cross-linking trans-1,4-cyclohexanediamine with 1,3-dibromo-2-propanol using a condensation reaction without the use of toxic cross- linking agents is developed.
Abstract: Bacterial infections are a common problem associated with wound treatment that imposes a significant burden on healthcare systems and patients. As a result, healthcare providers urgently need new treatment strategies to protect people. Hydrogel biomaterials with inherent antimicrobial properties offer an attractive and viable solution to this issue. Here, for the first time, we have developed a new efficient synthetic strategy to prepare cationic hydrogels (PHCI) with intrinsically efficient antimicrobial properties by chemically cross-linking trans-1,4-cyclohexanediamine with 1,3-dibromo-2-propanol using a condensation reaction without the use of toxic cross-linking agents. As expected, the prepared PHCI hydrogel possessed an inherent antibacterial ability that can adsorb and kill Staphylococcus aureus and Escherichia coli electrostatically. Notably, in vivo experiments on normal and diabetic rat models confirmed that the PHCI hydrogel can quickly stop bleeding, efficiently kill bacteria, promote the conversion of macrophages from the proinflammatory M1 phenotype to the repaired M2 phenotype, and accelerate collagen deposition and blood vessel formation, thereby achieving rapid wound healing. Overall, this work presents an effective antibacterial dressing that might provide a facile but effective approach for clinical wound management.