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Hydrogel dressings traditionally promote wound healing by maintaining moisture and preventing infection rather than by actively stimulating the skin to regulate cell behavior. Electrical stimulation (ES) is known to modulate skin cell behavior and to promote wound healing. This study describes the first multifunctional conductive hydrogel for wound healing and health monitoring based on a deep eutectic solvent (DES). Sodium hyaluronate and polydopamine constituted the hydrogel skeleton, and tea tree oil and Panax notoginseng extract were used as the active ingredients to induce adhesion, promote antioxidant and antibacterial activity, and support biocompatibility of the hydrogel. The inclusion of DES increases the temperature resistance of the hydrogel and improves its environmental adaptability. We used a small, portable coin battery-powered to provide electrical stimulation. Treatment with both the hydrogel and ES resulted in a stronger therapeutic effect than that provided by the commercial DuoDERM dressing. The hydrogel detected movement and strain when applied as a sensor. Overall, this study reports the development of a multifunctional conductive hydrogel dressing based on DES as a wound healing and health monitor., Competing Interests: Declaration of competing interest We guarantee that this manuscript is not under consideration for publication and has not been published elsewhere in any medium including electronic journals and computer databases of a public nature. All the authors listed have approved the manuscript that is enclosed. The authors declare no competing financial interests. Declarations of interest: none., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Electrochemical determination of luteolin and baicalein always needs acidic supporting electrolyte to guarantee good sensitivity. Therefore, most of the reported electrochemical sensors of luteolin and baicalein are unsuitable for detection of neutral actual samples. It is necessary to design a highly sensitive sensor for direct determination of them in neutral conditions. In this study, poly(N-isopropylacrylamide-acrylic acid) hydrogel particles (NIPA/AA) and multiwall carbon nanotubes (MWCNTs) composite modified glassy carbon electrode (GCE) was fabricated by a simple casting method. The voltammetric results showed that the NIPA/AA particle film provided acidic environment for proton-electron coupled reaction in neutral mediums. The near-surface pH of the electrode was related on the loaded amount of the NIPA/AA particles in pH range from 4.2 to 5.9. The voltammetric behaviors of luteolin and baicalein at the NIPA/AA-MWCNTs-GCE were studied by cyclic voltammetry. The peak separations between cathodic and anodic peaks were decreased and peak currents were increased because of decrease in pH and increase in ion conductivity at the local electrode surface. The sensitivity of the electrode was investigated by differential pulse voltammetry. Even under neutral conditions, the plots of the oxidation currents of luteolin and baicalein were dependent linearly on their concentration with detection limit of 14.5 pM and 44.4 pM, respectively. Moreover, the proposed NIPA/AA-MWCNTs-GCE was also successfully applied for determination of luteolin and baicalein in peanut shell, Huang-qin and tomato samples., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Three-dimensional multicellular tumor spheroids have become critical for anticancer study since they may provide a better model than conventional monolayer cultures of cancer cells. Various methods for tumor spheroid formation have been explored. However, only one kind of hydrogel was used in these methods, which has an influence on the size and morphology of the obtained tumor spheroids. Herein, we present a microfluidic droplet-based method for the formation of multicellular tumor spheroids using alginate and matrigel mixed hydrogel beads. By on-chip changing the flow rate of the two hydrogel solutions, mixed hydrogel beads with different volume ratios between alginate and matrigel are obtained. Meanwhile, human cervical carcinoma (HeLa) cells are encapsulated in the mixed hydrogel beads. Acridine orange and propidium iodide double-staining assay shows that the viability of cells encapsulated in the mixed hydrogel beads was more than 90%. After 4 day culture, the multicellular tumor spheroids were successfully formed with spherical shape and uniform size distribution compared with spheroids formed in pure alginate beads. Cytoskeletal analysis by TRITC-phalloidin staining show that HeLa cells in the mixed hydrogel beads closely link to each other. The dose-dependent response assay of HeLa cell spheroids to vincristine show that multicellular spheroids have more powerful resistance to vincristine compared to conventional monolayer culture cells. Taken together, this novel technology may be of importance to facilitate in vitro culture of tumor spheroids for their ever-increasing utilization in modern cell-based medicine.

[Display omitted] • A hydrogel with ROS/glucose and exosomes-released properties was developed. • The hydrogel could reduce ROS and inflammatory response by repairing the ETC. • The hydrogel offers a localized exosomes dual-response release strategy. With numerous attempts at chronic wound healing in recent years, significant challenges pertaining to diabetic wound healing have arisen. These challenges result from excessive oxidative stress, vulnerability to bacterial infection, and persistent inflammation during the healing process. In response to the lack of a specific exosomes-sustained release system tailored for diabetic wounds, a reactive oxygen species (ROS)/glucose dual-responsive stimulated exosomes-released self-healing antibacterial antioxidant conductive multifunctional hydrogel has been developed, utilizing a simplistic "one-pot" method. This innovative hydrogel is constructed from a harmonious blend of polydopamine grafted MXene (PMX), chlorogenic acid (CA), L-ascorbate-2-phosphate trisodium slat (L), and adipose-derived stem cells (ADSCs) derived exosomes (E) with phenylboronic acid modified flaxseed gum (LG-PBA), chemically cross-linked with polyvinyl alcohol (PVA) to generate dynamic phenylboronate ester bond, to obtain P-LP-PMX-CA-L@E hydrogel. It was further demonstrated that the ROS/glucose-responsive exosomes-released P-LP-PMX-CA-L@E hydrogel integrated system could reduce ROS and inflammatory response by repairing the electron transfer chain, thereby facilitating skin damage repair in a mouse type I diabetic model. In conclusion, the multifunctional P-LP-PMX-CA-L@E hydrogel, endowed with stimuli-responsive exosomes release capability, exhibits a promoting effect on the healing of chronic diabetic wounds and offers a localized exosomes dual-response release strategy for the treatment of type I diabetic wounds. [ABSTRACT FROM AUTHOR]

Baesd on previous researches, the natural deep eutectic solvent (DES) has enormous potential to be used in the fabrication of hydrogel wound dressing due to its outstanding properties including cytocompatibility, degradability and solubility. In order to further improve the antibaterial capacity of hydrogel, in the present study sodium hyaluronate (SH) and the natural DES were utilized to develop a novel hydrogel wound dressing by dopamine (DA) coated SH with in situ reduction of silver nanoparticles (DES-DASH@Ag). Furthermore, during the preparation process, we discovered for the first time that the DES can be used to fill the freeze-dried DASH to prepare a hydrogel (DES-DASH), which was promising to utilized in the fabrication of other hydrogels. Besides, the chemical and physical properties as well as wound healing capacity of the DES-DASH@Ag hydrogel were characterized. As a result, the DES-DASH@Ag hydrogel presented good cytocompatibility tested using NIH-3 T3 fibroblast cells, and prominent antibacterial effect against two types of bacteria infecting exposed wound. Furthermore, the hydrogel facilitated regeneration of mouse skin tissue in the wound area. The overall performance of DES-DASH@Ag hydrogel suggested that it could be a promising wound dressing in modern medicine. [ABSTRACT FROM AUTHOR]

The healing of infected wounds has always been a clinical challenge. With the increasing threat of drug resistance due to antibiotic overuse, it is imperative to improve antibacterial wound dressings. In this study, we designed a double network (DN) hydrogel via a "one pot method" with antibacterial activity, and natural polysaccharides with the potential to promote skin wound healing were used. That is, a DN hydrogel matrix was formed by the hydrogen bond crosslinking of curdlan and the covalent crosslinking of flaxseed gum under the action of borax. We added ε-polylysine (ε-PL) as a bactericide. Tannic acid/ferric ion (TA/Fe3+) complex was also introduced into the hydrogel network as a photothermal agent to induce photothermal antibacterial properties. The hydrogel had fast self-healing, tissue adhesion, mechanical stability, good cell compatibility and photothermal antibacterial activity. In vitro studies of hydrogel showed its ability to inhibit S. aureus and E. coli. In vivo experiments also demonstrated the significant healing effect of hydrogel when used to treat wounds infected by S. aureus by promoting collagen deposition and accelerating the formation of skin appendage. This work provides a new design for the preparation of safe antibacterial hydrogel wound dressings and demonstrates great potential for promoting wound healing of bacterial infections. [ABSTRACT FROM AUTHOR]

Flexible, wearable sensors are attracting considerable interest because of their potential applications for human–machine interfaces, human-activity monitoring, and personal healthcare diagnosis. Hydrogels are promising material candidates for the wearable sensors due to their biocompatibility, high water content, structural similarity to natural soft tissues, and resemblance to extracellular matrix. However, the wearable hydrogel sensors have the limitations of poor adhesion and low electroconductivity. Herein, a healable, adhesive, and conductive wearable hydrogel sensor was designed by incorporating polydopamine decorated carbon nanotubes (PDA-CNTs) and FeCl 3 into acrylamide-co-acrylic acid polymer (P(AAm-co-AAc)) matrix, forming a catechol/P(AAm-co-AAc)/Fe3+ double-network hydrogel sensor. The hydrogel sensor displayed good stretchability and high sensitivity with a gauge factor of 44.2 at 700% strain. And it exhibited fast and repeatable self-healing ability (healed completely after 60 s at room temperature without any external assistance). The resistance of the hydrogel showed repeatable and periodic variations during multiple cyclic stretching (1000 cycles), demonstrating good stability of this hydrogel sensor. The PDA-CNT hydrogel also showed strong adhesiveness to various substrates, including glass, metal, and plastic. When adhered onto a human body, the hydrogel was able to accurately monitor various motions, such as the bending of finger, wrist, elbow, and knee. These results showed the hydrogel sensor's sensitivity and repeatability for detecting human motions. The healable, adhesive, conductive hydrogel is a promising material for wearable sensors to monitor human motion and can be used for personal healthcare diagnosis and therapy. [Display omitted] [ABSTRACT FROM AUTHOR]

In this study, we used the polysaccharide ulvan from the green macroalgae Ulva fenestrata to prepare the hydrogel for chronic diabetic wound healing. A natural polysaccharide-based hydrogel matrix (UC-DPA-Ag hydrogel) was prepared using ulvan dialdehyde, chitosan, dopamine (DPA) and silver nanoparticles (Ag NPs). Human umbilical cord mesenchymal stem cell lyophilized powder (hUC-MSCs) was loaded into the hydrogel to develop a novel chronic diabetic wound healing material (UC-DPA-Ag@hUC-MSCs). The resulting hydrogel features adequate mechanical properties, swelling capability, adhesiveness, antioxidant, antibacterial ability, and promoting cell proliferation and migration. In vivo wound healing in type II diabetic mellitus mouse wound model showed that hUC-MSCs loaded UC-DPA-Ag hydrogel could accelerate wound healing effectively. This advanced hydrogel provides a facile and effective way for diabetic chronic wound management. Furthermore, it offers a new route for the utilizing Ulva as a valuable biomaterial for the global and large-scale production of valued added biomaterials. Human umbilical cord mesenchymal stem cells seeded ulva fenestrata derivative driven functional hydrogel was developed as a chronic diabetic wound healing dressing. In vivo experiments showed that as-prepared dressing could accelerate diabetic mice wound healing. We demonstrated that incorporation of hUC-MSCs into ulvan hydrogel markedly upregulated capase3-dependent BCL2 level, also can activate PCNA and AKT, as well as increase proliferation and migration rate of HUVECs. [Display omitted] [ABSTRACT FROM AUTHOR]