Gelatin-Reinforced Zwitterionic Organohydrogel with Tough, Self-Adhesive, Long-Term Moisturizing and Antifreezing Properties for Wearable Electronics.

Strong mechanical performance, appropriate adhesion capacity, and excellent biocompatibility of conductive hydrogel-based sensors are of great significance for their application. However, conventional conductive hydrogels usually exhibit insufficient mechanical strength and adhesion. In addition, they will lose flexibility and conductivity under subzero temperature and a dry environment owing to inevitable freezing and evaporation of water. In this study, a tough, flexible, self-adhesive, long-term moisturizing, and antifreezing organohydrogel was prepared, which was composed of gelatin, zwitterionic poly [2-(methacryloyloxy) ethyl] dimethyl-(3-sulfopropyl) (PSBMA), MXene nanosheets, and glycerol. Natural gelatin was incorporated to enhance mechanical performance via the entanglement of a physical cross-linked network and a PSBMA network, which was also used as a stabilizer to disperse MXene into the organohydrogel. Zwitterionic PSBMA endowed the organohydrogel with good adhesion and self-healing properties. Long-term moisturizing properties and antifreeze tolerance could be achieved owing to the synergistic water retention capacity of PSBMA and glycerol. The resulting PSBMA-gelatin-MXene-glycerol (PGMG) organohydrogel exhibited high mechanical fracture strength (0.65 MPa) and stretchability (over 1000%), excellent toughness (3.87 MJ/m3), strong and repeated adhesion to diverse substrates (e.g., paper, glass, silicon rubber, iron, and pig skin), good fatigue resistance (under the cyclic stretching-releasing process), and rapid recovery capacity. Moreover, the PGMG organohydrogel showed good stability under -40 °C. The sensor based on PGMG organohydrogel could tightly attach to the human skin and real-time-monitor the motions of joints (e.g., bending of the finger, wrist, elbow, and knee) and the change in mood such as smiling and frowning. Therefore, PGMG organohydrogels have a huge potential for wearable sensors under room temperature or extreme environments.

Zwitterionic Hydrogel with High Transparency, Ultrastretchability, and Remarkable Freezing Resistance for Wearable Strain Sensors.

Multifunctional hydrogel with outstanding conductivity and mechanical flexibility has received enormous attention as wearable electronic devices. However, fabricating transparent, ultrastretchable, and biocompatible hydrogel with low-temperature stability still remains a tremendous challenge. In this study, an ultrastretchable, highly transparent, and antifreezing zwitterionic-based electronic sensor is developed by introducing zwitterionic proline (ZP) into gellan gum/polyacrylamide (GG/PAAm) double network (DN) hydrogel. The existence of ZP endows the hydrogel with remarkable frost resistance. The toughness and transparency of zwitterionic Ca-GG/PAAm-ZP DN hydrogel can be maintained down to -40 °C. Also, the zwitterionic hydrogel shows good biocompatibility and protein adsorption resistance. The zwitterionic Ca-GG/PAAm-ZP DN hydrogel-based strain sensor can accurately monitor human motions (such as speaking and various joint bendings) under a broad temperature range from -40 to 25 °C. The zwitterionic Ca-GG/PAAm-ZP DN hydrogel-based strain sensor will be of immense value in the field of wearable electronic devices, especially for extreme environment applications.

Comparative Study on Pharmacokinetics of Four Active Compounds in Rat Plasma after Oral Administration of Raw and Wine Processed Chuanxiong Rhizoma.

In Chinese medicine, the effect of promoting blood circulation and removing stasis could be enhanced after Chuanxiong Rhizoma is processed by wine. However, the relevant mechanism remains unclear. In this manuscript, a rapid and sensitive quantification method employing ultrahigh performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was established and validated to simultaneously determine butylidenephthalide, ligustilide, senkyunolide A and ferulic acid in rat plasma after oral administration of raw Chuanxiong Rhizoma (RCR) and wine-processed Chuanxiong Rhizoma (WCR) respectively. All analytes were extracted from plasma by proteins precipitation with methanol. Chromatographic separation was carried out on a Hypersil GOLD C18 column by using a gradient mobile phase system of acetonitrile and water with 0.01% formic acid, the flow rate was 0.3 mL/min. For exact mass detecting, quick switching mode was used, positive and negative ions could be detected in one injection. The pharmacokinetic profiles of four components in the two groups were evaluated and compared. The results showed that, compared to the RCR group, the Vd and AUC0→t values of four active compounds were increased and decreased respectively in WCR group, which revealed the effect of wine processing to Chuanxiong Rhizoma: the stronger the effect, the wider the distribution.

Chitosan-enhanced nonswelling hydrogel with stable mechanical properties for long-lasting underwater sensing.

Existing anti-swelling hydrogels with poor mechanical strength restrict their underwater human monitoring as wearable electronic sensing equipment. Herein, a nonswelling double network (DN) hydrogel with strong self-recoverability (97.22%) was developed by adding chitosan (CS) to poly(acrylic acid-2-methoxyethyl acrylate)-Fe3+ [P(AA-MEA)-Fe] network. Owing to the introduction of CS, the hydrogel displayed excellent nonswelling properties under aqueous solutions (pH = 1, 4 and 7), physiological saline, seawater, dodecane, n-hexane and chloroform. Besides, CS improved mechanical properties of hydrogel through non-covalent network (large stretchability of 1199%, tensile strength of 0.462 MPa and toughness of 2.01 MJ/m3). Surprisingly, the hydrogel still reached the extensibility (1072%) and tensile stress (0.467 MPa) even after immersing in water for 7 days. Fabricating hydrogel as flexible strain sensor, periodic real-time signals of human movements (e.g., joint actions and electronic skin touching) were accurately monitored under the water and seawater. The nonswelling P(AA-MEA)-CS-Fe hydrogel shows huge potential in underwater sensing.

A Reasonable Evaluation of Chuanxiong Rhizoma Processing with Wine through Comparative Pharmacokinetic Study of Bioactive Components: Dominant Effect on Middle Cerebral Artery Occlusion Model Rats.

According to the ancient documents and Chinese herbal medicine processing experience, Chuanxiong Rhizoma was usually processed with yellow rice wine to improve efficacy. However, the relevant mechanisms are still unclear so far. In this study, a validated ultrahigh-performance liquid chromatography tandem mass spectrometry method was used to compare the pharmacokinetics of four representative components in middle cerebral artery occlusion rats after oral administration of raw and wine-processed Chuanxiong Rhizoma. The neurobehavioral scores and 2,3,5-triphenyltetrazolium chloride staining were employed to evaluate the model. Biological samples were prepared by protein precipitation with methanol. All analytes were separated on an ACQUITY BEH C18 column through gradient elution using acetonitrile and 0.01% of formic acid as mobile phase, and the flow rate was 0.3 mL/min. The results showed that the maximum plasma concentrations, the area values under the concentration-time curves of senkyunolide A, and ferulic acid in wine-processed Chuanxiong Rhizoma were all higher than in raw Chuanxiong Rhizoma, which were completely opposite to our previous studies in normal rats. Compared with normal rats, the theory that wine processing could enhance the efficacy of Chuanxiong Rhizoma may be better reflected in model rats.

Polysaccharides and proteins-based nanogenerator for energy harvesting and sensing: A review.

Nanogenerator is a promising energy harvesting device that can scavenge tiny mechanical energy from the surrounding environment, and then convert it into electricity. Natural bio-polymers are the potential candidates for the design of nanogenerators due to their excellent characteristics like piezoelectricity, triboelectricity, non-toxicity, biocompatibility and biodegradability. Especially, nanogenerators using bio-sourced polymers as the core raw materials are suitable for wearable and implantable devices. In this review, major advancements in the sensing field of nanogenerators based on natural polysaccharides and proteins (cellulose, chitosan, alginate, agarose, starch, lignin, silk fibroin, collagen, gelatin, keratin, peptide, M13 bacteriophage, ß-cyclodextrin, spider silk, etc.) are summarized. Also, challenges in the improvement of electric output performance, flexibility, anti-humidity and energy management for natural polymers based-nanogenerators are proposed. In the future, they will be applied in daily life as an alternative for traditional power source after addressing issues mentioned above.

Polysaccharides as separation media for the separation of proteins, peptides and stereoisomers of amino acids.

Reliable separation of peptides, amino acids and proteins as accurate as possible with the maximum conformation and biological activity is crucial and essential for drug discovery. Polysaccharide, as one of the most abundant natural biopolymers with optical activity on earth, is easy to be functionalized due to lots of hydroxyl groups on glucose units. Over the last few decades, polysaccharide derivatives are gradually employed as effective separation media. The highly-ordered helical structure contributes to complex, diverse molecular recognition ability, allowing polysaccharide derivatives to selectively interact with different analytes. This article reviews the development, application and prospects of polysaccharides as separation media in the separation of proteins, peptides and amino acids in recent years. The chiral molecules mechanism, advantages, limitations, development status and challenges faced by polysaccharides as separation media in molecular recognition are summarized. Meanwhile, the direction of its continued development and future prospects are also discussed.

Antifouling Antioxidant Zwitterionic Dextran Hydrogels as Wound Dressing Materials with Excellent Healing Activities.

Hydrogels as wound dressings have received great attention in recent years. It is highly important yet challenging to develop hydrogel dressings that are biocompatible and that can promote wound healing by lowering the risk of inflammatory responses. In this work, we designed and prepared zwitterionic dextran-based hydrogels using carboxybetaine dextran (CB-Dex) and sulfobetaine dextran (SB-Dex) as raw materials, respectively. The efficacy of CB-Dex and SB-Dex hydrogels in promoting wound recovery was evaluated using a mouse skin wound model. Results suggested that the zwitterionic dextran wound dressings showed a faster healing rate than natural dextran hydrogel and a commercial wound dressing (Duoderm film) due to their excellent protein resistance and capacity to scavenge free hydroxyl radicals. In addition, both CB-Dex and SB-Dex hydrogel wound dressings showed excellent cytocompatibility with NIH3T3 and L929 cells, as well as antibacterial adhesion against Staphylococcus aureus and Escherichia coli. Furthermore, both zwitterionic hydrogels demonstrated self-healing properties and can be stretched to adapt to irregular full-thickness wound beds. More importantly, they can be removed from the wound site painlessly by washing with normal saline. Overall, this work provided a new pathway to fabricate multifunctional polysaccharide hydrogels for wound treatment and pain relief when changing wound dressings.