NIR responsive scaffold with multistep shape memory and photothermal-chemodynamic properties for complex tissue defects repair and antibacterial therapy.

Complex tissue damage accompanying with bacterial infection challenges healthcare systems globally. Conventional tissue engineering scaffolds normally generate secondary implantation trauma, mismatched regeneration and infection risks. Herein, we developed an easily implanted scaffold with multistep shape memory and photothermal-chemodynamic properties to exactly match repair requirements of each part from the tissue defect by adjusting its morphology as needed meanwhile inhibiting bacterial infection on demand. Specifically, a thermal-induced shape memory scaffold was prepared using hydroxyethyl methacrylate and polyethylene glycol diacrylate, which was further combined with the photothermal agent iron tannate (FeTA) to produce NIR light-induced shape memory property. By varying ingredients ratios in each segment, this scaffold could perform a stepwise recovery under different NIR periods. This process facilitated implantation after shape fixing to avoid trauma caused by conventional methods and gradually filled irregular defects under NIR to perform suitable tissue regeneration. Moreover, FeTA also catalyzed Fenton reaction at bacterial infections with abundant H2O2, which produced excess ROS for chemodynamic antibacterial therapy. As expected, bacteriostatic rate was further enhanced by additional photothermal therapy under NIR. The in vitro and vivo results showed that our scaffold was able to perform high efficacy in both antibiosis, inflammation reduction and wound healing acceleration, indicating a promising candidate for the regeneration of complex tissue damage with bacterial infection.

An Integrated All-Natural Conductive Supramolecular Hydrogel Wearable Biosensor with Enhanced Biocompatibility and Antibacterial Properties.

Conductive hydrogels exhibit tremendous potential for wearable bioelectronics, biosensing, and health monitoring applications, yet concurrently enhancing their biocompatibility and antimicrobial properties remains a long-standing challenge. Herein, we report an all-natural conductive supramolecular hydrogel (GT5-DACD2-B) prepared via the Schiff base reaction between the biofriendly dialdehyde cyclodextrin and gelatin. The potent antibacterial agent fusidic acid (FA) is incorporated through host-guest inclusion, enabling 100% inhibition of Staphylococcus aureus proliferation. The biocompatibility of our hydrogel is bolstered with tannic acid (TA) facilitating antibacterial effects through interactions with gelatin, while borax augments conductivity. This supramolecular hydrogel not only exhibits stable conductivity and rapid response characteristics but also functions as a flexible sensor for monitoring human movement, facial expressions, and speech recognition. Innovatively integrating biocompatibility, antimicrobial activity, and conductivity into a single system, our work pioneers a paradigm for developing multifunctional biosensors with integrated antibacterial functionalities, paving the way for advanced wearable bioelectronics with enhanced safety and multifunctionality.

Tannic Acid-Based Self-Assembling Nanocarriers with Antiphotobleaching and Controlled Releasing Properties for Collaborative Near-Infrared Photothermal/Photodynamic Therapy.

Near-infrared (NIR) organic materials have been widely developed for tumor phototherapy due to their deep tumor penetration, good biodegradability, and high photothermal conversion (PCE). However, most of the NIR organic dyes are easily destroyed by photooxidation due to their big and long conjugated structures, such as cyanine dyes. Under light irradiation, the reactive oxygen species (ROS) produced by these NIR dyes can easily break their conjugated skeleton, resulting in a dramatic decrease in phototherapeutic efficiency. Herein, an NIR organic dye cyanine dye (CyS) and a photosensitizer methylene blue (MB) were chosen to prepare nanocarrier CMTNPs by facile self-assembling with a natural antioxidant, tannic acid (TA). TA can greatly enhance the stability of NIR cyanine dyes by scavenging ROS. Furthermore, CMTNPs have a character of pH/thermal dual response, allowing for controlled release of MB in the slightly acidic tumor environment during photothermal therapy. The released MB can turn on both fluorescence and photodynamic therapy effects. In vitro and in vivo experiments demonstrated the remarkable tumor ablation ability of CMTNPs. Thus, our study provided an antiphotobleaching and controlled release photosensitizer strategy through the introduction of antioxidant TA into the nanocarrier for efficient collaborative photothermal/photodynamic therapy.

An Ultrathin Coating of Microcapsules Enhances the Function of Encapsulated Hepatocyte Spheroids.

Maintaining the differentiated phenotype and function of primary hepatocytes in vitro and in vivo represents a distinct challenge. Our paper describes microcapsules comprised of a bioactive polymer and overcoated with an ultrathin film as a means of maintaining the function of entrapped hepatocytes for at least two weeks. We previously demonstrated that heparin (Hep)-based microcapsules improved the function of entrapped primary hepatocytes by capturing and releasing cell-secreted inductive signals, including hepatocyte growth factor (HGF). Further enhancement of hepatic function could be gained by loading exogenous HGF into microcapsules. In this study, we demonstrate that an ultrathin coating of tannic acid (TA) further enhances endogenous HGF signaling for entrapped hepatocytes and increases by 2-fold the rate of uptake of exogenous HGF by Hep microcapsules. Hepatocytes in overcoated microcapsules exhibited better function and hepatic gene expression than in capsules without a TA coating. Our study showcases the potential application of ultrathin coatings to modulate the bioactivity of microcapsules and may enable the use of encapsulated hepatocytes for modeling drug toxicity or treating liver diseases.

First Insight into Lignin Valorization as a Promising Biopolymer for the Modulation of the Physicochemical Properties of Port Wine.

Lignosulfonate (LS), kraft lignin (KL), and organosolv lignin (OL) were evaluated as potential modulating agents of the physicochemical properties of Port wine at two different concentrations for 7 and 30 days. KL and LS demonstrated the ability to remove proteins and potentiate the anthocyanin concentration. LS reduced the tannin content and the interaction of salivary acidic proline-rich proteins with wine phenolic compounds. None of the lignin promoted a perceptible color change; however, the yellowish color of KL and OL at 100 g/hL contributed to an increase in the yellow tones of wines. Lignin improved wine aroma by reducing the amount of unwanted volatiles by 30% and increasing the content of ethyl esters associated with fruity aromas by up to 60%. The results suggest that lignin, especially LS, can be employed as a modulating agent, positively impacting wine's physicochemical properties. This valorization of a byproduct opens up new opportunities for the wine industry.

Controlled preparation of tannic acid-derived carbonized dots and their use to inhibit amyloid aggregation and promote aggregate disaggregation.

Tannic acid (TA)-derived carbon dots (TACDs) were synthesized for the first time via a solvothermal method using TA as one of the raw materials, which may effectively inhibit amyloid fibril aggregation and disaggregate mature fibril. The fluorescent property of TACDs were modulated by adjusting the ratio of TA to o-phenylenediamine (oPD), and TACDs fabricated with the precursor ratio as 1:1 showed the best fluorescent property. Circular dichroism spectra (CD) showed that the structure of ß-sheet decreased as the concentration of TACDs increased. The inhibition efficiency, as confirmed by thioflavin T (ThT) and transmission electron microscopy (TEM), is extraordinary at 98.16%, whereas disaggregation efficiency is noteworthy at 97.97%, and the disaggregated lysozyme fibrils did not reaggregate after 7 days. More critically, TACDs can also alleviate the cellular toxicity caused by Aß fibrils and improve cell viability. This work offers a new perspective on the design of scavengers for amyloid plaques.

Tannic acid elicits differential gene regulation in prostate cancer apoptosis.

Prostate cancer is a significant global health concern that requires innovative therapeutic investigations. Here, the potential anticancer properties of tannic acid were evaluated by examining its effects on apoptosis in prostate cancer cell lines. PC-3 and LnCaP prostate adeno carcinoma cells, along with PNT1A prostate control cells, were cultured and divided into untreated and tannic acid-treated groups. Cell proliferation, cytotoxicity, and effects of tannic acid on the cell death mechanism were evaluated. mRNA expression levels of 84 genes were explored in cells following tannic acid treatment. Notably, tannic acid-induced down-regulation of several pro-survival genes, including ATM, BCL2, BCL2A1, BIK, BIRC2, BIRC3, BRE, CASP3, CASP6, CASP8, CHEK2, CRADD, PPIA, RPA3, TNFSF18, TRAF1, TRAF2, TRAF4, and TRAF5 in both cell lines. Moreover, tannic acid treatment led to the up-regulation of various pro-apoptotic genes, such as BCL10, BIRC3, BNIP3, CASP1, CASP5, CD40, CIDEB, DAPK2, FASLG, GADD45A, MYD88, RPA 3, TNFRSF10D, TNFRSF17, TNFRSF8, TNFSF13B, TNFSF4, TNFSF7, TNFSF8, TNFSF9, TP53, TRAF1, and TRAF2 in both PC-3 and LnCap cells. These findings highlight tannic acid's ability to induce apoptosis in prostate cancer cells through pro-apoptotic pathways. This study concludes that tannic acid selectively inhibits prostate cancer cell growth.

The role of TRPA1 and TRPV1 in the perception of astringency.

Astringency, commonly described as a drying, roughening, and/or puckering sensation associated with polyphenol-rich foods affects their palatability. While the compounds eliciting astringency are known, its mechanism of action is debated. This study investigated the role of transient receptor potential (TRP) channels A1 and V1 in astringency perception. If TRP A1 or V1 have a functional role in astringency perception, then desensitizing these receptors should decrease perceived astringency. Thirty-seven panelists underwent unilateral lingual desensitization of TRP A1 and V1 channels using mustard oil and capsaicin, respectively. Panelists then evaluated four astringent stimuli: epicatechin (EC), epigallocatechin gallate (EGCG), tannic acid (TA), and potassium alum (Alum), via 2-AFC and intensity ratings. When TRPA1 receptors were desensitized on one half of the tongue via mustard oil, no significant differences were observed between the treated and untreated sides for both 2-AFC and intensity ratings. Similarly, when TRPV1 receptors were desensitized on one half of the tongue via capsaicin, no significant differences were observed between the treated and untreated sides for both 2-AFC and intensity ratings. These findings challenge the notion that TRP channels play a pivotal role in astringency perception.

The influence mechanism of pH and polyphenol structures on the formation, structure, and digestibility of pea starch-polyphenol complexes via high-pressure homogenization.

The formation of starch-polyphenol complexes through high-pressure homogenization (HPH) is a promising method to reduce starch digestibility and control postprandial glycemic responses. This study investigated the combined effect of pH (5, 7, 9) and polyphenol structures (gallic acid, ferulic acid, quercetin, and tannic acid) on the formation, muti-scale structure, physicochemical properties, and digestibility of pea starch (PS)-polyphenol complexes prepared by HPH. Results revealed that reducing pH from 9 to 5 significantly strengthened the non-covalent binding between polyphenols and PS, achieving a maximum complex index of 13.89 %. This led to the formation of complexes with higher crystallinity and denser structures, promoting a robust network post-gelatinization with superior viscoelastic and thermal properties. These complexes showed increased resistance to enzymatic digestion, with the content of resistant starch increasing from 28.66 % to 42.00 %, rapidly digestible starch decreasing from 42.82 % to 21.88 %, and slowly digestible starch reducing from 71.34 % to 58.00 %. Gallic acid formed the strongest hydrogen bonds with PS, especially at pH 5, leading to the highest enzymatic resistance in PS-gallic acid complexes, with the content of resistant starch of 42.00 %, rapidly digestible starch of 23.35 % and slowly digestible starch of 58.00 %, and starch digestion rates at two digestive stages of 1.82 × 10-2 min-1 and 0.34 × 10-2 min-1. These insights advance our understanding of starch-polyphenol interactions and support the development of functional food products to improve metabolic health by mitigating rapid glucose release.

HPLC METHOD FOR THE QUANTIFICATION OF SOME ACTIVE FLAVONOIDS IN ETHYL ACETATE EXTRACT OF LEAVES OF BUTEA MONOSPERMA LINN.

AIM: The aim of the present investigation is to study HPLC process to evaluate Some Active Flavonoids in Ethyl Acetate Extract of Leaves of Butea monosperma Linn. MATERIAL AND METHODS: Using a soxhlation device, the leaves of Butea monosperma Linn. were extracted in stages. Each powdered batch (500g) was extracted in stages with polarity-graded solvents such as petroleum ether (Pet. Et) (60-80º), chloroform (CHCl3), ethyl acetate (EtOAc) using a soxhlet extractor. Alkaloids, flavonoids, glycosides, tannins, phenols, and steroids, among other chemical families of components, were identified through qualitative phytochemical screenings of each extract. To make a 10 g/ml stock, standard phenolic markers like quercetin, rutin, catechin, gallic acid, and chlorogenic acid were dissolved in methanol. Phytoconstituents were separated and identified from extracts using various solvents and combinations of solvents, which were chosen after consulting the literature. RESULTS AND DISCUSSION: Preliminary phytochemical screening showed the revealed that the leaves contain steroid, triterpenoids, fatty acid and alkaloids. While the ethyl acetate extract found to contain therapeutically important phytoconstitutes such as steroids, triterpenoids, saponins, flavonoids, and tannins. Bioactive extracts of Butea monosperma were found to include flavonoids and phenolic substances. In ethyl acetate extract, various flavonoids and phenolic compounds were discovered. CONCLUSION: This is a preliminary report on the identification of phytochemical and HPLC evaluation of ethyl acetate extract of leaves of Butea monosperma Linn. and to unravel the mechanisms driving bioactive qualities and the existence of putative synergy among these substances, more research is needed on the isolation and characterization of individual Flavonoids or phenolic compounds.

Modified Chitosan-Based Coating/Packaging Composites with Enhanced Antibacterial, Antioxidant, and UV-Resistant Properties for Fresh Food Preservation.

Chitosan-based biomass packaging materials are a promising material for food preservation, but their limited solubility, antioxidant capacity, UV resistance, and mechanical properties severely restrict their application. In this study, we developed a novel chitosan-based coating/packaging composite (QCTO) using quaternary ammonium salt and tannic acid (TA)-modified chitosan (QCS-TA) and oxidized chitosan (OCS). The introduction of quaternary ammonium salt and TA effectively improves the water solubility and antibacterial, antioxidant, and UV-resistant properties of chitosan. The Schiff-base bond formed between OCS and QCS-TA, along with the TA-mediated multiple interactions, conferred the prepared composite film with good mechanical properties (69.9 MPa tensile strength) and gas barrier performance to water (14.3 g·h-1·m-2) and oxygen (3.5 g·mm·m-2·h-1). Meanwhile, the prepared QCTO composites demonstrate excellent biocompatibility and safety and are applied as coatings for strawberries and bananas as well as packaging films for mushrooms. These preservation experiments demonstrated that the prepared composites are able to effectively reduce weight loss, prevent microbial growth, maintain color, and significantly prolong the shelf life of fresh products (bananas, strawberries, and mushrooms extended shelf life by 6, 5, and 6 days, respectively). Therefore, the developed QCTO coating/packaging film shows great potential for applications in the field of food preservation and packaging.

TME-Responsive Nanoplatform with Glutathione Depletion for Enhanced Tumor-Specific Mild Photothermal/Gene/Ferroptosis Synergistic Therapy.

Background: Triple negative breast cancer (TNBC) is one of the worst prognosis types of breast cancer that urgently needs effective therapy methods. However, cancer is a complicated disease that usually requires multiple treatment modalities. Methods: A tumor microenvironment (TME)-responsive PFC/TRIM37@Fe-TA@HA (abbreviated as PTFTH) nanoplatform was constructed by coating Fe3+ and tannic acid (TA) on the surface of TRIM37-siRNA loaded phase-transition perfluorocarbon (PFC) nanodroplets and further modifying them with hyaluronic acid (HA) to achieve tumor-specific mild photothermal/gene/ferroptosis synergistic therapy (MPTT/GT/ Ferroptosis) in vitro. Once internalized into tumor cells through CD44 receptor-mediated active targeting, the HA shell of PTFTH would be preliminarily disassembled by hyaluronidase (HAase) to expose the Fe-TA metal-phenolic networks (MPNs), which would further degrade in response to an acidic lysosomal environment, leading to HAase/pH dual-responsive release of Fe3+ and PFC/TRIM37. Results: PTFTH showed good biocompatibility in vitro. On the one hand, the released Fe3+ could deplete the overexpressed glutathione (GSH) through redox reactions and produce Fe2+, which in turn converts endogenous H2O2 into highly cytotoxic hydroxyl radicals (•OH) for chemodynamic therapy (CDT). On the other hand, the local hyperthermia generated by PTFTH under 808 nm laser irradiation could not only improve CDT efficacy through accelerating the Fe2+-mediated Fenton reaction, but also enhance TRIM37-siRNA delivery for gene therapy (GT). The consumption of GSH and accumulation of •OH synergistically augmented intracellular oxidative stress, resulting in substantial tumor cell ferroptosis. Moreover, PTFTH possessed outstanding contrast enhanced ultrasound (CEUS), photoacoustic imaging (PAI) and magnetic resonance imaging (MRI) ability. Conclusion: This PTFTH based multiple-mode therapeutic strategy has successfully achieved a synergistic anticancer effect in vitro and has the potential to be translated into clinical application for tumor therapy in future.

Fabrication and Application of Tannin Double Quaternary Ammonium Salt/Polyvinyl Alcohol as Efficient Sterilization and Preservation Material for Food Packaging.

Food packaging films play a vital role in preserving and protecting food. The focus has gradually shifted to safety and sustainability in the preparation of functional food packaging materials. In this study, a bisquaternary ammonium salt of tannic acid (BQTA) was synthesized, and the bioplastics based on BQTA and polyvinyl alcohol (PVA) were created for packaging applications. The impact of BQTA on antibacterial effect, antioxidant capacity, opacity, ultraviolet (UV) protective activity, mechanical strength, thermal stability, and anti-fog of the resultant bioplastics was examined. In vitro antibacterial experiments confirmed that BQTA possesses excellent antimicrobial properties, and only a trace amount addition of BQTA in PVA composite film could inhibit about 100% of Escherichia coli and Staphylococcus aureus. Compared to BQTA/PVA bioplastics with pure PVA, the experiment findings demonstrate that BQTA/PVA bioplastics show strong antioxidant and UV protection action and the performance of fruit preservation. It also revealed a small improvement in thermal stability and tensile strength. The small water contact angle, even at low BQTA concentrations, gave BQTA/PVA bioplastics good anti-fog performance. Based on the findings, bioplastics of BQTA/PVA have the potential to be used to create packaging, and they can be applied as the second (inner) layer of the primary packaging to protect food freshness and nutrition due to their antioxidant activity and biocompatibility.

Synergetic effect of Accentuated Cut Edges (ACE) and macerating enzymes on the phenolic composition of Marquette red wines.

One of the challenges of cold-hardy grape cultivars is their typical low content of tannins, alongside the presence of anthocyanin diglucoside and high acidity, which can lead to unbalanced red wines. This study hypothesized that the combination of Accentuated Cut Edges (ACE) and macerating enzymes would improve phenolics extraction from grape skins after disruption. The effects of those two winemaking techniques, either used separately or together, on red wine quality characteristics were investigated at crushing, bottling, and after six or nine months of aging. Overall, the combination of treatments improved the concentration of monomeric phenolics (20 %) and tannins (21 %) after nine months of aging. ACE or enzyme treatment separately applied had little impact on phenolics extraction in finished wines. This study exhibited a potential strategy to modify phenolics profile through the synergistic effect of ACE and macerating enzymes by causing cellular breakdown in a cold-hardy red grape cultivar.

A low-swelling alginate hydrogel with antibacterial hemostatic and radical scavenging properties for open wound healing.

Development of a low-cost and biocompatible hydrogel dressing with antimicrobial, antioxidant, and low swelling properties is important for accelerating wound healing. Here, a multifunctional alginate hydrogel dressing was fabricated using the D-(+)-gluconic acidδ-lactone/CaCO3system. The addition of hyaluronic acid and tannic acid (TA) provides the alginate hydrogel with anti-reactive oxygen species (ROS), hemostatic, and pro-wound healing properties. Notably, soaking the alginate hydrogel in a poly-ϵ-lysine (EPL) aqueous solution enables the alginate hydrogel to be di-crosslinked with EPL through electrostatic interactions, forming a dense network resembling 'armor' on the surface. This simple one-step soaking strategy provides the alginate hydrogel with antibacterial and anti-swelling properties. Swelling tests demonstrated that the cross-sectional area of the fully swollen multifunctional alginate hydrogel was only 1.3 times its initial size, thus preventing excessive wound expansion caused by excessive swelling. After 5 h ofin vitrorelease, only 7% of TA was cumulatively released, indicating a distinctly slow-release behavior. Furthermore, as evidenced by the removal of 2,2-diphenyl-1-picrylhydrazyl free radicals, this integrated alginate hydrogel systems demonstrate a notable capacity to eliminate ROS. Full-thickness skin wound repair experiment and histological analysis of the healing site in mice demonstrate that the developed multifunctional alginate hydrogels have a prominent effect on extracellular matrix formation and promotion of wound closure. Overall, this study introduces a cost-effective and convenient multifunctional hydrogel dressing with high potential for clinical application in treating open wounds.

Injectable Tannin-Containing Hydroxypropyl Chitin Hydrogel as Novel Bioactive Pulp Capping Material Accelerates Repair of Inflamed Dental Pulp.

Conventional pulp capping materials have limited anti-inflammatory capacity. It is necessary to develop more effective pulp capping material for the treatment of inflamed pulps. Tannic acid (TA) is a natural, water-soluble polyphenol with antimicrobial and anti-inflammatory properties. This study aimed to investigate the effects of a tannin-containing hydroxypropyl chitin hydrogel (HPCH/TA hydrogel) as an innovative pulp capping material. The physicochemical properties of the composite hydrogels were characterized. The effects of HPCH/TA hydrogel as a pulp capping material were evaluated in vitro and in vivo. The underlying mechanism of the anti-inflammatory effects of HPCH/TA hydrogel was explored. The HPCH/TA hydrogel demonstrated favorable temperature sensitivity, injectability, and antibacterial properties. In vitro, the HPCH/TA hydrogel effectively promoted the proliferation of human dental pulp cells and inhibited interleukin-1ß, interleukin-6, and tumor necrosis factor-α expression, possibly by suppressing the nuclear factor kappa-B pathway. In vivo, on the fourth day after capping, the HPCH/TA hydrogel group showed lower inflammatory scores compared to the control and iRoot BP Plus (commercial pulp capping material) group. By the sixth week, complete reparative dentin formation was observed in the HPCH/TA hydrogel group, with no difference in thickness compared to the iRoot BP Plus group. Collectively, the HPCH/TA hydrogel holds promise as a bioactive pulp capping material for promoting the repair of inflamed pulp in vital pulp therapy.

Chitosan-coated PLGA microemulsion loaded with tannic acid against Escherichia coli in vitro and in vivo.

The overuse of antibiotics has resulted in a surge of drug-resistant bacteria, making the pursuit of natural antimicrobials an urgent and significant trend. Encapsulation and nanoparticulation are effective ways to enhance the antibacterial properties of natural drugs. In this study, we encapsulated tannic acid (TA) with chitosan (CS) and poly (lactide-co-glycolide) (PLGA) using the emulsion-solvent evaporation method to enhance the antimicrobial effect of TA. We prepared a bilayer membrane spherical nanoemulsion of TA-PLGA-CS (TPC) with uniform size of 559.87 ± 1.16 nm, and zeta potential of 59.53 ± 1.07 mV. TPC could be stably stored for 90 days at 4°C without affecting the properties of the emulsion, and the minimum bactericidal concentration against four strains of Escherichia coli (E. coli) remained unchanged for 60 d. The results indicated that TPC enhanced the inhibitory effect of TA against E. coli. Scanning electron microscope images revealed that TPC treatment caused damage to the bacterial cell membrane. In addition, in vivo experiments indicated that TPC exhibited a superior therapeutic effect on artificial colibacillosis in chickens infested with Avian pathogenic Escherichia coli, as evidenced by the changes in body weight and a reduction bacterial load in heart. Furthermore, TPC reversed the down-regulation of catalase, glutathione peroxidase1 (GPX1), and GPX7 gene expression levels in intestinal tissues. Compared to the model group, TPC treatment elevated serum glutathione peroxidase activities and lowered myeloperoxidase and lactate dehydrogenase levels, offering antioxidant protection that was slightly better than that of doxycycline hydrochlorid group. In summary, we prepared a novel TA antimicrobial preparation with significant antioxidant potential and inhibitory effect against E. coli both in vitro and in vivo.

Interfacial Assembly of Free-Standing Polymer-Phenolic Films for Antibacterial and Antiultraviolet Applications.

We report a facile interfacial assembly strategy for the preparation of flexible polyphenol-based films for antibacterial and antiultraviolet applications. The free-standing films can be instantaneously formed via spraying tannic acid (TA) at the surface of carboxymethyl chitosan (CMCS) solutions. Compared with the traditional casting-evaporation procedure on solid substrates, the liquid interfacial assembly method for the construction of free-standing films is rapid and facile, which prevents the interface separation procedure from the substrates. The thickness and mechanical properties of the films are well controlled by changing the incubation time. The low-field nuclear magnetic resonance was used to analyze the water distributions inside the films and to distinguish the cross-linked structure of CMCS-TA films with different thicknesses, revealing the dynamics of the film formation process. Importantly, the films exhibit outstanding antibacterial and antiultraviolet properties, which are promising in the applications of wound dressings. This study provides a new avenue for the assembly of flexible free-standing films with multifunctionality via a facile and low-cost fabrication process.

Durable Flexible Conductive Fiber Based on Cross-Linking Network Tannic Acid/Polypyrrole for Wearable Thermotherapy Monitoring System.

Intelligent wearable textiles have garnered attention and advancement, particularly in the realms of thermotherapy and health monitoring. As a critical component of intelligent wearable textiles, conductive fibers are expected to have long-term stable and durable conductivity. In this work, a highly stretchable and conductive fiber based on tannic acid/polypyrrole was developed. The conductive network was formed by doping TA into PPy, resulting in enhanced stretchability of PPy on the surface of PU. TA also improves the interface interaction between PPy and PU to gain more firm attachment of PPy, which achieves high conductivity (0.89 ± 0.23 S/cm) and durability. Furthermore, the stretchable conductive fiber also exhibited intelligent responses to electricity, light, and deformation. They can serve as heat sources under the action of electricity and light (temperature was raised to 42 °C under 4 V and 54 °C under solar radiation stimuli) and can also monitor the movements of humans, making them potential applications in thermotherapy textiles and intelligent sensing equipment. A PU/TA/PPy-based all-in-one smart wearable system was fabricated using textile molding technology capable of all-weather thermal therapy and motion detection. This fiber fabrication technology and integrated system offer insights for the future development of smart wearable devices.

A sequential dual-locked luminescent copper nanocluster probe for tumor cell imaging and killing.

A sequential dual-locked luminescent copper nanoclusters (CuNCs) probe was designed and synthesized for the specific imaging and selective killing of tumor cells. This nanoprobe was prepared by first forming a Fe3+-coupled tannic acid (TA)-stabilized CuNCs (CuNCs-FeIII), which is in quenching state due to the electron transfer between CuNCs and Fe3+, and then coating a protectable layer of hyaluronic acid (HA) on the surface of CuNCs-FeIII to form the final dual-locked nanoprobe (CuNCs-FeIII@HA). When the nanoprobe of CuNCs-FeIII@HA target enter the tumor cells through CD44-HA receptor, HAase will first digest the HA layer of the nanoprobes, and then, GSH over-expressed in tumor cells will reduce Fe3+ to Fe2+, thus restoring the fluorescence emission of CuNCs and at the same time killing the tumor cells with the hydroxyl free radicals (∙OH) produced by the Fenton reaction between Fe2+ and H2O2. This sequential dual-locked luminescent nanoprobe of CuNCs-FeIII@HA has been successfully used for the specific imaging and selective killing of tumor cells.