pH/GSH dual-responsive nanoparticle for auto-amplified tumor therapy of breast cancer.

Breast cancer remains a malignancy that poses a serious threat to human health worldwide. Chemotherapy is one of the most widely effective cancer treatments in clinical practice, but it has some drawbacks such as poor targeting, high toxicity, numerous side effects, and susceptibility to drug resistance. For auto-amplified tumor therapy, a nanoparticle designated GDTF is prepared by wrapping gambogic acid (GA)-loaded dendritic porous silica nanoparticles (DPSNs) with a tannic acid (TA)-Fe(III) coating layer. GDTF possesses the properties of near-infrared (NIR)-enhanced and pH/glutathione (GSH) dual-responsive drug release, photothermal conversion, GSH depletion and hydroxyl radical (·OH) production. When GDTF is exposed to NIR laser irradiation, it can effectively inhibit cell proliferation and tumor growth both in vitro and in vivo with limited toxicity. This may be due to the synergistic effect of enhanced tumor accumulation, and elevated reactive oxygen species (ROS) production, GSH depletion, and TrxR activity reduction. This study highlights the enormous potential of auto-amplified tumor therapy.

Starch-based biodegradable films amended with nano-starch and tannic acid-coated nano-starch exhibit enhanced mechanical and functional attributes with antimicrobial activity.

Starch-based biofilms are biodegradable, but their application is limited by lower mechanical strength and absence of antimicrobial properties. In this context, the present study attempted to unleash the potential of nanotechnology for synthesizing nano-starch (NS) and tannic acid-coated nano-starch (T-NS) for augmenting the tensile strength and antimicrobial properties of starch-based biofilms. Moreover, this study reports one of the first such attempts to improve the commercial viability of starch extracted from the corms of Amorphophallus paeoniifolius. In this study, NS and T-NS samples were first synthesized by the physical and chemical modification of the native starch (S) molecules. The NS and T-NS samples showed significantly smaller granule size, lower moisture content, and swelling power. Further, amendments with NS and T-NS samples (25 % and 50 %) to the native starch molecules were performed to obtain biofilm samples. The NSB (NS amended) and T-NSB (T-NS amended) biofilms showed comparatively higher tensile strength than SB films (100 % starch-based). The T-NSB showed greater antimicrobial activity against gram-positive and gram-negative bacteria. All the biofilms showed almost complete biodegradation in soil (in 10 days). Therefore, it can be concluded that additives like NS and T-NS can improve starch-based biofilms' mechanical strength and antimicrobial properties with considerable biodegradability.

Selective Binding of Tannic Acid-Conjugated Lipid Nanovesicles to Proline-Rich Proteins Enhances Transdermal Lipophilic-Antioxidant Delivery.

Tannic acid (TA) possesses a notable ability to adhere to proline-rich proteins that make up skin cells and the extracellular matrix (ECM) in the skin tissue. Drug carriers with this specific adhesion ability exhibit improved drug delivery efficiency on the skin. Taking advantage of this, this study presents skin-adhesive TA-conjugated lipid nanovesicles (TANVs) for enhanced transdermal antioxidant delivery. We found that TANVs exhibited selective intermolecular interactions with keratinocyte proline-rich proteins (KPRPs) and collagen that makes up skin cells by hydrogen bonding and van der Waals interactions, further enabling the strong bonding to macroscopic skin itself and ECM. We used vitamin E (α-tocopherol), which is known to effectively reduce oxidative stress but has limited skin penetration, as a drug to verify improved in vitro delivery and therapeutic efficacy. The evaluation revealed that the antioxidant-loaded TANVs exerted excellent scavenging effects against reactive oxygen species induced by ultraviolet light or peroxides in the skin, thereby enabling the development of an active drug delivery system for dermal therapy.

A simple and effective method for smartphone-based detection of polyamines in oral cancer.

Oral cancer accounts for 50%-70% of all cancer-related deaths in India and ranks sixth among the most frequent cancers globally. Roughly 90% of oral malignancies are histologically arise from squamous cells and are therefore called oral squamous cell carcinoma. Organic polycations known as biogenic polyamines, for example, putrescine (Put), spermidine (Spd), and spermine (Spm), are vital for cell proliferation, including gene expression control, regulation of endonuclease-mediated fragmentation of DNA, and DNA damage inhibition. Higher Spm and Spd levels have been identified as cancer biomarkers for detecting tumour development in various cancers. The current study utilises tannic acid, a polyphenolic compound, as a reducing and capping agent to fabricate AuNPs via a one-step microwave-assisted synthesis. The fabricated TA@AuNPs were utilised as a nanoprobe for colourimetric sensing of polyamines in PBS. When TA@AuNPs are added to the polyamine, the amine groups in polyamines interact with the phenolic groups of TA@AuNPs via hydrogen bonding or electrostatic interactions. These interactions cause the aggregation of TA@AuNPs, resulting in a red shift of the Surface Plasmon Resonance band of TA@AuNPs from 530 nm to 560 nm. The nanoprobe was found to be highly specific for Spm at low concentrations. TA@AuNPs were able to detect Spm successfully in artificial saliva samples. On recording the RGB values of the sensing process using a smartphone app, it was found that as the nanoparticles aggregated due to the presence of Spm, the intensity of theR-value decreased, indicating the aggregation of TA@AuNPs due to interaction with the polyamine.

Enhancing diabetic wound healing with a pH/glucose dual-responsive hydrogel for ROS clearance and antibacterial activity.

Currently, the treatment of diabetic wounds in clinical practice is still unsatisfactory due to the risks of oxidative damage and bacterial infection during the healing process. An optimal wound dressing should exhibit robust capabilities in scavenging reactive oxygen species (ROS) and combatting bacterial growth. In this study, we utilized borax as a crosslinker and prepared a pH/glucose dual-responsive composite hydrogel based on poly(vinyl alcohol) (PVA), sodium alginate (SA), and tannic acid (TA). This hydrogel, loaded with cerium dioxide, serves as an effective ROS scavenger, promoting wound closure by reducing the level of ROS in the wound area. Additionally, the hydrogel can release the antibacterial drug ofloxacin in response to the low pH and high glucose microenvironment in infected wounds. Results from skin defect model in diabetic mice demonstrated this ROS-scavenging and antibacterial hydrogel can suppress inflammation and accelerate wound healing. In summary, our work provides a new perspective on a local and stimulus-responsive drug delivery strategy for treating diabetic wounds.

Changes in the Physicochemical and Bioactive Properties of Yerba Mate Depending on the Brewing Conditions.

Yerba Mate drink made from dried and crushed leaves and twigs of Paraguayan holly (Ilex paraguariensis A. St.-Hil.), which is a valuable source of bioactive substances, in particular antioxidants. The available literature lacks data on changes in the content and profile of bioactive compounds such as tannins, caffeine, the phenolic acid profile of flavonoids and carotenoids, as well as total polyphenol content and antioxidant activity in Yerba Mate infusions depending on different brewing conditions, and how different brewing conditions affect the physicochemical properties of these infusions. Therefore, this study evaluated the physicochemical properties of dried and Yerba Mate infusions prepared via single and double brewing processes at 70 °C and 100 °C. The organoleptic evaluation, as well as the instrumental color measurement, showed significant changes in the total color difference (ΔE) and the L*a*b* chromatic coordinates of dried Yerba Mate samples and their infusions. Moreover, the research showed higher contents of tannins (mean 1.36 ± 0.14 g/100 g d.m.), caffeine (mean 17.79 ± 3.49 mg/g d.m.), carotenoids (mean 12.90 ± 0.44 µg/g d.m.), phenolic acids (mean 69.97 ± 7.10 mg/g d.m.), flavonoids (mean 5.47 ± 1.78 mg/g d.m.), total polyphenols (mean 55.26 ± 8.51 mg GAE/g d.m.), and antioxidant activity (mean 2031.98 ± 146.47 µM TEAC/g d.m.) in single-brewed Yerba Mate infusions compared to double-brewed (0.77 ± 0.12 g/100 g d.m., 14.28 ± 5.80 mg/g d.m., 12.67 ± 0.62 µg/g d.m., 57.75 ± 8.73 mg/g d.m., 3.64 ± 0.76 mg/g d.m., 33.44 ± 6.48 mg GAE/g d.m. and 1683.09 ± 155.34 µM TEAC/g d.m., respectively). In addition, infusions prepared at a lower temperature (70 °C) were characterized by a higher content of total polyphenols and higher antioxidant activity, in contrast to the tannin and carotenoid contents, the levels of which were higher at 100 °C than at 70 °C. Considering the high amount of bioactive ingredients, in particular antioxidants, and a wide range of health benefits, it is worth including Yerba Mate in the daily diet.

A Comprehensive Analysis of Diversity, Structure, Biosynthesis and Extraction of Biologically Active Tannins from Various Plant-Based Materials Using Deep Eutectic Solvents.

This paper explores the emerging subject of extracting tannins from various plant sources using deep eutectic solvents (DESs). Tannins are widely used in the food and feed industries as they have outstanding antioxidant qualities and greatly enhance the flavor and nutritional content of a wide range of food products. Organic solvents are frequently used in traditional extraction techniques, which raises questions about their safety for human health and the environment. DESs present a prospective substitute because of their low toxicity, adaptability, and environmental friendliness. The fundamental ideas supporting the application of DESs in the extraction of tannins from a range of plant-based materials frequently used in daily life are all well covered in this paper. Furthermore, this paper covers the impact of extraction parameters on the yield of extracted tannins, as well as possible obstacles and directions for future research in this emerging subject. This includes challenges such as high viscosity, intricated recovery of compounds, thermal degradation, and the occurrence of esterification. An extensive summary of the diversity, structure, biosynthesis, distribution, and roles of tannins in plants is given in this paper. Additionally, this paper thoroughly examines various bioactivities of tannins and their metabolites.

Layer-By-Layer Designed Spark-Type AuCuPt Alloy with Robust Broadband Absorption to Enhance Sensitivity in Flexible Detection of Estriol by a Lateral Flow Immunoassay.

Excessive intake of estrogen poses significant health risks to the human body; hence, there is a necessity to develop rapid detection methods to monitor its levels of addition. Gold nanoparticles (AuNPs), commonly utilized as colorimetric signal labels, find extensive application in lateral flow immunoassay (LFIA). However, the detection sensitivity of traditional AuNPs-LFIA is typically constrained by low molar extinction coefficients and reliance on a single signal. Herein, in this work, unique spark-type AuCuPt nanoflowers modified with tannic acid (AuCuPt@TA) were precisely designed by reasonable layer-by-layer element composition and green modification. The obtained AuCuPt displays robust broadband absorption spanning the visible to near-infrared spectrum, showcasing a notable molar extinction coefficient of 2.38 × 1012 M-1 cm-1 and a photothermal conversion efficiency of 48.5%. Based on this, selecting estriol (E3) as a model analyte, colorimetric/photothermal dual-signal LFIA (CLFIA and PLFIA) was developed. Limits of detection (LOD) of the CLFIA and PLFIA were achieved at 0.033 ng mL-1 and 0.021 ng mL-1, respectively, which represent a 9.3- and 14.6-fold improvement compared to the visual LOD of AuNPs-LFIA. Moreover, the application feasibility of the immunoassay was further evaluated in the milk and pork with satisfactory recoveries ranging from 86.21% to 117.91%. Thus, this work has enhanced the performance of LFIA for E3 detection and exhibited enormous potential for other sensing platform construction.

Dual drug-loaded metal-phenolic networks for targeted magnetic resonance imaging and synergistic chemo-chemodynamic therapy of breast cancer.

The development of nanomedicines with simplified compositions and synergistic theranostic functionalities remains a great challenge. Herein, we develop a simple method to integrate both atovaquone (ATO, a mitochondrial inhibitor) and cisplatin within tannic acid (TA)-iron (Fe) networks coated with hyaluronic acid (HA) for targeted magnetic resonance (MR) imaging-guided chemo-chemodynamic synergistic therapy. The formed TFP@ATO-HA displayed good colloidal stability with a mean size of 95.5 nm, which could accumulate at tumor sites after circulation and be specifically taken up by metastatic 4T1 cells overexpressing CD44 receptors. In the tumor microenvironment, TFP@ATO-HA could release ATO/cisplatin and Fe3+ in a pH-responsive manner, deplete glutathione, and generate reactive oxygen species with endogenous H2O2 for chemodynamic therapy (CDT). Additionally, ATO could enhance chemotherapeutic efficacy by inhibiting mitochondrial respiration, relieving hypoxia, and amplifying the CDT effect by decreasing intracellular pH and elevating Fenton reaction efficiency. In vivo experiments demonstrated that TFP@ATO-HA could effectively inhibit tumor growth and suppress lung metastases without obvious systemic toxicity. Furthermore, TFP@ATO-HA exhibited a r1 relaxivity of 2.6 mM-1 s-1 and targeted MR imaging of 4T1 tumors. Dual drug-loaded metal-phenolic networks can be easily prepared and act as effective theranostic nanoplatforms for targeted MR imaging and synergistic chemo-chemodynamic therapy.

Tannic acid modified keratin/sodium alginate/carboxymethyl chitosan biocomposite hydrogels with good mechanical properties and swelling behavior.

Natural polymer-based hydrogels have demonstrated great potential as wound-healing dressings. They help to maintain a moist wound environment as well as promote faster healing. In this work, a multifunctional hydrogel was prepared using keratin, sodium alginate, and carboxymethyl chitosan with tannic acid modification. Micro-morphology of hydrogels has been performed by scanning electron microscopy. Fourier Transform Infrared Spectroscopy reveals the presence of hydrogen bonding. The mechanical properties of the hydrogels were examined using a universal testing machine. Furthermore, we investigated several properties of the modified hydrogel. These properties include swelling rate, water retention, anti-freezing properties, antimicrobial and antioxidant properties, hemocompatibility evaluation and cell viability test in vitro. The modified hydrogel has a three-dimensional microporous structure, the swelling rate was 1541.7%, the elastic modulus was 589.74 kPa, the toughness was 211.74 kJ/m3, and the elongation at break was 75.39%, which was similar to the human skin modulus. The modified hydrogel also showed inhibition of S. aureus and E. coli, as well as a DPPH scavenging rate of 95%. In addition, the modified hydrogels have good biological characteristics. Based on these findings, the K/SA/CCS hydrogel holds promise for applications in biomedical engineering.

Pectin forms polymeric pigments by complexing anthocyanins during red winemaking and ageing.

The long-term stability of red wine color depends on the formation of polymeric pigments from anthocyanins. Although there is still a lot of uncertainty about the specific structure of this diverse group of pigments, there is consensus that they are reaction products of anthocyanins and other polyphenols. Interactions between anthocyanins and pectic polysaccharides have been suggested to stabilize anthocyanins. This study explores the impact of such interactions by adding pectin during red winemaking. The results demonstrate that these interactions induce the formation of additional polymeric pigments which enhance the pigment stability during fermentation and aging. While initial pigment formation is higher in wines with added pectin, a notable proportion of the complexes degrades in the later stages of fermentation. Presumably, tannins form insoluble complexes with pectin, reducing tannin concentration by more than 300 mg/L. Anthocyanin concentrations decrease by over 400 mg/L, and polymeric pigments double. Anthocyanins that form polymeric pigments with pectic polysaccharides expand the range of pigments in red wines with possible consequences for the sensory properties of the wine. These findings highlight the complex interactions between pectin, anthocyanins, and tannins, and their influence on pigment formation and wine composition during fermentation and aging.

Borate bonds-containing pH-responsive chitosan hydrogel for postoperative tumor recurrence and wound infection prevention.

Chitosan has been widely used in biomedical fields due to its good antibacterial properties, excellent biocompatibility, and biodegradability. In this study, a pH-responsive and self-healing hydrogel was synthesized from 3-carboxyphenylboronic acid grafted with chitosan (CS-BA) and polyvinyl alcohol (PVA). The dynamic boronic ester bonds and intermolecular hydrogen bonds are responsible for the hydrogel formation. By changing the mass ratio of CS-BA and PVA, the tensile stress and compressive stress of hydrogel can controlled in the range of 0.61 kPa - 0.74 kPa and 295.28 kPa - 1108.1 kPa, respectively. After doping with tannic acid (TA)/iron nanocomplex (TAFe), the hydrogel successful killed tumor cells through the near infrared laser-induced photothermal conversion and the TAFe-triggered reactive oxygen species generation. Moreover, the photothermal conversion of the hydrogel and the antibacterial effect of CS and TA give the hydrogel a good antibacterial effect. The CS-BA/PVA/TAFe hydrogel exhibit good in vivo and in vitro anti-tumor recurrence and antibacterial ability, and therefore has the potential to be used as a powerful tool for the prevention of local tumor recurrence and bacterial infection after surgery.

Deciphering inhibitory activity of marine algae Ecklonia cava phlorotannins against SARS CoV-2 main protease: A coupled in-silico docking and molecular dynamics simulation study.

The onset of COVID-19 due to the SARS CoV-2 virus has spurred an urgent need for potent therapeutics and vaccines to combat this global pandemic. The main protease (Mpro) of the virus, crucial in its replication, has become a focal point in developing anti-COVID-19 drugs. The cysteine protease Mpro in SARS CoV-2 bears a significant resemblance to the same protease found in SARS CoV-1. Previous research highlighted phlorotannins derived from Ecklonia cava, an edible marine algae, as inhibitors of SARS CoV-1 Mpro activity. However, it remains unclear whether these marine-derived phlorotannins also exert a similar inhibitory effect on SARS CoV-2 Mpro. To unravel this, our study utilized diverse in-silico methodologies. We explored the pharmacological potential of various phlorotannins (phloroglucinol, triphloretol-A, eckol, 2-phloroeckol, 7-phloroeckol, fucodiphloroethol G, dieckol, and phlorofucofuroeckol-A) and assessed their binding efficacies alongside established Mpro inhibitors (N3 and lopinavir) through molecular docking studies. Among these compounds, five phlorotannins (eckol, 2-phloroeckol, 7-phloroeckol, dieckol, and phlorofucofuroeckol-A) exhibited potent binding affinities comparable to or surpassing N3 and lopinavir, interacting especially with the catalytic residues His41 and Cys145 of Mpro. Moreover, molecular dynamics simulations revealed that these five Mpro-phlorotannin complexes displayed enhanced stability and maintained comparable or slightly reduced compactness. They exhibited reduced conformational changes and increased expansion relative to the Mpro-N3 and/or Mpro-lopinavir complex. Our MM-GBSA analysis further supported these findings. Overall, our investigation highlights the potential of these five phlorotannins in inhibiting the proteolytic function of SARS CoV-2 Mpro, offering promise for anti-COVID-19 drug development.

Antibacterial, antioxidant, Cr(VI) adsorption and dye adsorption effects of biochar-based silver nanoparticles­sodium alginate-tannic acid composite gel beads.

Ultrasonic extraction of Osmanthus fragrans was used for reducing Ag+ to prepare AgNPs, which were further loaded on barley distiller's grains shell biochar. By supplementary of sodium alginate and tannic acid, composite gel beads were prepared. The physical properties of biochar-based AgNPs­sodium alginate-tannic acid composite gel beads (C-Ag/SA/TA) were characterized. SEM, FTIR, and XRD showed that biochar-based AgNPs were compatible with sodium alginate-tannic acid. CAg greatly improved the dissolution, swelling, and expansion of gel beads. Through the analysis by the agar diffusion method, C-Ag/SA/TA gel beads had high antibacterial activity (inhibition zone: 22 mm against Escherichia coli and 20 mm against Staphylococcus aureus). It was observed that C-Ag/SA/TA composite gel beads had high antioxidant capacity and the free radical scavenging rate reached 89.0 %. The dye adsorption performance of gel beads was studied by establishing a kinetic model. The maximum adsorption capacities of C-Ag/SA/TA gel beads for methylene blue and Congo red were 166.57 and 318.06 mg/g, respectively. The removal rate of Cr(VI) reached 96.4 %. These results indicated that the prepared composite gel beads had a high adsorption capacity for dyes and metal ions. Overall, C-Ag/SA/TA composite gel beads were biocompatible and had potential applications in environmental pollution treatment.

Tannic acid and quaternized chitosan mediated puerarin-loaded octacalcium phosphate /sodium alginate scaffold for bone tissue engineering.

Current limitations in mechanical performance and foreign body reactions (FBR) often lead to implant failure, restricting the application of bioceramic scaffolds. This study presents a novel 3D-printed scaffold that combines the release of anti-inflammatory drugs with osteogenic stimulation. Initially, the inorganic and organic phases were integrated to ensure the scaffold's mechanical integrity through catechol chemistry and the electrostatic interactions between tannic acid and quaternary ammonium chitosan. Subsequently, layers of polydopamine-encapsulated puerarin-loaded zeolitic imidazolate framework-8 (ZIF-8) were self-assembled onto the stent's surface, creating the drug-loaded scaffold that improved drug release without altering the scaffold's structure. Compared with unloaded scaffolds, the puerarin-loaded scaffold demonstrated excellent osteogenic differentiation properties along with superior anti-inflammatory and osteogenic effects in a range of in vitro and in vivo studies. RNA sequencing clarified the role of the TNF and NF/κB signaling pathways in these effects, further supporting the scaffold's osteogenic potential. This study introduces a novel approach for creating drug-loaded scaffolds, providing a unique method for treating cancellous bone defects.

Simultaneous usage of sulforaphane nanoemulsion and tannic acid in ternary chitosan/gelatin/PEG hydrogel for knee cartilage tissue engineering: In vitro and in vivo study.

The therapeutic potential of tissue engineering in addressing articular cartilage defects has been a focal point of research for numerous years. Despite its promising outlook, a persistent challenge within this domain is the lack of sufficient functional integration between engineered and natural tissues. This study introduces a novel approach that employs a combination of sulforaphane (SFN) nanoemulsion and tannic acid to enhance cartilage tissue engineering and promote tissue integration in a rat knee cartilage defect model. To substantiate our hypothesis, we conducted a series of in vitro and in vivo experiments. The SFN nanoemulsion was characterized using DLS, zeta potential, and TEM analyses. Subsequently, it was incorporated into a ternary polymer hydrogel composed of chitosan, gelatin, and polyethylene glycol. We evaluated the hydrogel with (H-SFN) and without (H) the SFN nanoemulsion through a comprehensive set of physicochemical, mechanical, and biological analyses. For the in vivo study, nine male Wistar rats were divided into three groups: no implant (Ctrl), H, and H-SFN. After inducing a cartilage defect, the affected area was treated with tannic acid and subsequently implanted with the hydrogels. Four weeks post-implantation, the harvested cartilage underwent histological examination employing H&E, safranin O/fast green, alcian blue, and immunohistochemistry staining techniques. Our results revealed that the SFN nanodroplets had an average diameter of 75 nm and a surface charge of -11.58 mV. Moreover, degradation, swelling rates, hydrophilicity, and elasticity features of the hydrogel incorporating SFN were improved. Histopathological analysis indicated a higher production of GAGs and collagen in the H-SFN group. Furthermore, the H-SFN group exhibited superior cartilage regeneration and tissue integration compared to the Ctrl and H groups. In conclusion, the findings of this study suggest the importance of considering cell protective properties in the fabrication of scaffolds for knee cartilage defects, emphasizing the potential significance of the proposed SFN nanoemulsion and tannic acid approach in advancing the field of cartilage tissue engineering.

Multifunctional chitosan-cross linked- curcumin-tannic acid biocomposites disrupt quorum sensing and biofilm formation in pathogenic bacteria.

Natural products have a long history of success in treating bacterial infections, making them a promising source for novel antibacterial medications. Curcumin, an essential component of turmeric, has shown potential in treating bacterial infections and in this study, we covalently immobilized curcumin (Cur) onto chitosan (CS) using glutaraldehyde and tannic acid (TA), resulting in the fabrication of novel biocomposites with varying CS/Cur/TA ratios. Comprehensive characterization of these ternary biocomposites was conducted using FTIR, SEM, XPS, and XRD to assess their morphology, functional groups, and chemical structures. The inhibitory efficacy of these novel biocomposites (n = 4) against the growth and viability of Pseudomonas aeruginosa (ATCC27853) and Chromobacterium violaceum (ATCC12472) was evaluated and the most promising composite (C3) was investigated for its impact on quorum sensing (QS) and biofilm formation in these bacteria. Remarkably, this biocomposite significantly disrupted QS circuits and effectively curtailed biofilm formation in the tested pathogens without inducing appreciable toxicity. These findings underscore its potential for future in vivo studies, positioning it as a promising candidate for the development of biofilm disrupting antibacterial agents.

Combining QCM-D with live-cell imaging reveals the impact of serum proteins on the dynamics of fibroblast adhesion on tannic acid-functionalised surfaces.

Nanocoatings based on plant polyphenols have been recently suggested as a potent strategy for modification of implant surfaces for enhancing host cell attachment and reducing bacterial colonisation. In this study we aimed to investigate how serum proteins impact the early adhesion dynamics of human gingival fibroblasts onto titanium surfaces coated with tannic acid (TA). Silicate-TA nanocoatings were formed on titanium and pre-conditioned in medium supplemented with 0, 0.1, 1 or 10% FBS for 1 hour. Dynamics of fibroblasts adhesion was studied using quartz crystal microbalance with dissipation (QCM-D). Time-lapse imaging was employed to assess cell area and motility, while immunofluorescence microscopy was used to examine cell morphology and focal adhesion formation. Our results showed that in serum-free medium, fibroblasts demonstrated enhanced and faster adhesion to TA coatings compared to uncoated titanium. Increasing the serum concentration reduced cell adhesion to nanocoatings, resulting in nearly complete inhibition at 10% FBS. This inhibition was not observed for uncoated titanium at 10% FBS, although cell adhesion was delayed and progressed slower compared to serum-free conditions. In addition, 1% FBS dramatically reduced cell adhesion on uncoated titanium. We revealed a positive relationship between changes in dissipation and changes in cell spreading area, and a negative relationship between dissipation and cell motility. In conclusion, our study demonstrated that serum decreases fibroblasts interaction with surfaces coated with TA in a concentration dependent manner. This suggests that controlling serum concentration can be used to regulate or potentially prevent fibroblasts adhesion onto TA-coated titanium surfaces.

Polyphenolic Nanoparticle-Modified Probiotics for Microenvironment Remodeling and Targeted Therapy of Inflammatory Bowel Disease.

Inflammatory bowel diseases (IBDs) refer to multifaceted disorders in the intestinal microenvironment and microbiota homeostasis. In view of the broad bioactivity and high compatibility of polyphenols, there is considerable interest in developing a polyphenol-based collaborative platform to remodel the IBD microenvironment and regulate microbiota. Here, we demonstrated the coordination assembly of nanostructured polyphenols to modify probiotics and simultaneously deliver drugs for IBD treatment. Inspired by the distinctive structure of tannic acid (TA), we fabricated nanostructured pBDT-TA by using a self-polymerizable aromatic dithiol (BDT) and TA, which exhibited excellent antioxidant and anti-inflammatory capability in vitro. We thus coated pBDT-TA and sodium alginate (SA) to the surface of Escherichia coli Nissle 1917 layer by layer to construct the collaborative platform EcN@SA-pBDT-TA. The modified probiotics showed improved resistance to oxidative and inflammatory stress, which resulted in superior colon accumulation and retention in IBD model mice. Further, EcN@SA-pBDT-TA could alleviate dextran sulfate sodium (DSS)-induced colitis by controlling the inflammatory response, repairing intestinal barriers, and modulating gut microbiota. Importantly, EcN@SA-pBDT-TA-mediated IBD drug delivery could achieve an improved therapeutic effect in DSS model mice. Given the availability and functionality of polyphenol and prebiotics, we expected that nanostructured polyphenol-modified probiotics provided a solution to develop a collaborative platform for IBD treatment.

Prussian blue nanocubes with peroxidase-like activity for polyphenol detection in commercial beverages.

The present study describes an efficient method for the determination of polyphenol content in beverages based on a composite material of graphene oxide decorated with Prussian blue nanocubes (rGO/PBNCs). In this method, rGO/PBNCs act as a nanoenzyme with peroxidase-like catalytic activity and produce a colorimetric product in the presence of hydrogen peroxide and tetramethylbenzidine (TMB). To verify the effectiveness of the method, we used two model standards for antioxidants: gallic acid (GA) and tannic acid (TA). The method validation included a comparison of the performance of a natural enzyme and an artificial one (rGO/PBNCs) and two polyphenols in the analysis of commercial beverage samples. After optimization, a pH of 4, ambient temperature (22 °C), a reaction time of 2 minutes and an rGO/PBNCs concentration of 0.01 µg mL-1 were found to be the most favorable conditions. The detection limits obtained were 5.6 µmol L-1 for GA and 1.5 µmol L-1 for TA. Overall, rGO/PBNCs offer advantages over natural enzymes in terms of stability, versatility, scalability and durability, making them attractive candidates for a wide range of catalytic and sensory applications.