Hyaluronic acid/tannic acid hydrogel sunscreen with excellent anti-UV, antioxidant, and cooling effects

Recent Advances of Sustainable UV Shielding Materials: Mechanisms and Applications

The escalating global threat of ultraviolet (UV) radiation is manifested through multifaceted damage pathways including cutaneous carcinogenesis, photodegradation of organic substrates, marine ecosystem destabilization, and infrastructure weathering. These urgent challenges have catalyzed sustained interdisciplinary efforts toward advanced UV-shielding technologies spanning biomedical, environmental, and industrial domains. Current material arsenals include melanin, lignin, tannin, polydopamine, zinc oxide and titanium dioxide, etc. These materials can be applied to diverse fields such as food packaging, sunscreen fabrics, sunscreen creams, eyeglasses, and sunscreen films through tailored processing techniques and employing distinct photoprotective mechanisms. Notwithstanding significant progress, the development of an integrated selection framework that reconciles efficiency, durability, and environmental compatibility persists as a critical knowledge gap. In this context, the main mechanisms of various types of UV shielding materials and their applications in different fields are described systematically. Subsequently, a comparative analysis of the advantages and shortcomings of different materials is presented, focusing on their UV shielding efficiency and stability impact. Moreover, the review delves into their unique value in specific scenarios. Finally, building on these analyses, current challenges and future development prospects of UV shielding materials are further discussed, with emphasis on scalability, eco-friendly alternatives, and multifunctional integration, providing valuable insights and guidance for advancing research and promoting sustainable and functional innovations in this field.

Hyaluronic acid-grafted titanium dioxide nanoparticles for moisture-retentive and non-cytotoxic sunscreen creams

The escalating UV exposure has emerged as a significant threat to human health, manifesting in both acute and chronic health impairments. To mitigate these risks, a biosafety sunscreen cream was prepared for UV protection and moisturization. TiO2 nanoparticles (NPs) were sequentially coated with Al(OH)3 and chemically grafted with hyaluronic acid (HA) to produce TiO2-g-HA NPs. The optimized TiO2-g-HA0.1 NPs achieved a grafting efficiency of 6.2 %, enhancing its sun protection factor (SPF) from 13.3 ± 1.4 (TiO2 NPs) to 19.1 ± 0.7. In the contrast, the TiO2-g-HA0.1 NPs exhibited a low photocatalytic activity to avoid the generation of hydroxyl radicals in a sunscreen formation. The TiO2-g-HA NPs under a state of aqueous slurries were then incorporated into a commercial sunscreen formulation. The TiO2-g-HA0.1 Cream demonstrated exceptional stability, retaining >95 % of its initial SPF (24.5 ± 0.3) after 10 heating-cooling cycles, with no phase separation observed. In addition, the TiO2-g-HA0.1 Cream sustained an enhanced moisturization performance (>80.0 % hydration retention under thermal and convective stress). Biocompatibility assessments on HaCaT keratinocytes revealed minimal cytotoxicity, with 88.5 ± 0.9 % cell viability for the TiO2-g-HA0.1 Cream. Moreover, in vitro penetration profiles were possessed with the BALB/c mouse skin, confirming most nanoparticles retained on the epidermal surface for the TiO2-g-HA0.1 Cream.

Recent advances in tannic acid-based gels: Design, properties, and applications

With the flourishing of mussel-inspired chemistry, the fast-growing development for environmentally friendly materials, and the need for inexpensive and biocompatible analogues to PDA in gel design, TA has led to its gradual emergence as a research focus due to its remarkable biocompatible, renewable, sustainable and particular physicochemical properties. As a natural building block, TA can be used as a substrate or crosslinker, ensuring versatile functional polymeric networks for various applications. In this review, the design of TA-based gels is summarized in detail (i.e., different interactions such as: metal coordination, electrostatic, hydrophobic, host-guest, cation-π and π-π stacking interactions, hydrogen bonding and various reactions including: phenol-amine Michael and Schiff base, phenol-thiol Michael addition, phenol-epoxy ring opening reaction, etc.). Subsequently, TA-based gels with a variety of functionalities, including mechanical, adhesion, conductive, self-healing, UV-shielding, anti-swelling, anti-freezing, shape memory, antioxidant, antibacterial, anti-inflammatory and responsive properties are introduced in detail. Then, a summary of recent developments in the use of TA-based gels is provided, including bioelectronics, biomedicine, energy, packaging, water treatment and other fields. Finally, the difficulties that TA-based gels are currently facing are outlined, and an original yet realistic viewpoint is provided in an effort to spur future development.

Tannic acid-assisted exfoliation of molybdenum disulfide for enhancing the multifunctional properties of natural rubber latex-coated polycotton fabrics

The development of multifunctional textiles can be achieved through coating techniques. Natural rubber latex (NRL) presents a promising bio-based coating material. Although, NRL can improve the mechanical properties, NRL alone does not provide multifunctionality. Therefore, incorporating filler into NRL is essential to impart additional functionalities to textiles. This study presents a facile method for fabricating multifunctional textiles by combining NRL with tannic acid (TA)-exfoliated molybdenum disulfide (MoS2) nanosheets (MT). MoS2 was exfoliated using TA via sand grinding, and the resulting nanosheets dispersion was incorporated into NRL, which was then applied to polycotton fabric via a single dipping method. Coating with NRL alone lacked functional properties and MoS2 without TA led to aggregation. TA alone also failed to improve certain properties. However, the synergy among NRL, MoS2 and TA significantly improved the mechanical strength, antibacterial properties, hydrophilicity, self-cleaning ability, stain removal efficiency, acid resistance, ultraviolet blocking, and washing durability. These multifunctional coated fabrics hold great potential for application in medical and protective clothing.

Emerging roles of hyaluronic acid hydrogels in cancer treatment and wound healing: A review

Hyaluronic acid (HA)-derived hydrogels demonstrate a significant development in the biomedical uses, especially in cancer treatment and wound repair. Cancer continues to be one of the leading causes of death worldwide, with current therapies frequently impeded by lack of specificity, side effects, and the emergence of resistance. HA hydrogels, characterized by their distinctive three-dimensional structure, hydrophilic nature, and biocompatibility, develop an advanced platform for precise drug delivery, improving therapeutic results while minimizing systemic toxicity. These hydrogels facilitate the controlled release of drugs, genes, and various therapeutic substances, enhancing the effectiveness of chemotherapy, radiotherapy, and immunotherapy. Additionally, they can be designed to react to stimuli such as pH, light, and magnetic fields, enhancing their therapeutic capabilities. In the process of wound healing, the hydrophilic and porous characteristics of HA hydrogels establish a moist environment encouraging cell growth and contributes to the tissue recovery. By imitating the extracellular matrix, they promote tissue regeneration, improve angiogenesis, and influence immune reactions. This review examines the various functions of HA-based hydrogels in cancer treatment and wound healing, highlighting their advancement, applications, and ability to change existing therapeutic methods in these important health sectors.

A Chinese drug-compatibility-based approach to purslane hydrogels for acute eczema therapy

Purslane (Portulaca oleracea L.) with heat-clearing and detoxicating, anti-inflammatory and resolving swelling, relieving itching and astringing function, has remarkable efficacy for acute eczema. However, most of the clinical applications of purslane are freshly prepared decoction, not as easy to apply as cream, because the decoction is easy to breed bacteria and easy to oxidize. Here, based on the theory of Chinese medicines compatibility, we made a purslane-tannic acid hydrogel (PL-HATA) by simple methods under mild conditions to solve the drawbacks of easy oxidation and inconvenience of use of Purslane. The antimicrobial activity of PL-HATA hydrogel can exert an excellent antimicrobial effect, reducing the flora on the skin of acute eczema and further relieving the symptoms of acute eczema. At the same time, it creates a normal reactive oxygen species (ROS) microenvironment for acute eczema and promotes recovery from acute eczema. It also improves the symptoms of acute eczema by promoting cell proliferation and migration. Importantly, it resulted in improved skin lesion scores, scratching behavior, eosinophil infiltration, swelling and inflammation levels, immune homeostasis, and histopathological changes in rats with acute eczema. Besides, HATA hydrogel is not only suitable for Purslane's decocted metabolites but also for Purslane's freshly squeezed metabolites. This purslane application protocol solved the drawbacks of Purslane's decoction, improved its storage stability and convenience of use, which is the key issue to further promote its clinical application.

Bioactive Deep Eutectic Solvent-Involved Sprayable Versatile Hydrogel for Monkeypox Virus Lesions Treatment

To address the issues of infectious virus, bacterial secondary infections, skin pigmentation, and scarring caused by monkeypox virus (MPXV), a sprayable hydrogel with versatile functions was developed with comprehensive properties. Based on current research, the bioactive deep eutectic solvent (DES) of rosmarinic acid-proanthocyanidin-glycol (RPG) was designed and synthesized as active agent, and molecular docking was applied to discover its binding to MPXV proteins through H-bonds and van der Waals interactions, and the docking results show the binding energies between RA, PC, Gly and MPXV proteins are -58.7188, -50.2311, and -18.4755 kcal/mol, respectively. Additionally, poly(vinyl alcohol) (PVA), borate, and xylitol (Xyl) were integrated with RPG to prepare the PB-RPG-Xyl hydrogel, which was characterized by popular ways. The pH-responsive properties of the hydrogel accelerated the release of RPG under acidic conditions, resulting in an increased cumulative release percentage of 84.83% at pH 5.5 at 210 min. Besides that, it was proved to have the expected sprayability, self-healing, adhesion, and shape-adaptability. The results of molecular dynamic simulation were meaningful to understanding its formation and self-healing mechanisms. Furthermore, the hydrogel shows ideal degradability, removability, and biocompatibility. Lastly, its multiple functions were systematically explored, including UV-blocking, blood clotting, cooling, antioxidant, antibacterial, and virus inhibition properties. The developed sprayable PB-RPG-Xyl hydrogel represents the first promising dressing based on natural bioactive DES for MPXV lesions management, which not only expands the application of green solvents in health care but also provides a convenient and effective treatment process for MPXV infection in the face of difficult skin lesions and complex treatment needs.

Preparation of Green Tea Polyphenol-Loaded Diacylglycerol Nanostructured Lipid Carrier Hydrogels and Their Activities Related to Skin Protection

Diacylglycerol (DAG) is a functional oil but is rarely used in the cosmetic industry because low solubility, susceptibility to leakage and low viscosity to skin are still the main hurdles. A novel diacylglycerol nanostructured lipid carrier hydrogel (GTP-DAG-NLC-GEL) loaded with green tea polyphenol (GTP) was designed and successfully prepared to broaden DAG's application in cosmetics, which significantly improved GTP stability and skin stickiness of DAG. The results showed that DAG-NLC-GEL had good viscosity, which was 980 Pa·s when the shear rate was 5 rpm, and its viscosity decreased quickly with the increase in shear rate, making it easily expand on skin. Meanwhile, the encapsulation rate and drug loading of GTP in GDP-DAG-NLC-GEL reached 86.7% and 2.6%, respectively, and the DPPH free radicals scavenging rate and inhibition rate of the advanced glycation end-products (AGEs) were 85.46% and 89.72%, respectively, which indicate that GTP-DAG-NLC-GEL has significant skin sunscreen, antioxidant and anti-glycation activities. The GTP-loaded nanostructured lipid carrier hydrogel can be deemed to have great prospects for skin protection in cosmetics.

Fabrication of high internal phase emulsions (HIPEs) using pea protein isolate-hyaluronic acid-tannic acid complexes: Application of curcumin-loaded HIPEs as edible inks for 3D food printing

Pea protein isolate (PPI)-hyaluronic acid (HA)-tannic acid (TA) ternary complexes were assembled using non-covalent interactions, their potential application in 3D printing and delivery of curcumin were investigated. As the HA-to-TA ratio in the complexes changed from 1:0 to 0:1, the oil-water interfacial tension first decreased and then increased, and the secondary structure of the proteins changed. The composition of the complexes (HA-to-TA ratio) was optimized to produce high internal phase emulsions (HIPEs) containing small uniform oil droplets with good storage and thermal stability. When the HA to TA ratio is 7:1 (P-H7-T1), HIPEs exhibited better viscosity, viscoelasticity, and thixotropy, which contributed to its preferable 3D printing. Moreover, curcumin-loaded HIPEs stabilized by P-H7-T1 showed a high lipid digestibility (≈101%) and curcumin bioaccessibility (≈79%). In summary, the PPI-HA-TA-stabilized HIPEs have good potential to be 3D-printable materials that could be loaded with bioactive components.

Revitalizing Effect on the Scalp After Injection with a Mechanically Stabilized Hyaluronic Acid Complex in Subjects with Androgenetic Alopecia

Background: Treatments for androgenetic alopecia (AGA) include different drugs, but a treatment based on stabilized hyaluronic acid has not been tested. The aim of this study is to clinically evaluate the effect of six sessions of injections using a hyaluronic acid compound supplemented with vitamins, ions, and amino acids (CH) on hair density and quality in volunteers. Methods: For this purpose, twenty-six healthy volunteers of both sexes with moderate AGA were injected with 3 mL of CH using the micro-papule technique. All received six CH sessions at two-week intervals. Hair loss, hair thickness, and shine were assessed using macro-photographs. A follow-up questionnaire was given to the volunteers at 40 days and at 90 days after the last treatment to determine their level of satisfaction. In addition, a dermatological control was carried out to assess the tolerance of the treatment applied. Results: The results indicate that, after treatment with CH, there is a significant improvement in the thickness, shine, and density of scalp hair, and that the treatment significantly reduces hair loss on the scalp. On a dermatological level, the tolerability of the treatment was excellent with no complications observed. In total, 88.5% of the volunteers indicated that CH treatment improved their appearance. In summary, it can be said that CH treatment reduces hair loss and promotes hair growth. Conclusions: It is suggested that this treatment is effective in reducing the signs and symptoms of alopecia.

Tannic acid based multifunctional hydrogels with mechanical stability for wound healing

Conventional wound dressings have poor tissue adhesion and mechanical stability, restricting their applications in dynamic motion environments. Tannic acid (TA) was ideal candidates for current dressing materials due to their well-known antioxidant and anti-inflammatory properties. However, the inevitable polymerization problem of TA limited the one-step synthesis of dressings. Herein, we reported a simple one-pot method to prepare double-network hydrogels containing N-acryloyl glycinamide (NAGA), N-hydroxyethyl acrylamide (HEAA) and TA. The resulting NHT hydrogel exhibited excellent tensile properties, fatigue resistance, and notch insensitivity to ensure mechanical stability under large deformation and stress in vitro. The NHT hydrogel also demonstrated room-temperature self-healing, broad adhesion to various substrates, synergistic swelling ability. In addition, catechol and benzene rings from TA helped shield against UV radiation and acted as free radical scavengers to relieve oxidative stress in wound damage. As a result, full-layer wounds in mice treated with NHT patches showed a higher healing rate, in which epithelialization was completed within 14 days. The integrated function enables hydrogel to maintain mechanical stability in dynamic motion environments with high strain and defects, with great potential for future clinical translation.

Protective effect of ferulic acid-hyaluronic acid copolymer against UVB irradiation in a human HaCaT cell line

Excessive UVB exposure increased the production of reactive oxygen species (ROS), leading to oxidative damage and epidermal inflammation. To enhance UVB protection effect, a strong phenolic antioxidant, ferulic acid (FA) was designed onto HA via a free radical mediated method. Our previous work has confirmed its structural characterization and in vitro antioxidant. The aim of this study was to evaluate its protective effects against UVB-induced damage in human HaCaT cells. We observed a significant reduction in cell viability to 57.43 % following UVB exposure at a dose of 80 mJ/cm2. However, pretreatment with FA-HA (250 to 2000 μg·mL-1) significantly attenuated cytotoxicity in a dose-dependent manner. Furthermore, FA-HA was found to suppress the intracellular generation of ROS and up-regulated the expression of the antioxidant enzyme superoxide dismutase (SOD). The elevated levels of pro-inflammatory cytokines, including interleukin-1 beta (IL-1β), interleukin-6 (IL-6), interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-α) as well as the mRNA expression of matrix metalloproteinase-1/9 (MMP-1/9) induced by UVB irradiation, were also effectively reduced by FA-HA. Additionally, FA-HA treatment decreases the phosphorylation of mitogen-activated protein kinase (MAPK) and activator protein-1 (AP-1), ultimately preventing apoptosis. These findings suggest that FA-HA is a promising candidate for UVB protection in skincare formulations.

A sustainable zein-based adhesive for various substrates with improved adhesion and stability

Biomass-based adhesives are gaining attention as environmentally friendly alternatives to toxic petroleum-based adhesives. However, biomass-based adhesives exhibit poor adhesive properties and are highly susceptible to failure in humid environments. In this study, a zein-based adhesive with high adhesive strength and good water resistance was prepared by optimizing the solvent composition and adding tannic acid. Adding 10 wt% acetic acid to an aqueous ethanol solvent increased the shear strength by 45.4 % to 3.09 MPa. Moreover, the addition of 6 wt% tannic acid improved the shear strength of the zein-based adhesive in humid environments from 0.63 to 1.58 MPa. The tannic acid-reinforced zein-based adhesive exhibited good adhesive strength in both humid and dry environments, which was maintained for 30 days on glass, and could be applied to a wide range of substrates. Moreover, the adhesive showed an antioxidant activity >94 %, excellent thermal stability, biocompatibility, and antibacterial effect. Therefore, this adhesive has great application prospects in medical, packaging, and other fields.

Functional hyaluronic acid microneedles for skin photoaging based on collagen induction and oxidative stress regulation strategies

Photoaging holds remarkable importance for skin health and senescence. Ultraviolet (UV) irradiation results in the disruption of the extracellular matrix (ECM) microenvironment, the degradation of collagen, and the generation of oxidative stress. Traditional hyaluronic acid (HA) exhibits a diminished capacity to stimulate collagen regeneration, and hampered by its poor permeability as a macromolecule, ultimately resulting in constrained therapeutic outcomes for the treatment of photoaging. In this study, HA/PX was prepared by functional modification of HA with sulfonate-rich or phosphatidylcholine-rich polymers, which could complement the loss of ECM and ameliorate the senescence of human fibroblasts (HDFs) and hairless mouse models subjected to UVB-induced photoaging. The results indicate that HA/PX exhibits superior abilities in delaying cellular aging, promoting collagen regeneration, and resisting reactive oxygen species (ROS) compared to HA. Furthermore, HA/PX shows good biocompatibility both in vivo and in vitro, without causing allergic reactions or other adverse effects. We also demonstrated that the transdermal delivery of HA/PX via microneedle arrays (MNs) can significantly mitigate wrinkles and skin damage in photoaged nude mice, and achieve the treatment of skin photoaging by enhancing epidermal thickness, promoting collagen deposition, and reducing oxidative stress. Therefore, our research offers a novel possibility for future anti-aging therapeutic strategies.

Polyphenol-hyaluronic acid-based hydrogel remodels the wound microenvironment and eliminates bacterial infection for accelerating wound healing

The wound microenvironment, often characterized by alkaline pH and severe hypoxia, presents significant challenges to the healing of bacterial-infected wounds. While considerable research has focused on improving wound healing through effective bacterial elimination using advanced therapeutic approaches, the importance of regulating the wound microenvironment has received less emphasis. In this work, we developed a biocompatible hydrogel, HTFC, by incorporating CaO2 nanoparticles (CaO2 NPs) into a gel formed by tannic acid (TA), hyaluronic acid (HA), and Fe3+. The HA and TA in HTFC hydrogel help to create a slightly acidic microenvironment, facilitating the decomposition of CaO2 NPs to release H2O2 for chemodynamic therapy (CDT). The reduction properties of TA promote the recycling of Fe3+/Fe2+, enhancing CDT efficacy and partially converting H2O2 to O2, thereby alleviating hypoxia. Additionally, FeIIITA complexes in HTFC enhance CDT through photothermal therapy (PTT)-induced improvement of the Fenton reaction. This multifunctional hydrogel, with its synergistic effects of PTT and CDT, along with its ability to remodel the wound microenvironment from hypoxic and alkaline to normoxic and acidic, accelerates the bacterial-infected wound healing process.

Advances in hyaluronic acid: Bioactivity, complexed biomaterials and biological application: A review

Hyaluronic acid (HA) is a natural glycosaminoglycan found in the human body, particularly in the extracellular matrix of body fluids and tissues. It plays a critical role in cellular processes of living organisms by maintaining tissue hydration, cell proliferation, differentiation, and inflammatory response. HA exhibits significant biological activity in skin care, aesthetic anti-aging, medical orthopedic repair, gynecological cancer monitoring, and other pathological conditions. Due to its exceptional biocompatibility, biodegradability, lack of toxicity, non-immunogenicity, and its capacity to bond with other substances, various HA-based biomedical products like hydrogels, microneedles, and microspheres have been developed. These innovations have also been applied in various medical and health fields, such as bone and tissue regeneration, gels for medical aesthetic fillers, and gynecology-related cancer treatment, utilizing the HA drug delivery pathway. The interest in HA and its products is increasing due to their biological functions. Therefore, this review aimed to summarize the biological properties of HA and to focus on its applications in the bone tissue engineering and healthcare, for HA has some practical applications of HA-based complexes in biomedical materials, tissue repair, medical aesthetics, and gynecology. Through this review, we seek to offer theoretical research assistance for the development of HA-based bioproducts in the healthcare domain and provide innovative insights for human health.

Tannic acid crosslinked chitosan/gelatin/SiO2 biopolymer film with superhydrophobic, antioxidant and UV resistance properties for prematuring fruit packaging

The environmental pollution caused by plastic films urgently requires the development of non-toxic, biodegradable, and renewable biopolymer films. However, the poor waterproof and UV resistance properties of biopolymer films have limited their application in fruit packaging. In this work, a novel tannic acid cross-linked chitosan/gelatin film with hydrophobic silica coating (CGTS) was prepared. Relying on the adhesion of tannic acid and gelatin to silica, the coating endows CGTS film with excellent superhydrophobic properties. Especially, the contact angle reaches a maximum value 152.6°. Meanwhile, tannic acid enhanced the mechanical strength (about 36.1 %) through the forming of hydrogen bonding and the network structure. The prepared CGTS films showed almost zero transmittance to ultraviolet light and exhibited excellent radical scavenging ability (∼76.5 %, DPPH). Hence, CGTS film is suitable as a novel multifunctional packaging material for the agriculture to protect premature fruits, or the food industry used in environments exposed to ultraviolet radiation and rainwater.

A Comprehensive Review on Starch-Based Hydrogels: From Tradition to Innovation, Opportunities, and Drawbacks

Natural hydrogels based on renewable and inexpensive sources, such as starch, represent an interesting group of biopolymeric materials with a growing range of applications in the biomedical, cosmeceutical, and food sectors. Starch-based hydrogels have traditionally been produced using different processes based on chemical or physical methods. However, the long processing times, high energy consumption, and safety issues related to the synthesis of these materials, mostly causing severe environmental damage, have been identified as the main limitations for their further exploitation. Therefore, the main scientific challenge for research groups is the development of reliable and sustainable processing methods to reduce the environmental footprint, as well as investigating new low-cost sources of starches and individuating appropriate formulations to produce stable hydrogel-based products. In the last decade, the possibility of physically modifying natural polysaccharides, such as starches, using green or sustainable processing methods has mostly been based on nonthermal technologies including high-pressure processing (HPP). It has been demonstrated that the latter exerts an important role in improving the physicochemical and techno-functional properties of starches. However, as for surveys in the literature, research activities have been devoted to understanding the effects of physical pre-treatments via high-pressure processing (HPP) on starch structural modifications, more so than elucidating its role and capacity for the rapid formation of stable and highly structured starch-based hydrogels with promising functionality and stability, utilizing more sustainable and eco-friendly processing conditions. Therefore, the present review addresses the recent advancements in knowledge on the production of sustainable starch-based hydrogels utilizing HPP as an innovative and clean-label preparation method. Additionally, this manuscript has the ambition to give an updated overview of starch-based hydrogels considering the different types of structures available, and the recent applications are proposed as well to critically analyze the main perspectives and technological challenges for the future exploitation of these novel structures.

DNA Damage-Sensitized metal phenolic nanosynergists potentiate Low-Power phototherapy for osteosarcoma therapy

Non-invasive and efficient photodynamic therapy (PDT) holds great promise to circumvent resistance to traditional osteosarcoma (OS) treatments. Nevertheless, high-power PDT applied in OS often induces photothermogenesis, resulting in normal cells rupture, sustained inflammation and irreversible vascular damage. Despite its relative safety, low-power PDT fails to induce severe DNA damage for insufficient reactive oxygen species (ROS) production. Herein, a non-ROS-dependent DNA damage-sensitizing strategy is introduced in low-power PDT to amplify the therapeutic efficiency of OS, where higher apoptosis is achieved with low laser power. Inspired by the outstanding DNA damage performance of tannic acid (TA), TA-based metal phenolic networks (MPNs) are engineered to encapsulate hydrophobic photosensitizer (purpurin 18) to act as DNA damage-sensitized nanosynergists (TCP NPs). Specially, under low-power laser irradiation, the TCP NPs can boost ROS instantly to trigger mitochondrial dysfunction simultaneously with upregulation of DNA damage levels triggered by TA to reinforce PDT sensitization, evoking potent antitumor effects. In addition, TCP NPs exhibit long-term retention in tumor, greatly benefiting sustained antitumor performances. Overall, this study sheds new light on promoting the sensitivity of low-power PDT by strengthening DNA damage levels and will benefits advanced OS therapy.

Orally ingestible medication utilizing layered double hydroxide nanoparticles strengthened alginate and hyaluronic acid-based hydrogel bead for bowel disease management

In the treatment of bowel diseases such as ulcerative colitis through oral administration, an effective drug delivery system targeting the colon is crucial for enhancing efficacy and minimizing side effects of therapeutic agents. This study focuses on the development of a novel nanocomposite hydrogel bead comprising a synergistic blend of biological macromolecules, namely sodium alginate (ALG) and hyaluronic acid (HA), reinforced with layered double hydroxide nanoparticles (LDHs) for the oral delivery of dual therapeutics. The synthesized hydrogel bead exhibits significantly enhanced gel strength and controllable release of methylprednisolone (MP) and curcumin (CUR), serving as an anti-inflammatory drug and a mucosal healing agent, compared to native ALG or ALG/HA hydrogel beads without LDHs. The physicochemical properties of the synthesized LDHs and hydrogel beads were characterized using various techniques, including scanning electron microscopy, zeta potential measurement, transmission electron microscopy, X-ray diffraction, and energy-dispersive X-ray spectroscopy. In vitro release studies of MP and CUR under simulated gastrointestinal tract (GIT) conditions demonstrate the superior controlled release property of the nanocomposite hydrogel bead, particularly in minimizing premature drug release in the upper GIT environment while sustaining release of over 82 % of drugs in the colonic environment. Thus, the modularly engineered carrier designed for oral colon targeting holds promise as a potential candidate for the treatment of ulcerative colitis.

Insights into the molecular mechanisms, structure-activity relationships and application prospects of polysaccharides by regulating Nrf2-mediated antioxidant response

The occurrence and development of many diseases are closely related to oxidative stress. In this context, accumulating evidence suggests that Nrf2, as the master switch of cellular antioxidant signaling, plays a central role in controlling the expression of antioxidant genes. The core molecular mechanism of polysaccharides treatment of oxidative stress-induced diseases is to activate Keap1/Nrf2/ARE signaling pathway, promote nuclear translocation of Nrf2, and up-regulate the expression of antioxidant enzymes. However, recent studies have shown that other signaling pathways in which polysaccharides exert antioxidant effects, such as PI3K/Akt/GSK3β, JNK/Nrf2 and NF-κB, have complex crosstalk with Keap1/Nrf2/ARE, may have direct effects on the nuclear translocation of Nrf2. This suggests a new strategy for designing polysaccharides as modulators of Nrf2-dependent pathways to target the antioxidant response. Therefore, in this work, we investigate the crosstalk between Keap1/Nrf2/ARE and other antioxidant signaling pathways of polysaccharides by regulating Nrf2-mediated antioxidant response. For the first time, the structural-activity relationship of polysaccharides, including molecular weight, monosaccharide composition, and glycosidic linkage, is systematically elucidated using principal component analysis and cluster analysis. This review also summarizes the application of antioxidant polysaccharides in food, animal production, cosmetics and biomaterials. The paper has significant reference value for screening antioxidant polysaccharides targeting Nrf2.

Advancements in sunscreen formulations: integrating polyphenolic nanocarriers and nanotechnology for enhanced UV protection

Sunscreens are essential in protecting the skin from harmful effects of ultraviolet radiation (UVR). These formulations, designed to absorb, block, or scatter UVR, offer vital protection against skin aging, sunburns, and the development of skin cancers like melanomas. However, some sunscreens, especially those containing organic/chemical compounds, can cause allergic reactions. To address this, researchers are extensively investigating formulations that incorporate plant extracts rich in polyphenols, such as flavonoids and carotenoids, which can be considered safer alternatives. Products derived from plants are commonly used in cosmetics to counteract skin aging due to their antioxidant activity that combat harmful free radicals. This review focuses on evaluating the advancements in chemical and natural sunscreens, exploring the integration of polyphenolic nanocarriers within sunscreen formulas, their interaction with UVR, and utilizing nanotechnology to enhance their effectiveness. An attempt has been made to highlight the concerns related to toxicity associated with their use and notable advancements in the regulatory aspects governing their utilization.

Effect of post-heat treatment on the UV transmittance, hydrophobicity, and tensile properties of PVA/Uncaria gambir extract blend films

The physical and mechanical properties of biopolymers can be improved by heating technologies. In this research, we improved the properties of Polyvinyl alcohol (PVA)/Uncaria gambir extract (UGE) blend films by post-heating method. After post-heating, the blend film exhibited higher resistance to UV light and improved contact angle performance, while water vapor permeability and moisture absorption decreased. The tensile strength and toughness of the PVA/UGE blend film with a post-heating duration of 40 min were 68.8 MPa and 57.7 MPa, respectively, an increase of 131 % and 127 %, compared to films without post-heating. This facile and cost-effective fabrication method, with environmentally friendly properties, can be applied to biodegradable PVA/UGE blend films to achieve desired properties for optical devices or food packaging materials.

Multifunctional tannic acid-based nanocomposite methacrylated silk fibroin hydrogel with the ability to scavenge reactive oxygen species and reduce inflammation for bone regeneration

The microenvironment of bone defect site is vital for bone regeneration. Severe bone defect is often accompanied with severe inflammation and elevated generation of reactive oxygen species (ROS) during bone repair. In recent years, the unfriendly local microenvironment has been paid more and more attention. Some bioactive materials with the ability to regulate the microenvironment to promote bone regeneration urgently need to be developed. Here, we develop a multifunctional composite hydrogel composed of photo-responsive methacrylate silk fibroin (SFMA), laponite (LAP) nanocomposite and tannic acid (TA), aiming to endow hydrogel with antioxidant, anti-inflammatory and osteogenic induction ability. Characterization results confirmed that the SFMA-LAP@TA hydrogel could significantly improve the mechanical properties of hydrogel. The ROS-Scavenging ability of the hydrogel enabled bone marrow mesenchymal stem cells (BMSCs) to survive against H2O2-induced oxidative stress. In addition, the SFMA-LAP@TA hydrogel effectively decreased the expression of pro-inflammatory factors in RAW264.7. More importantly, the SFMA-LAP@TA hydrogel could enhance the expression of osteogenic markers of BMSCs under inflammatory condition and greatly promote new bone formation in a critical-sized cranial defect model. Above all, the multifunctional hydrogel could effectively promote bone regeneration in vitro and in vivo by scavenging ROS and reducing inflammation, providing a prospective strategy for bone regeneration.

Mussel-Inspired Self-Adhesive and Tough Hydrogels for Effectively Cooling Solar Cells and Thermoelectric Generators

Adhesive hydrogel-based evaporative cooling, which necessitates no electricity input, holds promise for reducing energy consumption in thermal management. Herein, inspired by the surface attachment of mussel adhesive proteins via abundant dynamic covalent bonds and noncovalent interactions, we propose a facile strategy to fabricate a self-adhesive cooling hydrogel (Li-AA-TA-PAM) using a copolymer of acrylamide (AM) and acrylic acid (AA) as the primary framework. The monomers formed hydrogen bonds between their carboxyl and amide groups, while tannic acid (TA), rich in catechol groups, enhances the adhesion of the hydrogel through hydrogen bonding. The hydrogel demonstrated strong adhesion to various material surfaces, including plastic, ceramic, glass, and metal. Even under high-speed rotation, it still maintains robust adhesion. The adhesion strength of the Li-AA-TA-PAM hydrogel to aluminum foil reached an impressive value of 296.875 kPa. Interestingly, the excellent contact caused by robust adhesion accelerates heat transfer, resulting in a rapid cooling performance, which mimics the perspiration of mammals. Lithium bromide (LiBr) with hydroactively sorptive sites is introduced to enhance sorption kinetics, thereby extending the effective cooling period. Consequently, the operation temperature of commercial polycrystalline silicon solar cells was reduced by 16 °C under an illumination of 1 kW m-2, and the corresponding efficiency of energy conversion was increased by 1.14%, thereby enhancing the output properties and life span of solar cells. The strategy demonstrates the potential for refrigeration applications using viscous gels.

Effect of Tannic Acid Concentrations on Temperature-Sensitive Sol-Gel Transition and Stability of Tannic Acid/Pluronic F127 Composite Hydrogels

Recently, interest in polyphenol-containing composite adhesives for various biomedical applications has been growing. Tannic acid (TA) is a polyphenolic compound with advantageous properties, including antioxidant and antimicrobial properties. Additionally, TA contains multiple hydroxyl groups that exhibit biological activity by forming hydrogen bonds with proteins and biomacromolecules. Furthermore, TA-containing polymer composites exhibit excellent tissue adhesion properties. In this study, the gelation behavior and adhesion forces of TA/Pluronic F127 (TA/PluF) composite hydrogels were investigated by varying the TA and PluF concentrations. PluF (above 16 wt%) alone showed temperature-responsive gelation behavior because of the closely packed micelle aggregates. After the addition of a small amount of TA, the TA/PluF hydrogels showed thermosensitive behavior similar to that of PluF hydrogels. However, the TA/PluF hydrogels containing more than 10 wt% TA completely suppressed the thermo-responsive gelation kinetics of PluF, which may have been due to the hydrogen bonds between TA and PluF. In addition, TA/PluF hydrogels with 40 wt% TA showed excellent tissue adhesion properties and bursting pressure in porcine intestinal tissues. These results are expected to aid in understanding the use of mixtures of TA and thermosensitive block copolymers to fabricate adhesive hydrogels for versatile biomedical applications.

Transparent multifunctional cellulose-based conductive hydrogel for wearable strain sensors and arrays

Conductive hydrogels as promising candidate materials for flexible strain sensors have gained considerable attentions. However, it is still a great challenge to construct hydrogel with multifunctional performance via natural polymer. Herein, a novel multifunctional conductive hydrogel based on methylcellulose and cellulose nanocrystal was prepared via a facile and low-cost strategy. Methylcellulose (MC) was introduced to not only guarantee the stability of tannic acid coated cellulose nanocrystal (TA@CNCs) in LiCl solution, but also improve anti-freezing ability. The obtained hydrogel exhibited high transparency (98 % at 800 nm), good stretchability (663.1 %), low temperature tolerance (-23.9 °C), superior conductivity (2.89 S/m) and excellent UV shielding behavior. Flexible strain sensor assembled by the prepared hydrogels can be used to detect human body motions include subtle and large motions, and exhibited good sensitivity and stability over a wide temperature range. Multiple flexible hydrogels can also be assembled into a 3D sensor array to detect the distribution and magnitude of spatial pressure. Therefore, the hydrogels prepared via natural polymers will have broad application prospects in wearable devices, electronic skin and multifunctional sensor components.

Flexible cellulose nanofibers/MXene composite films for UV-shielding packaging

Cellulose nanofibers (CNF) based films are promising packaging materials, but the lack of special functions (especially UV-shielding property) usually restrict their further applications. In this work, MXene was incorporated into the CNF film by a direct solvent volatilization induced film forming method to study its UV-shielding property for the first time, which avoided the using of a vacuum filtration equipment. The composite films containing glycerin could be folded repeatedly without breaking, showing good flexibility. The structure and properties of MXene/CNF composite films (CMF) were characterized systematically. The results showed that MXene distributed uniformly in the CNF film matrix and there was strong hydrogen bonding interaction between CNF and MXene. The tensile strength and Young's modulus of the composite films could reach 117.5 MPa and 2.23 GPa, which was 54.1 % and 59.2 % higher than those of pure CNF film, respectively. With the increase of MXene content, both the UVA and UVB shielding percentages increased significantly from 17.2 % and 25.5 % to 100.0 %, showing excellent UV-shielding property. Moreover, CMF exhibited a low oxygen permeability (OP) value of 0.39 cc μm d-1 m-2 kPa-1, a low water vapor permeability (WVP) value of 5.13 × 10-11 g-1s-1Pa-1 and a high antibacterial rate against E. coli (94.1 % at 24 h), showing potential application in the packaging field.

Multifunctional sodium lignosulfonate/xanthan gum/sodium alginate/polyacrylamide ionic hydrogels composite as a high-performance wearable strain sensor

Recently, conductive hydrogels have shown great promise in flexible electronics and are ideal materials for the preparation of wearable strain sensors. However, developing a simple method to produce conductive hydrogels with excellent mechanical properties, self-adhesion, transparency, anti-freezing, and UV resistance remains a significant challenge. A novel sodium lignosulfonate/xanthan gum/sodium alginate/polyacrylamide/Zn2+/DMSO (SLS/XG/SA/PAM/Zn2+/DMSO) ionic conductive hydrogel was developed using a one-pot method. The resulting ionic conductive hydrogels have excellent mechanical properties (stress: 0.13 MPa, strain: 1629 %), high anti-fatigue properties, self-adhesion properties (iron: 7.37 kPa, pigskin: 4.74 kPa), anti-freezing (freezing point: -33.49 °C) and UV resistance by constructing a chemical and physical hybrid cross-linking network. In particular, the conductivity of G hydrogel reached 6.02 S/m at room temperature and 5.52 S/m at -20 °C. Thus, the hydrogel was assembled into a flexible sensor that could distinguish a variety of large and small scales human movements, such as joint bending, swallowing and speaking in real time with high stability and sensitivity. Moreover, the hydrogel could be used as electronic skin just like human skin and touch screen pen to write.

Hyaluronic acid/polyphenol sunscreens with broad-spectrum UV protection properties from tannic acid and quercetin

Currently, commercial sunscreens cause a number of biotoxicity and environmental issues, making it imperative to develop biocompatible alternatives. In this study, we aimed to develop an alternative sunscreen from two ecofriendly and biocompatible natural polyphenolic compounds, tannic acid (TA) and quercetin (Que). The sunscreen was prepared through a simple process using an oil-in-water emulsion as the medium and hyaluronic acid (HA) as the base polymer to improve biocompatibility. The HA/TA/Que. sunscreen prepared in this study exhibits 0 % transmittance in the UVB region and <15 % transmittance in the UVA region, resulting in excellent sun-protection properties (SPF 30). Remarkably, the as-prepared HA/TA/Que. sunscreen has a suitable viscosity and similar UV protection properties to those of commercial sunscreens. The HA/TA/Que. sunscreen also exhibits 90.4 % antioxidant activity against 2,2-diphenyl-1-picrylhydrazyl, demonstrating an ability to effectively capture reactive oxygen species that directly affect the skin. In addition, the cell viability was >90 % at a concentration of 50 μg/mL after 7 days, indicating excellent cytocompatibility. Owing to its various advantageous features, the HA/TA/Que. sunscreen with excellent sun protection properties and multiple functionalities is expected to resolve many environmental and biological issues caused by commercial sunscreens.

Cold plasma treatment of tannic acid as a green technology for the fabrication of advanced cross-linkers for bioactive collagen/gelatin hydrogels

Tannic acid (TA) is a natural compound studied as the cross-linker for biopolymers due to its ability to form hydrogen bonds. There are different methods to improve its reactivity and effectiveness to be used as a modifier for biopolymeric materials. This work employed plasma to modify tannic acid TA, which was then used as a cross-linker for fabricating collagen/gelatin scaffolds. Plasma treatment did not cause any significant changes in the structure of TA, and the resulting oxidized TA showed a higher antioxidant activity than that without treatment. Adding TA to collagen/gelatin scaffolds improved their mechanical properties and stability. Moreover, the obtained plasma-treated TA-containing scaffolds showed antibacterial properties and were non-hemolytic, with improved cytocompatibility towards human dermal fibroblasts. These results suggest the suitability of plasma treatment as a green technology for the modification of TA towards the development of advanced TA-crosslinked hydrogels for various biomedical applications.

Hyaluronic acid/tannic acid films for wound healing application

In this study, thin films based on hyaluronic acid (HA) with tannic acid (TA) were investigated in three different weight ratios (80HA/20TA, 50HA/50TA, 20HA/80TA) for their application as materials for wound healing. Surface free energy, as well as their roughness, mechanical properties, water vapor permeability rate, and antioxidant activity were determined. Moreover, their compatibility with blood and osteoblast cells was investigated. The irritation effect caused by hyaluronic acid/tannic acid films was also considered with the use of are constructed human epidermis model. The irritation effect for hyaluronic acid/tannic acid films by the in vitro method was also studied. The low surface free energy, surface roughness, and antioxidant activity presented by the obtained films were examined. All the tested compositions of hyaluronic acid/tannic acid films were hemocompatible, but only films based on 50HA/50TA were fully cytocompatible. Regarding the potential implantation, all the films except 80HA/20TA showed appropriate mechanical properties. The specimens did not exert the irritation effect during the studies involving reconstructed human epidermis.

An ECM-mimicking assembled gelatin/hyaluronic acid hydrogel with antibacterial and radical scavenging functions for accelerating open wound healing

A multifunctional hydrogel dressing with hemostatic, antibacterial, and reactive oxygen species (ROS)-removing properties is highly desirable for the clinical treatment of open wounds. Although many wound dressings have been prepared, the modification of polymers is often involved in the preparation process, and the uncertainty of biological safety and stability of modified polymers hinders the clinical application of products. In this study, inspired by the composition and crosslinking pattern of extracellular matrix (ECM), a deeply ECM-mimicking multifunctional hydrogel dressing is created. Tannic acid (TA) and poly-ϵ-lysine (EPL) are added into a gelatin/hyaluronic acid (Gel/HA) matrix, and a stable hydrogel is formed due to the formation of the triple helix bundles of gelatin and hydrogen bonds between polymers. The introduction of TA and EPL endows the ECM-mimicking hydrogel with stable rheological properties, as well as antibacterial and hemostatic functions. The as-produced hydrogels have suitable swelling ratio, enzyme degradability, and good biocompatibility. In addition, it also shows a significant ability to eliminate ROS, which is confirmed by the elimination of 2,2-diphenyl-1-picrylhydrazyl free radical. Full-thickness skin wound repair experiment and histological analysis of the healing site in mice demonstrate that the developed ECM-mimicking Gel/HA hydrogels have a prominent effect on ECM formation and promotion of wound closure. Taken together, these findings suggest that the multifunctional hydrogels deeply mimicking the ECM are promising candidates for the clinical treatment of open wounds.

A hydrogel system for drug loading toward the synergistic application of reductive/heat-sensitive drugs

The preparation of hydrogels as drug carriers via radical-mediated polymerization has significant prospects, but the strong oxidizing ability of radicals and the high temperatures generated by the vigorous reactions limits the loading for reducing/heat-sensitive drugs. Herein, an applicable hydrogel synthesized by radical-mediated polymerization is reported for the loading and synergistic application of specific drugs. First, the desired sol is obtained by polymerizing functional monomers using a radical initiator, and then tannic-acid-assisted specific drug mediates sol-branched phenylboric acid group to form the required functional hydrogel (New-gel). Compared with the conventional single-step radical-mediated drug-loading hydrogel, the New-gel not only has better chemical/physical properties but also efficiently loads and releases drugs and maintains drug activity. Particularly, the New-gel has excellent loading capacity for oxygen, and exhibits significant practical therapeutic effects for diabetic wound repair. Furthermore, owing to its high light transmittance, the New-gel synergistically promotes the antibacterial effect of photosensitive drugs. This gelation strategy for loading drugs has further promising biomedical applications.

New developments in sunscreens

Topical sunscreen application is one of the most important photoprotection tool to prevent sun damaging effects in human skin at the short and long term. Although its efficacy and cosmeticity have significantly improved in recent years, a better understanding of the biological and clinical effects of longer wavelength radiation, such as long ultraviolet A (UVA I) and blue light, has driven scientists and companies to search for effective and safe filters and substances to protect against these newly identified forms of radiation. New technologies have sought to imbue sunscreen with novel properties, such as the reduction of calorific radiation. Cutaneous penetration by sunscreens can also be reduced using hydrogels or nanocrystals that envelop the filters, or by binding filters to nanocarriers such as alginate microparticles, cyclodextrins, and methacrylate polymers. Finally, researchers have looked to nature as a source of healthier products, such as plant products (e.g., mycosporines, scytonemin, and various flavonoids) and even fungal and bacterial melanin, which could potentially be used as substitutes or enhancers of current filters.

Tannic-Acid-Enriched Poly(vinyl alcohol) Nanofibrous Membrane as a UV-Shie lding and Antibacterial Face Mask Filter Material

Face masks are increasingly important in the battle against infectious diseases and air pollution. Nanofibrous membranes (NFMs) are promising filter layers for removing particulate matter (PM) without restricting air permeability. In this study, tannic-acid-enriched poly(vinyl alcohol) (PVA-TA) NFMs were fabricated by electrospinning PVA solutions containing large amounts of tannic acid (TA), a multifunctional polyphenol compound. We were able to prepare uniform electrospinning solution without coacervate formation by inhibiting the robust hydrogen bonding between PVA and TA. Notably, the NFM maintained its fibrous structure even under moist conditions after heat treatment without the use of a cross-linking agent. Further, the mechanical strength and thermal stability of the PVA NFM were improved by the introduction of TA. The functional PVA NFM with a high TA content showed excellent UV-shielding (UV-A: 95.7%, UV-B: 100%) and antibacterial activity against Escherichia coli (inhibition zone: 8.7 ± 1.2 mm) and Staphylococcus aureus (inhibition zone: 13.7 ± 0.6 mm). Moreover, the particle filtration efficiency of the PVA-TA NFM for PM_0.6 particles was 97.7% at 32 L min^-1 and 99.5% at 85 L min^-1, indicating excellent filtration performance and a low pressure drop. Therefore, the TA-enriched PVA NFM is a promising mask filter layer material with excellent UV-blocking and antibacterial properties and has the potential for various practical applications.

Effect and mechanism of fish scale extract natural hydrogel on skin protection and cell damage repair after UV irradiation

Skin lesions caused by ultraviolet radiation exposure seriously reduce people's life quality, safe natural products development to prevent and repair ultraviolet damage is an effective strategy. We investigated the protective and reparative effects of the natural composite gel (SE-gel) derived from fish scales on UV-irradiated skin by inhibiting reactive oxygen species (ROS) -mediated oxidative stress and inflammatory responses. Our results showed that SE-gel rich in glycine and proline had good ultraviolet absorption, water absorption, moisturizing and free radical scavenging abilities. In vitro, SE-gel could improve UV-irradiated L929 cell viability by 1.24 times via inhibiting 50% ROS production and malondialdehyde, and improving superoxide dismutase activity to reduce oxidative stress caused by UV irradiation. In UV-irradiated mouse skin damage model, SE-gel prevent UV-induced skin erythema, epidermal thickening, collagen fiber degradation and disruption, and reduced UV-induced inflammatory response via NF-κB signaling pathway, showing potential application in UV-irradiated skin damage prevention and repair.

Development of Solid Lipid Nanoparticle-Loaded Polymeric Hydrogels Containing Antioxidant and Photoprotective Bioactive Compounds of Safflower (Carthamus tinctorius L.) for Improved Skin Delivery

Safflower (Carthamus tinctorius L.) is a potent natural antioxidant because of active compounds such as quercetin (QU) and luteolin (LU). These components prevent damage to the skin caused by free radicals from UV rays. However, due to the poor solubility and transdermal permeation, the effectiveness of the compounds in showing their activity was limited. In this study, we develop solid lipid nanoparticle (SLN)-based hydrogel formulations to enhance the solubility and penetration of two bioactive compounds found in safflower petals extract (SPE). The hot emulsification-ultrasonication method was used to produce SLNs, and to obtain high antioxidant activity, 100% v/v ethanol was used in the extraction procedure. The results showed that this approach could encapsulate >80% of both QU and LU. Moreover, Fourier transform infrared (FTIR), differential scanning calorimetry (DSC), and powder X-ray diffraction (PXRD) spectra indicated that most of the QU and LU were trapped in a lipid matrix and dispersed homogeneously at the molecular level, increasing the solubility. Additionally, SLN-hydrogel composites are able to release two lipophilic bioactive compounds for 24 h, which also demonstrated increased skin retention and penetrability of the QU and LU up to 19-fold. In vitro blood biocompatibility showed that no hemolytic toxicity was observed below 500 μg/mL. Accordingly, the formulation was considered safe for use. Sun protective factor (SPF) test shows a value above 15, showing an excellent promising application as the photoprotective agent to prevent symptoms associated with photoinduced skin aging.

Bioactive Edible Sodium Alginate Films Incorporated with Tannic Acid as Antimicrobial and Antioxidative Food Packaging

Currently, biodegradable and functional food packaging materials have attracted more and more attention due to their potential advantages. Biopolymers are one of the promising materials used to produce biodegradable food packaging films, and sodium alginate (SA) is one of the most used polysaccharides. In this work, we explored a novel edible sodium alginate (SA)/tannic acid (TA) film as biodegradable active food packaging material. The impact of TA concentration on the UV light blocking ability, transparency, water vapor barrier ability, mechanical strength, antioxidant, and antimicrobial activity of the SA-TA films was comprehensively investigated. Fourier transform infrared spectroscopy results revealed that strong hydrogen bonding was the main intermolecular interaction between SA and TA. As TA concentration in the films increased, the water vapor permeability (WVP) decreased from 1.24 × 10^-6 to 0.54 × 10^-6 g/m/h/Pa, the DPPH radical scavenging activity increased from 0.008% to 89.02%. Moreover, the incorporation of TA effectively blocked UV light and elevated antimicrobial activity against Escherichia coli. Overall, the SA films with TA exhibited better water vapor barrier ability, remarkable UV-light barrier ability and antioxidant activity while showing a slight decrease in light transmittance. These results indicated the potential application of TA as a functional additive agent for developing multifunctional food packaging materials.

Pharmacological effects and mechanisms of tannic acid

In recent years, increasing attention has been paid to the pharmacological efficacy of tannins. Tannic acid (TA), the simplest hydrolysable tannin that has been approved by the FDA as a safe food additive, is one of the most important components of these traditional medicines. Studies have shown that TA displays a wide range of pharmacological activities, such as anti-inflammatory, neuroprotective, antitumor, cardioprotective, and anti-pathogenic effects. Here, we summarize the known pharmacological effects and associated mechanisms of TA. We focus on the effect and mechanism of TA in various animal models of inflammatory disease and organ, brain, and cardiovascular injury. Moreover, we discuss the possible molecular targets and signaling pathways of TA, in addition to the pharmacological effects of TA-based nanoparticles and TA in combination with chemotherapeutic drugs.

The Importance of Antioxidant Biomaterials in Human Health and Technological Innovation: A Review

Biomaterials come from natural sources such as animals, plants, fungi, algae, and bacteria, composed mainly of protein, lipid, and carbohydrate molecules. The great diversity of biomaterials makes these compounds promising for developing new products for technological applications. In this sense, antioxidant biomaterials have been developed to exert biological and active functions in the human body and industrial formulations. Furthermore, antioxidant biomaterials come from natural sources, whose components can inhibit reactive oxygen species (ROS). Thus, these materials incorporated with antioxidants, mainly from plant sources, have important effects, such as anti-inflammatory, wound healing, antitumor, and anti-aging, in addition to increasing the shelf-life of products. Aiming at the importance of antioxidant biomaterials in different technological segments as biodegradable, economic, and promising sources, this review presents the main available biomaterials, antioxidant sources, and assigned biological activities. In addition, potential applications in the biomedical and industrial fields are described with a focus on innovative publications found in the literature in the last five years.

Preparation and Properties of Salecan-Soy Protein Isolate Composite Hydrogel Induced by Thermal Treatment and Transglutaminase

Salecan (Sal) is a novel marine microbial polysaccharide. In the present research, Sal and soy protein isolate (SPI) were adopted to fabricate Sal-SPI composite hydrogel based on a stepwise process (thermal treatment and transglutaminase induction). The effect of Sal concentration on morphology, texture properties, and the microstructure of the hydrogel was evaluated. As Sal concentration varied from 0.4 to 0.6 wt%, hydrogel elasticity increased from 0.49 to 0.85 mm. Furthermore, the internal network structure of Sal-SPI composite hydrogel also became denser and more uniform as Sal concentration increased. Rheological studies showed that Sal-SPI elastic hydrogel formed under the gelation process. Additionally, FTIR and XRD results demonstrated that hydrogen bonds formed between Sal and SPI molecules, inferring the formation of the interpenetrating network structure. This research supplied a green and simple method to fabricate Sal-SPI double network hydrogels.

Tannic acid: a versatile polyphenol for design of biomedical hydrogels

Tannic acid (TA), a natural polyphenol, is a hydrolysable amphiphilic tannin derivative of gallic acid with several galloyl groups in its structure. Tannic acid interacts with various organic, inorganic, hydrophilic, and hydrophobic materials such as proteins and polysaccharides via hydrogen bonding, electrostatic, coordinative bonding, and hydrophobic interactions. Tannic acid has been studied for various biomedical applications as a natural crosslinker with anti-inflammatory, antibacterial, and anticancer activities. In this review, we focus on TA-based hydrogels for biomaterials engineering to help biomaterials scientists and engineers better realize TA's potential in the design and fabrication of novel hydrogel biomaterials. The interactions of TA with various natural or synthetic compounds are deliberated, discussing parameters that affect TA-material interactions thus providing a fundamental set of criteria for utilizing TA in hydrogels for tissue healing and regeneration. The review also discusses the merits and demerits of using TA in developing hydrogels either through direct incorporation in the hydrogel formulation or indirectly via immersing the final product in a TA solution. In general, TA is a natural bioactive molecule with diverse potential for engineering biomedical hydrogels.

An Overview on Recent Progress of the Hydrogels: From Material Resources, Properties to Functional Applications

Hydrogels, as the most typical elastomer materials with three-dimensional network structures, have attracted wide attention owing to their outstanding features in fields of sensitive stimulus response, low surface friction coefficient, good flexibility and bio-compatibility. Because of numerous fresh polymer materials (or polymerization monomers), hydrogels with various structure diversities and excellent properties are emerging, and the development of hydrogels is very vigorous over the past decade. This review focuses on state-of-the-art advances, systematically reviews the recent progress on construction of novel hydrogels utilized several kinds of typical polymerization monomers, and explores the main chemical and physical cross-linking methods to develop the diversity of hydrogels. Following the aspects mentioned above, the classification and emerging applications of hydrogels, such as pH response, ionic response, electrical response, thermal response, biomolecular response, and gas response, are extensively summarized. Finally, we have done this review with the promises and challenges for the future evolution of hydrogels and their biological applications. cross-linking methods; functional applications; hydrogels; material resources This article is protected by copyright. All rights reserved.