Hydrogels for Medical Device Protection

Preparing antifreeze and sterilization hydrogel without complex equipment by dissolving polymer monomer in water, adding cross-linking agent, initiator, antifreeze (glycerol and trehalose), and bactericide, and solidifying the mixed solution to form the antifreeze sterilization hydrogel. This allows preparing hydrogel materials that meet certain needs through simple reactions without requiring complex equipment.

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Slow-release antibacterial hydrogel dressing with improved rigidity and sustained drug release for wound healing applications. The dressing is made by coating antibacterial agents inside microsphere beads and then encapsulating those beads in a hydrogel. The microsphere coating improves the dressing rigidity and prevents burst release of the antibacterials. The double coating also enhances the drug release rate compared to just using the microsphere or hydrogel alone.

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Preparation method for a multifunctional hydrogel sensor that can adhere well in humid environments. The method involves synthesizing a hydrogel containing alginate doped with dopa (dopamine) and mixing it with other components like bovine serum albumin, polyacrylic acid, and MXene nanosheets. The hydrogel can be used as a capacitive, strain, or bioelectrode sensor due to its unique electrical properties. The dopa-alginate component improves humidity adhesion, and the MXene enhances strain sensitivity. The hydrogel can be prepared by electro-oxidizing the alginate-dopa, followed by crosslinking with other polymers and MXene.

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Wearable sweat sensor for monitoring sweat composition and levels in real-time using flexible, wireless, miniaturized, anti-pollution electrodes that can directly measure biochemicals like vitamin C and uric acid in sweat without pretreatment. The sensor uses a stretchable hydrogel composite electrode material with self-healing properties and selective catalytic function for vitamin C and uric acid in sweat. It also has an iontophoresis electrode decorated with pilocarpine to stimulate sweating. The sensor is connected wirelessly to a mobile device for monitoring via Bluetooth.

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Hydrogels containing a cross-linkable urethane-based polymer for controlled release of antimicrobial agents like iodine in wound dressings. The hydrogels have a unique polymer composition with at least one polymer backbone of PEG and at least one backbone of PVP, PNVCL, or a combination. This allows complexation of antimicrobials like iodine by the PEG segments, enabling prolonged release compared to uncomplexed iodine. The hydrogels can be used in wound dressings for controlled antimicrobial therapy to reduce infection risk and avoid excessive iodine burst release.

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Fully flexible wearable smart sensing device for monitoring multiple physiological signals like electrical, chemical, and physical signals in parallel. The device uses hydrogel-based flexible sensors with adjustable mechanical properties that match skin elasticity. The hydrogel sensors have differential receptors filled with Hofmeister ions to selectively respond to specific biochemicals. The device has a flexible circuit to wirelessly transmit the multivariate biochemical data. The hydrogel sensors provide stable signal acquisition during movement, and the flexible device fits the body better than rigid sensors.

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Synthesis of a continuously active antibacterial hydrogel for wound healing that can also measure temperature and humidity. The hydrogel contains ovotransferrin, a protein from egg white, which has strong antibacterial properties due to its ability to bind iron and inhibit bacterial feeding. The hydrogel can also monitor wound conditions by incorporating temperature and humidity sensors. The ovotransferrin hydrogel provides simultaneous antibacterial wound healing and environmental sensing capabilities.

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Intelligent antibacterial hydrogel for rapid wound healing that releases antibiotics slowly at normal body temperature and rapidly when the wound temperature exceeds 37.5°C. The hydrogel contains antibacterial agents, cyclodextrin, polyacrylic acid, agar, pH regulator, and water. The composition allows gradual antibiotic release at physiological temperature but accelerated release at higher wound temperatures to prevent infection.

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A reinforced antiseptic hydrogel bandage for wound healing that provides protection, prevents infection, and promotes wound healing. The bandage is made from a hydrogel containing pectin, sodium alginate, plasticizers, preservative, disinfectant, and chlorhexidine. The hydrogel absorbs excess exudate, keeps the wound moist, prevents drying, and maintains a moist environment. The bandage with chlorhexidine provides antimicrobial protection against bacteria like Staphylococcus aureus and Pseudomonas aeruginosa. The hydrogel also has a reinforcing element like cotton or polypropylene for strength. The bandage is applied to wounds to protect, prevent infection, and promote healing.

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Medical hydrogel dressing for preventing new scar formation in wounds. The dressing has a hydrogel core surrounded by protective films, adhesives, and seals to create a moist healing environment that promotes wound healing without scarring. The hydrogel absorbs exudate and forms a gel to keep the wound moist. The protective films prevent sticking and allow air exchange. The adhesives secure the dressing to the skin. Seals prevent leakage. The hydrogel has high water content, absorbs exudate, promotes capillary formation, and releases growth factors.

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Self-curing amorphous hydrogel pressure ulcer dressing that tightly adheres to the wound site without needing to cut or tape it. The dressing has a sandwich structure with an upper and lower hydrogel layer sandwiched by an elastic reinforcing interlayer. The interlayer contains hydrogel, guar gum, and hydrolyzed elastin. The elastin provides elastic support and fixes the layers together. The hydrogel layers absorb exudate and promote healing, while the elastin reinforces the dressing. The dressing also has a self-curing outer layer that solidifies when exposed to oxygen.

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Intelligent human-computer interaction sensing device based on MXene/PAA hydrogel that can provide flexible, sensitive, self-healing, and biocompatible sensors for applications like wearables, smart fabrics, and medical implants. The sensor consists of MXene/PAA hydrogel adhered to the body, copper foils connected to the hydrogel ends, and wires connecting to a signal acquisition module. The module processes the body motion signals, converts them to electrical signals, and transmits to a mechanical control module for actuation. The MXene/PAA hydrogel provides flexible strain sensing with self-healing and adhesive properties.

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Wearable self-powered sensor and monitoring device that can generate electricity from body heat and detect physiological signals without an external power source. The sensor has two parts: a flexible hydrogel for sensing applications and a thermoelectric device for power generation. The hydrogel contacts the skin and changes resistance in response to strain or pressure. The thermoelectric device converts the temperature difference between the skin and device into voltage. Connecting them in series forms a closed circuit that can power electronics and provide sensing signals. The hydrogel also improves thermoelectric power output by increasing the temperature difference.

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Hydrogel dressing for wound healing that promotes wound healing by combining mechanical activity and immune regulation. The dressing is made from a semi-interpenetrating network hydrogel composed of poly(N-isopropylacrylamide), polymethacrylic acid, and gelatin. The hydrogel strongly adheres to skin and contracts in response to skin temperature. The interspersed polymethacrylic acid promotes wound healing by regulating macrophages and blood vessel formation. The gelatin improves ductility and biocompatibility. The dressing accelerates wound healing through a mechanically active and immunomodulating adhesive.

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Biocompatible sensor devices and systems for passive, wireless, long-term monitoring of environmental stimuli like glucose, pH, oil, and chemicals in aqueous environments. The sensors have stacked, resonant-coupled split ring resonators with interlayers that absorb, swell, or deform in response to stimuli. The interlayers are biocompatible materials like silk, hydrogels, membranes, and films. The sensors operate without batteries or electronics by modifying capacitance in response to stimuli. They can be affixed to skin, implanted, or integrated into body tissues for long-lasting, passive, wireless monitoring of internal fluids and substances.

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Moisture-regulating wound dressings that promote faster healing by maintaining optimal moisture levels at the wound site. The dressings are made from chitosan hydrogels that can absorb and release moisture in response to the wound environment. This prevents excessive drying or over-saturation of the wound. The chitosan hydrogels are synthesized by either physical or chemical methods. The dressings can also be activated with anions or cations to enhance their moisture-regulating properties.

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Medical hydrogel non-porous moisture-permeable membrane for wound healing that has high antibacterial properties, good waterproof and breathable characteristics, and is non-adhesive. The membrane is made by combining a hydrogel with a non-porous vapor barrier film. The hydrogel is a methacrylate esterified gelatin copolymerized with N-isopropylacrylamide. The barrier film is modified with hydroxyl groups to allow chemical bonding with the hydrogel. The hydroxyl groups on the film surface react with a crosslinking agent to form a hydroxyl-rich structure. This enables chemical bonding between the hydrogel and the barrier film. The hydrogel has copper-based MOF nanoparticles loaded in it for antibacterial effects. The barrier film provides waterproofing and breathability. The hydrogel's temperature-

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Biomedical sensor devices for measuring analyte concentrations in vivo using stimulus-responsive hydrogels. The sensors have a thin film polymer substrate with an integrated electric sensing element like a microcoil. A hydrogel is attached to one side of the substrate and changes shape in response to analytes. This deformation alters the sensing element's impedance, allowing concentration measurement. The small size and flexibility of the sensor devices enable in vivo use. The sensors can be integrated into catheters for minimally invasive monitoring.

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Flexible self-healing conductive hydrogel sensor with good mechanical properties, conductivity, self-healing, and compressibility for applications like biosensors and smart skins. The sensor is made by interpenetrating networks of polyacrylamide and acetoacetated polyvinyl alcohol. Iron ions chelate with the acetoacetate groups to provide conductivity and self-healing. The hydrogel has high elongation, strength, and rebound, as well as reversible shape changes under compression. The sensor's electrical signals change with external force, allowing monitoring of human motion and physiological signals.

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Tough hydrogel coatings that combine the benefits of hydrogels like biocompatibility and low friction with the mechanical properties of substrates like elastomers. The coatings are made by grafting hydrogel chains onto substrate surfaces. This creates a hydrogel-substrate laminate with an impermeable substrate sandwiched between hydrogel layers. The hydrogel coatings are stretchy and tough due to a double network of crosslinked polymer chains. They can be tuned to match mechanical properties from pure substrate to pure hydrogel. The coatings can also contain therapeutic agents and sensors to release drugs or detect conditions. The hydrogel-substrate bonding provides robustness and prevents permeation through the laminate.

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