Search Results (87)

Biocompatible stimuli-sensitive hydrogels are a versatile and promising class of materials with significant potential for various biomedical applications. These ‘’smart’’ hydrogels can dynamically respond to external environmental stimuli such as pH, temperature, enzymes, or biomolecular interactions, enabling controlled drug release, tissue regeneration, wound healing, and biosensing applications. Hydrogels derived from natural polymers, including chitosan, alginate, collagen, and hyaluronic acid, offer key advantages such as intrinsic biocompatibility, biodegradability, and the ability to mimic the extracellular matrix. Their ability to respond to environmental stimuli—including pH, temperature, redox potential, and enzymatic activity—enables control over drug release and tissue regeneration processes. This review explores the fundamental principles governing the design, properties, and mechanisms of responsiveness of natural stimuli-sensitive hydrogels. It also highlights recent advancements in their biomedical applications, discusses existing challenges, and outlines future research directions aimed at improving their functional performance and therapeutic potential for sustainable healthcare solutions. Full article

Reversible adhesives enable temporary yet robust bonding between surfaces, allowing controlled detachment without structural or interfacial damage. This capability is gaining increasing recognition as a crucial requirement for sustainable technologies, where repairability, reusability, and minimal waste are key objectives. Among the diverse strategies explored for reversible adhesion (including supramolecular assemblies, bioinspired dry adhesives, and stimuli-responsive polymers), hydrogel-based systems have emerged as particularly versatile candidates due to their tunable mechanics, elasticity, and intrinsic biocompatibility. Recent studies highlight the use of renewable or biodegradable polymers to develop sustainable, water-rich hydrogel networks with controllable adhesive properties, minimizing environmental impact while maintaining performance. Despite these advances, significant challenges still hinder full implementation: biopolymer-based systems such as chitosan or starch often exhibit strong but poorly controllable adhesion, compromising reversibility and reusability. This review provides a comprehensive overview of strategies for developing hydrogel-based reversible adhesives, focusing on sustainable material selection, molecular design principles, and the underlying mechanisms of bonding and debonding. Furthermore, characterization methodologies, from conventional mechanical testing to surface-sensitive and dynamic techniques, are discussed in detail to establish structure–property–function relationships. Finally, emerging directions and application opportunities are outlined, offering a framework for the rational design of next-generation, sustainable adhesive systems. Full article

Conductive hydrogels (CHs) have attracted significant attention in the fields of flexible electronics, human–machine interaction, and electronic skin (e-skin) due to their self-adhesiveness, environmental stability, and multi-stimuli responsiveness. However, integrating these diverse functionalities into a single conductive hydrogel system remains a challenge. In this study, polyvinyl alcohol (PVA) and polyacrylamide (PAM) were used as the dual-network matrix, lithium chloride and MXene were added, and a simple immersion strategy was adopted to synthesize a multifunctional MXene-based conductive hydrogel in a glycerol/water (1:1) binary solvent system. A subsequent investigation was then conducted on the hydrogel. The prepared PVA/PAM/LiCl/MXene hydrogel exhibits excellent tensile properties (~1700%), high electrical conductivity (1.6 S/m), and good self-healing ability. Furthermore, it possesses multimodal sensing performance, including humidity sensitivity (sensitivity of −1.09/% RH), temperature responsiveness (heating sensitivity of 2.2 and cooling sensitivity of 1.5), and fast pressure response/recovery times (220 ms/230 ms). In addition, the hydrogel has successfully achieved real-time monitoring of human joint movements (elbow and knee bending) and physiological signals (pulse, breathing), as well as enabled monitoring of spatial pressure distribution via a 3 × 3 sensor array. The performance and versatility of this hydrogel make it a promising candidate for next-generation flexible sensors, which can be applied in the fields of human health monitoring, electronic skin, and human–machine interaction. Full article

Poly(carboxybetaine methacrylate)s (PCBMA) belongs to a class of zwitterionic polymers that offer promising alternatives to polyethylene glycol (PEG) in biomedical applications. This review highlights how the unique zwitterionic structure of PCBMA dictates its strong antifouling behavior, low immunogenicity, and sensitivity to environmental stimuli such as pH and ionic strength. These features make PCBMA promising for designing advanced systems suited for complex biological environments. This review describes PCBMA-based materials—ranging from hydrogels, nanogels, and surface coatings to drug carriers and protein conjugates—and critically evaluates their performance in drug delivery, tissue engineering, diagnostics, and implantable devices. Comparative studies demonstrated that PCBMA consistently outperformed other zwitterionic polymers and PEG in resisting protein adsorption, maintaining bioactivity of conjugated molecules, and ensuring long circulation times in vivo. Molecular dynamics simulations provide additional information into the hydration shells and conformational behaviors of PCBMA in aqueous dispersions. These insights underscore PCBMA’s broad potential as a promising high-performance material for next generation healthcare technologies. Full article

Research into oral mucosa-targeted drug delivery systems (DDS) is rapidly evolving, with growing emphasis on enhancing bioavailability and precision targeting while overcoming the unique anatomical and physiological barriers of the oral environment. Despite considerable progress, challenges such as enzymatic degradation, limited mucosal penetration, and solubility issues continue to hinder therapeutic success. Recent advancements have focused on innovative formulation strategies—including nanoparticulate and biomimetic systems—to improve delivery efficiency and systemic absorption. Simultaneously, smart and stimuli-responsive materials are emerging, offering dynamic, environment-sensitive drug release profiles. One particularly promising area involves the application of glycosaminoglycans, a class of naturally derived polysaccharides with excellent biocompatibility, mucoadhesive properties, and hydrogel-forming capacity. These materials not only enhance drug residence time at the mucosal site but also enable controlled release kinetics, thereby improving therapeutic outcomes. However, critical research gaps remain: standardized, clinically meaningful mucoadhesion/permeation assays and robust in vitro–in vivo correlations are still lacking; long-term stability, batch consistency of GAGs, and clear regulatory classification (drug, device, or combination) continue to impede scale-up and translation. Patient-centric performance—palatability, mouthfeel, discreet wearability—and head-to-head trials versus standard care also require systematic evaluation to guide adoption. Overall, converging advances in GAG-based films, hydrogels, and nanoengineered carriers position oral mucosal delivery as a realistic near-term option for precision local and selected systemic therapies—provided the field resolves standardization, stability, regulatory, and usability hurdles. Full article

Heparin-based delivery platforms have gained increasing attention in regenerative medicine due to their exceptional affinity for growth factors and versatility in structural and functional design. This review first introduces the molecular biosynthesis and physicochemical diversity of heparin, which underpin its binding selectivity and degradability. It then categorizes the delivery platforms into microspheres, nanofibers, and hydrogels, with detailed discussions on their fabrication techniques, biofunctional integration of heparin, and release kinetics. Special focus is given to stimuli-responsive systems—including pH-, enzyme-, redox-, thermal-, and ultrasound-sensitive designs—which allow spatiotemporal control over growth factor release. The platform applications are organized by tissue types, encompassing soft tissue regeneration, bone and cartilage repair, neuroregeneration, cardiovascular regeneration, wound healing, anti-fibrotic therapies, and cancer microenvironment modulation. Each section provides recent case studies demonstrating how heparin enhances the bioactivity, localization, and therapeutic efficacy of pro-regenerative or anti-pathologic growth factors. Collectively, these insights highlight heparin’s dual role as both a carrier and modulator, positioning it as a pivotal component in next-generation, precision-targeted delivery systems. Full article

Surgical procedures trigger dynamic inflammatory responses that influence postoperative pain, wound healing, and long-term outcomes. Conventional therapies rely on the systemic delivery of anti-inflammatory and analgesic agents, which often lack spatiotemporal precision and carry significant side effects. Inflammation-responsive hydrogels offer a promising alternative by enabling localized, stimulus-adaptive drug release aligned with the evolving biochemical milieu of surgical wounds. These smart biomaterials respond to endogenous triggers, such as reactive oxygen species, acidic pH, and proteolytic enzymes, allowing precise modulation of inflammation and tissue repair. This narrative review outlines the pathophysiological features of perioperative inflammation and the design principles of responsive hydrogel systems, including pH-, reactive oxygen species-, enzyme-sensitive, and multi-stimuli platforms. We evaluated the integration of key payloads, NSAIDs, corticosteroids, α₂-adrenergic agonists, and biologics, highlighting their therapeutic synergy and translational relevance. Preclinical studies across soft tissue, orthopedic, thoracic, and abdominal models have demonstrated the efficacy of these systems in modulating immune responses, reducing pain, and enhancing regeneration. Despite these encouraging results, challenges remain, including trigger fidelity, surgical compatibility, and regulatory readiness. Future advances in biosensor integration, logic-based design, and artificial intelligence-guided formulation may accelerate clinical translation. Inflammation-responsive hydrogels represent a transformative strategy for precise perioperative care. Full article

Wearable conductive hydrogel sensors, which are highly convenient, have attracted attention for their great potential in human motion monitoring and smart healthcare. However, the self−adhesive properties, sensing performance, and stability of traditional hydrogels are not ideal, which seriously hinders their use in monitoring and diagnosing joints throughout the human body. Here, CaCl₂ is used to crosslink PVA to improve its self−adhesive properties, and it is then combined with a CNT conductive network. Next, a cyclic freeze–thaw strategy is utilized to fabricate a wearable PVA−Ca−CNT hydrogel with excellent self-adhesive properties and stability. PVA−Ca−CNT hydrogels can adhere to various substrates, with a maximum self-adhesion strength of 398 kPa and a unit adhesion energy of as high as 305 μJ cm⁻². Furthermore, the CNT three−dimensional network enhances the tensile strength to 110 kPa, with almost no hysteresis. Based on resistance changes, PVA−Ca−CNT hydrogel exhibits a sensitivity of up to 11.11 as a strain sensor as well as a response to strain stimuli within 180 ms. When PVA−Ca−CNT hydrogel is adhered to the surface of human skin, it operates as a sensor for monitoring human movement. Not only can it accurately monitor the movement positions of major joints in the human body, it can also accurately identify tiny movements of the fingers and be used as a finger Morse code output device, which demonstrates the enormous potential of human motion monitoring systems based on self−adhesive hydrogel sensors in practical applications. Full article

By 2030, millions of new cancer cases will be diagnosed, as well as millions of cancer-related deaths. Traditional drug delivery methods have limitations, so developing smart drug delivery systems (SDDs) has emerged as a promising avenue for more effective and precise cancer treatment. Nanotechnology, particularly nanomedicine, provides innovative approaches to enhance drug delivery, including the use of nanoparticles. One such type of SDD is thermosensitive nanoparticles, which respond to internal and external stimuli, such as temperature changes, to release drugs precisely at tumor sites and minimize off-target effects. On the other hand, hyperthermia is a cancer treatment mode that goes back centuries and has become popular because it can target cancer cells while sparing healthy tissue. This paper presents a comprehensive review of smart thermosensitive nanoparticles for cancer treatment, with a primary focus on organic nanoparticles. The integration of hyperthermia with temperature-sensitive nanocarriers, such as micelles, hydrogels, dendrimers, liposomes, and solid lipid nanoparticles, offers a promising approach to improving the precision and efficacy of cancer therapy. By leveraging temperature as a controlled drug release mechanism, this review highlights the potential of these innovative systems to enhance treatment outcomes while minimizing adverse side effects. Full article

The development of multifunctional conductive hydrogels with rapid self-healing capabilities and powerful sensing functions is crucial for advancing wearable electronics. This study designed and prepared a polyvinyl alcohol (PVA)–borax hydrogel incorporating carbon nanotubes (CNTs) and biomass carbon nanospheres (CNPs) as dual-carbon fillers. This hydrogel exhibits excellent conductivity, mechanical flexibility, and self-recovery properties. Serving as a highly sensitive piezoresistive sensor, it efficiently converts mechanical stimuli into reliable electrical signals. Sensing tests demonstrate that the CNT/CNP/PVA–borax hydrogel sensor possesses an extremely fast response time (88 ms) and rapid recovery time (88 ms), enabling the detection of subtle and rapid human motions. Furthermore, the hydrogel sensor also exhibits outstanding cyclic stability, maintaining stable signal output throughout continuous loading–unloading cycles exceeding 3200 repetitions. The hydrogel sensor’s characteristics, including rapid self-healing, fast-sensing response/recovery, and high fatigue resistance, make the CNT/CNP/PVA–borax conductive hydrogel an ideal choice for multifunctional wearable sensors. It successfully monitored various human motions. This study provides a promising strategy for high-performance self-healing sensing devices, suitable for next-generation wearable health monitoring and human–machine interaction systems. Full article

Digital light processing (DLP) technology stands out as a groundbreaking method in the field of biomedical engineering that enables the production of highly precise structures using photopolymerizable materials. Smart materials such as shape memory polymers, hydrogels, and nanocomposites are used as ideal materials for personalized medicine applications thanks to their properties such as superior mechanical strength, biocompatibility, and sensitivity to environmental stimuli in DLP technology. The integration of these materials with DLP enables the production of functional and complex structures, especially in areas such as bone and soft tissue engineering, drug delivery, and biosensor production. However, limited material diversity, scalability problems in production processes, and technical difficulties in optimizing bioprinting parameters are among the main obstacles in this field. This study systematically examines the role of smart biomaterials in DLP-based bioprinting processes. It addresses the innovative applications of these materials in tissue engineering and regenerative medicine. It also comprehensively evaluates its contributions to biomedical applications and discusses future research areas to overcome current limitations. Full article

Drug resistance remains a major barrier to effective cancer treatment, contributing to poor patient outcomes. Multifunctional biomaterials integrating electrical and catalytic properties offer a transformative strategy to target diverse resistance mechanisms. This review explores their ability to modulate cellular processes, remodel the tumor microenvironment (TME), and enhance drug delivery. Electrically active biomaterials enhance drug uptake and apoptotic sensitivity by altering membrane potentials, ion channels, and intracellular signaling, synergizing with chemotherapy. Catalytic biomaterials generate reactive oxygen species (ROS), activate prodrugs, reprogram hypoxic and acidic TME, and degrade the extracellular matrix (ECM) to improve drug penetration. Hybrid nanomaterials (e.g., conductive hydrogels, electrocatalytic nanoparticles), synergize electrical and catalytic properties for localized, stimuli-responsive therapy and targeted drug release, minimizing systemic toxicity. Despite challenges in biocompatibility and scalability, future integration with immunotherapy, personalized medicine, and intelligent self-adaptive systems capable of real-time tumor response promises to accelerate clinical translation. The development of these adaptive biomaterials, alongside advancements in nanotechnology and AI-driven platforms, represents the next frontier in precision oncology. This review highlights the potential of multifunctional biomaterials to revolutionize cancer therapy by addressing multidrug resistance at cellular, genetic, and microenvironmental levels, offering a roadmap to improve therapeutic outcomes and reshape oncology practice. Full article

Bone defects caused by various traumas and diseases such as osteoporosis, which affects bone density, and osteosarcoma, which affects the integrity of bone structure, are now well known. Given this situation, several innovative research projects have been reported to improve orthopedic methods and technologies that positively contribute to the regeneration of affected bone tissue, representing a significant advance in regenerative medicine. This review article comprehensively analyzes the transition from existing methods and technologies for implants and bone tissue regeneration to innovative biomaterials. These biomaterials have been of great interest in the last decade due to their physicochemical characteristics, which allow them to overcome the most common limitations of traditional grafting methods, such as the availability of biomaterials and the risk of rejection after their application in regenerative medicine. This could be achieved through an exhaustive study of the applications and properties of various materials with potential applications in regenerative medicine, such as using magnetic nanoparticles and hydrogels sensitive to external stimuli, including pH and temperature. In this regard, this review article describes the most relevant compounds used in bone tissue regeneration, promoting the integration of these biomaterials with the affected area’s bone structure, thereby allowing for regeneration and preventing amputation. Additionally, the types of interactions between biomaterials and mesenchymal stem cells and their effects on bone tissue are discussed, which is critical for developing biomaterials with optimal regenerative properties. Furthermore, the mechanisms of action of the various biomaterials that enhance osteoconduction and osteoinduction, ensuring the success of orthopedic therapies, are analyzed. This enables the treatment of bone defects tailored to each patient’s condition, thereby avoiding limb amputation. Consequently, a promising future for regenerative medicine is emerging, with various therapies that could revolutionize the management of bone defects, offering more efficient and safer solutions. Full article

Cellulose, a widely abundant natural polymer, is well recognized for its remarkable properties, such as biocompatibility, degradability, and mechanical strength. Conductive hydrogels, with their unique ability to conduct electricity, have attracted significant attention in various fields. The combination of cellulose and conductive hydrogels has led to the emergence of cellulose-based conductive hydrogels, which show great potential in flexible electronics, biomedicine, and energy storage. This review article comprehensively presents the latest progress in cellulose-based conductive hydrogels. Firstly, it provides an in-depth overview of cellulose, covering aspects like its structure, diverse sources, and classification. This emphasizes cellulose’s role as a renewable and versatile material. The development and applications of different forms of cellulose, including delignified wood, bacterial cellulose, nanocellulose, and modified cellulose, are elaborated. Subsequently, cellulose-based hydrogels are introduced, with a focus on their network structures, such as single-network, interpenetrating network, and semi-interpenetrating network. The construction of cellulose-based conductive hydrogels is then discussed in detail. This includes their conductive forms, which are classified into electronic and ionic conductive hydrogels, and key performance requirements, such as cost-effectiveness, mechanical property regulation, sensitive response to environmental stimuli, self-healing ability, stable conductivity, and multifunctionality. The applications of cellulose-based conductive hydrogels in multiple areas are also presented. In wearable sensors, they can effectively monitor human physiological signals in real time. In intelligent biomedicine, they contribute to wound healing, tissue engineering, and nerve regeneration. In flexible supercapacitors, they offer potential for green and sustainable energy storage. In gel electrolytes for conventional batteries, they help address critical issues like lithium dendrite growth. Despite the significant progress, there are still challenges to overcome. These include enhancing the multifunctionality and intelligence of cellulose-based conductive hydrogels, strengthening their connection with artificial intelligence, and achieving simple, green, and intelligent large-scale industrial production. Future research directions should center around exploring new synthesis methods, optimizing material properties, and expanding applications in emerging fields, aiming to promote the widespread commercialization of these materials. Full article

Hydrogels are innovative materials characterized by a water-swollen, crosslinked polymeric network capable of retaining substantial amounts of water while maintaining structural integrity. Their unique ability to swell or contract in response to environmental stimuli makes them integral to biomedical applications, including drug delivery, tissue engineering, and wound healing. Among these, “smart” hydrogels, sensitive to stimuli such as pH, temperature, and light, showcase reversible transitions between liquid and semi-solid states. Thermoresponsive hydrogels, exemplified by poly(N-isopropylacrylamide) (PNIPAM), are particularly notable for their sensitivity to temperature changes, transitioning near their lower critical solution temperature (LCST) of approximately 32 °C in water. Structurally, PNIPAM-based hydrogels (PNIPAM-HYDs) are chemically versatile, allowing for modifications that enhance biocompatibility and functional adaptability. These properties enable their application in diverse therapeutic areas such as cancer therapy, phototherapy, wound healing, and tissue engineering. In this review, the unique properties and behavior of smart PNIPAM are explored, with an emphasis on diverse synthesis methods and a brief note on biocompatibility. Furthermore, the structural and functional modifications of PNIPAM-HYDs are detailed, along with their biomedical applications in cancer therapy, phototherapy, wound healing, tissue engineering, skin conditions, ocular diseases, etc. Various delivery routes and patents highlighting therapeutic advancements are also examined. Finally, the future prospects of PNIPAM-HYDs remain promising, with ongoing research focused on enhancing their stability, responsiveness, and clinical applicability. Their continued development is expected to revolutionize biomedical technologies, paving the way for more efficient and targeted therapeutic solutions. Full article