Search Results (86)

Hydrogel-based optical sensors have emerged as a versatile class of analytical materials that combine soft-matter processability, tunable network chemistry, and compatibility with luminescent, colorimetric, photonic, and hybrid transduction strategies. Progress in the field is driven not by a single sensing mechanism, but by the convergence of key advances in material functionalization, embedded selectivity, operation across diverse sample matrices, mechanical and analytical robustness, and usability beyond the laboratory. Current systems include framework-integrated, nanoparticle-doped, probe-functionalized, photonic-crystal, enzyme-immobilized, and device-coupled hydrogels, reflecting growing architectural diversity and application-oriented engineering. Selectivity has likewise advanced from basic interferent screening to recognition-specific, imprinted, and pattern-discriminative formats suited to complex environmental, food, biological, and wearable settings. Evidence of stability, reusability, and deformation tolerance further suggests that many platforms are moving beyond proof-of-concept demonstrations toward credible real-world operation. At the same time, translational priorities such as portability, smartphone readout, implantable and epidermal formats, and multifunctionality spanning antimicrobial action, adsorption, anti-counterfeiting, and device integration are becoming increasingly prominent. Together, these trends show that hydrogel-based optical sensing is maturing into a materially rich, application-responsive domain. The key challenge ahead is to unify materials design, selectivity control, durability, and deployability in standardized, reproducible, and clinically or environmentally credible sensing platforms. Full article

In ulcerative colitis (UC), the therapeutic efficacy of nanoparticle (NP)-based drug delivery systems is limited by premature drug release, uptake or degradation of NPs during their passage through the harsh gastrointestinal tract (GIT) environment, poor colon targeting, and rapid NP clearance caused by diarrhea symptoms. This study focused on designing an advanced spatiotemporally controlled nanohybrid hydrogel drug delivery system to overcome these challenges. We developed a pH- and temperature-responsive polysaccharide-based hydrogel composed of chitosan (CS), β-glycerol phosphate disodium salt pentahydrate (GP), hydroxypropyl cellulose (HPC), and collagen type I (Col I), designated as CS/HHPC/Col I-GP. The hydrogel exhibited a dense and uniform porous reticular structure, with an average pore diameter of 127.45 ± 2.22 μm. The equilibrium swelling ratio of the CS/HHPC/Col I-GP was determined to be 32.10 ± 1.11 g/g, indicating excellent swelling capacity and sustained structural stability over 6 h—making it suitable for sustained drug release in the intestinal tract. Then, the prepared curcumin nanoparticles (CurNPs) were encapsulated into the CS/HHPC/Col I-GP hydrogel to form the CS/HHPC/Col I-GP-CurNPs composite. The polysaccharide-based hydrogel shell of the formulation withstood harsh gastrointestinal conditions, enabled targeted adhesion to the colon, and was specifically degraded by colonic enzymes. The CurNPs released in the colon benefit from their negatively charged characteristics, enabling accumulation at the positively charged inflamed sites and achieving sustained Cur release. The results of the gastrointestinal digestion simulation experiment showed that the cumulative release of CS/HHPC/Col I-GP-CurNPs was only 12.33 ± 2.17% in simulated gastric fluid (SGF) and reached 96.91 ± 1.98% in simulated colonic fluid (SCF) after 60 h. Cell and animal experimental data confirmed that the formulation significantly alleviated colitis symptoms by modulating the repolarization of pro-inflammatory M1 macrophages to anti-inflammatory M2 phenotypes and deactivating the TLR4/MyD88/NF-κB pathway. Furthermore, the integrity of the intestinal mucosal barrier and the gut microbiota were enhanced. This study provides a promising strategy for the oral drug treatment of UC. Full article

To overcome the limitations of conventional therapies, targeted delivery of therapeutic interventions is crucial. Specifically, novel hydrogels maximize efficacy while minimizing the premature degradation of therapeutic enzymes. Therefore, the present study aimed to evaluate a developed pH-responsive inulin–sodium alginate (Na⁺ alginate) hydrogel bead system for colon-specific release of serine protease. Scanning electron microscope (SEM) images revealed structural differences between blank and encapsulated hydrogel beads. Fourier transform infrared spectroscopy (FTIR) spectra further confirmed the successful encapsulation of the bacterial serine protease in inulin-Na⁺ alginate (IN-Na⁺ Alg-SP). Thermogravimetric analysis (TGA) confirmed the thermal stability of hydrogel beads over a wide temperature range. Fabricated IN-Na⁺ Alg hydrogel beads displayed an entrapment efficiency of 54 ± 0.99% with an apparent activity of 260 U/mL. In vitro studies confirmed pH-responsive release with minimal release at pH 1.2 and sustained release at pH 7.4 over 4 h and 30 min. The ex vivo intestinal study confirms that the developed hydrogel has excellent potential as an oral colon-targeted drug delivery system for therapeutic enzymes. The release data best fit the second-order and Korsmeyer–Peppas models (R² > 0.96), indicating a combination of diffusion and erosion-controlled release mechanisms. These findings suggest that inulin-Na⁺ alginate hydrogels provide a promising carrier system for colon-specific delivery of serine protease with potential applications in targeted protein digestion and therapeutic interventions. Full article

Periodontitis is a chronic inflammatory condition characterized by the progressive destruction of periodontal supporting tissues. With a global prevalence exceeding 60%, it poses a significant public health challenge. Traditional therapeutic approaches, primarily mechanical debridement, systemic antibiotics, and surgical interventions, often face limitations such as incomplete biofilm removal, rapid drug clearance, and systemic adverse effects. To overcome these challenges, recent research has shifted towards the development of intelligent biomaterials capable of modulating the pathological microenvironment. These microenvironment-responsive strategies leverage unique biochemical signatures, including acidic pH, elevated reactive oxygen species (ROS), and enzymatic dysregulation, to facilitate precise, on-demand drug delivery at the lesion site. This review examines recent advances from three integrated perspectives: (1) material platforms (hydrogels, microneedles, fiber membranes, microspheres, inorganic nanoparticles, and vesicles); (2) responsive design (pH, ROS, enzyme, glucose, and multi-stimulus cascade logic); and (3) spatiotemporal functional orchestration (early-stage microecological remodeling, mid-stage osteoimmunomodulation, and late-stage tissue regeneration). Additionally, we analyze critical translational challenges, including manufacturing scalability, clinical sterilization, and long-term biosafety, while discussing prospects for clinical implementation. This review aims to provide a strategic roadmap and theoretical guidance for the development of next-generation precision therapies for periodontitis. Full article

This study systematically investigated the regulatory effects of different types of superabsorbent polymers (SAPs) on the growth and physiological characteristics of pakchoi (Brassica rapa subsp. chinensis) under drought stress. A pot-controlled experiment was conducted with two stress levels (severe drought and mild drought) and four SAP application ratios (0%, 0.25%, 0.5%, 0.75%). The acrylamide-based SAPs included a self-developed attapulgite clay hydrogel (ACH) and two commercially available mainstream SAPs. The results indicated that: (1) All SAP treatments mitigated the inhibitory effects of drought stress on pakchoi growth to varying degrees, with the 0.5% ACH application showing the most significant effect. Under severe drought, this treatment significantly increased leaf area, shoot fresh weight, and root fresh weight by 184.6%, 127.8%, and 24.6%, respectively, compared to the drought-stressed control without SAP. (2) At the physiological response level, ACH significantly optimized the osmotic adjustment system of pakchoi, manifesting as a significant 53.2% decrease in proline content and a significant 60.1% increase in soluble sugar content. Concurrently, it effectively maintained cell membrane stability, reducing malondialdehyde (MDA) content by a significant 51.6%, and effectively regulated the antioxidant defense system, modulating the activities of key antioxidant enzymes (SOD, CAT, and POD) to prevent oxidative damage. This study reveals that SAPs can effectively alleviate drought stress in pakchoi. Even under severe drought stress, leaf fresh weight reached approximately 67.99% of the normal level. An application rate of 0.5% ACH is identified as an efficient and recommended dose, offering a promising technological option for water-saving and sustainable vegetable production in arid and semi-arid regions. Full article

Inflammatory bowel disease (IBD), including Crohn’s disease and ulcerative colitis, is a chronic inflammatory disorder of the gastrointestinal tract that imposes an increasing global health burden. Conventional pharmacological treatments are often limited by systemic side effects and insufficient drug accumulation at inflamed intestinal sites. Enzyme-responsive polymeric drug delivery systems have emerged as a promising strategy to overcome these limitations by enabling site-specific and controlled drug release within the pathological microenvironment of the colon. This review summarizes recent advances in enzyme-responsive polymeric platforms designed for IBD therapy. We first discuss the altered enzymatic landscape in the intestinal microenvironment of IBD, including host-derived inflammatory enzymes such as esterases, matrix metalloproteinases, and hyaluronidase, as well as microbiota-derived enzymes such as azoreductase, cellulase, and amylase. These enzymes provide intrinsic biological triggers for selective polymer degradation and drug release. We then categorize enzyme-responsive polymeric delivery systems according to the enzymes involved and highlight representative material design strategies, including polymer prodrugs, core–shell nanocarriers, enzyme-degradable hydrogels, and polysaccharide-based carriers. Particular emphasis is placed on the multifunctional roles of polymers that enable targeted delivery, mucosal adhesion, and therapeutic synergy through bioactive degradation products. Finally, current challenges and future directions toward multi-stimuli-responsive systems and clinically translatable polymeric nanomedicine for precision IBD therapy are discussed. Full article

Bacterial cellulose (BC) has emerged as a structurally robust, biologically compatible, and highly adaptable biomaterial with significant potential for next-generation wound-care technologies. Its nanofibrillar, extracellular-matrix-like architecture provides exceptional moisture retention, mechanical stability, and conformability, enabling BC to function as an active scaffold rather than a traditional dressing. Advances in chemical modification, composite engineering, and bioactive functionalization, including antimicrobial metals, chitosan, biosurfactants, enzymes, and growth factors, have expanded BC’s therapeutic capabilities. Emerging smart BC dressings integrate biosensors, stimuli-responsive drug release, and 3D-printed architectures tailored to patient-specific wound geometries. Parallel developments in artificial intelligence (AI) are transforming BC production by optimizing bioprocessing, guiding genetic engineering, reducing culture media costs, and enabling real-time quality control, thereby improving scalability and industrial feasibility. These combined innovations position BC as a multifunctional, immunologically instructive, and digitally integrated platform for advanced regenerative wound care. This review reframes BC within the contemporary pathophysiology of chronic wounds, emphasizing its roles in immunomodulation, macrophage polarization, angiogenesis, mechanotransduction, and the disruption of mixed bacterial–fungal biofilms that characterize diabetic foot ulcers and other non-healing wounds. BC hydrogels typically contain >90–99% water and exhibit tensile strengths exceeding 200 MPa, enabling robust mechanical performance in wound environments. Advances in BC composites have demonstrated antimicrobial reductions of 3–5 log units against common chronic-wound pathogens. Full article

Polymer-based biosensors have evolved from passive supports into active functional elements that dictate analytical performance in complex real-world samples. This critical review with meta-trend analysis examines 96 original research articles published between 2015 and 2025, evaluating how four polymer classes (conductive polymers, redox-mediator polymers, hydrogels, and molecularly imprinted polymers) address matrix effects in food, beverage, environmental and clinical applications. Electrochemical detection dominates (79% of studies), with conductive polymers enabling low-potential operation that excludes electroactive interference. Hydrogels achieve superior precision (RSD below 3%) in protein-rich matrices through biocompatible microenvironments that preserve enzyme kinetics. Molecularly imprinted polymers provide unmatched stability in harsh environments for trace-level detection of heavy metals and toxins, though delayed response times from slow analyte diffusion persist. Critical evaluation exposes validation deficits: 91% of studies omit limits of quantification, while approximately one-third lack reproducibility (33%) and precision (30%). The multi-matrix challenge, maintaining calibration across different hostile environments, remains the primary barrier to commercial deployment. Advanced architectures, including nanocapsulation, hierarchical nanocomposites, and microneedle-integrated systems, offer pathways to overcome limitations in fouling resistance and operational stability. Full article

Biomaterials are engineered to interact with biological systems for therapeutic or diagnostic purposes. Among them, natural biomaterials offer important advantages over many synthetic polymers, including intrinsic biocompatibility, non-toxicity and biodegradability. Silk fibroin, a fibrous protein derived mainly from Bombyx mori cocoons, has re-emerged as a particularly versatile platform because it combines favourable mechanical, thermal, electrical and optical properties with aqueous processing and tuneable degradation. In this review, we first summarise the key structural, physicochemical and functional properties of regenerated silk fibroin, including its mechanical behaviour, thermal stability, dielectric and piezoelectric response, optical transparency and low autofluorescence. We then describe how extraction and regeneration protocols are used to produce defined material formats—fibres and nanofibrous mats, porous 3D scaffolds and hydrogels, sub-micron particles, thin films and microstructured devices—and outline major functionalisation strategies, ranging from physical blending and encapsulation to covalent chemistry, genetic engineering of recombinant silk variants, and enzyme-mediated conjugation approaches. Building on this foundation, we critically examine biomedical applications of silk fibroin with a particular emphasis on (i) hybrid silk–fluorophore systems for bioimaging and biosensing (nanodiamonds, quantum dots and organic dyes), (ii) optical fibre, wearable and edible sensors for health and food monitoring, (iii) wound dressings and wound-sensing platforms, and (iv) tissue engineering scaffolds and drug-delivery depots. Finally, we discuss current limitations, including process variability, the trade-offs introduced by blending and cross-linking, and the challenges posed by non-degradable inorganic fillers and clinical translation. Together, these perspectives highlight silk fibroin’s potential and constraints as a multifunctional biomaterial for next-generation biomedical devices and theranostic systems. Full article

Human induced pluripotent stem cell (iPSC)-derived brain organoids have emerged as powerful three-dimensional (3D) platforms for modeling human neurodevelopment and neurological disorders. However, the absence of a functional vascular network remains a critical limitation, restricting oxygen and nutrient delivery, impairing metabolic stability, and constraining long-term maturation. Conventional extracellular matrix (ECM) mimetics, such as Matrigel and other static synthetic hydrogels, provide biochemical support but fail to recapitulate the dynamic remodeling that characterizes the developing neurovascular niche. Recent advances in stimuli-responsive hydrogels offer spatiotemporal control over matrix stiffness, degradability, viscoelasticity, and biochemical cue presentation. In this review, we discuss dynamic hydrogel systems within a structure–property–function framework, highlighting how network chemistry and architecture may regulate endothelial sprouting, lumen formation, vascular stabilization, and neurovascular unit maturation in vascularized brain organoid models, based on evidence from both organoid studies and related biomaterial or vascular systems. Photoresponsive, enzyme-cleavable, thermo-responsive, supramolecular, bio-orthogonal click-based, and bioprinted platforms are discussed with emphasis on mechanotransduction, angiocrine signaling, and barrier specialization. Functional outcomes, including trans-endothelial electrical resistance, selective permeability, transporter expression, electrophysiological integration, and sustained perfusion, are discussed alongside translational challenges such as cytocompatibility, oxidative stress, scalability, and regulatory feasibility. Collectively, dynamic hydrogels provide a versatile biomaterial strategy for improving vascularization and aspects of functional maturation in brain organoid models with enhanced physiological relevance. Ultimately, stimuli-responsive hydrogel systems may serve as enabling platforms for engineering vascularized brain organoids and advancing human-relevant neurovascular disease modeling. Full article

Background/Objectives: Wound management presents a substantial clinical challenge due to the rising incidence of chronic wounds, infections, and the limitations of conventional dressings in creating an ideal healing microenvironment. This review aims to provide a comprehensive overview of advanced smart hydrogel platforms designed to improve wound healing outcomes, focusing on their capacity to respond adaptively to physiological and external stimuli. Methods: This article analyzes the core characteristics of smart hydrogels, specifically examining stimuli-responsive systems (pH, temperature, enzyme, light, and electricity). The review evaluates advanced configurations—including injectable, self-healing, and 3D-printable systems—and functionalized hydrogels integrated with antimicrobials, drugs, and nanocomposites. Additionally, essential characterization methodologies, biological assessments, and regulatory considerations for clinical translation are synthesized. Results: The literature, which is predominantly preclinical in nature, indicates that functionalized hydrogels significantly enhance tissue regeneration, angiogenesis, and infection control compared to traditional methods. Conductive hydrogels utilizing bioelectrical signals show particular promise in accelerating the healing process. While current clinical applications and commercial products demonstrate efficacy, significant barriers remain regarding large-scale manufacturing and regulatory approval. Conclusions: Smart hydrogels represent a transformative approach to precision wound management, offering superior adaptability and therapeutic delivery. To achieve widespread clinical adoption, future research must address manufacturing scalability and focus on emerging trends, such as the integration of biosensors and AI-powered monitoring systems, to create fully intelligent wound care solutions. Full article

Optimizing drug administration remains a central challenge in the development of modern therapies, especially in the context of conditions that require spatiotemporal control of active substance release. In this context, hydrogels have been intensively investigated as polymeric platforms for drug delivery, through their three-dimensional hydrophilic structure, tunable properties, and compatibility with biological environments. This analysis presents an integrated approach to hydrogels used in drug administration, addressing the physicochemical fundamentals, the constitutive polymeric materials, and the mechanisms of response to relevant physiological stimuli. Recent experimental studies have been discussed, which highlight the use of hydrogels based on natural, synthetic, and hybrid polymers for controlled and targeted release, in correlation with various administration routes, including oral, injectable, transmucosal, and topical ones. Advanced functionalization strategies that allow adaptive responses to pH, temperature, glucose, enzymes, and reactive oxygen species are also analyzed. Furthermore, emerging directions integrating hydrogels with biosensors, microdevices, and wireless communication systems for real-time monitoring and on-demand release are highlighted. Overall, the analysis emphasizes the role of smart hydrogels as multifunctional platforms for complex therapeutic strategies while also underlining the current challenges associated with clinical translation and long-term performance. Full article

Hydrogels are endowed with exceptional hydrophilicity and biocompatibility by their network structure, while also exhibiting soft physical properties similar to living tissues, which renders them ideal biomaterials. Responsive hydrogels—particularly those constructed from multicomponent systems including proteins, polysaccharides, peptides, and polyphenols—have emerged as a frontier research focus owing to their tunable responsiveness and controllable functional properties. In this review, hydrogel response mechanisms were categorized according to pH, ionic strength, temperature, light, enzymes, and multi-stimuli interactions. Key preparation strategies, encompassing chemical, physical, and enzymatic crosslinking, were systematically introduced. The preparation of hydrogels from various food-grade matrices, such as polysaccharide-based, protein-based, peptide-based, and polyphenol-based systems, was also summarized, with emphasis placed on how their tailored structures govern functional performance. Furthermore, innovative applications of responsive hydrogels were highlighted, including targeted delivery of nutrients and bioactive substances (e.g., probiotics, anthocyanins, vitamins) in functional foods, smart packaging and sensing for real-time freshness monitoring of meat and fruits, food quality detection through colorimetric and photothermal sensors, and 4D food printing for personalized nutrition and dysphagia-friendly foods. Full article

Rheumatoid arthritis (RA) is a chronic autoimmune disease that imposes substantial physical, emotional, and socioeconomic burdens on patients. Conventional therapeutic approaches are often limited by systemic toxicity, inadequate joint targeting, and variable patient responses, highlighting the urgent need for advanced drug delivery systems. Smart hydrogels have emerged as a promising platform for RA treatment due to their unique three-dimensional hydrophilic networks, excellent biocompatibility, and tunable physicochemical properties. This review systematically summarizes the preparation strategies and design principles of smart hydrogels, with an emphasis on chemically and physically crosslinked networks as well as composite systems. It further outlines the major stimulus-responsive release mechanisms—including temperature, pH, reactive oxygen species (ROS), light, and enzyme triggers—that enable targeted and controlled drug delivery within the inflamed joint microenvironment. Among the various types discussed, temperature-responsive and multi-responsive hydrogels are most frequently investigated for their potential to achieve localized, on-demand therapy. Despite considerable preclinical progress, the clinical translation of smart hydrogels faces critical challenges, including insufficient long-term biocompatibility data, lack of standardized evaluation protocols, and difficulties in scalable manufacturing. This review aims to provide a conceptual framework for the rational design of smart hydrogels and to stimulate interdisciplinary efforts toward overcoming existing translational barriers in RA treatment. Full article

Thermosensitive hydrogels have emerged as promising intelligent biomaterials for minimally invasive delivery and targeted therapy. Chitosan/gelatin thermosensitive hydrogels, integrating the biocompatibility, biodegradability, and antibacterial activity of chitosan with the excellent adhesive properties of gelatin, exhibit unique injectability, temperature-responsive gelation, and tunable physicochemical properties. This review systematically summarizes the key performance parameters of chitosan/gelatin thermosensitive hydrogels, including injectability, gelation characteristics (with sol-gel transition tunable between 37 and 42 °C to match diverse species’ body temperatures), mechanical properties, biocompatibility, degradation behavior (tunable from 1 to 8 weeks), drug-loading/release capabilities, and multi-stimuli responsiveness (pH/ROS/enzyme). It focuses on exploring their feasibility and suitability as acupoint embedding materials in Traditional Chinese Veterinary Medicine (TCVM), addressing the technical bottlenecks of traditional acupoint catgut embedding (e.g., unstable degradation, insufficient biocompatibility, and lack of drug-loading capacity). While recent studies have demonstrated the utility of such hydrogels in human disease models (e.g., rheumatoid arthritis and Parkinson’s disease), their translation to veterinary acupoint therapy remains largely unexplored. The prospective application of these hydrogels in treating common animal diseases (e.g., piglet diarrhea, canine degenerative joint disease, and equine laminitis) is, therefore, proposed and analyzed as an illustrative paradigm, emphasizing its integrated “stimulation–drug delivery” function and cross-species adaptability. Additionally, the current challenges (e.g., animal-specific formulation optimization, unclear mechanism of action, and insufficient long-term safety data) and future research directions (e.g., veterinary-specific formulation development, mechanistic exploration, and clinical translation) are highlighted. This review aims to promote the interdisciplinary integration of TCVM and smart biomaterials, provide precision strategies for animal disease treatment, and ultimately contribute to the modernization and standardization of TCVM technologies. Full article