Search Results (180)

Titanium is widely recognized as an interesting material for electrodes due to its excellent corrosion resistance, mechanical strength, and biocompatibility. However, further functionalization is often necessary to impart advanced interfacial properties, such as selective ion transport or stimuli responsiveness. In this context, the integration of smart polymers, such as poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA)—noted for its dual pH- and thermo-responsive behavior—has emerged as a promising approach to tailor surface properties for next-generation devices. This work compares two covalent immobilization strategies for PDMAEMA on titanium: the “graft-to” method, involving the attachment of pre-synthesized polymer chains, and the “graft-from” method, based on surface-initiated polymerization. The resulting materials were characterized with size exclusion chromatography (SEC) for molecular weight, Fourier-transform infrared spectroscopy (FTIR) for chemical structure, scanning electron microscopy (SEM) for surface morphology, and contact angle measurements for wettability. Electrochemical impedance spectroscopy and polarization studies were used to assess electrochemical performance. Both strategies yielded uniform and stable coatings, with the mode of grafting influencing both surface morphology and functional stability. These findings provide valuable insights into the development of adaptive, stimuli-responsive titanium-based interfaces in advanced electrochemical systems. Full article

Periodontitis, a chronic inflammatory disease, causes alveolar bone loss. Current treatments show limitations in achieving dual antimicrobial and anti-inflammatory effects. We evaluated an emodin-loaded thermoresponsive hydrogel as a local drug delivery system for periodontitis treatment. Emodin itself demonstrated antibacterial activity against Porphyromonas gingivalis, with minimal inhibitory and minimal bactericidal concentrations of 50 μM. It also suppressed mRNA expression of proinflammatory cytokines [tumor necrosis factor alpha, interleukin (IL)-1β, and IL-6] in lipopolysaccharide-stimulated RAW 264.7 cells. The hydrogel, formulated with poloxamers and carboxymethylcellulose, remained in a liquid state at room temperature and formed a gel at 34 °C, providing sustained drug release for 96 h and demonstrating biocompatibility with human periodontal ligament stem cells while exhibiting antibacterial activity against P. gingivalis. In a rat model of periodontitis, the hydrogel significantly reduced alveolar bone loss and inflammatory responses, as confirmed by micro-computed tomography and reverse transcription quantitative polymerase chain reaction of gingival tissue. The dual antimicrobial and anti-inflammatory properties of emodin, combined with its thermoresponsive delivery system, provide advantages over conventional treatments by maintaining therapeutic concentrations in the periodontal pocket while minimizing systemic exposure. This shows the potential of emodin-loaded thermoresponsive hydrogels as effective local delivery systems for periodontitis treatment. Full article

Traditional wound and burn treatments often fall short in balancing antimicrobial efficacy, patient comfort, and ease of application. This study introduces a novel, transparent, thermoresponsive sol–gel formulation incorporating polyhexamethylene biguanide (PHMB) for advanced topical therapy. Utilizing Poloxamer 407 as a biocompatible carrier, the formulation remains a sprayable liquid at room temperature and instantly gels upon contact with body temperature, enabling painless, pressure-free application on sensitive, injured skin. Comprehensive in vitro and in vivo evaluations confirmed the formulation’s broad-spectrum antimicrobial efficacy (≥5 log₁₀ reduction in 30 s), high biocompatibility (viability > 70% in fibroblasts), non-irritancy (OECD 425-compliant), and physical stability across three months. Importantly, the formulation maintained fibroblast migration capacity—crucial for wound regeneration—while exhibiting rapid sol-to-gel transition at ~34 °C. These findings highlight the system’s potential as a next-generation wound dressing with enhanced user compliance, transparent monitoring capability, and rapid healing support, particularly in disaster or emergency scenarios. Full article

In high-slope substrates, special requirements are imposed on sprayed ecological soil, which needs to exhibit high rheological properties before spraying and rapid curing after spraying. Traditional stabilizers are often unable to meet these demands. This study developed a thermo-responsive hydrogel stabilizer (HSZ) and applied it to ecological soil. The effects of HSZ on the rheological, mechanical, and vegetation performance of ecological soil were investigated, and the mechanism of the responsive carrier in the stabilizer was explored. The experimental results show that the ecological soil containing HSZ has high flowability before response, but its flowability rapidly decreases and consistency sharply increases after response. After the addition of HSZ, the 7 d unconfined compressive strength of the ecological soil reaches 1.55 MPa. The pH value of the ecological soil generally ranges from 6.5 to 8.0, and plant growth in a simulated vegetation box is favorable. Conductivity and viscosity tests demonstrate that the core–shell microcarriers, upon thermal response, release crosslinking components from the carrier, which rapidly react with the precursor solution components to form a curing system. This study provides a novel method for regulating ecological soil using a responsive stabilizer, further expanding its capacity to adapt to various complex scenarios. Full article

Mesoporous silica nanoparticles (MSNs) are gaining popularity in nanomedicine due to their large surface area, variable pore size, great biocompatibility, and chemical adaptability. In recent years, the combination of smart polymeric materials with MSNs has transformed the area of regulated drug administration, particularly under stimuli-responsive settings. Polymer-modified MSNs provide increased stability, longer circulation times, and, most crucially, the capacity to respond to diverse internal (pH, redox potential, enzymes, and temperature) and external (light, magnetic field, and ultrasonic) stimuli. These systems allow for the site-specific, on-demand release of therapeutic molecules, increasing treatment effectiveness while decreasing off-target effects. This review presents a comprehensive analysis of recent advancements in the development and application of polymer-functionalized MSNs for stimuli-triggered drug delivery. Key polymeric modifications, including thermoresponsive, pH-sensitive, redox-responsive, and enzyme-degradable systems, are discussed in terms of their design strategies and therapeutic outcomes. The synergistic use of dual or multiple stimuli-responsive polymers is also highlighted as a promising avenue to enhance precision and control in complex biological environments. Moreover, the integration of targeting ligands and stealth polymers such as PEG further enables selective tumor targeting and immune evasion, broadening the potential clinical applications of these nanocarriers. Recent progress in stimuli-triggered MSNs for combination therapies such as chemo-photothermal and chemo-photodynamic therapy is also covered, emphasizing how polymer modifications enhance responsiveness and therapeutic synergy. Finally, the review discusses current challenges, including scalability, biosafety, and regulatory considerations, and provides perspectives on future directions to bridge the gap between laboratory research and clinical translation. Full article

Advancements in thermoregulating textiles have been propelled by innovations in nanotechnology, composite materials, and smart fiber engineering. This article reviews recent scholarly papers on experimental passive and active thermoregulating textiles to present the latest advancements in these fabrics, their mechanisms of thermoregulation, and their feasibility for use. The review underscores that phase-change materials enhanced with graphene, boron nitride, and carbon nanofibers offer superior thermal conductivity, phase stability, and flexibility, making them ideal for wearable applications. Shape-stabilized phase-change materials and aerogel-infused fibers have shown promising results in outdoor, industrial, and emergency settings due to their durability and high insulation efficiency. Radiative cooling textiles, engineered with hierarchical nanostructures and Janus wettability, demonstrate passive temperature regulation through selective solar reflection and infrared emission, achieving substantial cooling effects without external energy input. Thermo-responsive, shape-memory materials, and moisture-sensitive polymers enable dynamic insulation and actuation. Liquid-cooling garments and thermoelectric hybrids deliver precise temperature control but face challenges in portability and power consumption. While thermoregulating textiles show promise, the main challenges include achieving scalable manufacturing, ensuring material flexibility, and integrating multiple functions without sacrificing comfort. Future research should focus on hybrid systems combining passive and active mechanisms, user-centric wearability studies, and cost-effective fabrication methods. These innovations hold significant potential for applications in extreme environments, athletic wear, military uniforms, and smart clothing, contributing to energy efficiency, health, and comfort in a warming climate. Full article

Access to clean water remains a critical global challenge, exacerbated by population growth, industrial activity, and climate change. In response, this study presents the development and characterization of thermo-responsive and salt-adaptive ultrafiltration membranes functionalized with a poly(N-isopropylacrylamide)–co-poly(dimethylacrylamide) (PNIPAM-co-PDMAC) copolymer. By combining the thermo-responsive properties of PNIPAM with the hydrophilic characteristics of PDMAC, these membranes exhibit dual-stimuli responsiveness to temperature and ionic strength, allowing for precise control of permeability and fouling resistance. The experimental results demonstrated that the copolymer’s hydration state and dynamic pore size modulation are sensitive to changes in salinity and temperature, with sodium chloride (NaCl) significantly influencing the transition behavior. Preliminary fouling tests confirmed the antifouling capabilities of these membranes, with salt-triggered hydration transitions effectively reducing irreversible fouling and extending membrane durability. The membranes’ reversible properties and adaptability to dynamic operating conditions highlight their potential to enhance the efficiency and sustainability of water treatment processes. Future investigations will focus on scaling up the fabrication process and assessing the long-term stability of these membranes under real-world conditions. This study underscores the promise of smart membrane systems for advancing global water sustainability. Full article

Background/Objectives: The management of ocular tumours is faced with the challenge of developing a suitable treatment strategy with consideration of the anatomical and physiological protective barriers of the eye. Interferon alpha has been employed to treat patients with ocular tumours for decades; however, its short half-life and poor tolerability necessitate frequent administration. This study focuses on the design of an injectable pH-responsive and protective nanoparticle system dispersed into a thermo-responsive hydrogel for site-specific sustained delivery of interferon alpha (IFN-α2b) in the treatment of ocular surface tumours. Methods: The synthesis of a poly(ethylene glycol)-poly(caprolactone)-poly(ethylene glycol) (PEG-PCL-PEG) triblock copolymer (PECE) was undertaken. The IFN-α2b was encapsulated in poly(β-amino ester) (PBAE) nanoparticles (NP) with pH-responsive characteristics to proposedly release the IFNα-2b in response to the acidic nature of the tumour microenvironment. This was followed by characterisation via Fourier transform infrared spectroscopy (FT-IR), ¹H-nuclear magnetic resonance (¹H-NMR) analysis, differential scanning calorimetry (DSC), X-ray powder diffraction (XRPD) analysis, thermogravimetric analysis (TGA), and thermal-transition analysis of the PECE hydrogels. Results: Release studies demonstrated that the PBAE nanoparticulate PEG-PCL-PEG hydrogel was both pH-responsive, while providing controlled release of IFN-α2b, and thermo-responsive. Release analysis highlighted that IFN-α2b-loaded NP dispersed into the hydrogel (IFNH) further prolonged the release of IFN-α2b with a pH-responsive yet controlled release rate in an acidic environment simulating a tumour microenvironment. The developed system proved to be biocompatible with human retinal pigment epithelial cells and the released IFN-α demonstrated bioactivity in the presence of an A172 glioblastoma cell line. Conclusions: In conclusion, the PECE hydrogel has promising potential for application as an ocular drug delivery system for the treatment of ocular tumours and could potentially overcome and prevent the drawbacks associated with the commercially available IFN-α2b injection. Full article

Background/Objective: A clinical need exists for more effective therapeutics and sustained drug delivery systems to promote ocular surface healing. This study tested the hypothesis that a novel biodegradable, thermoresponsive hydrogel loaded with the human recombinant (rh)MG53 protein, which we have demonstrated to promote corneal healing without fibrosis, would exhibit safety and biocompatibility in vitro and in vivo. Methods: Hydrogel optimization was performed based on varying concentrations of poloxamer 407, poloxamer 188, and hydroxypropyl methylcellulose. Hydrogels were characterized and potential toxicity was evaluated in vitro in cultured corneal epithelium, fibroblasts, and endothelium. In vivo safety and tolerability were assessed in mice and hydrogels were used to evaluate corneal healing following alkali injury. Results: The optimized hydrogel formulation did not result in any detrimental changes to the corneal cells and released functional rhMG53 protein for at least 24 h. In vivo rhMG53-loaded hydrogels improved re-epithelialization, reduced stromal opacification and vascularization, and promoted corneal nerve density. Mechanistically, rhMG53 reduced vascular endothelial cell migration and tube formation by inhibiting pSTAT3 signaling. Conclusions: Taken together, our poloxamer-based thermoresponsive hydrogel effectively released rhMG53 protein and enhanced multiple corneal healing outcomes. Full article

The rational design of ordered chromogenic supramolecular polymeric systems is critical for the advancement of next-generation stimuli-responsive, optical, and semiconducting materials. Previously, we reported the design of a stimuli-responsive, lamellar self-assembled platform composed of an imidazole-appended perylene diimide of varying methylene spacer length (n = 3, 4, and 6) and a commercially available diacid-functionalized diacetylene monomer, 10, 12 docosadiynedioic acid, in a 1:1 molar ratio. Herein, we expound on the importance of the composition of the imidazole-appended perylene diimide of varying methylene spacer length (n = 3, 4, and 6) and 10, 12 docosadiynedioic acid in the ratio of 2:1 to the supramolecular self-assembly, final morphology, and properties. Topochemical polymerization of the drop-cast films by UV radiation yielded blue-phase polydiacetylene formation, and subsequent thermal treatment of the films produced a thermoresponsive blue-to-red phase transformation. Differential scanning calorimetry (DSC) studies revealed a dual dependence of the methylene spacer length and stimuli treatment (UV and/or heat) on the thermal transitions of the films. Furthermore, small-angle X-ray scattering (SAXS) and wide-angle X-ray scattering (WAXS) showed well-defined hierarchical semiconducting nanostructures with interconnected “chessboard”-patterned lamellar stacking. Upon doping with an ionic liquid, the 2:1 platform showed higher ionic conductivity than the previous 1:1 one. The results presented here illustrate the importance of the composition and architecture to the ionic domain connectivity and ionic conductivity, which will have far-reaching implications for the rational design of semiconducting polymers for energy applications including fuel cells, batteries, ion-exchange membranes, and mixed ionic conductors. Full article

Local anesthetics (LAs) have been indispensable in clinical pain management, yet their limitations, such as short duration of action and systemic toxicity, necessitate improved delivery strategies. Hydrogels, with their biocompatibility, tunable properties, and ability to modulate drug release, have been extensively explored as platforms for enhancing LA efficacy and safety. This narrative review explores the historical development of LAs, their physicochemical properties, and clinical applications, providing a foundation for understanding the integration of hydrogels in anesthetic delivery. Advances in thermoresponsive, stimuli-responsive, and multifunctional hydrogels have demonstrated significant potential in prolonging analgesia and reducing systemic exposure in preclinical studies, while early clinical findings highlight the feasibility of thermoresponsive hydrogel formulations. Despite these advancements, challenges such as burst release, mechanical instability, and regulatory considerations remain critical barriers to clinical translation. Emerging innovations, including nanocomposite hydrogels, biofunctionalized matrices, and smart materials, offer potential solutions to these limitations. Future research should focus on optimizing hydrogel formulations, expanding clinical validation, and integrating advanced fabrication technologies such as 3D printing and artificial intelligence-driven design to enhance personalized pain management. By bridging materials science and anesthetic pharmacology, this review provides a comprehensive perspective on current trends and future directions in hydrogel-based LA delivery systems. Full article

Photodynamic therapy (PDT) is a light-activated chemical reaction used for the selective destruction of tissue. For this, various colorants may be applied, such as erythrosine (ERI), a dye already approved by the Food and Drug Administration (FDA) for various purposes. Although promising for PDT, ERI has a high hydrophilic profile that impacts its activity. To solve this, the combination of ERI with thermoresponsive and bioadhesive polymers may prove effective. Bio/mucoadhesive and thermoresponsive systems have attracted increasing interest in the development of novel pharmaceutical formulations for topical applications due to their ability to improve adhesion to the mucosa and prolong the residence time at the application site. In this study, systems based on poloxamer 407 (P407) in combination with cellulose derivatives (HPMC and NaCMC) were optimized, aiming at the topical release of ERI for PDT. The results demonstrated that the formulations containing low concentrations of cellulose derivatives exhibited greater adhesiveness and consistency at physiological temperature (37 °C), favoring the maintenance of the system at the application site. Regarding the gelation temperature (T_sol/gel), the formulations displayed values close to body temperature. The formulations with NaCMC showed a slightly higher T_sol/gel compared to HPMC ones, but it was adjustable by the polymer concentration. The addition of ERI influenced the mechanical and adhesive properties of the systems. In formulations containing HPMC, high concentrations of ERI increased bio/mucoadhesiveness, while in systems with NaCMC, the presence of ERI reduced this property. In both cases, the formulations maintained high consistency at 37 °C, contributing to the control of the active release at the application site. Rheological analysis revealed non-Newtonian behavior in all formulations, with greater consistency and elasticity at high temperatures. P407 was mainly responsible for the thermoresponsive transition from sol to gel, conferring desirable characteristics for topical application. Photodynamic activity was relevant in both formulations containing NaCMC and HPMC, which demonstrated greater capacity for degrading uric acid under light exposure. These systems are promising for the controlled release of drugs in photodynamic therapy, providing prolonged retention in the target tissue and maximizing the therapeutic efficacy of ERI. Full article

Oxidative stress plays a crucial role in chronic nasal disorders, contributing to inflammation, tissue damage, and impaired mucosal function, highlighting the need for targeted therapies. Recent advancements in nasal drug delivery systems have expanded their applications for treating respiratory and inflammatory conditions. Among these, hydrogel-based systems offer prolonged release of active pharmaceutical ingredients (APIs), enhancing therapeutic efficacy and reducing dosing frequency. This study initially evaluates the antioxidant, anti-inflammatory, antimicrobial, and cytotoxic properties of Nanotriphala, followed by its incorporation into a thermoresponsive in situ hydrogel system, which was subsequently developed and characterized as a novel formulation. Nanotriphala exhibited >90% cell viability and significantly reduced nitric oxide (NO) levels by 40.55 µg/mL at 250 µg/mL. The hydrogel was characterized by key parameters, including viscosity, gelling time, pH, gelling temperature, texture analysis, and ex vivo spreadability. Stability was assessed under various conditions, and mutagenicity and antimutagenicity were evaluated using the Ames test. Results showed that the hydrogel gelled at 34 °C, exhibited good spreadability (10.25 ± 0.28 cm), a viscosity of 227 ± 22 cP, and maintained a pH of 5.75 ± 0.01, with optimal hardness and adhesiveness suitable for nasal application. It demonstrated antimicrobial activity against E. coli, P. aeruginosa, S. aureus, and S. epidermidis at minimal bactericidal concentrations (MBCs) of 32, 2, 4, and 8 µg/mL, respectively, with low mutagenicity (mutagenic index < 2) and strong antimutagenic activity (>60%). The gallic acid content was 0.5796 ± 0.0218 µg/100 mL. Stability studies confirmed optimal storage at 4 °C. These findings suggest that in situ hydrogel loaded with Nanotriphala is a promising nasal drug delivery system for managing oxidative stress and related inflammatory conditions. Full article

An imbalance in the body’s pH or temperature may modify the immune response and result in ailments such as autoimmune disorders, infectious diseases, cancer, or diabetes. Dual pH- and thermo-responsive carriers are being evaluated as advanced drug delivery microdevices designed to release pharmaceuticals in response to external or internal stimuli. A novel drug delivery system formulated as hydrogel was developed by combining a pH-sensitive polymer (the “biosensor”) with a thermosensitive polymer (the delivery component). Thus, the hydrogel was created by cross-linking, using a solvent-free thermal approach, of poly(N-isopropylacrylamide-co-N-hydroyethyl acrylamide), P(NIPAAm-co-HEAAm), and poly(methylvinylether-alt-maleic acid), P(MVE/MA). The chemical structure of the polymers and hydrogels was analyzed using Fourier-transform infrared (FTIR) and proton nuclear magnetic resonance (¹H NMR) spectroscopies. The pH/thermosensitive hydrogel loses its thermosensitivity under physiological conditions but, remarkably, can recover the thermosensitive capabilities when certain physiologically active biomolecules, acting as triggering agents, electrostatically interact with pH-sensitive units. Our research aimed to develop a drug delivery system that could identify the disturbance of normal physiological parameters and instantaneously send a signal to thermosensitive units, which would collapse and modulate the release profiles of the drug. Full article

This study investigates the effects of homopolymer additives and kinetic traps on the self-assembly of poly(ethylene glycol)-b-poly(lactide) (PEG-PLA) block copolymer (BCP) nanostructures in aqueous environments. By using non-adsorbing PEG homopolymers to kinetically trap PEG-PLA nanostructures, we demonstrate that varying the concentration and molecular weight of the added PEG induces a reversible micelle-to-vesicle transition. This transition is primarily driven by changes in the molecular geometry of the PEG-PLA BCPs due to excluded volume screening effects. Additionally, the reversible vesicle-to-micelle transition upon PEG’s removal shows time and temperature dependency, highlighting the influence of the system’s kinetic nature. Intermediate structures observed during the transition support a mechanism based on shifts in the molecular geometry of PEG-PLA. As a proof of concept, we show that PEG-PLA vesicles can act as thermoresponsive delivery systems, retaining dye at low temperatures (4 °C) and releasing it upon heating (37 °C). Overall, this work presents a novel approach to controlling BCP nanostructures’ morphology, with implications for drug delivery and material science applications. Full article