Search Results (194)

Heterogeneous hydrogels capable of complex, programmable deformation are highly desirable for soft actuators, yet general strategies that simultaneously impart structural anisotropy, rapid responsiveness, and mechanical robustness remain limited. Here, a gradient anisotropic natural rubber-poly(N-isopropylacrylamide) (NR-PNIPAM) composite hydrogel is developed through a simple one-pot polymerization strategy by coupling pH-regulated colloidal stability with gravity-directed redistribution of natural rubber latex particles. Under an optimized pH window, NR nanoparticles gradually migrate during gelation and are fixed as a continuous gradient within the PNIPAM network, generating built-in structural asymmetry for nonuniform deformation. Meanwhile, NR nanoparticles act as soft reinforcing domains to improve mechanical strength, while water-soluble graphene nanosheets provide efficient photothermal conversion for remotely-controlled near-infrared (NIR)-responsive actuation. Benefiting from this synergistic design, the hydrogel exhibits programmable bending and localized folding with high actuation rates of 129° s⁻¹ and 46° s⁻¹, respectively, along with a tensile strength of 0.32 MPa and an active lifting capability exceeding 70 times its own weight. The material further enables biomimetic gripping and lifting under NIR stimulation. This work establishes a general route to robust gradient hydrogels by integrating colloidal regulation, structural anisotropy, and photothermal actuation, offering a versatile platform for high-performance soft intelligent systems. Full article

Photodynamic therapy (PDT) represents a promising non-antibiotic strategy for addressing bacterial and fungal infections, particularly in the context of increasing antimicrobial resistance and biofilm-associated disease. PDT is based on the light-induced activation of photosensitizers, leading to the generation of reactive oxygen species (ROS), including singlet oxygen (¹O₂), which induce oxidative damage to multiple microbial targets. Unlike conventional antimicrobial drugs that often act through specific molecular pathways, antimicrobial PDT produces simultaneous damage to membranes, proteins, nucleic acids, and extracellular biofilm components, thereby reducing the probability of resistance development. This review critically analyzes the cellular, biochemical, and biophysical determinants that govern PDT selectivity toward bacterial and fungal cells in comparison with mammalian host tissues. Particular attention is given to photosensitizer localization, membrane interactions, photobleaching, oxygen dependence, light penetration, and the balance between Type I and Type II photochemical mechanisms. The review provides a comparative overview of major molecular photosensitizer classes, including phenothiazines, porphyrins, chlorins, phthalocyanines, xanthene dyes, natural polyphenols, endogenous compounds, and advanced targeted photosensitizers. In addition, this review distinguishes molecular photosensitizers from nanotechnology-based platforms and delivery systems. Nanoparticles, polymeric carriers, hydrogels, and light-activated coatings are discussed not only as photosensitizer delivery tools, but also as systems that modulate aggregation, improve localization, enhance biofilm penetration, and enable surface-confined ROS generation. ROS are capable of causing phototoxic effects wherever they are located. Unless selectively accumulated by target organisms, there can be systemic phototoxicity. Overall, PDT should be regarded as a modular antimicrobial platform in which photosensitizer chemistry, formulation, light delivery, oxygen availability, and infection biology must be co-optimized. Although further studies are required to address clinical translation, regulatory complexity, material safety, and standardized treatment protocols, PDT offers a scientifically robust and clinically relevant approach that may complement conventional antibacterial and antifungal therapies, especially in localized, biofilm-associated, and device-related infections. Full article

Diabetic wounds are characterized by persistent hyperglycemia, excessive ROS accumulation, sustained inflammation, and impaired angiogenesis, yet current treatments remain suboptimal. To address these challenges, we developed a mild heat stimulating and microenvironment reprogramming hydrogel (termed C-4-N) via a green synthetic strategy. L-Arginine (L-Arg) triggered the spontaneous self-polymerization of protocatechuic aldehyde (PA) into poly (protocatechuic aldehyde) (PPA) nanoparticles, onto which ginsenoside Compound K (CK) was subsequently loaded, yielding CK/L-Arg/PPA nanoparticles. These nanoparticles were then uniformly embedded into a dynamic disulfide network composed of α-lipoic acid (LA)-modified chitosan (CS-LA) and 4-arm-PEG-SH under UV irradiation without toxic photo-initiators, forming the C-4-N hydrogel. The C-4-N hydrogel reprogrammed the diabetic wound microenvironment through three synergistic mechanisms, lowering blood glucose and scavenging ROS via the coordinated actions of LA, CK and PPA, promoting M1-to-M2 macrophage polarization via downregulation of pro-inflammatory cytokines (TNF-α, IL-6) and upregulation of anti-inflammatory cytokines (IL-10, TGF-β1), further amplified by mild photothermal stimulation of 40–43 °C. In a diabetic rat model, the C-4-N hydrogel achieved a near-complete wound closure rate of 99.49 ± 0.10% on day 13 upon mild photothermal stimulation, accompanied by enhanced re-epithelialization, organized collagen deposition, vascular maturation, and systemic glucose regulation. In summary, this green synthesized, mild heat-stimulating hydrogel establishes a synergistic microenvironment reprogramming paradigm for chronic diabetic wound managements. Full article

The global prevalence of autoimmune diseases ranges from 3% to 8%, with women at a significantly higher risk than men. The core mechanisms underlying these diseases include impaired T-cell and B-cell immune tolerance, abnormal cytokine production, and aberrant activation of related signaling pathways. Conventional treatments primarily focus on suppressing immune responses, but their efficacy remains limited and they are often associated with substantial side effects. Nanomedicine leverages nanoscale materials to enable precise diagnosis and targeted therapy. Nanocarriers can penetrate biological barriers, enhance cellular uptake, and prolong circulation time in vivo, demonstrating considerable potential for drug delivery. Common nanoscale drug delivery platforms include nanoparticles, polymeric micelles, liposomes, dendrimers, mesoporous materials, hydrogels, and exosomes. Each carrier type possesses distinct characteristics in terms of drug-loading capacity, stability, responsiveness, and biocompatibility, thereby enabling targeted delivery and controlled release. This review summarizes recent advances in nano-delivery technologies for three representative chronic autoimmune diseases: diabetes mellitus (DM), inflammatory bowel disease (IBD), and rheumatoid arthritis (RA). Nano-delivery systems can improve therapeutic outcomes by optimizing drug delivery, targeting complications, and modulating the pathological microenvironment. They enhance drug bioavailability, reduce off-target and systemic adverse effects, and provide novel strategies for the precise and efficient treatment of chronic autoimmune diseases. Full article

Polyampholyte (PA) hydrogels have attracted considerable attention due to their unique dynamic network structures and favorable biocompatibility. However, their low modulus severely limits applications in load-bearing aspects. Herein, we report ultrastiff PA nanocomposite hydrogels through the synergistic strategy of effective aggregation of hydrophilic silica (SiO₂) nanoparticles and multi-bond networks. Specifically, a high content of SiO₂ nanoparticles is first incorporated into a dynamic ionic PA network via in situ polymerization. The resulting hydrogel is subsequently dialyzed in a zirconium salt solution with strong coordination capability, achieving the ultrastiff nanocomposite hydrogel. In this strategy, the dynamic PA network infiltrated between the aggregated SiO₂ nanoparticles enables effective particle aggregation, while the dynamic PA network, consisting of ionic and metal-coordination bonds, provides efficient energy dissipation, resulting in a synergistic reinforcement effect. The effects of dialysis time, concentration of zirconium salt, and particle content on the swelling and mechanical behaviors of the hydrogels are systematically investigated. The optimized nanocomposite hydrogel exhibits a Young’s modulus and a tensile strength as high as 87.9 ± 5.9 MPa and 7.9 ± 0.1 MPa, respectively, which are 976 and 8.8 times those of the original neat PA hydrogel. This work provides an effective strategy for designing hydrogels with ultrahigh mechanical performance. Full article

Background: Conventional drug delivery systems often lead to fluctuating plasma concentrations (“Peak and Trough” phenomenon), causing toxicity or inefficacy. Microfluidics has emerged as a revolutionary tool to overcome, among other applications, the limitations of conventional bulk encapsulation methods, such as polydispersity and poor reproducibility. Methods: A systematic review of the literature published between 2020 and 2025 was conducted to evaluate the application of microfluidics in the synthesis of advanced nanomedicines. The review focused on Lipid Nanoparticles (LNPs), Polymeric Nanoparticles (PNPs), and Hydrogel Microspheres. Results: Microfluidics enables the production of monodisperse particles with precise control over geometry and drug loading stoichiometry. Key therapeutic applications include oncology (passive and active targeting), gene therapy (mRNA vaccines), and regenerative medicine (diabetic wound healing). Conclusions: While microfluidics offers superior quality control compared to bulk methods, industrial scalability remains the primary challenge, currently addressed through parallelization and continuous flow strategies. Full article

Wound healing remains a persistent health problem with no definitive solution. It is crucial to characterize the complex wound healing process and the various growth factors, cytokines, and polypeptides involved. Transforming growth factor beta1 (rhTGF-β1) stimulates different cell types, providing multifunctionality in the wound healing process. Since proteins are sensitive to proteases, drug delivery systems are needed. Developed polymeric carrier systems are as important as the active substance. The carrier systems used in our study aim to contribute to wound healing in addition to the rhTGF-β1. We hypothesized that PLGA nanoparticles embedded in PVA/Chitosan (PVA/Chi) hydrogels could enhance the therapeutic effect of rhTGF-β1. PVA/Chitosan hydrogels were prepared by the freezing/thawing method. Several characterization studies (Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), texture analysis, and cell culture) were performed to investigate the potential of the prepared formulations to enhance the therapeutic effect of rhTGF-β1. Hydrogel formulations reduced the inhibitory effect of rhTGF-β1 on keratinocytes. The H5 hydrogel exhibited a proliferative effect on fibroblast cells, which play a crucial role in wound healing, resulting in a 78.8% increase compared to the control. As the PVA content in the hydrogel formulations increased, bioadhesion and viscosity also increased. Although TGF-β1 inhibited keratinocytes, it induced migration of both NIH-3T3 and HACAT cell lines. The formulations developed exhibit the potential to improve the therapeutic efficacy of rhTGF-β1 in wound healing. A small amount of the protein can have the same therapeutic efficacy and fewer side effects because the developed polymeric carrier systems contribute to the therapeutic efficacy. Full article

Dynamic interactions among cells, including immune cells, stromal cells, endothelial cells, epithelial cells, and extracellular matrix (ECM) components, are involved in the wound healing process. In chronic wounds, particularly diabetic wounds, these interactions are hampered by prolonged inflammation and excessive reactive oxygen species generation by dysregulated immune cells, bacterial infection, and impaired angiogenesis. These pathological features have shifted the therapeutic strategies from wound coverage and antimicrobial protection toward regulation of the immune microenvironment. Polymeric and hybrid materials have emerged as promising platforms for this purpose because their versatile composition, structure, degradation behavior, mechanical properties, and drug loading capacities can be widely engineered to match the dynamic requirements of wound healing, particularly in immunomodulation strategies. In this review, we focus on the major immunological barriers and potential targets in the wound healing process using polymer-based materials. Overall, this review covers recent advances, design strategies, and challenges in immunomodulatory materials including polymer-based nanoparticles, nanofibers, hydrogels, and hybrid materials for wound repair. Full article

Chronic wounds, particularly those complicated by infection, present significant challenges in clinical management. The microenvironment of these wounds is typically characterized by the accumulation of reactive oxygen species (ROS) and abnormal local pH levels, both of which impede the healing process. Baicalin (BA), a natural flavonoid, exhibits anti-inflammatory activity, ROS-scavenging capability, and pro-healing effects. In this study, hydrogels were synthesized through photoinitiated radical polymerization of methacrylic anhydride (MAA) and dopamine (DA)-modified chondroitin sulfate (ChSMA-DA), grafting degrees of MA and DA were 58%, 23%, MPDA@MnO₂ nanoparticles (NPs), and methacrylated gelatin (GelMA). The gelation time, microtopography, swelling behavior, and water retention of the hydrogels were investigated, along with their degradation, rheological properties, and photothermal effects. The results indicate that swelling ratio (SR) and water retention (WR) of optimal HG-MPDA@MnO₂-M sample were 5.7, 82.42%, exhibited responsive behavior upon weakly acidic environment with pH 6.5 and elevated ROS levels, and exhibited a stable photothermal effect (photothermal conversion efficiency was 22.7%) under 808 nm near-infrared (NIR) light. Following the incorporation of the drug model BA, the cumulative release percentage over 24 h under the combined stimulation of pH 6.5, 1 mmol·L⁻¹ H₂O₂, and 808 nm NIR was 81.1%, significantly higher than either factor alone. These hydrogels show promise as an injectable dressing for chronic wounds, effectively integrating the internal microenvironment of the wound tissue with external NIR to modulate drug release. Full article

Modern wound care is challenged by the emergence of antibiotic-resistant bacterial strains, causing the need for advanced dressing materials that provide infection control while promoting healing. Although polyacrylamide (PAAm) hydrogels are widely investigated due to their biocompatibility, their lack of intrinsic antibacterial activity and poor mechanical properties restrict their clinical use. To overcome these limitations, this study proposes a natural–synthetic hydrogel that combines PAAm with TEMPO-oxidized cellulose nanofiber (TOCNF) functionalized silver nanoparticles (AgNPs). The synthesis is performed through the polymerization of the synthetic monomer in the presence of the TOCNF–AgNPs, the nanofibrillar cellulose simultaneously serving as a reducing and stabilizing agent for AgNPs, and as a plasticizer for the PAAm network. Morpho-structural analysis of the hybrid precursor (TOCNF–AgNPs) revealed two populations of AgNPs, offering a cumulative effect between rapid bacterial penetration and a prolonged ionic reservoir, while maintaining the stability of the system. The subsequent incorporation of the hybrid into PAAm matrix resulted in tunable swelling kinetics and mechanical properties. Wettability and surface stiffness improve with the increase in hybrid content. The antibacterial effect was confirmed by a colony-counting assay for formulations with higher AgNPs content, exhibiting inhibitory metabolic activity against several pathogenic strains. These results suggest that PAAm/TOCNF–AgNPs (PTA) nanocomposites represent a promising mechanically adaptive candidate for wound-care applications. Full article

Laser therapy is commonly associated with transient skin reactions such as erythema and edema, creating a need for effective post-procedural skincare strategies. In this study, we developed and characterized a novel bio-mask that integrates a hydrogel matrix with a lipid nanodispersion system designed to simultaneously deliver hydrophilic and hydrophobic active compounds. The key innovation of this formulation lies in the combination of a highly hydrophilic hydrogel structure with lipid nanoparticles embedded within a polymeric network, enabling enhanced bioavailability of active ingredients. Preliminary observations from instrumental measurements in a small group of healthy volunteers suggest that a single 60 min application resulted in notable improvements in skin hydration and elasticity, along with a reduction in transepidermal water loss (TEWL), erythema, and skin sensitivity. Furthermore, both the complete formulation and its individual components exhibited inhibitory activity against collagen and elastin glycation, while promoting type I procollagen synthesis. Importantly, this study provides new evidence for the synergistic interaction between hydrogel matrices and lipid nanodispersion systems in modulating skin barrier function and biochemical aging markers. The formulation, composed entirely of ingredients of natural origin, proved to be an effective carrier for active compounds and showed measurable benefits for skin hydration and barrier-related parameters. Full article

Boswellic acids (BAs), the major bioactive constituents of Boswellia serrata oleo–gum resin, exhibit well-documented anti-inflammatory and antioxidant activities, which correspond to their healing effects in arthritis, inflammatory bowel disease, asthma, metabolic syndrome, liver disorders, and certain cancers. However, their therapeutic potential is hindered by their poor aqueous solubility, low intestinal absorption, extensive metabolism, and overall low oral bioavailability. This review provides a comprehensive analysis of conventional Boswellia serrata products and advanced drug delivery systems designed to enhance the biological performance of BAs. We summarize recent developments in formulation strategies, including phytosomes, micelles, self-emulsifying drug delivery systems, solid lipid particles, polymeric nanoparticles, hydrogels, cyclodextrin complexes, metal-based nanocarriers, and hybrid delivery platforms. Available in vivo and cellular studies are critically evaluated, with a focus on disease-specific outcomes. Results indicate that emerging formulation technologies significantly increase the oral absorption, systemic exposure, and biological effectiveness of BAs. However, despite promising preclinical data, challenges remain regarding the standardization of Boswellia extracts, the stability of novel formulations, their safety, and limited clinical evaluation. By comparing the advantages and limitations of conventional preparations with modern drug delivery systems, this review outlines the most effective strategies to enhance the bioavailability of BAs and highlights future research directions for their translational development. Full article

The development of adsorbents with high adsorption capacity, easy separation, and good reusability is critical for the treatment of dye-contaminated wastewater. Herein, a novel magnetic composite hydrogel, P(AA-AM)/SA-BC-Fe₃O₄, was synthesized via free radical polymerization, integrating acrylic acid (AA), acrylamide (AM), sodium alginate (SA), biochar (BC), and magnetic Fe₃O₄ nanoparticles. The material was systematically characterized by FTIR, XRD, SEM, BET, and VSM, which confirmed the successful formation of a three-dimensional porous network with well-dispersed Fe₃O₄ nanoparticles and BC, endowing the hydrogel with superparamagnetic properties. The adsorption performance of the hydrogel towards methylene blue (MB) was evaluated under various conditions. The results demonstrated that the adsorption process followed the pseudo-second-order kinetic model and the Langmuir isotherm, indicating that chemisorption is an important mechanism in the monolayer adsorption process. The hydrogel exhibited excellent swelling properties and remarkable pH-dependent adsorption behavior, with optimal performance in weakly alkaline environments. Notably, the incorporation of BC enhanced the adsorption capacity, while Fe₃O₄ enabled rapid magnetic separation, with the adsorbent retaining approximately 77% of its initial capacity after five regeneration cycles. This work presents a promising strategy for constructing magnetic hydrogel adsorbents that synergistically combine high adsorption efficiency, facile separability, and good reusability for practical wastewater treatment applications. Full article

Chronic wounds, diabetic foot ulcers, venous leg ulcers, and pressure injuries affect millions of patients worldwide and cost healthcare systems in the order of $150 billion annually, yet treatment options have changed less than the scale of the problem would suggest. Biofilm formation, documented in up to 78% of chronic wounds, is a central cause: bacteria embedded in extracellular polymeric matrices tolerate antimicrobial concentrations up to 1000-fold higher than planktonic cells and sustain a chronic inflammatory state that actively prevents tissue repair. Hydrogels, crosslinked polymer networks with high water content and tunable physicochemical properties, have been widely studied as platforms for addressing these challenges, though the distance between laboratory results and clinical practice remains considerable. While recent reviews have summarized hydrogel materials or antimicrobial strategies in isolation, this review takes a different approach: we treat infection, biofilm persistence, and impaired regeneration as interconnected processes that must be addressed simultaneously, and we examine biofilm management as a distinct therapeutic target rather than merely a subset of antimicrobial delivery. We analyze hydrogel-based wound care across three integrated domains: design principles (natural, synthetic, and hybrid polymer systems; crosslinking strategies; and stimuli-responsive architectures), antimicrobial delivery (silver, antibiotics, antimicrobial peptides, natural agents, and controlled-release systems), and biofilm management (nanoparticle-mediated disruption, enzymatic EPS degradation, photodynamic approaches, quorum-sensing inhibition, and anti-adhesive surface engineering). For each area, we critically evaluate what the preclinical evidence supports, where it falls short, and what would be needed to bridge the gap to clinical application. Translation remains uneven. Among the many FDA- and EMA-cleared hydrogel dressings currently in clinical use, most are simple moisture-retaining or silver-containing formulations, while the multifunctional systems that dominate the research literature are at earlier stages of development. We discuss the main translational priorities, including more predictive preclinical models, long-term nanomaterial safety, harmonized outcome reporting, manufacturing scalability, and health economic evidence, as areas where further work can meaningfully accelerate clinical adoption. Full article

The quality of Surface-Enhanced Raman Chemical Imaging (SER-CI) rely on several parameters, among which the uniform deposition of metallic nanoparticles impacts greatly the result. Optimizing deposition protocols for biological samples is challenging due to inherent spatial heterogeneity, preventing the distinction between deposition artefacts and true analyte distribution. However, to optimize the deposition parameters, it is necessary to have a controlled experimental model. This study presents the development of a repeatable dried gelatine–agarose hydrogel as a controlled analytical substrate with the uniform spatial homogeneity of diphenhydramine hydrochloride as the experimental model for further nanoparticle deposition optimization. With its skin-mimicking Raman fingerprint, the proposed hydrogel enables the systematic evaluation of deposition techniques without biological variability. Confocal Raman imaging performances are as follows: the normalization-based ratio (I₁₀₀₃/I₁₄₆₉) achieved an intra-day RSD of 3.6–8.2%, inter-day RSD of 6.5%, and intra-day pixel-wise RSD (%) of 8.3–12.3%. The Distribution Homogeneity Index (DHI) confirmed the analyte’s uniform distribution. Drying kinetics modelling revealed a diffusion-based dehydration process, with repeatable batch production. Application of dried hydrogels for SERS chemical imaging confirmed diphenhydramine hydrochloride detectability inside the polymeric matrix, with the proportionality of intensity based on the diphenhydramine hydrochloride concentration. A preliminary performance comparison of nanoparticle deposition by drop-casting and spray-coating demonstrates the applicability of the developed model. This standardized matrix provides a reference platform for evaluating deposition homogeneity, distinguishing method performance from sample artefacts and accelerating chemical imaging method development and performance through optimization. Full article