Pullulan/Poly(vinyl alcohol) Hydrogels Loaded with Calendula officinalis Extract: Design and In Vitro Evaluation for Wound Healing Applications

Polysaccharide Hydrogels as Delivery Platforms for Natural Bioactive Molecules: From Tissue Regeneration to Infection Control

Polysaccharide-based hydrogels have emerged as indispensable materials in tissue engineering and wound healing, offering a unique combination of biocompatibility, biodegradability, and structural versatility. Indeed, their three-dimensional polymeric network and high water content closely resemble the natural extracellular matrix, creating a microenvironment for cell growth, differentiation, and tissue regeneration. Moreover, their intrinsic biodegradability, tunable chemical structure, non-toxicity, and minimal immunogenicity make them optimal candidates for prolonged drug delivery systems. Notwithstanding numerous advantages, these polysaccharide-based hydrogels are confronted with setbacks such as variability in material qualities depending on their source, susceptibility to microbial contamination, unregulated water absorption, inadequate mechanical strength, and unpredictable degradation patterns which limit their efficacy in real-world applications. This review summarizes recent advancements in the application of polysaccharide-based hydrogels, including cellulose, starch, pectin, zein, dextran, pullulan and hyaluronic acid as innovative solutions in wound healing, drug delivery, tissue engineering, and regenerative medicine. Future research should concentrate on optimizing hydrogel formulations to enhance their effectiveness in regenerative medicine and antimicrobial therapy.

Hypericum scabrum L.-infused locust bean gum/agar hydrogel film: A novel candidate for anti-aging facial mask applications

This study investigated the anti-aging potential of Hypericum scabrum L. extract and developed a biopolymer-based hydrogel film designed for use as a facial mask. The research evaluated key anti-aging properties, such as the inhibition of collagenase, elastase, and hyaluronidase enzymes, as well as antioxidant activity, and the cytotoxic, genotoxic, and antigenotoxic effects of the extract. Furthermore, the chemical profile of the extract was thoroughly analyzed using LC-MS/MS. The development of a hydrogel film containing locust bean gum (LBG), agar, and glycerol, integrated with H. scabrum extract, was undertaken to provide an innovative and environmentally sustainable solution for skin aging. The structural and functional characteristics of the hydrogel were analyzed using SEM, XRD, FTIR, and TGA/DTA. Additionally, mechanical testing, swelling, weight loss, thickness, in vitro release kinetics, and antibacterial properties were assessed. The H. scabrum extract demonstrated substantial collagenase inhibition, pronounced antioxidant effects, and no genotoxicity, while also exhibiting notable antigenotoxicity (24-69 %). SEM analysis revealed that the unswollen hydrogel had a uniform, smooth surface, while swelling led to a moderately rough texture with pore formation. The hydrogel exhibited rapid swelling (106 ± 1.52 %) and drug release (34.4 ± 0.21 %) within the first 10 min. Thickness and weight loss were within optimal ranges, and the hydrogel exhibited antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA). These findings suggest that the H. scabrum-infused hydrogel film has the potential to serve as a promising candidate for use as an anti-aging facial mask, offering effective anti-aging benefits in an eco-friendly, biocompatible, and sustainable formulation.

Unravelling the rheological and multifunctionality of Justicia adhatoda-impregnated carboxymethyl cellulose hydrogels for drug delivery systems

Herbal medicine harnesses the therapeutic properties of natural compounds, providing a sustainable approach to healthcare. Due to its limited aqueous solubility, therapeutic potential remains largely unexplored. The enhanced therapeutic potential of the herbal drug entails meticulous formulation and an effective drug delivery matrix. In this study, we formulated a hydrogel system based on Carboxymethylcellulose to deliver the herbal drug, J. adhatoda. The phytochemicals in the J. adhatoda extract involved in the crosslinking of the hydrogel via hydrogen bonding resulted from the interaction with the hydroxyl and carboxyl group of the polymeric chains, confirmed by the FT-IR studies. Rheological studies demonstrated improved mechanical properties with increasing extract concentration (20 μg to 100 μg), with yield stress increasing from 58.83 Pa to 121.5 Pa. The hydrogels exhibited significant antimicrobial activity, reducing biofilm formation against S. aureus, E. faecalis, E. coli, and K. pneumoniae by 71 %, 68 %, 61 %, and 57 %. Antioxidant activity improved with extract concentration, increasing from 29 % to 74 %. The optimal anticancer activity of the hydrogels showed IC50 values of 37.4 μL for MCF-7 and 65 μL for A431 cell lines. These findings demonstrate that J. adhatoda-impregnated CMC hydrogels offer enhanced bioactivity and mechanical strength, positioning them as promising candidates for biomedical applications.

The Potential of Hydrogel Preparations Containing Plant Materials in Supporting the Treatment of Vaginal and Vulvar Infections-Current State of Knowledge

Vaginal hydrogels are a modern alternative to solid (tablets, globules) and other semi-solid forms of medication (ointments, creams) in the control of pathogenic microorganisms in diseases of the female reproductive tract. This review aims to summarize the current state of knowledge regarding the efficacy of hydrogels containing plant materials in the treatment of vaginal and vulvar infections. New therapies are essential to address the growing antimicrobial resistance crisis. Google Scholar, Web of Science, Cochrane, and Medline (PubMed) databases were searched. Twenty-five studies were included in the review, including basic, pre-clinical, and clinical studies. The results obtained confirmed the therapeutic potential of plant raw materials embedded in the polymer matrix of hydrogels. However, due to the small number of clinical trials conducted, further research in this area is needed.

Advancing Gel Systems with Natural Extracts: Antioxidant, Antimicrobial Applications, and Sustainable Innovations

The integration of natural extracts into gel systems has emerged as a transformative approach to enhance functional properties, including antioxidant, antimicrobial, and therapeutic effects. This review underscores the remarkable potential of natural extract-enriched gels, which effectively combine sustainability with improved functionality. These bioactive compounds, sourced from plants and animals, encompass polyphenols, flavonoids, essential oils, chitosan, proteins, and polysaccharides. They provide an eco-friendly alternative to synthetic additives and find applications across various sectors, including pharmaceuticals, cosmetics, and food packaging. Despite their promise, challenges remain, such as the variability in natural extract composition, the stability of bioactive compounds, and scalability for industrial use. To address these issues, innovative strategies like nanoencapsulation, responsive hydrogels, and AI-driven optimization have demonstrated significant progress. Additionally, emerging technologies, such as 3D printing and adherence to circular economy principles, further enhance the versatility, efficiency, and sustainability of these systems. By integrating these advanced tools and methodologies, gel systems enriched with natural extracts are well-positioned to meet contemporary consumer and industrial demands for multifunctional and eco-friendly products. These innovations not only improve performance but also align with global sustainability goals, setting the stage for widespread adoption and continued development in various fields.

Investigation of Silver- and Plant Extract-Infused Polymer Systems: Antioxidant Properties and Kinetic Release

This study evaluated the impact of silver particles, suspended in Arnica montana flower extract, on the physicochemical characteristics and release dynamics of antioxidant compounds in PVP (polyvinylpyrrolidone)-based hydrogel systems. The hydrogels were synthesized via photopolymerization with fixed amounts of crosslinker (PEGDA) and photoinitiator, while the concentration of the silver-infused extract was systematically varied. Key properties, including the density, porosity, surface roughness, swelling capacity, and water vapor transmission rate (WVTR), were quantitatively analyzed. The results demonstrated that increasing the silver content reduced the hydrogel density from 0.6669 g/cm3 to 0.2963 g/cm3 and increased the porosity from 4% to 11.04%. The surface roughness parameters (Ra) rose from 8.42 µm to 16.33 µm, while the WVTR increased significantly from 65.169 g/m2·h to 93.772 g/m2·h. These structural changes directly influenced the release kinetics of antioxidant compounds, with kinetic modeling revealing silver-dependent variations in the evaluated release mechanisms. This innovative approach of integrating silver particles and plant-derived antioxidants into hydrogels highlights a novel pathway for tailoring material properties. The observed enhanced porosity and moisture regulation underscore the hydrogels' potential for biomedical applications, particularly in wound care, where controlled moisture and antioxidant delivery are critical. These findings provide new insights into how silver particles modulate hydrogel structures and functionalities.

Recent Advances in Poly(vinyl alcohol)-Based Hydrogels

Poly(vinyl alcohol) (PVA) is a versatile synthetic polymer, used for the design of hydrogels, porous membranes and films. Its solubility in water, film- and hydrogel-forming capabilities, non-toxicity, crystallinity and excellent mechanical properties, chemical inertness and stability towards biological fluids, superior oxygen and gas barrier properties, good printability and availability (relatively low production cost) are the main aspects that make PVA suitable for a variety of applications, from biomedical and pharmaceutical uses to sensing devices, packaging materials or wastewater treatment. However, pure PVA materials present low stability in water, limited flexibility and poor biocompatibility and biodegradability, which restrict its use alone in various applications. PVA mixed with other synthetic polymers or biomolecules (polysaccharides, proteins, peptides, amino acids etc.), as well as with inorganic/organic compounds, generates a wide variety of materials in which PVA's shortcomings are considerably improved, and new functionalities are obtained. Also, PVA's chemical transformation brings new features and opens the door for new and unexpected uses. The present review is focused on recent advances in PVA-based hydrogels.

Chitosan-Oxidized Pullulan Hydrogels Loaded with Essential Clove Oil: Synthesis, Characterization, Antioxidant and Antimicrobial Properties

Emulsion hydrogels are promising materials for encapsulating and stabilizing high amounts of hydrophobic essential oils in hydrophilic matrices. In this work, clove oil-loaded hydrogels (CS/OP-C) are synthesized by combining covalent and physical cross-linking approaches. First, clove oil (CO) was emulsified and stabilized in a chitosan (CS) solution, which was further hardened by Schiff base covalent cross-linking with oxidized pullulan (OP). Second, the hydrogels were subjected to freeze-thaw cycles and, as a result, the clove oil was stabilized in physically cross-linked polymeric walls. Moreover, due to cryogelation, the obtained hydrogels exhibited sponge-like porous interconnected morphology (160-250 µm). By varying the clove oil content in the starting emulsion and the degree of cross-linking, the hydrogels displayed a high water retention capacity (swelling ratios between 1300 and 2000%), excellent elastic properties with fast shape recovery (20 s) after 70% compression, and controlled in vitro clove oil release in simulated skin conditions for 360 h. Furthermore, the prepared clove oil-loaded hydrogels had a strong scavenging activity of 83% and antibacterial and antifungal properties, showing a bacteriostatic effect after 48 and 72 h against S. aureus and E. coli. Our results recommend the new clove oil-embedded emulsion hydrogels as promising future materials for application as wound dressings.

Antimicrobial Activity of Artemisia dracunculus Oil-Loaded Agarose/Poly(Vinyl Alcohol) Hydrogel for Bio-Applications

In this study, the potential use of Artemisia dracunculus essential oil in bio-applications was investigated. Firstly, the phytochemicals from Artemisia dracunculus were analyzed by different methods. Secondly, the Artemisia dracunculus essential oil was incorporated into the hydrogel matrix based on poly(vinyl alcohol) (PVA) and agar (A). The structural, morphological, and physical properties of the hydrogel matrix loaded with different amounts of Artemisia dracunculus essential oil were thoroughly investigated. FTIR analysis revealed the successful loading of the essential oil Artemisia dracunculus into the PVA/A hydrogel matrix. The influence of the mechanical properties and antimicrobial activity of the PVA/A hydrogel matrix loaded with different amounts of Artemisia dracunculus was also assessed. The antimicrobial activity of Artemisia dracunculus (EO Artemisia dracunculus) essential oil was tested using the disk diffusion method and the time-kill assay method after entrapment in the PVA/A hydrogel matrices. The results showed that PVA/agar-based hydrogels loaded with EO Artemisia dracunculus exhibited significant antimicrobial activity (log reduction ratio in the range of 85.5111-100%) against nine pathogenic isolates, both Gram-positive (S. aureus, MRSA, E. faecalis, L. monocytogenes) and Gram-negative (E. coli, K. pneumoniae, S. enteritidis, S. typhimurium, and A. salmonicida). The resulted biocompatible polymers proved to have enhanced properties when functionalized with the essential oil of Artemisia dracunculus, offering opportunities and possibilities for novel applications.

Poly(Vinyl Alcohol)/Bovine Serum Albumin Hybrid Hydrogels with Tunable Mechanical Properties

In this study, a new strategy was adopted for obtaining polymer/protein hybrid hydrogels with shape stability and tunable mechanical or rheological characteristics by using non-toxic procedures. A chemical network was created using a poly(vinyl alcohol)(PVA)/bovine serum albumin (BSA) mixture in aqueous solution in the presence of genipin and reduced glutathione (GSH). Then, a second physical network was formed through PVA after applying freezing/thawing cycles. In addition, the protein macromolecules formed intermolecular disulfide bridges in the presence of GSH. In these conditions, multiple crosslinked networks were obtained, determining the strengthening and stiffening into relatively tough porous hydrogels with tunable viscoelasticity and a self-healing ability. A SEM analysis evidenced the formation of networks with interconnected pores of sizes between 20 μm and 50 μm. The mechanical or rheological investigations showed that the hydrogels' strength and response in different conditions of deformation were influenced by the composition and crosslinking procedure. Thus, the dynamics of the hybrid hydrogels can be adjusted to mimic the viscoelastic properties of the native tissues. The dynamic water vapor-sorption ability, swelling behavior in an aqueous environment, and bioadhesive properties were also investigated and are discussed in this paper. The hybrid hydrogels with tunable viscoelasticity can be designed on request, and they are promising candidates for tissue engineering, bioinks, and wound dressing applications.

Unraveling the New Perspectives on Antimicrobial Hydrogels: State-of-the-Art and Translational Applications

The growing impact of infections and the rapid emergence of antibiotic resistance represent a public health concern worldwide. The exponential development in the field of biomaterials and its multiple applications can offer a solution to the problems that derive from these situations. In this sense, antimicrobial hydrogels represent a promising opportunity with multiple translational expectations in the medical management of infectious diseases due to their unique physicochemical and biological properties as well as for drug delivery in specific areas. Hydrogels are three-dimensional cross-linked networks of hydrophilic polymers that can absorb and retain large amounts of water or biological fluids. Moreover, antimicrobial hydrogels (AMH) present good biocompatibility, low toxicity, availability, viscoelasticity, biodegradability, and antimicrobial properties. In the present review, we collect and discuss the most promising strategies in the development of AMH, which are divided into hydrogels with inherent antimicrobial activity and antimicrobial agent-loaded hydrogels based on their composition. Then, we present an overview of the main translational applications: wound healing, tissue engineering and regeneration, drug delivery systems, contact lenses, 3D printing, biosensing, and water purification.