Hydrogel Matrix Research Articles

Functional Hydrogel Interfaces for Cartilage and Bone Regeneration.

Effective treatment of bone diseases is quite tricky due to the unique nature of bone tissue and the complexity of the bone repair process. In combination with biological materials, cells and biological factors can provide a highly effective and safe treatment strategy for bone repair and regeneration, especially based on these multifunctional hydrogel interface materials. However, itis still a challenge to formulate hydrogel materials with fascinating properties (e.g., biological activity, controllable biodegradability, mechanical strength, excellent cell/tissue adhesion, and controllable release properties) for their clinical applications in complex bone repair processes. In this review, we will highlight recent advances in developing functional interface hydrogels. We then discuss the barriers to producing of functional hydrogel materials without sacrificing their inherent properties, and potential applications in cartilage and bone repair are discussed. Multifunctional hydrogel interface materials can serve as a fundamental building block for bone tissue engineering.

A light-cured injectable composite hydrogel based on chitosan and decellularized matrix modulates stem cell aggregation behavior for accelerating cartilage defect repair.

Cartilage repair remains a formidable challenge because of its limited regenerative capacity. Construction of a biomimetic hydrogel matrix that can induce cell aggregation is a promising therapeutic option. Cell aggregates are more beneficial than dissociated cells for improving survival and chondrogenic differentiation, thereby facilitating cartilage repair. Herein, we report a light-cured injectable composite hydrogel with cellular aggregation properties for cartilage defect repair that combines methacrylated chitosan (CSMA) and a methacrylate-modified decellularized extracellular matrix (dECMMA). The CSMA promotes cell aggregate formation by enhancing cadherin expression. The dECMMA retains many inherent components and bioactive factors, thereby providing a more natural microenvironment for cell proliferation and differentiation. By precisely adjusting the compositions of the CSMA and dECMMA, it was possible to fine-tune their physicochemical properties and biochemical cues. The results showed that a composite hydrogel composed of 2% (m/v) CSMA and 5% (m/v) dECMMA exhibited good injectability, appropriate degradability and mechanical properties, and regulated the formation of bone marrow mesenchymal stem cell aggregates. Transplantation of the composite hydrogel loaded with bone marrow mesenchymal stem cells (BMSCs) into a cartilage defect model demonstrated effective hyaline cartilage repair. Thus, light-cured injectable composite hydrogels embedded with BMSCs holds clinical promise for cartilage defect repair.

Tamarind seed gum-based hydrogel for the targeted delivery of imidazobenzothiazole sulfonamide derivative as an anticancer agent.

The current investigation intended to assess the controlled delivery of 7-sulfonamide-2-(4-methylphenyl) imidazo[2,1-b] [1, 3] benzothiazole an anticancer agent (ACA) by tamarind seed gum-based hydrogel; for its potential activity against hepatocellular carcinoma. The FTIR spectra, SEM, 13C NMR, PXRD, and TGA analyses evidenced the successful loading of ACA into the hydrogel system. The rheological testing conveyed the increase in the elastic nature of ACA-loaded hydrogel helping in an effective release. In-vitro delivery of ACA from the hydrogel matrix was maximum at pH 5.5 with controlled and prolonged release of 98.93 ± 1 % over 1680 min. The ACA-release kinetics was well-fitted to the Hill equation model (R2 = 0.9925), leading to a non-Fickian diffusion process (n = 0.5217). The tamarind seed gum-based hydrogel as a potential matrix for the oral administration of the ACA at hepatocellular carcinoma was envisaged and acute oral toxicity assessment on the Drosophila Melanogaster model indicated a high safety profile in-vivo. The ACA-loaded TG-g-poly (AMPS) system showed an enhanced anticancer activity with an IC50 value of 37.27 μg/mL than the ACA (IC50 = 44.75 μg/mL). Studies on the ACA-loaded hydrogel's ability to induce apoptosis in hepatocellular carcinoma cells further supported its anticancer effectiveness in-vitro.

Monitoring of the Local Extracellular Environment Using Chiral Gold Nanoparticles.

In three-dimensional (3D)-printed tissue models, sensitive, noninvasive techniques are required to detect in situ changes in hydrogel structure caused by cellular remodeling. We demonstrate herein that circular dichroism (CD) spectroscopy provides a reliable method for detecting hydrogel structural variations. We probe directly the plasmonic optical activity of chiral gold nanorods (c-AuNRs) embedded within the hydrogel matrix, in response to variations in the local environment. Unlike extinction spectroscopy, we found that CD features such as zero-point crossings do not get masked by the strong scattering due to the porous hydrogel structure and are therefore sensitive to changes in the refractive index of the medium, reversible swelling and deswelling of the hydrogel, and other interactions between the hydrogel and the c-AuNR surface. By culturing metastatic breast cancer cells within the 3D hydrogel nanocomposite, we demonstrate that CD can noninvasively probe the restructuring of the hydrogel. This study highlights the potential of CD spectroscopy in combination with c-AuNRs to investigate complex changes in biological or polymeric systems.

Synergistic Antibacterial Action of Norfloxacin-Encapsulated G4 Hydrogels: The Role of Boronic Acid and Cyclodextrin

In this present study, we developed and characterized a series of supramolecular G4 hydrogels by integrating β-cyclodextrin (β-CD) and boronic acid linkers into a supramolecular matrix to enhance antibacterial activity against Staphylococcus aureus (S. aureus). We systematically investigated how varying the number of free boronic acid moieties (ranging from two to six), along with guanosine and β-CD content, influences both the structural integrity and antimicrobial efficacy of these materials. Comprehensive characterization using FTIR, circular dichroism, X-ray diffraction, SEM, AFM, and rheological measurements confirmed successful synthesis and revealed that higher boronic acid content correlated with a stronger, more organized network. The most effective hydrogel displayed an inhibition zone of 25 mm in disk diffusion assays, and was further explored as a drug delivery platform, with the aim to exploit the capacity of the free β-CD cavity of the hydrogels to incorporate hydrophobic drugs. Norfloxacin (Nfx), a poorly water-soluble antibiotic, was successfully encapsulated within the hydrogel matrix through the inclusion of complex formation with β-CD, improving its solubility and enabling sustained, targeted release. The Nfx-loaded hydrogel expanded the inhibition zone to 49 mm and completely eradicated S. aureus cells within 24 h, outperforming both the unloaded hydrogel and free Nfx. These results highlight the synergistic effect of boronic acid moieties and controlled drug release, underlining the potential of these hydrogels as versatile platforms for localized antimicrobial therapy, such as in wound dressings or implant coatings. Nevertheless, further in vivo studies and long-term stability assessments are needed to fully establish clinical relevance, safety, and scalability before these systems can be translated into routine healthcare applications.

3D Printing Organogels with Bioderived Cyrene for High-Resolution Customized Hydrogel Structures.

3D printing techniques are increasingly being explored to produce hydrogels, versatile materials with a wide range of applications. While photopolymerization-based 3D printing can produce customized hydrogel shapes and intricate structures, its reliance on rigid printing conditions limits material properties compared to those of extrusion printing. To address this limitation, this study employed an alternative approach by printing an organogel precursor using vat polymerization with organic solvents instead of water, followed by solvent exchange after printing to create the final hydrogel material. Using mask stereolithography (mSLA), we evaluated the effects of solvent choice on a novel and recently developed 3D-printed supramolecular hydrogel, cross-linked with quaternized chitosan/acrylate salt. In this study, we compared the conventional solvent dimethyl sulfoxide (DMSO) with the bioderived solvent Cyrene. Our findings reveal that hydrogels produced with Cyrene-based 3D printing exhibit weaker strength but high swelling capacity and elasticity, resilience to cyclic loading, and the ability to produce detailed and accurate 3D-printed objects. These results provide insights into the solvent-dependent mechanical and physical characteristics of 3D-printed hydrogels and underscore the potential of Cyrene as a sustainable alternative for polymeric synthesis.

High-Strength Anisotropic Fluorescent Hydrogel Based on Solvent Exchange for Patterning.

Aggregation-induced emission (AIE)-active fluorescent hydrogel materials have found extensive applications in soft robotics, wearable electronics, information encryption, and biomedicine. Nevertheless, it continues to be difficult to create hydrogels that are both highly luminescent and possess strong mechanical capabilities. This study introduces a combined approach of prestretching and solvent exchange to create anisotropic luminous hydrogels made of poly(methacrylic acid-methacrylamide). This method restricts the intrachain rotation of AIE molecules and adjusts the orientation of the polymer network. The increased luminescence and mechanical qualities are determined to be caused by the clustering of AIE molecules, the creation of the associated hydrophobic phase and the asymmetrical polymer network. The fluorescent hydrogels exhibit exceptional mechanical characteristics, including a high fracture stress of 5.97 MPa, an outstanding elastic modulus of 93.97 MPa, and a fracture toughness of 7.21 MJ/m3. Furthermore, the AIE fluorescent hydrogels demonstrate outstanding water retention, antiswelling capabilities, and a writing function for solvent-regulated fluorescent information. This work presents a highly efficient technique for creating anisotropic hydrogels with changeable luminescence properties, which have the potential to be used in several applications, including information encryption, flexible sensors, and soft robots.

Magnetic Nanoactuator-Protein Fiber Coated Hydrogel Dressing for Well-Balanced Skin Wound Healing and Tissue Regeneration.

Despite significant progress in skin wound healing, it is still a challenge to construct multifunctional bioactive dressings based on a highly aligned protein fiber coated hydrogel matrix for antifibrosis skin wound regeneration that is indistinguishable to native skin. In this study, a "dual-wheel-driven" strategy is adopted to modify the surface of methacrylated gelatin (GelMA) hydrogel with highly aligned magnetic nanocomposites-protein fiber assemblies (MPF) consisting of photothermal responsive antibacteria superparamagnetic nanocomposites-fibrinogen (Fg) complexes as the building blocks. Whole-phase healing properties of the modified hydrogel dressing, GelMA-MPF (GMPF), stem from the integration of Fg protein with RGD peptide activity decorated on the surface of the antibacterial magnetic nanoactuator, facilitating facile and reproducible dressing preparation by self-assembly and involving biochemical, morphological, and biophysical cues. Payload and substantial release of copper ions for in situ catalytic production of nitric oxide (NO) from the fiber inorganic skeleton adsorbed by Fg molecules collectively regulate the proliferation, migration, reorganization, and transdifferentiation behavior of fibroblasts and fulfill antifibrosis in the process of skin wound healing and subcutaneous appendage regeneration. In full-thickness skin lesion mouse models, the complete regeneration of skin tissue with regenerated hair follicle cells and capillary blood vessels is realized in a temporally and spatially ordered manner.

Soft hydrogel-embedded ceramic skeleton mimicking bone structure via sacrificial bond concept.

Bone, consisting of calcium phosphate minerals, rigid collagen fibrils, and acidic proteins, exhibits stiff and tough mechanical properties. On a molecular scale, covalent cross-linking in proteins and ionic interactions within proteins and at the protein-mineral boundary contribute to bone's toughness. In addition, hierarchical structures, like the sponge-like arrangement, are also crucial for the energy dissipation system in bone. Inspired by the multiple sacrificial bonds found in bone, we developed a soft/hard composite made up of two components with contrasting mechanical properties: a porous calcium phosphate skeleton and an acidic polymer hydrogel matrix. The porous ceramic skeleton alone is extremely rigid but brittle. However, the presence of the hydrogel matrix transforms the brittle nature of the porous ceramic skeleton into a soft/hard composite with stretchable and tough characteristics. The composite exhibits significant energy dissipation due to the fracture of the ceramic skeleton under small deformation, while catastrophic failure of the composite is prevented because the hybridized matrix disperses the damage throughout the entire sample. The Ca2+-mediated ionic bonding within the matrix hydrogel and at the boundary between the gel and skeleton effectively transfers the stress, enhancing the composite's toughness. Furthermore, the cyclic deformation generates new bare surfaces on the ceramic skeleton, leading to increased interaction between the matrix and these new surfaces, which enhances the composite's healing capability. This study demonstrates that the concept of multiple sacrificial bonds in bone is a smart strategy for designing polymer-ceramic composites with excellent mechanical properties.

Designing polydopamine embedded hydrogel with high-stable adhesion and long-term stability at high temperature

Adhesive hydrogels show great potential for use in tissue repair, soft robotics, ionic devices, and oil and gas extraction. However, there remains a challenge in fabriacting hydrogels with direct stable adhesion and long-term stability at high temperatures. Here, drawing inspiration from the adhesive property and thermal stability of polydopamine (PDA), we propose a facile one-pot method to construct PDA-embedded hydrogel with high-stable adhesive properties across a wide temperature range of 25 to 90 °C. The stable adhesion performance is attributed to the synergy of multiple non-covalent interactions of PDA embedded in the hydrogel matrix and cooperation of cationic group in funcational monomer (3-acrylamidopropyl) trimethylammonium chloride. This hydrogel can undergo rapid gelation process within a few hundred seconds at high temperatures and acquire favorable mechanical strength as well as long-term resistance to high temperatures. Moreover, the hydrogel is applied in proof-of-concept demonstrations as a high-temperature plugging material in an enclosed enverioment, which exhibits an outstanding pressure-bearing capacity of 7.6 MPa for 1 mm cracks at 90 °C, and it further forms secondary plugging region even after breakage. This study envisages that the bioinspired hydrogel, endowed with its remarkable thermal adhesion abilities, holds promising prospects for extensive utiliaztion in high-temperature environments.

The effect of additive biomaterials on the printability and characterization of PCL-based composite scaffolds fabricated by screw extrusion 3D printing

Abstract To enhance cell adhesion and cell interactions for diverse tissue engineering applications, polycaprolactone (PCL) has been integrated with few biomaterials such as ceramic (i.e. tricalcium phosphate - TCP), hydrogel (i.e. sodium alginate - SA), and synthetic polymer materials (i.e. polyethylene glycol - PEG). Each type of additive material presents typical characteristics, the comparison among these three biomaterial types is currently inadequate. In this study, a 3D printer using direct powder screw extrusion technique was applied for fabricating three types of PCL-based composite scaffolds (namely, PCL-PEG, PCL-SA, and PCL-TCP) which are representative of each type of additive material. The experimental evaluation on the printability, scaffold morphology, surface roughness, hydrophobicity, and cell proliferation of these PCL-based composite scaffolds were compared under the same conditions. The results demonstrated that the additive materials with an amount from 20 wt% have a notable effect on the printability of PCL matrix material and significant enhancement of cell proliferation. The incorporation of PEG with PCL is the most effective choice to increase the hydrophilicity of the scaffold surface. The PCL-SA scaffold provided a more favorable environment for cells at the initial stage, whereas the PCL-TCP scaffold demonstrated superior cell proliferation over time. These findings also demonstrate the feasibility of a direct powder screw extrusion printhead on 3D printing for composite scaffolds in tissue engineering applications.

Multifunctional hydrogel scaffolds based on polysaccharides and polymer matrices promote bone repair: A review.

With the advancement of medical technology, the utilization of bioactive materials to promote bone repair has emerged as a significant research area. Hydrogels, as biomaterials, play a crucial role in bone tissue engineering. These hydrogels exhibit high biocompatibility, providing in vivo ecological conditions conducive to cell survival, and offer substantial advantages in facilitating bone repair. Different matrices of hydrogels serve distinct functions. In recent years, numerous researchers have developed a variety of novel hydrogel materials utilizing diverse matrices. These materials not only enhance the osteogenic induction capacity of hydrogels but also improve their efficacy as scaffolds in the treatment of complex bone defects, such as those resulting from trauma, tumor resection, or large bone defects due to infection. This article primarily analyzes the role of hydrogels that utilize polysaccharides and polymers as matrices in bone tissue repair, focusing on the creation of an optimal microenvironment to promote bone regeneration. These investigations deepen the understanding of the mechanisms underlying the action of hydrogels and establish a foundation for future advancements in the biomedical field.

Synergistic topical cancer therapy using dual drug delivery of dexamethasone and 5-fluorouracil via deoxycholic acid micelle-carboxymethyl cellulose hydrogel composites.

Topical formulations containing 5-Fluorouracil (5-FU) have been proven effective in preventing the proliferation of skin cancer cells. However, their use is linked to side effects such as inflammatory and allergic reactions. Dexamethasone (Dexa) is a synthetic glucocorticoid used across allergic reactions which can be useful in preventing the 5-FU side effects. This study aims to introduce 5-FU loaded deoxycholic acid micelles (DCA Mics) incorporated into carboxymethyl cellulose hydrogel matrix (CMC Hyd) containing Dexa to design Mic/Hyd based carriers cross-linked by physical and chemical cross-linker. The release of 5-FU and Dexa from the final formulation at a pH of 5.5 was around 55 % after 5 h. The final formulation shows the pH-controlled release by crosslinking CMC Hyd, increasing the release of Dexa at physiological pH. The MTT results showed both Hyd and the synthesized Mics were non-toxic, but the toxicity increased significantly when 5-FU was incorporated into the formulation. 5-FU@Mic (IC50 = 5.5 μg/mL) was observed to be more potent cytotoxic against A431 compared to the free drugs 5-FU (IC50 = 17.5 μg/mL), and final formulation (IC50 = 26 μg/mL). The dual drug delivery systems might provide insights into the potential of pre-exposure of Dexa for mitigating inflammation caused by 5-FU.

Portable foodborne pathogen detection via ratiometric fluorescence nanoprobe for adenosine triphosphate quantification based on DNA-functionalized metal-organic framework.

The increasing incidence of foodborne illnesses highlights the need for rapid, sensitive, and portable methods to detect pathogenic bacteria in food. In this work, we develop a portable method that utilizes a ratiometric fluorescence nanoprobe for adenosine triphosphate (ATP) quantification. The nanoprobe is constructed by encapsulating Ru(bpy)32+ within a zirconium-based metal-organic framework, followed by functionalization of double-stranded DNA (dsDNA). This design permits SYBR Green I (SGI) to intercalate into dsDNA, conferring the nanoprobe with dual-emission property. The presence of ATP disrupts dsDNA structure, quenching SGI fluorescence while maintaining Ru(bpy)32+ fluorescence, providing a stable reference signal. This differential response enables the nanoprobe to achieve ratiometric ATP detection with high precision and sensitivity, with a detection limit of 0.63μM. Since ATP is a reliable biomarker for viable bacterial cells, a portable hydrogel kit was further developed by integrating the ratiometric fluorescence nanoprobe into an agarose hydrogel matrix. The validation of the kit was conducted using a smartphone application for color recognition, enabling the rapid and on-site detection of pathogens in milk samples. The kit exhibits exceptional sensitivity with a detection limit of 10CFU/mL, making it a promising tool for real-time bacteria detection in food safety monitoring.

Miniaturization and Characterization of Patient Derived Hepatocellular Carcinoma Tumor Organoid Cultures for Cancer Drug Discovery Applications.

Patient derived tumor organoid (PDTO) models retain the structural, morphological, genetic, and clonal heterogeneity of the original tumors. The ability to efficiently generate, expand, and biobank PDTOs has the potential to make the clinical diversity of cancer accessible for personalized medicine assay guided therapeutic drug selection and drug discovery. We describe the miniaturization and growth in 96- and 384-well formats of a single non-tumor liver and two Hepatocellular carcinoma (HCC) organoids derived from cryopreserved PDTO cells and the application of high content imaging (HCI) to characterize the models and enhance drug sensitivity testing. Non-invasive sequentially acquired transmitted light images showed that seeding cryopreserved cells from non-tumoral and HCC PDTOs into 96- or 384-well plates in reduced growth factor Matrigel (rgf-MG) that were fed with growth medium every 3 days supported organoid growth up to 15 days. The number and sizes of organoids increased with longer times in culture. HCC PDTO's had more heterogeneous morphologies than non-tumor organoids with respect to size, shape, and optical density. Organoids cultured in rgf-MG could be stained in situ with HCI reagents without mechanical, chemical or enzymatic disruption of the hydrogel matrices and quantitative data extracted by image analysis. Hoechst and live/dead reagents provided organoid numbers and viability comparisons. HCC PDTO's stained with phalloidin or immuno-stained with α-tubulin antibodies revealed F-actin and microtubule cytoskeleton organization. HCC PDTO's stained with antibodies to signaling pathway proteins and their phosphorylation status allowed comparisons of relative expression levels and inference of pathway activation. Images of HCC PDTO's exposed to ellipticine showed that drugs penetrate Matrigel hydrogels and accumulate in organoid cells. 9-day 384-well HCC organoid cultures exhibited robust and reproducible growth signals suitable for cancer drug testing. Complimenting cell viability readouts with multiple HCI parameters including morphological features and dead cell staining improved the analysis of drug impact and enhanced the value that could be extracted from these more physiologically relevant three-dimensional HCC organoid cultures.

Alginate-Based Hydrogels with Amniotic Membrane Stem Cells for Wound Dressing Application.

Chronic wounds are a common clinical problem that necessitate the exploration of novel regenerative therapies. We report a method to investigate the in vitro wound healing capacity of an innovative biomaterial, which is based on amniotic membrane-derived stem cells (AMSCs) embedded in an alginate hydrogel matrix. The aim of this study was to prepare an sodium alginate-based hydrogel, cross-linked calcium chloride (CaCl2) with the active ingredient AMSC (AMSC/Alg-H) and to evaluate its in vitro effectiveness for wound closure. This hydrogel preparation involved combining sterile solutions of AMSC, sodium alginate, and CaCl2, followed by rinsing with serum-free media. The cells were cultured in different 6-well plates, namely sodium alginate, calcium chloride, AMSC, Alg-H, and AMSC/Alg-H, in complete medium with 10% FBS. The hydrogel was successfully formulated, as confirmed by characterization techniques including Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FTIR) spectroscopy, Differential Scanning Calorimetry (DSC), Cytotoxicity Studies, TGF-β1 Level Measurement by ELISA, and Cell Scratch Wound Assay. Cryo-EM characterization of the Alg-H preparation successfully demonstrated the encapsulation of MSCs. FTIR and DSC analyses indicate that crosslinking transpires in Alg-H encapsulating AMSC. The AMSC/Alg-H preparation showed no significant difference in toxicity compared to HaCaT cells (p < 0.05), indicating it was not toxic to HaCaT cells. Furthermore, in the scratch wound assay test at 24hours, the AMSC/Alg-H preparation achieved 100% wound closure, outperforming both AMSC and Alg-H alone. In vitro assessment revealed that AMSC/Alg-H significantly enhanced key wound healing processes, including cell proliferation and migration, compared to Alg-H. Our study demonstrated the promising potential of AMSC/Alg-H as an enhanced regenerative therapy for in vitro wound healing. AMSC/Alg-H was able to maintain the viability of AMSCs and facilitate the formation of tissue-like structures.

Self-reduction of gold@platinum bimetallic nanoparticles on Ti3C2Tx MXene nanoribbons coupled with hydrogel and smartphone technology for colorimetric detection of silver ions.

In recent years, numerous colorimetric methods have been developed for the detection of silver ions (Ag+), yet there remains a need for a simple, sensitive, real-time and quantitative sensing platform. Herein, Ti3C2Tx MXene nanoribbons (Ti3C2TxNRs) were utilized as the carrier material, and gold@platinum (Au@Pt) bimetallic nanoparticles were decorated onto the Ti3C2TxNR surface, for the first time, via a facile self-reduction method. The resulting Au@Pt-Ti3C2TxNR nanohybrid exhibited excellent catalytic activity, facilitating the oxidation of 3,3',5,5'-tetramethylbenzidine, a colorless substrate, to generate a blue product (oxTMB), displaying prominent peroxidase-like activity. In the presence of Ag+, a remarkable inhibiting effect was observed on the catalytic activity of the Au@Pt-Ti3C2TxNR nanohybrids, effectively halting the generation of oxTMB. Based on this, the as-obtained Au@Pt-Ti3C2TxNR nanozyme was then utilized to develop a novel colorimetric sensing platform for Ag+ detection, with a low detection limit of 1.57 nM and a wide linear detection range from 5.0 nM to 9.0 μM. In addition, by combining the unique advantages of hydrogel materials and smartphone technology, a simple, real-time and quantitative platform for Ag+ monitoring was constructed, highlighting its potential for practical applications in Ag+ detection.

Design and Characterization of Novel Polymeric Hydrogels with Protein Carriers for Biomedical Use.

Hydrogels are three-dimensional polymeric matrices capable of absorbing significant amounts of water or biological fluids, making them promising candidates for biomedical applications such as drug delivery and wound healing. In this study, novel hydrogels were synthesized using a photopolymerization method and modified with cisplatin-loaded protein carriers, as well as natural extracts of nettle (Urtica dioica) and chamomile (Matricaria chamomilla L.). The basic components of the hydrogel were polyvinylpyrrolidone and polyvinyl alcohol, while polyethylene glycol diacrylate was used as a crosslinking agent and 2-methyl-2-hydroxypropiophenone as a photoinitiator. The hydrogels demonstrated high swelling capacities, with values up to 4.5 g/g in distilled water, and lower absorption in Ringer's solution and simulated body fluid (SBF), influenced by ionic interactions. Wettability measurements indicated water contact angles between 51° and 59°, suggesting balanced hydrophilic properties conducive to biomedical applications. Surface roughness analyses revealed that roughness values decreased after incubation, with Ra values ranging from 6.73 µm before incubation to 5.94 µm after incubation for samples with the highest protein content. Incubation studies confirmed the stability of the hydrogel matrix, with no significant structural degradation observed over 20 days. However, hydrogels containing 2.0 mL of protein suspension exhibited structural damage and were excluded from further testing. The synthesized hydrogels show potential for application as carriers in localized drug delivery systems, offering a platform for future development in areas such as targeted therapy for skin cancer or other localized treatments.

In English

In recent years, significant progress has been made in both the synthesis of metal nanoparticles and the creation of hydrogel platforms. It is assumed that their synergistic combination will allow to create the advanced hydrogel nanocomposites for the repair of anatomical and functional disorders of the human body, as well as for the needs of reconstructive surgery. The aim of the study is to develop a porous polymeric material based on polyvinylformal with incorporated functional hydrogels and gold nanoparticles, the study of its physicochemical properties and biocompatibility in vitro and in vivo. The developed hybrid hydrogel material is intended for use in reconstructive surgery of the oculo-orbital area and for filling postoperative cavities with simultaneous prevention of recurrence. The morphology of the synthesized hybrid hydrogel composites with gold nanoparticles was investigated by means of electron microscopy (SEM), while their thermal stability was studied by TGA and DSC methods. It was proved that the synthesized hybrid hydrogel materials demonstrate thermal stability in a wide temperature range, which significantly exceeds the range of their application, and can withstand steam sterilization (121 °C) without significant changes. The synthesized hybrid hydrogels were characterized as biocompatible in vitro according to the parameters of cytotoxicity, genotoxicity and biochemical markers (ATPase and LDHase activity) using L929 cell line. The study of the soft tissue reaction to implantation in vivo demonstrated the formation of fibrous tissue on the periphery and inside the implant, and a marked decrease in macrophage-histiocyte reaction and inflammatory infiltration in favor of fibroblastic proliferation and the absence of resorption, which creates the prerequisites for a stable clinical result. Thus, the developed spongy hybrid hydrogel material can be used in reconstructive surgery of the maxillofacial and ophthalmic-orbital areas.

Manipulating Toughness and Microstructure in Polyelectrolyte Complex Hydrogels with Competitive Surfactant Micelles.

Polyelectrolyte complex (PEC) hydrogels provide a promising strategy to develop a class of physically cross-linked networks characterized by exceptional toughness and self-healing properties. However, the precise control of the microstructure and the enhancement of mechanical properties still pose challenges in the field of PEC hydrogels. Herein, we propose a strategy to manipulate the structure of PEC with competitively charged surfactant micelles, leveraging the spatially confined surface charge and excluded volume effects to overcome coacervation issues associated with the PEC, thus achieving a simple one-step preparation of macroscopically uniform and tough PEC hydrogels. Specifically, polyelectrolyte complex/surfactant micelle (PEC-SM) hybrid hydrogels were prepared by one-step copolymerization of chitosan (CS)/acrylic acid/cetyltrimethylammonium bromide (CTAB) micelles. The content of CTAB micelles was found to continuously modulate both the structure and the mechanical properties of the resulting PEC-SM hydrogel network. On one hand, reversible deformation-recovery behavior exhibited by CTAB cavity micelles through hydrophobic interactions efficiently dissipates energy; on the other hand, competition between CS chains and CTAB micelles for electrostatic binding sites with poly(acrylic acid), along with excluded volume effects of CTAB micelles, imparts a hierarchical structure upon the PEC-SM hydrogel. Rheology provided detailed insights into the viscoelastic behaviors of PEC-SM hydrogels at varying CTAB concentrations. The intermolecular interaction and heterogeneous network structure of physically cross-linked PEC-SM hydrogels with CTAB micelles were elucidated by solid-state nuclear magnetic resonance (NMR) spectroscopy. On the basis of rheology and NMR results, complemented by other characterization analyses, the physical illustration of the PEC-SM hybrid hydrogel network structure regulated by competitive surfactant micelles is presented. This work offers valuable in-depth insight into polyelectrolyte complexation and provides a foundation for the development of robust PEC hydrogel materials.