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Gels, Volume 9, Issue 9 (September 2023) – 96 articles

Cover Story (view full-size image): The contamination of aqueous resources with radioactive substances is among the critical aspects of environmental pollution. Inspiration from silaffins, the proteins that mediate silica shell formation to diatoms, leads to the replication of their action with hyperbranched poly(ethylene imine). In this context, two similar methods that yielded xerogels and nanoparticles with different compositions and properties were developed. Both variants were found to have a very low environmental impact, since they do not require organic solvents or high temperatures and do not produce toxic byproducts. This work investigates americium and uranium ion adsorption from ultra-pure water and seawater under various pH levels and temperatures. view this paper
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18 pages, 13376 KiB  
Article
Thermosensitive Hydrogel-Functionalized Mesoporous Silica Nanoparticles for Parenteral Application of Chemotherapeutics
by Christina Voycheva, Marta Slavkova, Teodora Popova, Diana Tzankova, Denitsa Stefanova, Virginia Tzankova, Ivelina Ivanova, Stanislav Tzankov, Ivanka Spassova, Daniela Kovacheva and Borislav Tzankov
Gels 2023, 9(9), 769; https://doi.org/10.3390/gels9090769 - 21 Sep 2023
Cited by 3 | Viewed by 1299
Abstract
Hydrogels can offer many opportunities for drug delivery strategies. They can be used on their own, or their benefits can be further exploited in combination with other nanocarriers. Intelligent hydrogels that react to changes in the surrounding environment can be utilized as gatekeepers [...] Read more.
Hydrogels can offer many opportunities for drug delivery strategies. They can be used on their own, or their benefits can be further exploited in combination with other nanocarriers. Intelligent hydrogels that react to changes in the surrounding environment can be utilized as gatekeepers and provide sustained on-demand drug release. In this study, a hybrid nanosystem for temperature- and pH-sensitive delivery was prepared from MCM-41 nanoparticles grafted with a newly synthesized thermosensitive hydrogel (MCM-41/AA-g-PnVCL). The initial particles were chemically modified by the attachment of carboxyl groups. Later, they were grafted with agar (AA) and vinylcaprolactam (VCL) by free radical polymerization. Doxorubicin was applied as a model hydrophilic chemotherapeutic drug. The successful formulation was confirmed by FT-IR and TGA. Transmission electron microscopy and dynamic light scattering analysis showed small particles with negative zeta potential. Their release behaviour was investigated in vitro in media with different pH and at different temperatures. Under tumour simulating conditions (40 °C and pH 4.0), doxorubicin was almost completely released within 72 h. The biocompatibility of the proposed nanoparticles was demonstrated by in vitro haemolysis assay. These results suggest the possible parenteral application of the newly prepared hydrogel-functionalized mesoporous silica nanoparticles for temperature-sensitive and pH-triggered drug delivery at the tumour site. Full article
(This article belongs to the Special Issue Hydrogelated Matrices: Structural, Functional and Applicative Aspects)
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18 pages, 1792 KiB  
Review
From Free Tissue Transfer to Hydrogels: A Brief Review of the Application of the Periosteum in Bone Regeneration
by Hai Xin, Eva Tomaskovic-Crook, D S Abdullah Al Maruf, Kai Cheng, James Wykes, Timothy G. H. Manzie, Steven G. Wise, Jeremy M. Crook and Jonathan R. Clark
Gels 2023, 9(9), 768; https://doi.org/10.3390/gels9090768 - 21 Sep 2023
Cited by 3 | Viewed by 1752
Abstract
The periosteum is a thin layer of connective tissue covering bone. It is an essential component for bone development and fracture healing. There has been considerable research exploring the application of the periosteum in bone regeneration since the 19th century. An increasing number [...] Read more.
The periosteum is a thin layer of connective tissue covering bone. It is an essential component for bone development and fracture healing. There has been considerable research exploring the application of the periosteum in bone regeneration since the 19th century. An increasing number of studies are focusing on periosteal progenitor cells found within the periosteum and the use of hydrogels as scaffold materials for periosteum engineering and guided bone development. Here, we provide an overview of the research investigating the use of the periosteum for bone repair, with consideration given to the anatomy and function of the periosteum, the importance of the cambium layer, the culture of periosteal progenitor cells, periosteum-induced ossification, periosteal perfusion, periosteum engineering, scaffold vascularization, and hydrogel-based synthetic periostea. Full article
(This article belongs to the Special Issue Hydrogel for Tissue Regeneration)
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23 pages, 6854 KiB  
Article
Tioconazole-Loaded Transethosomal Gel Using Box–Behnken Design for Topical Applications: In Vitro, In Vivo, and Molecular Docking Approaches
by Muhammad Imran Qureshi, Qazi Adnan Jamil, Faisal Usman, Tanveer A. Wani, Mudassir Farooq, Hamid Saeed Shah, Hassan Ahmad, Ruqaiya Khalil, Muhammad Sajjad, Seema Zargar and Safina Kausar
Gels 2023, 9(9), 767; https://doi.org/10.3390/gels9090767 - 21 Sep 2023
Viewed by 1951
Abstract
Tioconazole (TCZ) is a broad-spectrum fungicidal BCS class II drug with reported activity against Candida albicans, dermatophytes, and certain Staphylococci bacteria. We report the use of TCZ-loaded transethosomes (TEs) to overcome the skin’s barrier function. TCZ-loaded TEs were fabricated by using [...] Read more.
Tioconazole (TCZ) is a broad-spectrum fungicidal BCS class II drug with reported activity against Candida albicans, dermatophytes, and certain Staphylococci bacteria. We report the use of TCZ-loaded transethosomes (TEs) to overcome the skin’s barrier function. TCZ-loaded TEs were fabricated by using a cold method with slight modification. Box–Behnken composite design was utilized to investigate the effect of independent variables. The fabricated TEs were assessed with various physicochemical characterizations. The optimized formulation of TCZ-loaded TEs was incorporated into gel and evaluated for pH, conductivity, drug content, spreadability, rheology, in vitro permeation, ex vivo permeation, and in vitro and in vivo antifungal activity. The fabricated TCZ-loaded TEs had a % EE of 60.56 to 86.13, with particle sizes ranging from 219.1 to 757.1 nm. The SEM images showed spherically shaped vesicles. The % drug permeation was between 77.01 and 92.03. The kinetic analysis of all release profiles followed Higuchi’s diffusion model. The FTIR, DSC, and XRD analysis showed no significant chemical interactions between the drug and excipients. A significantly higher antifungal activity was observed for TCZ-loaded transethosomal gel in comparison to the control. The in vivo antifungal study on albino rats indicated that TCZ-loaded transethosomal gel showed a comparable therapeutic effect in comparison to the market brand Canesten®. Molecular docking demonstrated that the TCZ in the TE composition was surrounded by hydrophobic excipients with increased overall hydrophobicity and better permeation. Therefore, TCZ in the form of transethosomal gel can serve as an effective drug delivery system, having the ability to penetrate the skin and overcome the stratum corneum barrier with improved efficacy. Full article
(This article belongs to the Special Issue Functional Gel Materials and Applications)
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18 pages, 4716 KiB  
Article
Three-Dimensional Printing Parameter Optimization for Salmon Gelatin Gels Using Artificial Neural Networks and Response Surface Methodology: Influence on Physicochemical and Digestibility Properties
by Nailín Carvajal-Mena, Gipsy Tabilo-Munizaga, Marleny D. A. Saldaña, Mario Pérez-Won, Carolina Herrera-Lavados, Roberto Lemus-Mondaca and Luis Moreno-Osorio
Gels 2023, 9(9), 766; https://doi.org/10.3390/gels9090766 - 20 Sep 2023
Viewed by 1079
Abstract
This study aimed to optimize the 3D printing parameters of salmon gelatin gels (SGG) using artificial neural networks with the genetic algorithm (ANN-GA) and response surface methodology (RSM). In addition, the influence of the optimal parameters obtained using the two different methodologies was [...] Read more.
This study aimed to optimize the 3D printing parameters of salmon gelatin gels (SGG) using artificial neural networks with the genetic algorithm (ANN-GA) and response surface methodology (RSM). In addition, the influence of the optimal parameters obtained using the two different methodologies was evaluated for the physicochemical and digestibility properties of the printed SGG (PSGG). The ANN-GA had a better fit (R2 = 99.98%) with the experimental conditions of the 3D printing process than the RSM (R2 = 93.99%). The extrusion speed was the most influential parameter according to both methodologies. The optimal values of the printing parameters for the SGG were 0.70 mm for the nozzle diameter, 0.5 mm for the nozzle height, and 24 mm/s for the extrusion speed. Gel thermal properties showed that the optimal 3D printing conditions affected denaturation temperature and enthalpy, improving digestibility from 46.93% (SGG) to 51.52% (PSGG). The secondary gel structures showed that the β-turn structure was the most resistant to enzymatic hydrolysis, while the intermolecular β-sheet was the most labile. This study validated two optimization methodologies to achieve optimal 3D printing parameters of salmon gelatin gels, with improved physicochemical and digestibility properties for use as transporters to incorporate high value nutrients to the body. Full article
(This article belongs to the Special Issue Recent Developments in Food Gels)
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18 pages, 3752 KiB  
Article
Agarose Cryogels: Production Process Modeling and Structural Characterization
by Raffaele Mancino, Diego Caccavo, Anna Angela Barba, Gaetano Lamberti, Alice Biasin, Angelo Cortesi, Gabriele Grassi, Mario Grassi and Michela Abrami
Gels 2023, 9(9), 765; https://doi.org/10.3390/gels9090765 - 20 Sep 2023
Viewed by 1196
Abstract
A cryogel is a cross-linked polymer network with different properties that are determined by its manufacturing technique. The formation of a cryogel occurs at low temperatures and results in a porous structure whose pore size is affected by thermal conditions. The adjustable pore [...] Read more.
A cryogel is a cross-linked polymer network with different properties that are determined by its manufacturing technique. The formation of a cryogel occurs at low temperatures and results in a porous structure whose pore size is affected by thermal conditions. The adjustable pore sizes of cryogels make them attractive for diverse applications. In this study, the influence of the external operational temperature, which affects the cooling and freezing rates, on the production of cryogels with 2% w/w agarose is investigated. Moreover, a mathematical model is developed to simulate the cryogel production process and provide an initial estimate of the pore size within the structure. The predictions of the model, supported by qualitative light microscopy images, demonstrate that cryogels produced at higher process temperatures exhibit larger pore sizes. Moreover, the existence of pore size distribution within the gel structure is confirmed. Finally, stress relaxation tests, coupled with an image analysis, validates that cryogels produced at lower temperatures possess a higher stiffness and slower water release rates. Full article
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18 pages, 6751 KiB  
Article
Water Consolidation Performance of Acrylic-Polymer-Modified Materials and Their Concrete Impermeability Repair Characteristics
by Dong Yan, Lipeng Lai, Xuedang Xiao, Lei Zhang, Zilong Zhao and Jun Zhao
Gels 2023, 9(9), 764; https://doi.org/10.3390/gels9090764 - 19 Sep 2023
Cited by 1 | Viewed by 1051
Abstract
Acrylic materials exhibit favorable grouting repair performance. However, their curing products are easily inclined to drying shrinkage, and their concrete impermeability repair characteristics have seldom been investigated. To improve material properties, reveal the impermeability repair mechanism, and address drying shrinkage, this study proposed [...] Read more.
Acrylic materials exhibit favorable grouting repair performance. However, their curing products are easily inclined to drying shrinkage, and their concrete impermeability repair characteristics have seldom been investigated. To improve material properties, reveal the impermeability repair mechanism, and address drying shrinkage, this study proposed the addition of styrene–acrylate copolymer emulsion (styrene–acrylic emulsion) to the grouting material to prepare two-component acrylate grouting materials. Using orthogonal and single-factor tests combined with physical and mechanical properties, the mechanical properties and impermeability repair performance (physical and mechanical properties combined) of grouting materials were analyzed and studied, and the optimal ratio of each component of acrylate grouting materials was determined. Results show that (1) the hydrogel produced by the reaction of sodium methacrylate with hydroxyethyl acrylate has good physical and mechanical properties. (2) With the increase in the accelerator dosage, the setting time of slurry initially decreases and then increases; as the initiator dosage increases, the setting time of slurry decreases, which is negatively correlated with the initiator dosage. (3) Talcum powder can improve the physical and chemical properties of gel and enhance the reliability and durability of acrylate grouting materials, and the comprehensive performance is the best at a dosage of 3%. (4) Styrene–acrylic emulsion can increase the solid content and reduce the volume drying shrinkage when added to grouting materials. The fractured impermeable specimens were repaired by grouting with prepared acrylate grouting materials and cured for 24 h for the impermeability test, and the water pressure for the 24 h impermeability repair was 1.0 MPa. This study’s results provide important reference and basis for revealing the impermeability principle of acrylate grouting materials and evaluating their impermeability. Full article
(This article belongs to the Special Issue Functional Gel Materials and Applications)
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15 pages, 6125 KiB  
Article
Novel Modified Styrene-Based Microspheres for Enhancing the Performance of Drilling Fluids at High Temperatures
by Xianfa Zhang, Jingping Liu, Jinsheng Sun, Kaihe Lv, Zonglun Wang, Zhe Xu and Yuanwei Sun
Gels 2023, 9(9), 763; https://doi.org/10.3390/gels9090763 - 19 Sep 2023
Cited by 1 | Viewed by 902
Abstract
Ensuring wellbore stability is of utmost importance for safety when drilling in deep formations. However, high temperatures severely disrupt the drilling fluid gel system, leading to severe stability issues within ultra-deep formations containing micropores. This study focused on the development of a polymer-based [...] Read more.
Ensuring wellbore stability is of utmost importance for safety when drilling in deep formations. However, high temperatures severely disrupt the drilling fluid gel system, leading to severe stability issues within ultra-deep formations containing micropores. This study focused on the development of a polymer-based plugging material capable of withstanding high temperatures up to 200 °C. A kind of microsphere, referred to as SST (styrene–sodium styrene sulfonate copolymer), was synthesized with a particle size of 322 nm. Compared to polystyrene, the thermal stability of SST is greatly improved, with a thermal decomposition temperature of 362 °C. Even after subjecting SST to hot rolling at 200 °C for 16 h, the particle size, elemental composition, and zeta potential remained stable within an aqueous dispersion system. The results of core displacement and NMR tests demonstrate that SST considerably reduces the pore diameter with a remarkable plugging efficiency of 78.9%. Additionally, when drilling fluids reach 200 °C, SST still enhances drilling fluid suspension and dispersion, and reduces fluid loss by over 36% by facilitating the dispersion of clay particles, improving the gel structure of the drilling fluid, resisting clay dehydration, and promoting plugging. The development of SST provides valuable insights into the preparation of high-temperature-resistant microspheres and the formulation of effective plugging agents for deep-well drilling fluids. Full article
(This article belongs to the Special Issue Polymer Gels for the Oil and Gas Industry)
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18 pages, 7858 KiB  
Article
Biocompatible Anisole-Nonlinear PEG Core–Shell Nanogels for High Loading Capacity, Excellent Stability, and Controlled Release of Curcumin
by Jing Shen, Jiangtao Zhang, Weitai Wu, Probal Banerjee and Shuiqin Zhou
Gels 2023, 9(9), 762; https://doi.org/10.3390/gels9090762 - 18 Sep 2023
Cited by 3 | Viewed by 1085
Abstract
Curcumin, a nontoxic and cheap natural medicine, has high therapeutic efficacy for many diseases, including diabetes and cancers. Unfortunately, its exceedingly low water-solubility and rapid degradation in the body severely limit its bioavailability. In this work, we prepare a series of biocompatible poly(vinyl [...] Read more.
Curcumin, a nontoxic and cheap natural medicine, has high therapeutic efficacy for many diseases, including diabetes and cancers. Unfortunately, its exceedingly low water-solubility and rapid degradation in the body severely limit its bioavailability. In this work, we prepare a series of biocompatible poly(vinyl anisole)@nonlinear poly(ethylene glycol) (PVAS@PEG) core–shell nanogels with different PEG gel shell thickness to provide high water solubility, good stability, and controllable sustained release of curcumin. The PVAS nanogel core is designed to attract and store curcumin molecules for high drug loading capacity and the hydrophilic nonlinear PEG gel shell is designed to offer water dispersibility and thermo-responsive drug release. The nanogels prepared are monodispersed in a spherical shape with clear core–shell morphology. The size and shell thickness of the nanogels can be easily controlled by changing the core–shell precursor feeding ratios. The optimized PVAS@PEG nanogels display a high curcumin loading capacity of 38.0 wt%. The nanogels can stabilize curcumin from degradation at pH = 7.4 and release it in response to heat within the physiological temperature range. The nanogels can enter cells effectively and exhibit negligible cytotoxicity to both the B16F10 and HL-7702 cells at a concentration up to 2.3 mg/mL. Such designed PVAS@PEG nanogels have great potential to be used for efficient drug delivery. Full article
(This article belongs to the Special Issue Recent Advances in Microgels/Nanogels)
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17 pages, 9085 KiB  
Article
Multifunctional Drugs-Loaded Carbomol Hydrogel Promotes Diabetic Wound Healing via Antimicrobial and Immunoregulation
by Hehui Wang, Jiale Jin, Chi Zhang, Fangyi Gong, Baiwen Hu, Xiaochuan Wu, Ming Guan and Dongdong Xia
Gels 2023, 9(9), 761; https://doi.org/10.3390/gels9090761 - 18 Sep 2023
Viewed by 1286
Abstract
Diabetic wound healing poses a significant clinical dilemma. Bacterial infection and immune dysregulation are the predominant reasons. However, conventional wound dressings with a single treatment approach often limit therapeutic efficacy and continue working with difficulty. These limitations cause high treatment failure for diabetic [...] Read more.
Diabetic wound healing poses a significant clinical dilemma. Bacterial infection and immune dysregulation are the predominant reasons. However, conventional wound dressings with a single treatment approach often limit therapeutic efficacy and continue working with difficulty. These limitations cause high treatment failure for diabetic wounds. In this study, we developed a multiple drug-loaded carbomer hydrogel containing Que/Van/Rif (QVR-CBMG) for the simultaneous treatment of infection and immune dysregulation. Honeycomb-like QVR-CBMG hydrogel exhibits excellent abilities to eliminate bacterial infection and biofilms in vitro. Moreover, QVR-CBMG hydrogel possesses an immunomodulatory capacity via affecting the Sirt3/SOD2 signaling pathway to promote M2 macrophages. Furthermore, QVR-CBMG hydrogel effectively promotes wound healing in diabetic rats through several mechanisms. The multidrug-loaded wound dressing not only eliminates bacterial infection and facilitated angiogenesis but also promotes collagen deposition and remodulates the local immune microenvironment in the areas of wounds. In summary, this synthetic strategy to eliminate infection and regulate immune disorders has potential translational value for the prevention and management of diabetic wounds. Full article
(This article belongs to the Special Issue Advances in Biomedical Hydrogels)
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20 pages, 4541 KiB  
Article
Feasibility of Enzymatic Protein Extraction from a Dehydrated Fish Biomass Obtained from Unsorted Canned Yellowfin Tuna Side Streams: Part I
by Federica Grasso, Diego Méndez-Paz, Rebeca Vázquez Sobrado, Valentina Orlandi, Federica Turrini, Giulia De Negri Atanasio, Elena Grasselli, Micaela Tiso and Raffaella Boggia
Gels 2023, 9(9), 760; https://doi.org/10.3390/gels9090760 - 18 Sep 2023
Cited by 2 | Viewed by 1644
Abstract
This study presents for the first time a scalable process for the extraction of valuable proteins starting from samples of unsorted mixed tuna scraps which were previously dehydrated by an industrial patented process. The aims of this work were both to avoid the [...] Read more.
This study presents for the first time a scalable process for the extraction of valuable proteins starting from samples of unsorted mixed tuna scraps which were previously dehydrated by an industrial patented process. The aims of this work were both to avoid the onerous sorting step of tuna leftovers, which generally consists of isolating skin and bones for collagen/gelatin extraction, and to improve the logistic of managing highly perishable biomass thanks to the reduction in its volume and to its microbiological stabilization. In view of a zero-waste economy, all the protein fractions (namely, non-collagenous proteins NCs and ALKs, gelatin, and hydrolyzed gelatin peptides, HGPs) isolated in the proposed single cascade flowchart were stabilized and preliminarily characterized. The extraction flowchart proposed allows one to obtain the following most promising compounds: 1.7 g of gelatin, 3.2 g of HGPs, and 14.6 g of NCs per 100 g of dehydrated starting material. A focus on oven-dried gelatin was reported in terms of proximate analysis, amino acid composition, color parameters, FT-IR spectrum, pH, and viscoelastic properties (5 mPa·s of viscosity and 14.3 °C of gelling temperature). All the obtained extracts are intended to be exploited in food supplements, feed, fertilizers/plant bio-stimulants, packaging, and the cosmetic industry. Full article
(This article belongs to the Special Issue Food Gels and Edible Gels)
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17 pages, 3714 KiB  
Article
Flaxseed Gum/Arabic Gum/Tween 80-Based Oleogel as a Fat Substitute Applied in Emulsified Sausage: Physicochemical Properties, Sensory Attributes and Nutritional Quality
by Qiaomei Zhu, Fu Chen, Peiyang Li, Tao Wu, Yijun Pan and Min Zhang
Gels 2023, 9(9), 759; https://doi.org/10.3390/gels9090759 - 18 Sep 2023
Viewed by 1565
Abstract
In the present study, flaxseed gum (FG), Arabic gum (GA) and Tween 80 were used to prepare oleogels through an emulsion-templated method, and the obtained oleogels were designed for the partial substitution of pork fat in emulsified sausage. An increment in FG concentrations [...] Read more.
In the present study, flaxseed gum (FG), Arabic gum (GA) and Tween 80 were used to prepare oleogels through an emulsion-templated method, and the obtained oleogels were designed for the partial substitution of pork fat in emulsified sausage. An increment in FG concentrations enhanced the viscoelasticity of emulsions, which resulted in the improved stability of emulsion systems, with smaller droplet sizes. In addition, increased FG concentrations contributed to higher mechanical strength, denser network structure and lower oil loss of oleogels. As a fat substitute, the prepared oleogels improved the textural properties and nutritional quality of emulsified sausages. With the increase in the substitution level of oleogels, the hardness and chewiness of the emulsified sausage increased, and the cooking loss decreased. Meanwhile, the reformulation with oleogels decreased the saturated fat from 57.04 g/100 g lipid to 12.05 g/100 g lipid, while increasing the ratio of omega-6 to omega-3 essential fatty acids from 0.10 to 0.39. The obtained results demonstrated that the flaxseed gum/Arabic gum/Tween 80-based oleogels had huge potential to successfully replace pork fat in emulsified sausage products. Full article
(This article belongs to the Special Issue Advances in Polymer Rheology)
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12 pages, 276 KiB  
Article
Hydrogel Coating versus Calcium Sulphate Beads as a Local Antibiotic Carrier for Debridement Procedures in Acute Periprosthetic Joint Infection: A Preliminary Study
by Daniele De Meo, Paolo Martini, Maria Francesca Pennarola, Giovanni Guarascio, Marco Rivano Capparuccia, Giancarlo Iaiani, Vittorio Candela, Stefano Gumina and Ciro Villani
Gels 2023, 9(9), 758; https://doi.org/10.3390/gels9090758 - 18 Sep 2023
Viewed by 1152
Abstract
Periprosthetic joint infections (PJI) are among the most difficult complications to treat in orthopaedic surgery. Debridement, antibiotics, and implant retention (DAIR) represent an efficient strategy for acute PJI, especially when resorbable local antibiotic carriers and coatings are used. The aim of this pilot [...] Read more.
Periprosthetic joint infections (PJI) are among the most difficult complications to treat in orthopaedic surgery. Debridement, antibiotics, and implant retention (DAIR) represent an efficient strategy for acute PJI, especially when resorbable local antibiotic carriers and coatings are used. The aim of this pilot study was to evaluate the difference between using antibiotic-loaded hydrogel (ALH) and calcium sulphate (CS) beads in the DAIR procedure. We analysed 16 patients who had been treated since 2018 for acute PJI, namely eight patients with knee PJI (50%), seven with hip PJI (43.7%), and one with shoulder PJI (6.2%). Nine patients were treated with the Debridement, Antibiotic Coating and Retention of the Implant (DACRI) method, while seven were treated with the Debridement, Antibiotic Pearls, Retention of the Implant (DAPRI) method. We found no significant differences between the two groups in terms of age, sex, the American Society of Anesthesiologists risk score, Charlson Comorbidity Index, localisation, days from onset to diagnosis and pathogenesis. Furthermore, no differences were found between the DACRI and DAPRI groups in terms of infection control (15 patients, 93.75% with p = 0.36) and last C-Reactive Protein values (p = 0.26), with a mean follow-up of 26.1 ± 7.7 months. Treatment for one patient affected by knee Candida albicans PJI in the DACRI group was not successful. In conclusion, DAPRI and DACRI appear to be safe and effective treatments for PJIs. This evidence will encourage the development of new clinical research into local carriers and coatings for use in acute implant-associated infections. Full article
(This article belongs to the Special Issue Engineering Hydrogel for Biomedical Applications)
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20 pages, 3123 KiB  
Article
Modification of Acorn Starch Structure and Properties by High Hydrostatic Pressure
by Luís M. G. Castro, Ana I. Caço, Carla F. Pereira, Sérgio C. Sousa, María E. Brassesco, Manuela Machado, Óscar L. Ramos, Elisabete M. C. Alexandre, Jorge A. Saraiva and Manuela Pintado
Gels 2023, 9(9), 757; https://doi.org/10.3390/gels9090757 - 17 Sep 2023
Viewed by 1090
Abstract
Despite being rich in starch, over half of acorn production is undervalued. High hydrostatic pressure was used to modify the properties of Q. pyrenaica (0.1 and 460 MPa for 20 min) and Q. robur (0.1 and 333 MPa for 17.4 min) acorn starches [...] Read more.
Despite being rich in starch, over half of acorn production is undervalued. High hydrostatic pressure was used to modify the properties of Q. pyrenaica (0.1 and 460 MPa for 20 min) and Q. robur (0.1 and 333 MPa for 17.4 min) acorn starches to obtain high-valued ingredients. Pressure significantly altered the span distribution and heterogeneity of the acorn starch granules depending on the species, but their morphology was unaffected. Pressurization increased the amylose/amylopectin ratio and damaged starch contents, but the effect was more prominent in Q. pyrenaica than in Q. robur. However, the polymorphism, relative crystallinity, gelatinization temperatures, and enthalpies were preserved. The pressure effect on the starch properties depended on the property and species. The solubility, swelling power, and acorn gels’ resistance towards deformation for both species decreased after pressurization. For Q. pyrenaica starch, the in vitro digestibility increased, but the pseudoplastic behavior decreased after pressurization. No differences were seen for Q. robur. Regarding the commercial starch, acorn starches had lower gelatinization temperatures and enthalpies, lower in vitro digestibility, lower resistance towards deformation, superior pseudoplastic behavior, and overall higher solubility and swelling power until 80 °C. This encourages the usage of acorn starches as a new food ingredient. Full article
(This article belongs to the Special Issue Hydrogelated Matrices: Structural, Functional and Applicative Aspects)
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16 pages, 3339 KiB  
Article
A Carboxyethylchitosan Gel Cross-Linked with Glutaraldehyde as a Candidate Carrier for Biomedical Applications
by Anastasia Korel, Alexander Samokhin, Ekaterina Zemlyakova, Alexander Pestov, Elena Blinova, Maxim Zelikman, Vadim Tkachenko, Viktoria Bets, Svetlana Kretien, Elena Arzhanova and Ekaterina Litvinova
Gels 2023, 9(9), 756; https://doi.org/10.3390/gels9090756 - 16 Sep 2023
Cited by 2 | Viewed by 959
Abstract
To date, few publications describe CEC’s properties and possible applications—thus, further evaluation of these properties is a point of interest. The present in vitro model study aimed to evaluate a carboxyethylchitosan (CEC) gel with a degree of substitution of 1, cross-linked with glutaraldehyde [...] Read more.
To date, few publications describe CEC’s properties and possible applications—thus, further evaluation of these properties is a point of interest. The present in vitro model study aimed to evaluate a carboxyethylchitosan (CEC) gel with a degree of substitution of 1, cross-linked with glutaraldehyde at a polymer:aldehyde molar ratio of 10:1, as a potential carrier for delivering bacteriophages to various pH-fixed media (acidic, alkaline), and including gastrointestinal tract (GIT) variable medium. A quantitative analysis of bacteriophages released from the gel was performed using photon correlation spectrophotometry, and phage activity after emission into medium was evaluated using the spot test. The results showed that the CEC gel’s maximum swelling ratios were at a nearly neutral alkaline pH. Increasing temperature enhances the swelling ratio of the gel independent from pH, up to 1127% at 37 °C and alkaline pH. The UV and photon correlation spectrophotometry showed equal gel release kinetics in both fixed media with acidic (pH = 2.2) and alkaline (pH = 7.4) pH environments at 37 °C, with the maximum release within two hours. However, phage lytic activity in the spot test during this simulation was absent. At the same time, we obtained an opaque phage lytic activity in the alkaline pH-fixed medium for at least three hours. Phages released from the tested CEC gel in different pHs suggest that this gel could be used for applications that require fast release at the treatment site both in acidic and alkaline pH. Such treatment sites could be a wound or even soil with mild acidic or alkaline pH. However, such CEC gel is not suitable as a delivery system to the GIT because of possible transported acid-sensitive agent (such as phages) release and destruction already in the stomach. Full article
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22 pages, 14791 KiB  
Article
Polyurethane Degradable Hydrogels Based on Cyclodextrin-Oligocaprolactone Derivatives
by Alexandra-Diana Diaconu, Corina-Lenuta Logigan, Catalina Anisoara Peptu, Constanta Ibanescu, Valeria Harabagiu and Cristian Peptu
Gels 2023, 9(9), 755; https://doi.org/10.3390/gels9090755 - 16 Sep 2023
Cited by 1 | Viewed by 915
Abstract
Polymer networks based on cyclodextrin and polyethylene glycol were prepared through polyaddition crosslinking using isophorone diisocyanate. The envisaged material properties are the hydrophilic character, specific to PEG and cyclodextrins, and the capacity to encapsulate guest molecules in the cyclodextrin cavity through physical interactions. [...] Read more.
Polymer networks based on cyclodextrin and polyethylene glycol were prepared through polyaddition crosslinking using isophorone diisocyanate. The envisaged material properties are the hydrophilic character, specific to PEG and cyclodextrins, and the capacity to encapsulate guest molecules in the cyclodextrin cavity through physical interactions. The cyclodextrin was custom-modified with oligocaprolactone to endow the crosslinked material with a hydrolytically degradable character. SEM, DTG, and FTIR characterization methods have confirmed the morphology and structure of the prepared hydrogels. The influence of the crosslinking reaction feed was investigated through dynamic rheology. Further, thermal water swelling and hydrolytic degradation in basic conditions revealed the connectivity of the polymer network and the particular influence of the cyclodextrin amount in the crosslinking reaction feed on the material properties. Also, levofloxacin was employed as a model drug to investigate the drug loading and release capacity of the prepared hydrogels. Full article
(This article belongs to the Special Issue Advanced Hydrogels for Tissue Engineering and Drug Delivery)
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15 pages, 1166 KiB  
Review
Nanocomposite Hydrogels and Extracellular Matrix—Advantages and Associated Risks
by Garry Kerch
Gels 2023, 9(9), 754; https://doi.org/10.3390/gels9090754 - 16 Sep 2023
Viewed by 1107
Abstract
Hydrogels can be considered as mimics of the extracellular matrix (ECM). Through integrins, the cytoskeleton is connected to the ECM, and cytoskeleton tension depends on ECM stiffness. A number of age-related diseases depend on cellular processes related to cytoskeleton function. Some examples of [...] Read more.
Hydrogels can be considered as mimics of the extracellular matrix (ECM). Through integrins, the cytoskeleton is connected to the ECM, and cytoskeleton tension depends on ECM stiffness. A number of age-related diseases depend on cellular processes related to cytoskeleton function. Some examples of cancer initiation and progression and heart disease in relation to ECM stiffness have been analyzed. The incorporation of rigid particles into the ECM can increase ECM stiffness and promote the formation of internal residual stresses. Water migration, changes in water binding energy to biomactomolecules, and changes in the state of water from tightly bound water to free and loosely bound water lead to changes in the stiffness of the ECM. Cardiac tissue engineering, ECM stiffness and cancer, the equivalence of ECM stiffness, oxidative stress, inflammation, multi-layer polyelectrolyte complex hydrogels and bioprinting, residual internal stresses, viscoelastic hydrogels, hydrogel nanocomposites, and the effect of water have been reported. Special attention has been paid to the role of bound water and internal stresses in ECM stiffness. The risks related to rigid particle incorporation into the ECM have been discussed. The potential effect of polyphenols, chitosan, and chitosan oligosaccharide on ECM stiffness and the potential for anti-TNF-α and anti-NF-κB therapies have been discussed. Full article
(This article belongs to the Special Issue Hydrogels: Synthesis, Characterization and Applications)
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21 pages, 3887 KiB  
Review
The Application of Nanogels as Efficient Drug Delivery Platforms for Dermal/Transdermal Delivery
by Panoraia I. Siafaka, Ece Özcan Bülbül, Mehmet Evren Okur, Ioannis D. Karantas and Neslihan Üstündağ Okur
Gels 2023, 9(9), 753; https://doi.org/10.3390/gels9090753 - 15 Sep 2023
Cited by 3 | Viewed by 1984
Abstract
The delivery of active molecules via the skin seems to be an efficient technology, given the various disadvantages of oral drug administration. Skin, which is the largest human organ of the body, has the important role of acting as a barrier for pathogens [...] Read more.
The delivery of active molecules via the skin seems to be an efficient technology, given the various disadvantages of oral drug administration. Skin, which is the largest human organ of the body, has the important role of acting as a barrier for pathogens and other molecules including drugs; in fact, it serves as a primary defense system blocking any particle from entering the body. Therefore, to overcome the skin barriers and poor skin permeability, researchers implement novel carriers which can effectively carry out transdermal delivery of the molecules. Another significant issue which medical society tries to solve is the effective dermal delivery of molecules especially for topical wound delivery. The application of nanogels is only one of the available approaches offering promising results for both dermal and transdermal administration routes. Nanogels are polymer-based networks in nanoscale dimensions which have been explored as potent carriers of poorly soluble drugs, genes and vaccines. The nanogels present unique physicochemical properties, i.e., high surface area, biocompatibility, etc., and, importantly, can improve solubility. In this review, authors aimed to summarize the available applications of nanogels as possible vehicles for dermal and transdermal delivery of active pharmaceutical ingredients and discuss their future in the pharmaceutical manufacturing field. Full article
(This article belongs to the Special Issue Designing Nanogels for Drug Delivery Systems)
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21 pages, 4687 KiB  
Article
Quality by Design-Optimized Glycerosome-Enabled Nanosunscreen Gel of Rutin Hydrate
by Md. Shabbir Alam, Niha Sultana, Md. Abdur Rashid, Yahya Alhamhoom, Asad Ali, Ayesha Waheed, Mo. Suheb Ansari, Mohd. Aqil and Mohd Mujeeb
Gels 2023, 9(9), 752; https://doi.org/10.3390/gels9090752 - 15 Sep 2023
Cited by 2 | Viewed by 1686
Abstract
Sunburn is caused by prolonged exposure to ultraviolet (UV) rays from the sun, resulting in redness of the skin as well as tenderness, swelling, and blistering issues. During the healing process, it can cause peeling, irritation, and some long-term effects, including premature aging, [...] Read more.
Sunburn is caused by prolonged exposure to ultraviolet (UV) rays from the sun, resulting in redness of the skin as well as tenderness, swelling, and blistering issues. During the healing process, it can cause peeling, irritation, and some long-term effects, including premature aging, pigmentation, and a high risk of skin cancer. Rutin has antioxidant and anti-inflammatory effects, which could potentially reduce inflammation and soothe sunburned skin. The objective of the current proposal is to develop and create carbopol gel-encased glycerosomes for the treatment of sunburn. The Design of Expert (DoE) technique was used to optimize the proposed formulation and was subjected to various characterization parameters such as nanovesicles size, polydispersity index (PDI), surface charge, entrapment efficiency (EE), and surface morphology. The optimized rutin-loaded glycerosomes (opt-RUT-loaded-GMs) were further characterised for drug release, 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assay, and confocal laser scanning microscopy (CLSM). The formulation showed sustained release, greater permeation into the skin, and good antioxidant activity. The dermatokinetic study of opt-RUT-loaded-GMs confirms that the Rutin hydrate had better retention in the epidermis as compared to the dermis, owing to its potential for long lasting protection after topical application. It was observed that the prepared formulation was stable, highly safe, and had good sun protection factor (SPF) values that could be used as a suitable option for topical drug administration to maximize the therapeutic efficacy of the drugs. Full article
(This article belongs to the Special Issue Gel-Based Materials: Preparations and Characterization)
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12 pages, 3097 KiB  
Article
Using the Water Absorption Ability of Dried Hydrogels to Form Hydrogel-Supported Lipid Bilayers
by Che-Lun Chin, Lu-Jan Huang, Zheng-Xian Lu, Wei-Chun Weng and Ling Chao
Gels 2023, 9(9), 751; https://doi.org/10.3390/gels9090751 - 15 Sep 2023
Viewed by 1285
Abstract
The formation of supported lipid bilayers (SLBs) on hydrogels can act as a biocompatible anti-fouling interface. However, generating continuous and mobile SLBs on materials other than conventional glass or mica remains a significant challenge. The interaction between lipid membrane vesicles and a typical [...] Read more.
The formation of supported lipid bilayers (SLBs) on hydrogels can act as a biocompatible anti-fouling interface. However, generating continuous and mobile SLBs on materials other than conventional glass or mica remains a significant challenge. The interaction between lipid membrane vesicles and a typical hydrogel is usually insufficient to induce membrane vesicle rupture and form a planar lipid membrane. In this study, we demonstrate that the water absorption ability of a dried polyacrylamide (PAAm) hydrogel could serve as a driving force to facilitate the formation of the hydrogel–SLBs. The absorption driving force vanishes after the hydrogels are fully hydrated, leaving no extra interaction hindering lipid lateral mobility in the formed SLBs. Our fluorescence recovery after photobleaching (FRAP) results show that SLBs only form on hydrogels with adequate absorption abilities. Moreover, we discovered that exposure to oxygen during drying could lead to the formation of an oxidized crust on the PAAm hydrogel surface, impeding SLB formation. Therefore, minimizing oxygen exposure during drying is crucial to achieving high-quality hydrogel surfaces for SLB formation. This water absorption method enables the straightforward fabrication of hydrogel–SLBs without the need for additional substrates or charges, thereby expanding their potential applications. Full article
(This article belongs to the Special Issue Functional Gel Materials and Applications)
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12 pages, 5451 KiB  
Review
Atomic Force Microscopy of Phytosterol Based Edible Oleogels
by Andrew B. Matheson, Vasileios Koutsos, Stephen R. Euston and Paul S. Clegg
Gels 2023, 9(9), 750; https://doi.org/10.3390/gels9090750 - 15 Sep 2023
Viewed by 1084
Abstract
This work reviews the use of atomic force microscopy (AFM) as a tool to investigate oleogels of edible triglyceride oils. Specific attention is given to those oleogels based on phytosterols and their esters, a class of material the authors have studied extensively. This [...] Read more.
This work reviews the use of atomic force microscopy (AFM) as a tool to investigate oleogels of edible triglyceride oils. Specific attention is given to those oleogels based on phytosterols and their esters, a class of material the authors have studied extensively. This work consists of a summary of the role of AFM in imaging edible oleogels, including the processing and preparation steps required to obtain high-quality AFM images of them. Finally, there is a comparison between AFM and other techniques that may be used to obtain structural information from oleogel samples. The aim of this review is to provide a useful introduction and summary of the technique for researchers in the fields of gels and food sciences looking to perform AFM measurements on edible oleogels. Full article
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15 pages, 7743 KiB  
Article
Heat-Treated Aramid Pulp/Silica Aerogel Composites with Improved Thermal Stability and Thermal Insulation
by Zhi Li, Kai Shen, Min Hu, Yury M. Shulga, Zhenkui Chen, Qiong Liu, Ming Li and Xiaoxu Wu
Gels 2023, 9(9), 749; https://doi.org/10.3390/gels9090749 - 14 Sep 2023
Cited by 1 | Viewed by 1371
Abstract
In this work, we prepared heat-treated aramid pulp/silica aerogel composites (AP/aerogels) and investigated in detail the feasibility of improving thermal stability and thermal insulation via tailored heat treatment. The microstructure and FTIR spectra reveal that AP/aerogels are formed by a physical combination of [...] Read more.
In this work, we prepared heat-treated aramid pulp/silica aerogel composites (AP/aerogels) and investigated in detail the feasibility of improving thermal stability and thermal insulation via tailored heat treatment. The microstructure and FTIR spectra reveal that AP/aerogels are formed by a physical combination of the silica aerogel matrix and aramid pulps. When the heat treatment temperature increases, the density slightly decreases and then increases to the maximum due to the significant volume shrinkage. The pyrolysis of aramid pulp and the collapse of silica skeletons occur during heat treatment; nevertheless, the typical structures of AP/aerogels do not change significantly. It is also found that both the hydrophobicity and the thermal insulation decrease with the increasing heat treatment temperature. We note that when the heat treatment is at 600 °C, the AP/aerogel still maintains a low density of 0.19 g/cm3 and a contact angle of 138.5°. The thermal conductivity is as low as 26.11 mW/m/K, measured using the transient hot wire method. Furthermore, the heat-treated AP/aerogels can avoid heat shock and possible thermal hazards during practical thermal insulation applications. The onset temperatures of the thermal decomposition of AP/aerogels increase from 298.8 °C for an untreated one to 414.7 °C for one treated at 600 °C, indicating that the thermal stability of AP/aerogels is improved significantly. This work provides a practical engineering approach to expand the thermal insulation applications of silica aerogel composites. Full article
(This article belongs to the Special Issue International Perspectives on Aerogels)
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18 pages, 3009 KiB  
Article
Design and Evaluation of Liposomal Sulforaphane-Loaded Polyvinyl Alcohol/Polyethylene Glycol (PVA/PEG) Hydrogels as a Novel Drug Delivery System for Wound Healing
by Hamide Hemati, Fateme Haghiralsadat, Mahdie Hemati, Ghasem Sargazi and Nastaran Razi
Gels 2023, 9(9), 748; https://doi.org/10.3390/gels9090748 - 14 Sep 2023
Cited by 6 | Viewed by 1708
Abstract
Hydrogel scaffold has been widely applied as drug delivery systems for treating skin injuries. However, the poor drug loading and rapid drug release of hydrogel restricted their application. In the current study, we present a nanoliposome containing sulforaphane (SF) as a nano-drug delivery [...] Read more.
Hydrogel scaffold has been widely applied as drug delivery systems for treating skin injuries. However, the poor drug loading and rapid drug release of hydrogel restricted their application. In the current study, we present a nanoliposome containing sulforaphane (SF) as a nano-drug delivery system that is encapsulated within the scaffold hydrogel system to overcome these limitations and improve wound healing. The hydrogel substrate consisting of 10% polyvinyl alcohol (PVA)/5% polyethylene glycol 400 (PEG400) was prepared by the freeze–thaw method, and the nanoliposomal system was manufactured by the thin film hydration method at different molar ratios of cholesterol: SPC: DPPC: DSPE-PEG2000. The nanoliposome and hydrogel system was characterized by physicochemical analyses. The findings achieved from the optimization of the sulforaphane-loaded nanoliposome (SFNL) displayed an increase in the molar ratio of SPC, leading to a higher entrapment efficiency and a gradual release profile. Narrow size distribution, optimal electrical charge, and the lack of molecular interactions between SF and nanoliposome components in the FTIR analysis make SFNL a suitable drug delivery system for the wound healing process. The obtained SFNL-encapsulated freeze–thawed hydrogel system has sufficient and specific swelling ability at different pH values and increased mechanical strength and elongation. Additionally, the release pattern of SFNL at different pH values showed that the release of SF from liposomes depends on the pH value of the environment and accelerates in line with decreasing pH values. Encapsulation of nanoliposomal SF in the hydrogel structure provides a sustained release pattern of SF compared to its free form and increased as the pH environments continued to raise. The cytotoxicity and cell uptake of SFNL-loaded hydrogels against human skin fibroblasts (HFF cell line) were investigated. The in vitro analyses displayed that the toxicity properties of SF and SFNL were dose-dependent, and SFNL exhibited lower toxicity compared to free SF. Furthermore, the proper cell compatibility of the prepared hydrogel against the HFF cell line was confirmed by the MTT assay. These findings imply that the hydrogel scaffold loaded with SFNL may have wound-healing potential. Full article
(This article belongs to the Section Gel Analysis and Characterization)
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16 pages, 5035 KiB  
Article
Effect of Moderate Electric Fields on the Physical and Chemical Characteristics of Cheese Emulsions
by Ipek Altay, Lucas Sales Queiroz, Naaman F. Nogueira Silva, Aberham Hailu Feyissa, Federico Casanova, Jens J. Sloth and Mohammad Amin Mohammadifar
Gels 2023, 9(9), 747; https://doi.org/10.3390/gels9090747 - 14 Sep 2023
Cited by 3 | Viewed by 1178
Abstract
Cheese powder is a multifunctional ingredient that is produced by spray drying a hot cheese emulsion called cheese feed. Feed stability is achieved by manipulating calcium equilibrium using emulsifying salts. However, the increased demand for ‘green’ products created a need for alternative production [...] Read more.
Cheese powder is a multifunctional ingredient that is produced by spray drying a hot cheese emulsion called cheese feed. Feed stability is achieved by manipulating calcium equilibrium using emulsifying salts. However, the increased demand for ‘green’ products created a need for alternative production methods. Therefore, this study investigated the impact of ohmic heating (OH) on Cheddar cheese, mineral balance, and the resulting cheese feed characteristics compared with a conventional method. A full factorial design was implemented to determine the optimal OH parameters for calcium solubilization. Electric field exposure and temperature had a positive correlation with mineral solubilization, where temperature had the greatest impact. Structural differences in pre-treated cheeses (TC) were analyzed using thermorheological and microscopic techniques. Obtained feeds were analyzed for particle size, stability, and viscosity. OH-treatment caused a weaker cheese structure, indicating the potential removal of calcium phosphate complexes. Lower component retention of OH_TC was attributed to the electroporation effect of OH treatment. Microscopic images revealed structural changes, with OH_TC displaying a more porous structure. Depending on the pre-treatment method, component recovery, viscosity, particle size distribution, and colloidal stability of the obtained feeds showed differences. Our findings show the potential of OH in mineral solubilization; however, further improvements are needed for industrial application. Full article
(This article belongs to the Special Issue Recent Advance in Food Gels)
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40 pages, 1970 KiB  
Review
Aerogel-Based Materials in Bone and Cartilage Tissue Engineering—A Review with Future Implications
by István Lázár, Ladislav Čelko and Melita Menelaou
Gels 2023, 9(9), 746; https://doi.org/10.3390/gels9090746 - 13 Sep 2023
Cited by 5 | Viewed by 2322
Abstract
Aerogels are fascinating solid materials known for their highly porous nanostructure and exceptional physical, chemical, and mechanical properties. They show great promise in various technological and biomedical applications, including tissue engineering, and bone and cartilage substitution. To evaluate the bioactivity of bone substitutes, [...] Read more.
Aerogels are fascinating solid materials known for their highly porous nanostructure and exceptional physical, chemical, and mechanical properties. They show great promise in various technological and biomedical applications, including tissue engineering, and bone and cartilage substitution. To evaluate the bioactivity of bone substitutes, researchers typically conduct in vitro tests using simulated body fluids and specific cell lines, while in vivo testing involves the study of materials in different animal species. In this context, our primary focus is to investigate the applications of different types of aerogels, considering their specific materials, microstructure, and porosity in the field of bone and cartilage tissue engineering. From clinically approved materials to experimental aerogels, we present a comprehensive list and summary of various aerogel building blocks and their biological activities. Additionally, we explore how the complexity of aerogel scaffolds influences their in vivo performance, ranging from simple single-component or hybrid aerogels to more intricate and organized structures. We also discuss commonly used formulation and drying methods in aerogel chemistry, including molding, freeze casting, supercritical foaming, freeze drying, subcritical, and supercritical drying techniques. These techniques play a crucial role in shaping aerogels for specific applications. Alongside the progress made, we acknowledge the challenges ahead and assess the near and far future of aerogel-based hard tissue engineering materials, as well as their potential connection with emerging healing techniques. Full article
(This article belongs to the Special Issue Aerogel Hybrids and Nanocomposites)
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12 pages, 2449 KiB  
Article
Characterization of Bioinks Prepared via Gelifying Extracellular Matrix from Decellularized Porcine Myocardia
by Héctor Sanz-Fraile, Carolina Herranz-Diez, Anna Ulldemolins, Bryan Falcones, Isaac Almendros, Núria Gavara, Raimon Sunyer, Ramon Farré and Jorge Otero
Gels 2023, 9(9), 745; https://doi.org/10.3390/gels9090745 - 13 Sep 2023
Viewed by 1150
Abstract
Since the emergence of 3D bioprinting technology, both synthetic and natural materials have been used to develop bioinks for producing cell-laden cardiac grafts. To this end, extracellular-matrix (ECM)-derived hydrogels can be used to develop scaffolds that closely mimic the complex 3D environments for [...] Read more.
Since the emergence of 3D bioprinting technology, both synthetic and natural materials have been used to develop bioinks for producing cell-laden cardiac grafts. To this end, extracellular-matrix (ECM)-derived hydrogels can be used to develop scaffolds that closely mimic the complex 3D environments for cell culture. This study presents a novel cardiac bioink based on hydrogels exclusively derived from decellularized porcine myocardium loaded with human-bone-marrow-derived mesenchymal stromal cells. Hence, the hydrogel can be used to develop cell-laden cardiac patches without the need to add other biomaterials or use additional crosslinkers. The scaffold ultrastructure and mechanical properties of the bioink were characterized to optimize its production, specifically focusing on the matrix enzymatic digestion time. The cells were cultured in 3D within the developed hydrogels to assess their response. The results indicate that the hydrogels fostered inter-cell and cell-matrix crosstalk after 1 week of culture. In conclusion, the bioink developed and presented in this study holds great potential for developing cell-laden customized patches for cardiac repair. Full article
(This article belongs to the Special Issue Hydrogels for 3D Printing)
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13 pages, 4565 KiB  
Article
Tissue Regeneration with Gelatine/Polysaccharide Derived Hydrogel Scaffolds: From Formulation to In Vivo Efficacy
by Jing Li, Keying He and Qian Xu
Gels 2023, 9(9), 744; https://doi.org/10.3390/gels9090744 - 13 Sep 2023
Viewed by 1058
Abstract
Combinations of different biomaterials with certain formulations may lead to improved properties and have significant potential for use in tissue regeneration applications. However, previously reported studies comparing biomaterials often suffered from inconsistent processing methods or inadequate comprehensive application research, hindering a comprehension of [...] Read more.
Combinations of different biomaterials with certain formulations may lead to improved properties and have significant potential for use in tissue regeneration applications. However, previously reported studies comparing biomaterials often suffered from inconsistent processing methods or inadequate comprehensive application research, hindering a comprehension of their efficacy in tissue engineering. This report explores the significance of screening the combination of gelatine with polysaccharide materials, specifically hyaluronic acid (HA) and carboxymethyl cellulose (CMC), using the same crosslinking method used for tissue regeneration. Hydrogel scaffolds (Gel/HA and Gel/CMC) at various concentrations were developed and characterized to assess their physiochemical properties. The results demonstrated that the hydrogels exhibited desirable mechanical properties, appropriate swelling behaviour, suitable porosity, and excellent cytocompatibility. In particular, the Gel1HA1 and Gel1CMC1 hydrogels showed remarkable cellular proliferation and aggregation. Further, we performed animal studies and explored the tissue regeneration effects of the Gel1HA1 and Gel1CMC1 hydrogels. Both hydrogels exhibited an accelerated wound closure rate and promoted vessel formation in a rodent full-thickness skin excisional model. Additionally, the subcutaneous implantation model demonstrated the induction of angiogenesis and collagen deposition within the implanted hydrogel samples. Overall, the hydrogels developed in this study demonstrated promising potential for use in the regeneration of soft tissue defects and this study emphasizes the significance of screening biomaterial combinations and formulations for tissue regeneration applications. Full article
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4 pages, 192 KiB  
Editorial
Editorial for Special Issue: Gel Films and Coatings Applied in Active Food Packaging
by Aris E. Giannakas
Gels 2023, 9(9), 743; https://doi.org/10.3390/gels9090743 - 13 Sep 2023
Viewed by 1239
Abstract
Nowadays, the global trends of bioeconomy and sustainability require the use of biobased raw materials in all scientific and application fields to reduce the global carbon dioxide fingerprint [...] Full article
(This article belongs to the Special Issue Bioactive Gel Films and Coatings Applied in Active Food Packaging)
13 pages, 2915 KiB  
Article
Gelatin/Hyaluronic Acid Photocrosslinked Double Network Hydrogel with Nano-Hydroxyapatite Composite for Potential Application in Bone Repair
by Jianuo Zheng, Yunping Wang, Yuwen Wang, Ruiping Duan and Lingrong Liu
Gels 2023, 9(9), 742; https://doi.org/10.3390/gels9090742 - 13 Sep 2023
Cited by 5 | Viewed by 1324
Abstract
The application of hydrogels in bone repair is limited due to their low mechanical strength. Simulating bone extracellular matrix, methylacrylylated gelatin (GelMA)/methylacrylylated hyaluronic acid (HAMA)/nano-hydroxyapatite(nHap) composite hydrogels were prepared by combining the double network strategy and composite of nHap in this study. The [...] Read more.
The application of hydrogels in bone repair is limited due to their low mechanical strength. Simulating bone extracellular matrix, methylacrylylated gelatin (GelMA)/methylacrylylated hyaluronic acid (HAMA)/nano-hydroxyapatite(nHap) composite hydrogels were prepared by combining the double network strategy and composite of nHap in this study. The precursor solutions of the composite hydrogels were injectable due to their shear thinning property. The compressive elastic modulus of the composite hydrogel was significantly enhanced, the fracture strength of the composite hydrogel nearly reached 1 MPa, and the composite hydrogel retained its high water content at above 88%. The composite hydrogels possess good compatibility with BMSCS and have the potential to be used as injectable hydrogels for bone defect treatment. Full article
(This article belongs to the Special Issue Hydrogel for Tissue Regeneration)
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15 pages, 1653 KiB  
Article
Nanogel-Based Delivery System for Lemongrass Essential Oil: A Promising Approach to Overcome Antibiotic Resistance in Pseudomonas aeruginosa Infections
by Mohammed F. Aldawsari, Ahmed I. Foudah, Pinki Rawat, Aftab Alam and Mohamad Ayman Salkini
Gels 2023, 9(9), 741; https://doi.org/10.3390/gels9090741 - 13 Sep 2023
Cited by 1 | Viewed by 1223
Abstract
The emergence of antibiotic-resistant strains of Pseudomonas aeruginosa (P. aeruginosa) presents a substantial obstacle in medical environments. To effectively tackle this problem, we suggest an innovative approach: employing a delivery system based on nanogels to administer lemongrass essential oil (LGO). Developed [...] Read more.
The emergence of antibiotic-resistant strains of Pseudomonas aeruginosa (P. aeruginosa) presents a substantial obstacle in medical environments. To effectively tackle this problem, we suggest an innovative approach: employing a delivery system based on nanogels to administer lemongrass essential oil (LGO). Developed PVA and PLGA nanoparticle formulation efficiently encapsulates LGO with 56.23% encapsulation efficiency by solvent extraction technique, preserving stability and bioactivity. Nanogel: 116 nm size, low polydispersity (0.229), −9 mV zeta potential. The nanogel’s controlled release facilitated targeted LGO delivery via pH-controlled dissolution. Pure LGO had the highest release rate, while LGO-NP and LGO-NP-CG exhibited slower rates. In 15 h, LGO-NP released 50.65%, and LGO-NP-CG released 63.58%, releasing 61.31% and 63.58% within 24 h. LGO-NP-CG demonstrated superior antioxidant activity, a lower MIC against P. aeruginosa, and the most potent bactericidal effect compared to other formulations. This underscores the versatile efficacy of LGO, suggesting its potential to combat antibiotic resistance and enhance treatment effectiveness. Moreover, employing a nanogel-based delivery approach for LGO offers an efficient solution to combat drug resistance in P. aeruginosa infections. By employing strategies such as nanogel encapsulation and controlled release, we can enhance the effectiveness of LGO against antibiotic-resistant strains. This study establishes a robust foundation for exploring innovative approaches to treating P. aeruginosa infections using nanomedicine and paves the way for investigating novel methods of delivering antimicrobial drugs. These efforts contribute to the ongoing battle against antibiotic resistance. Full article
(This article belongs to the Special Issue Nanosized Gel as a Drug Delivery System)
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21 pages, 7105 KiB  
Article
Developing a Prolamin-Based Gel for Food Packaging: In-Vitro Assessment of Cytocompatibility
by Franziska Trodtfeld, Tina Tölke and Cornelia Wiegand
Gels 2023, 9(9), 740; https://doi.org/10.3390/gels9090740 - 12 Sep 2023
Viewed by 1388
Abstract
Growing environmental concerns drive efforts to reduce packaging waste by adopting biodegradable polymers, coatings, and films. However, biodegradable materials used in packaging face challenges related to barrier properties, mechanical strength, and processing compatibility. A composite gel was developed using biodegradable compounds (prolamin, d-mannose, [...] Read more.
Growing environmental concerns drive efforts to reduce packaging waste by adopting biodegradable polymers, coatings, and films. However, biodegradable materials used in packaging face challenges related to barrier properties, mechanical strength, and processing compatibility. A composite gel was developed using biodegradable compounds (prolamin, d-mannose, citric acid), as a coating to increase the oxygen barrier of food packaging materials. To improve gel stability and mechanical properties, the gels were physically cross-linked with particles synthesized from tetraethyl orthosilicate and tetramethyl orthosilicate precursors. Additionally, biocompatibility assessments were performed on human keratinocytes and fibroblasts, demonstrating the safety of the gels for consumer contact. The gel properties were characterized, including molecular structure, morphology, and topography. Biocompatibility of the gels was assessed using bioluminescent ATP assay to detect cell viability, lactate dehydrogenase assay to determine cell cytotoxicity, and a leukocyte stimulation test to detect inflammatory potential. A composite gel with strong oxygen barrier properties in low-humidity environments was prepared. Increasing the silane precursor to 50 wt% during gel preparation slowed degradation in water. The addition of citric acid decreased gel solubility. However, higher precursor amounts increased surface roughness, making the gel more brittle yet mechanically resistant. The increase of precursor in the gel also increased gel viscosity. Importantly, the gels showed no cytotoxicity on human keratinocytes or fibroblasts and had no inflammatory effects on leukocytes. This composite gel holds promise for oxygen barrier food packaging and is safe for consumer contact. Further research should focus on optimizing the stability of the oxygen barrier in humid environments and investigate the potential sensitizing effects of biodegradable materials on consumers. Full article
(This article belongs to the Special Issue Recent Developments in Food Gels)
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