Biopolymers for hydrogels in cosmetics: review

Hydrogels of levan polysaccharide: A systematic review

Levan is a fructose-based homopolysaccharide renowned for its unique properties, including exceptional adhesive strength, self-assembly capability, low viscosity, and bioactivities such as prebiotic, anti-cancer, anti-inflammatory, and anti-diabetic effects. These characteristics have created increasing interest in levan-based biomaterials over the past decade, positioning levan as a highly under-explored biopolymer for a wide range of applications, from medicine to cosmetics. As a result, levan-based hydrogels have emerged as promising biomaterials in drug delivery, tissue engineering, and cosmetic formulations, owing to their extracellular matrix-mimicking structure, tunable mechanical properties, and controlled cargo release capabilities. This review is the first to comprehensively examine the advancements in levan-based hydrogel research, systematically analyzing their biomedical applications and comparing them with other biopolymer-based hydrogels. Key questions regarding levan's potential as an alternative to established hydrogel systems are explored, highlighting areas requiring further research. By assessing trends and findings in the literature, this review provides an overview of the advantages, limitations, and prospects of levan hydrogels. Our analysis establishes a foundation for the continued development of levan-derived biomaterials, fostering broader adoption in biomedical and industrial applications.

Development and efficacy of arbutin-loaded agarose hydrogel for antioxidant and depigmentation applications

Skin whitening and depigmentation are key strategies in skincare, representing a major global market. However, prolonged use of high concentrations of chemicals in skincare products can lead to skin disorders and premature aging. Biopolymer-based hydrogels offer a promising alternative by enabling sustained transdermal delivery of bioactive molecules while minimizing adverse effects. This study aimed to develop a novel bioactive hydrogel using thermosensitive, low-temperature-melting agarose (AGE) and the non-toxic tyrosinase inhibitor arbutin (ABN). Fourier transform infrared spectroscopy (FTIR) analysis confirmed the successful incorporation of ABN into the AGE hydrogel, while X-ray diffraction (XRD) analysis revealed the formation of new amorphous peaks, indicating composite hydrogel formation. Field emission scanning electron microscope (FE-SEM) imaging showed that freeze-dried AGE-ABN exhibited a smaller, more longitudinal porous structure compared to AGE alone. ABN release was dependent on its initial concentration, with higher release rates correlating with increased antioxidant activity. The 10-minute extract of freeze-dried AGE-ABN (0.1 %) hydrogel demonstrated DPPH (39.16 ± 0.72 %), FRAP (78.37 ± 2.24 %), and ABTS (92.40 ± 0.02 %) radical scavenging activities. Additionally, AGE-ABN (0.1 %) exhibited significant tyrosinase inhibition (27.90 ± 0.02 %), highlighting its potential for depigmentation. Importantly, the hydrogel promoted a human keratinocyte (HaCaT) cell growth without inducing cytotoxicity.

Hyperelastic Swelling of Stiff Hydrogels

Hydrogels are swollen polymer networks where elastic deformation is coupled to nanoscale fluid flow. As a consequence, hydrogels can withstand large strains and exhibit nonlinear, hyperelastic properties. Previous studies have shown that low-modulus hydrogels and semiflexible biopolymer networks universally contract when sheared on timescales much longer than the poroelastic relaxation timescale. Using rheological and tribological measurements, we find that stiff polyacrylamide and polyacrylic acid hydrogels, with moduli of order ∼10-100  kPa, exclusively swell (dilate) when sheared. Poroelastic relaxation was examined using strain-controlled compression, indicating a volumetric diffusion constant of order 10^{-9} m^{2}/s. Upon shearing, we observed an increase in normal stress that varied quadratically with shear strain, which persisted for hours. Moreover, we show that this dilatant behavior manifests as swelling during tribological sliding, imbibing the hydrogel with fluid. We suggest that this inherent, hyperelastic dilatancy is an important feature in all stiff hydrogels, and may explain rehydration and mechanical rejuvenation in biological tissues such as cartilage.

Application of Polysaccharides in Hydrogel Biomaterials

Natural compounds incorporated into hydrogel materials have been widely used to support wound healing due to their numerous properties. The aim of this research was to produce hydrogel biomaterials with the addition of adjuvants, such as sodium alginate and polyethylene glycol diacrylate (PEGDA) with the addition of ethylene ginger extract (EEI). A thermogravimetric (TG) study, differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), water absorption testing and microscopic analysis were carried out to determine the properties of the developed dressing. The conducted research showed that the 4%Alg/12%PEGDA hydrogel was characterized by the best water absorption values and the slowest weight loss as a function of temperature. Additionally, the 4%Alg/12%PEGDA hydrogel had the best ability to dissipate stress in its structure. It was found that the addition of the ginger modifier had a negative effect on the water absorption values. Hydrogel containing 4%Alg 12%PEGDA 12%EEI showed the best hydrophilic properties and the highest ionic conductivity. The studies conducted showed that both the addition of PEGDA and EEI to hydrogels affects the increase in acidity of dressings. This is important because maintaining an acidic wound microenvironment is a potential therapeutic strategy for wound management. Therefore, although further research is needed, it is possible that 4%Alg 12%PEGDA 12%EEI hydrogel could be used as a high-performance wound dressing.

Naturally derived hydrogels for wound healing

Natural hydrogels have garnered increasing attention due to their natural origins and beneficial roles in wound healing. Hydrogel water-retaining capacity and excellent biocompatibility create an ideal moist environment for wound healing, thereby enhancing cell proliferation and tissue regeneration. For this reason, naturally derived hydrogels formulated from biomaterials such as chitosan, alginate, gelatin, and fibroin are highly promising due to their biodegradability and low immunogenic responses. Recent integrated approaches to utilizing new technologies with bioactive agents have significantly improved the mechanical properties of hydrogels and the controlled release and delivery of active compounds, thereby increasing the efficiency of the treatment processes. Herein, this review highlights the advantages and the challenges of natural hydrogels in wound healing, focusing on their mechanical strength, controlled degradation rates, safety and efficiency validation, and the potential for incorporating advanced technologies such as tissue engineering and gene therapy for utilization in personalized medicine.

Hydrogel-Based Continuum Soft Robots

This paper comprehensively reviews the latest advances in hydrogel-based continuum soft robots. Hydrogels exhibit exceptional flexibility and adaptability compared to traditional robots reliant on rigid structures, making them ideal as biomimetic robotic skins and platforms for constructing highly accurate, real-time responsive sensory interfaces. The article systematically summarizes recent research developments across several key dimensions, including application domains, fabrication methods, actuator technologies, and sensing mechanisms. From an application perspective, developments span healthcare, manufacturing, and agriculture. Regarding fabrication techniques, the paper extensively explores crosslinking methods, additive manufacturing, microfluidics, and other related processes. Additionally, the article categorizes and thoroughly discusses various hydrogel-based actuators responsive to solute/solvent variations, pH, chemical reactions, temperature, light, magnetic fields, electric fields, hydraulic/electro-osmotic stimuli, and humidity. It also details the strategies for designing and implementing diverse sensors, including strain, pressure, humidity, conductive, magnetic, thermal, gas, optical, and multimodal sensors. Finally, the paper offers an in-depth discussion of the prospective applications of hydrogel-based continuum soft robots, particularly emphasizing their potential in medical and industrial fields. Concluding remarks include a forward-looking outlook highlighting future challenges and promising research directions.

Current Approaches in Cosmeceuticals: Peptides, Biotics and Marine Biopolymers

Today's consumer perception and expectations of personal care have gone beyond merely cleansing, moisturizing, and makeup products, focusing more on the reduction or elimination of signs of aging. Cosmeceuticals, developed to create a more youthful appearance, commonly contain substances with therapeutic and physiological effects. The development of cosmeceutical products containing peptides, biotic ingredients, and marine-based compounds has become a highly popular strategy to enhance anti-aging effects and better address consumer demands. Peptides are frequently used in anti-aging products due to their effects on enhancing fibroblast proliferation and collagen synthesis, contributing to the skin's barrier function, and reducing skin pigmentation. Meanwhile, biotic components are extensively evaluated for their potential to improve barrier function by maintaining the balance of the skin microflora. On the other hand, the increasing interest of cosmetic consumers in natural and eco-friendly products, along with the rich biodiversity in the oceans and seas, has made marine-derived substances highly significant for the cosmetic industry. Marine polysaccharides are particularly valuable as biopolymers, offering useful properties for gel formation in cosmetic formulations. This review discusses scientific studies and commercially available products using peptides, biotic and marine-based compounds in cosmetic formulations, their cosmetic and cosmeceutical benefits, and the challenges in the formulation design of these products.

Biomimetic Hydrogels - Tools for Regenerative Medicine, Oncology, and Understanding Medical Gas Plasma Therapy

Biomimetic hydrogels enable biochemical, cell biology, and tissue-like studies in the third dimension. Smart hydrogels are also frequently used in tissue engineering and as drug carriers for intra- or extracutaneous regenerative medicine. They have also been studied in bio-sensor development, 3D cell culture, and organoid growth optimization. Yet, many hydrogel types, adjuvant components, and cross-linking methods have emerged over decades, diversifying and complexifying such studies. Here, an evaluative overview is provided, mapping potential applications to the corresponding hydrogel tuning. Strikingly, hydrogels are ideal for studying locoregional therapy modalities, such as cold medical gas plasma technology. These partially ionized gases produce various reactive oxygen species (ROS) types along with other physico-chemical components such as ions and electric fields, and the spatio-temporal effects of these components delivered to diseased tissues remain largely elusive to date. Hence, this work outlines the promising applications of hydrogels in biomedical research in general and cold plasma science in particular and underlines the great potential of these smart scaffolds for current and future research and therapy.

Development of κ-Carrageenan/Gelatin pH-Responsive Hydrogels for Potential Skin Regeneration Application

Advanced skin care involves innovative, multifunctional, and bio-inspired biomaterials capable of regenerating skin tissue. Here, we report the facile route for the fabrication of the bio-sourced pH-responsive hydrogels based on κ-carrageenan and gelatin, with properties desirable for the treatment of versatile skin disorders. The extensive characterization revealed differences in physicochemical properties due to chemical modifications of the hydrogels. Porosity ranged from 21.67% to 95.81%. By modifying κ-carrageenan hydrogels with gelatin, the Young's modulus values increased proportionally with the gelatin content, ranging from 0.23 to 2.90 MPa, while native κ-carrageenan hydrogels had the lowest values (0.12-0.42 MPa) and native gelatin hydrogels had the highest (10.85-18.03 MPa). Native κ-carrageenan hydrogels exhibited the most pronounced swelling (18.6-27.0), followed by gelatin-modified κ-carrageenan hydrogels (6.5-23.0) and native gelatin hydrogels (7.8-9.0). The native κ-carrageenan hydrogels also displayed the highest water vapor transmission rate (WVTR) (259.99 ± 16-279.91 ± 19 g m-2 day-1), while the presence of gelatin lowered it. The hydrogels were preliminary exposed to human fibroblasts (MRC-5 cell line) and then to Caenorhabditis elegans to reveal the effects on whole living organisms. The summarized results suggest that the hydrogels represent advantageous and versatile biocompatible biomaterials set for further investigation as delivery platforms for bioactive molecules suitable for skin tissue regeneration.

Automated Analysis of Soft Matter Interfaces, Interactions, and Self-Assembly with PySoftK

Molecular dynamics simulations have become essential tools in the study of soft matter and biological macromolecules. The large amount of high-dimensional data associated with such simulations does not straightforwardly elucidate the atomistic mechanisms that underlie complex materials and molecular processes. Analysis of these simulations is complicated: the dynamics intrinsic to soft matter simulations necessitates careful application of specific, and often complex, algorithms to extract meaningful molecular scale understanding. There is an ongoing need for high-quality automated computational workflows to facilitate this analysis in a reproducible manner with minimal user input. In this work, we introduce a series of molecular simulation analysis tools for investigating interfaces, molecular interactions (including ring-ring stacking), and self-assembly. In addition, we include a number of auxiliary tools, including a useful function to unwrap molecular structures that are greater than half the length of their corresponding simulation box. These tools are contained in the PySoftK software package, making the application of these algorithms straightforward for the user. These new simulation analysis tools within PySoftK will support high-quality, reproducible analysis of soft matter and biomolecular simulations to bring about new predictive understanding in nano- and biotechnology.

Unlocking the Potential of Keratin: A Comprehensive Exploration from Extraction and Structural Properties to Cross-Disciplinary Applications

The rapid expansion of the livestock and poultry industry has led to a considerable increase in slaughter byproducts; however, exploring their potential applications still needs to be improved. These underutilized byproducts, which include nails, hides, skins, and bones, represent a significant loss of valuable biological resources. Among these materials, keratin has garnered considerable attention due to its unique properties as a natural biopolymer. Keratin exhibits outstanding mechanical properties and biocompatibility and has attracted increasing attention for its recovery and conversion into relevant application materials. However, natural keratin typically has a high sulfur content, complex 3D structure, and abundant hydrogen and disulfide bonds, which cause challenges in application. Current extraction for keratin includes physical, chemical, biological, and hybrid approaches. Combining multiple methods synergistically enhances protein extraction efficiency and purity, and facilitates the exploration of structure and functional properties. This review encompasses the structural characteristics, properties, extraction methods, and research progress related to keratin. The preparation and application of keratin composite materials in different forms, such as fibers, films, hydrogels, and scaffolds, are illustrated. Applications in several fields, including biomedicine, flexible electronic components, environmental materials and food packaging are discussed. Hopefully, this paper will provide a comprehensive understanding and guidance for further development and application of keratin materials.

Advances in Cellulose-Based Hydrogels: Current Trends and Challenges

This paper provides a solid foundation for understanding the synthesis, properties, and applications of cellulose-based gels. It effectively showcases the potential of these gels in diverse applications, particularly in biomedicine, and highlights key synthesis methods and properties. However, to push the field forward, future research should address the gaps in understanding the environmental impact, mechanical stability, and scalability of cellulose-based gels, while also considering how to overcome barriers to their industrial use. This will ultimately allow for the realization of cellulose-based gels in large-scale, sustainable applications.

Preparation of Patchouli Oil Microemulsion Gel and Its Topical Application to Ameliorate Atopic Dermatitis in Mice

Patchouli oil (PO) is a natural substance famous for its immune-enhancing and anti-inflammatory effects. Atopic dermatitis (AD) is characterized by epidermal gene mutations, skin barrier dysfunction, and immune dysregulation, making patchouli volatile oil a potential candidate for AD treatment. Initially, PO was mixed with ethyl oleate (EO), castor oil ethoxylated ether-40 (EL-40), anhydrous ethanol, and water to form a patchouli oil microemulsion (PO-ME) system. The formulation ratios were optimized using the Box-Behnken design-effect surface method, and their products were characterized for type, particle size, polydispersity index (PDI), and appearance. Additionally, patchouli oil microemulsion gel (PO-MEG) was developed with a specified concentration of 1.5% carbomer-940 as the matrix, and its pH, stability, viscosity, and permeability were evaluated. We assessed the irritation tests of PO-MEG using a rat self-control model and the Cell Counting Kit-8 (CCK-8) assay. The results demonstrated that should be attributed to non-irritating. This study also assessed the efficacy of optimized PO-MEG on AD-like symptoms using a 2,4-dinitrochlorobenzene (DNCB)-induced BALB/c mouse model. Compared with the model group, the in vivo efficacy studies have shown the PO-MEG group significantly reduces dermatitis scores, mast cell counts, epidermal thickness, and levels of pro-inflammatory cytokines and immune factors in skin homogenates. This suggests that PO-MEG would become a safer topical formulation for treating atopic dermatitis.

Microneedles based on hyaluronic acid-polyvinyl alcohol with antibacterial, anti-inflammatory, and antioxidant effects promote diabetic wound healing

Diabetic wound healing has become one of the major clinical burdens due to uncontrolled bacterial growth and an increase in the risk of various microbial infections. Despite excellent antioxidant properties, the poor aqueous solubility of resveratrol (RES) hampers its applicability. In this study, we proposed a novel multifunctional microneedle patch loaded with RES-encapsulated polymeric micelles. Resveratrol micelles (RES MC) were loaded in the microneedle tip, while the base part was coated with the antibiotic gentamicin (GEN) to promote wound healing. The microneedle tip composed of sodium hyaluronate (HA) could effectively deliver the anti-inflammatory and antioxidant RES MC. Furthermore, the base of the microneedle patch composed of polyvinyl alcohol (PVA) offered excellent flexibility, releasing GEN and providing resistance to bacterial contamination, thereby further promoting wound repair. In vitro antibacterial experiments indicated that the bactericidal rate reached 99 %. Further, the wound healing rate was recorded as 86.05 % on the 11th day of diabetes wound treatment. Together, the multifunctional microneedle patch with excellent biocompatibility exhibited anti-inflammatory, antioxidant, and antibacterial effects on the wound healing process, potentiating its efficacy in the treatment of diabetic wounds.

The Properties of Thin Films Based on Chitosan/Konjac Glucomannan Blends

In this work, blend films were prepared by blending 2% chitosan (CS) and 0.5% konjac glucomannan (KGM) solutions. Five ratios of the blend mixture were implemented (95:5, 80:20, 50:50, 20:80, and 5:95), and a pure CS film and a pure KGM film were also obtained. All the polymeric films were evaluated using FTIR spectroscopy, mechanical testing, SEM and AFM imaging, thermogravimetric analyses, swelling and degradation analyses, and contact angle measurements. The CS/KGM blends were assessed for their miscibility. Additionally, the blend films' properties were evaluated after six months of storage. The proposed blends had good miscibility in a full range of composition proportions. The blend samples, compared to the pure CS film, indicated better structural integrity. The surface structure of the blend films was rather uniform and smooth. The sample CS/KGM 20:80 had the highest roughness value (Rq = 12.60 nm). The KGM addition increased the thermal stability of films. The blend sample CS/KGM 5:95 exhibited the greatest swelling ability, reaching a swelling degree of 946% in the first fifteen minutes of the analysis. Furthermore, the addition of KGM to CS improved the wettability of the film samples. As a result of their good mechanical properties, surface characteristics, and miscibility, the proposed CS/KGM blends are promising materials for topical biomedical and cosmetic applications.

Revolutionizing Intervertebral Disc Regeneration: Advances and Future Directions in Three-Dimensional Bioprinting of Hydrogel Scaffolds

Hydrogels are multifunctional platforms. Through reasonable structure and function design, they use material engineering to adjust their physical and chemical properties, such as pore size, microstructure, degradability, stimulus-response characteristics, etc. and have a variety of biomedical applications. Hydrogel three-dimensional (3D) printing has emerged as a promising technique for the precise deposition of cell-laden biomaterials, enabling the fabrication of intricate 3D structures such as artificial vertebrae and intervertebral discs (IVDs). Despite being in the early stages, 3D printing techniques have shown great potential in the field of regenerative medicine for the fabrication of various transplantable tissues within the human body. Currently, the utilization of engineered hydrogels as carriers or scaffolds for treating intervertebral disc degeneration (IVDD) presents numerous challenges. However, it remains an indispensable multifunctional manufacturing technology that is imperative in addressing the escalating issue of IVDD. Moreover, it holds the potential to serve as a micron-scale platform for a diverse range of applications. This review primarily concentrates on emerging treatment strategies for IVDD, providing an in-depth analysis of their merits and drawbacks, as well as the challenges that need to be addressed. Furthermore, it extensively explores the biological properties of hydrogels and various nanoscale biomaterial inks, compares different prevalent manufacturing processes utilized in 3D printing, and thoroughly examines the potential clinical applications and prospects of integrating 3D printing technology with hydrogels.

Self-Assembly Behavior of Collagen and Its Composite Materials: Preparation, Characterizations, and Biomedical Engineering and Allied Applications

Collagen is the oldest and most abundant extracellular matrix protein and has many applications in biomedical, food, cosmetic, and other industries. Previous reviews have already introduced collagen's sources, structures, and biosynthesis. The biological and mechanical properties of collagen-based composite materials, their modification and application forms, and their interactions with host tissues are pinpointed. It is worth noting that self-assembly behavior is the main characteristic of collagen molecules. However, there is currently relatively little review on collagen-based composite materials based on self-assembly. Herein, we briefly reviewed the biosynthesis, extraction, structure, and properties of collagen, systematically presented an overview of the various factors and corresponding characterization techniques that affect the collagen self-assembly process, and summarize and discuss the preparation methods and application progress of collagen-based composite materials in different fields. By combining the self-assembly behavior of collagen with preparation methods of collagen-based composite materials, collagen-based composite materials with various functional reactions can be selectively prepared, and these experiences and outcomes can provide inspiration and practical techniques for the future development directions and challenges of collagen-based composite biomaterials in related applications fields.

Comprehensive review on collagen extraction from food by-products and waste as a value-added material

The consumption of animal products has witnessed a significant increase over the years, leading to a growing need for industries to adopt strict waste control measures to mitigate environmental impacts. The disposal of animal waste in landfill can result in diverse and potentially hazardous decomposition by-products. Animal by-products, derived from meat, poultry, seafood and fish industries, offer a substantial raw material source for collagen and gelatin production due to their high protein content. Collagen, being a major protein component of animal tissues, represents an abundant resource that finds application in various chemical and material industries. The demand for collagen-based products continues to grow, yet the availability of primary material remains limited and insufficient to meet projected needs. Consequently, repurposing waste materials that contain collagen provides an opportunity to meet this need while at the same time minimizing the amount of waste that is dumped. This review examines the potential to extract value from the collagen content present in animal-derived waste and by-products. It provides a systematic evaluation of different species groups and discusses various approaches for processing and fabricating repurposed collagen. This review specifically focuses on collagen-based research, encompassing an examination of its physical and chemical properties, as well as the potential for chemical modifications. We have detailed how the research and knowledge built on collagen structure and function will drive the new initiatives that will lead to the development of new products and opportunities in the future. Additionally, it highlights emerging approaches for extracting high-quality protein from waste and discusses efforts to fabricate collagen-based materials leading to the development of new and original products within the chemical, biomedical and physical science-based industries.

Biodegradable Natural Hydrogels for Tissue Engineering, Controlled Release, and Soil Remediation

This article provides insights into hydrogels of the most promising biodegradable natural polymers and their mechanisms of degradation, highlighting the different possibilities of controlling hydrogel degradation rates. Since biodegradable hydrogels can be designed as scaffolding materials to mimic the physical and biochemical properties of natural tissues, these hydrogels have found widespread application in the field of tissue engineering and controlled release. In the same manner, their potential as water reservoirs, macro- and microelement carriers, or matrixes for the selective adsorption of pollutants make them excellent candidates for sustainable soil amendment solutions. Accordingly, this article summarizes the recent advances in natural biodegradable hydrogels in the fields of tissue engineering, controlled release, and soil remediation, emphasizing the new opportunities that degradability and its tunability offer for the design and applicability of hydrogels.

A Comprehensive Review on Starch-Based Hydrogels: From Tradition to Innovation, Opportunities, and Drawbacks

Natural hydrogels based on renewable and inexpensive sources, such as starch, represent an interesting group of biopolymeric materials with a growing range of applications in the biomedical, cosmeceutical, and food sectors. Starch-based hydrogels have traditionally been produced using different processes based on chemical or physical methods. However, the long processing times, high energy consumption, and safety issues related to the synthesis of these materials, mostly causing severe environmental damage, have been identified as the main limitations for their further exploitation. Therefore, the main scientific challenge for research groups is the development of reliable and sustainable processing methods to reduce the environmental footprint, as well as investigating new low-cost sources of starches and individuating appropriate formulations to produce stable hydrogel-based products. In the last decade, the possibility of physically modifying natural polysaccharides, such as starches, using green or sustainable processing methods has mostly been based on nonthermal technologies including high-pressure processing (HPP). It has been demonstrated that the latter exerts an important role in improving the physicochemical and techno-functional properties of starches. However, as for surveys in the literature, research activities have been devoted to understanding the effects of physical pre-treatments via high-pressure processing (HPP) on starch structural modifications, more so than elucidating its role and capacity for the rapid formation of stable and highly structured starch-based hydrogels with promising functionality and stability, utilizing more sustainable and eco-friendly processing conditions. Therefore, the present review addresses the recent advancements in knowledge on the production of sustainable starch-based hydrogels utilizing HPP as an innovative and clean-label preparation method. Additionally, this manuscript has the ambition to give an updated overview of starch-based hydrogels considering the different types of structures available, and the recent applications are proposed as well to critically analyze the main perspectives and technological challenges for the future exploitation of these novel structures.

Tissue regeneration properties of hydrogels derived from biological macromolecules: A review

The successful tissue engineering depends on the development of biologically active scaffolds that possess optimal characteristics to effectively support cellular functions, maintain structural integrity and aid in tissue regeneration. Hydrogels have emerged as promising candidates in tissue regeneration due to their resemblance to the natural extracellular matrix and their ability to support cell survival and proliferation. The integration of hydrogel scaffold into the polymer has a variable impact on the pseudo extracellular environment, fostering cell growth/repair. The modification in size, shape, surface morphology and porosity of hydrogel scaffolds has consequently paved the way for addressing diverse challenges in the tissue engineering process such as tissue architecture, vascularization and simultaneous seeding of multiple cells. The present review provides a comprehensive update on hydrogel production using natural and synthetic biomaterials and their underlying mechanisms. Furthermore, it delves into the application of hydrogel scaffolds in tissue engineering for cardiac tissues, cartilage tissue, adipose tissue, nerve tissue and bone tissue. Besides, the present article also highlights various clinical studies, patents, and the limitations associated with hydrogel-based scaffolds in recent times.

New Polymeric Hydrogels with Cannabidiol and α-Terpineol as Potential Materials for Skin Regeneration-Synthesis and Physicochemical and Biological Characterization

Dermatology and cosmetology currently prioritize healthy, youthful-looking skin. As a result, research is being conducted worldwide to uncover natural substances and carriers that allow for controlled release, which could aid in the battle against a variety of skin illnesses and slow the aging process. This study examined the biological and physicochemical features of novel hydrogels containing cannabidiol (CBD) and α-terpineol (TER). The hydrogels were obtained from ε-caprolactone (CL) and poly(ethylene glycol) (PEG) copolymers, diethylene glycol (DEG), poly(tetrahydrofuran) (PTHF), 1,6-diisocyanatohexane (HDI), and chitosan (CHT) components, whereas the biodegradable oligomers were synthesized using the enzyme ring-opening polymerization (e-ROP) method. The in vitro release rate of the active compounds from the hydrogels was characterized by mainly first-order kinetics, without a "burst release". The antimicrobial, anti-inflammatory, cytotoxic, antioxidant, and anti-aging qualities of the designed drug delivery systems (DDSs) were evaluated. The findings indicate that the hydrogel carriers that were developed have the ability to scavenge free radicals and impact the activity of antioxidant enzymes while avoiding any negative effects on keratinocytes and fibroblasts. Furthermore, they have anti-inflammatory qualities by impeding protein denaturation as well as the activity of proteinase and lipoxygenase. Additionally, their ability to reduce the multiplication of pathogenic bacteria and inhibit the activity of collagenase and elastase has been demonstrated. Thus, the developed hydrogel carriers may be effective systems for the controlled delivery of CBD, which may become a valuable tool for cosmetologists and dermatologists.

FT-IR, FT-raman and UV spectra and ab initio HF and DFT study of conformational analysis, molecular structure and properties of ortho- meta- and para-chlorophenylboronic acid isomers

In this study, the FT-IR, FT-Raman, and UV-Vis spectroscopic properties of three monosubstituted phenylboronic acid derivatives: ortho-chlorophenylboronic acid (o-ClPhBA), meta-chlorophenylboronic acid (m-ClPhBA) and para-chlorophenylboronic acid (p-ClPhBA) molecules are investigated both experimentally and theoretically using Density Functional Theory (B3LYP) and Hartree Fock (HF). In order to find the stable possible conformations of the compounds, the conformational analysis was carried out by running potential energy surface (PES) scan by means of rotation of two structural parameters, the dihedral angles indicated as φ2 (C6-B-O1-H1A) and φ3 (C6-B-O2-H2A), varying from -180° to 180° with an increment of 10° using B3LYP/6-31G level of theory. Also, to determinate the most stable conformer for all the molecules, potential energy curve (PEC) the stable possible conformations on PES scan were investigated as a function of φ1 (C1-C6-B-O1) dihedral angle from 0° up to 180° with an increment of 10° using B3LYP/6-311++G(d,p) and HF/6-311++G(d,p) level of theory. For all the studied compounds, two conformational structures (conformer anti-anti, syn-syn) that did not have imaginary frequency values outside the equilibrium state (conformer anti-syn) were detected theoretically at the both methods. Due to their conformational flexibility, the relative stabilities of the anti-syn, anti-anti, and syn-syn conformers of o-ClPhBA, m-ClPhBA, and p-ClPhBA are 0.0, 4.66, and 6.76 kcal/mol, respectively, at the B3LYP/6-311++G(d,p) level of theory. For the HF/6-311++G(d,p) level of theory, the relative stabilities are 0.00, 4.54, and 6.11 kcal/mol for o-ClPhBA; 0.00, 3.98, and 1.51 kcal/mol for m-ClPhBA; and 0.00, 4.10, and 1.44 kcal/mol for p-ClPhBA, respectively. Some of the determined stable conformations of these molecules are different in symmetry groups. It was observed that the increase in the symmetry was effective in the of molecular properties, especially for vibrational frequencies. The structural parameter, dipole moments (μ), vibrational frequencies, polarizability (α), hyperpolarizability (β), the highest occupied molecular orbital (HOMO), and the lowest unoccupied molecular orbital (LUMO) of the stable conformers were calculated by using Ab initio HF/6-311++G(d,p) and DFT/B3LYP/6-311++G(d,p) level of theory. The assignments of fundamental vibrational modes of the studied molecule were performed based on total energy distribution (TED) analysis.

Cellulose-Based Hydrogels for Wastewater Treatment: A Focus on Metal Ions Removal

The rapid worldwide industrial growth in recent years has made water contamination by heavy metals a problem that requires an immediate solution. Several strategies have been proposed for the decontamination of wastewater in terms of heavy metal ions. Among these, methods utilizing adsorbent materials are preferred due to their cost-effectiveness, simplicity, effectiveness, and scalability for treating large volumes of contaminated water. In this context, heavy metal removal by hydrogels based on naturally occurring polymers is an attractive approach for industrial wastewater remediation as they offer significant advantages, such as an optimal safety profile, good biodegradability, and simple and low-cost procedures for their preparation. Hydrogels have the ability to absorb significant volumes of water, allowing for the effective removal of the dissolved pollutants. Furthermore, they can undergo surface chemical modifications which can further improve their ability to retain different environmental pollutants. This review aims to summarize recent advances in the application of hydrogels in the treatment of heavy metal-contaminated wastewater, particularly focusing on hydrogels based on cellulose and cellulose derivatives. The reported studies highlight how the adsorption properties of these materials can be widely modified, with a wide range of adsorption capacity for different heavy metal ions varying between 2.3 and 2240 mg/g. The possibility of developing new hydrogels with improved sorption performances is also discussed in the review, with the aim of improving their effective application in real scenarios, indicating future directions in the field.

Vitamin K (Menadione)-incorporated chitosan/alginate hydrogel as a novel product for periorbital hyperpigmentation

The possibility of controlling periorbital hyperpigmentation disorders is one of the most important research goals in cosmetic preparations. In the current investigation, 1% vitamin K (Vit K) was incorporated into a Chitosan/alginate hydrogel which aimed to increase the dermal delivery and anti-pigmentation effect. The Vit K-hydrogel was evaluated using several different tests, including volume expansion/contraction analysis, differential scanning calorimetry (DSC), scanning electron microscopy (SEM), ultraviolet (UV) absorbance spectroscopy, and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. Vit K hydrogel's drug release profile showed a steady increase over time. Furthermore, the modified Vit K hydrogel formulations showed no harmful effects in an in vitro cytotoxicity study. The Vit K hydrogel was tested for dermal irritation on Wistar rats, and the hydrogel was found to be non-irritating. Furthermore, Vit K-hydrogel inhibited melanin formation (31.76 ± 1.14%) and was remarkably higher than free Vit K. In addition, Vit K-hydrogel inhibited L-dopa auto-oxidation to a greater extent (94.80 ± 2.41%) in comparison with Vit K solution (73.95 ± 1.62%). Vit K-hydrogel enhanced percutaneous transport of Vit K, according to in vitro percutaneous absorption findings, suggesting that this innovative formulation may provide new therapeutic options for periorbital hyperpigmentation.

Copper supported modified magnetic carrageenan as a bio-based catalyst for the synthesis of novel scaffolds bearing the 1,2,3-triazole unit through the click reaction

The ongoing work delineates the design of a novel library of 1,2,3-triazole-attached phenylacetamides through molecular hybridization of propargyl and phenylacetamide derivatives. Copper-supported modified magnetic carrageenan serves as a green heterogeneous catalyst, ensuring high yield, efficient reaction times, high atom economy, utilization of an environmentally friendly catalyst from a natural source, and a straightforward workup procedure. The successful synthesis of the catalyst is confirmed and evaluated using various analytical techniques, while the synthetic compounds are characterized through 1H NMR and 13C NMR.

Development and Efficacy Evaluation of Innovative Cosmetic Formulations with Caryocar brasiliense Fruit Pulp Oil Encapsulated in Freeze-Dried Liposomes

Encapsulation and drying technologies allow the engineering of innovative raw materials from plant biodiversity, with potential applications in pharmaceutical and cosmetic fields. Lipid-based nanoencapsulation stands out for its efficiency, ease of production, and versatility in encapsulating substances, whether hydrophilic or lipophilic. This work aimed at encapsulating pequi oil in liposomes and freeze-dried liposomes to enhance its stability and functional benefits, such as skin hydration and anti-aging effects, for use in innovative cosmetic formulations. Pequi oil-extracted from the Caryocar brasiliense fruit pulp, a plant species from Brazilian plant biodiversity-is rich in secondary metabolites and fatty acids. Liposomes and dried liposomes offer controlled production processes and seamless integration into cosmetic formulations. The physicochemical analysis of the developed liposomes confirmed that the formulations are homogeneous and electrokinetically stable, as evidenced by consistent particle size distribution and zeta potential values, respectively. The gel-type formulations loaded with the dried liposomes exhibit enhanced skin hydration, improved barrier function, and refined microrelief, indicating improvements in skin conditions. These results highlight the potential of dried liposomes containing pequi oil for the development of innovative cosmeceutical products. This research contributes to the valorization of Brazilian biodiversity by presenting an innovative approach to leveraging the dermatological benefits of pequi oil in cosmetic applications.

Biomedical Trends in Stimuli-Responsive Hydrogels with Emphasis on Chitosan-Based Formulations

Biomedicine is constantly evolving to ensure a significant and positive impact on healthcare, which has resulted in innovative and distinct requisites such as hydrogels. Chitosan-based formulations stand out for their versatile utilization in drug encapsulation, transport, and controlled release, which is complemented by their biocompatibility, biodegradability, and non-immunogenic nature. Stimuli-responsive hydrogels, also known as smart hydrogels, have strictly regulated release patterns since they respond and adapt based on various external stimuli. Moreover, they can imitate the intrinsic tissues' mechanical, biological, and physicochemical properties. These characteristics allow stimuli-responsive hydrogels to provide cutting-edge, effective, and safe treatment. Constant progress in the field necessitates an up-to-date summary of current trends and breakthroughs in the biomedical application of stimuli-responsive chitosan-based hydrogels, which was the aim of this review. General data about hydrogels sensitive to ions, pH, redox potential, light, electric field, temperature, and magnetic field are recapitulated. Additionally, formulations responsive to multiple stimuli are mentioned. Focusing on chitosan-based smart hydrogels, their multifaceted utilization was thoroughly described. The vast application spectrum encompasses neurological disorders, tumors, wound healing, and dermal infections. Available data on smart chitosan hydrogels strongly support the idea that current approaches and developing novel solutions are worth improving. The present paper constitutes a valuable resource for researchers and practitioners in the currently evolving field.

Bactericidal Chitosan Derivatives and Their Superabsorbent Blends with ĸ-Carrageenan

The aim of this work is research dedicated to the search for new bactericidal systems for use in cosmetic formulations, dermocosmetics, or the production of wound dressings. Over the last two decades, chitosan, due to its special biological activity, has become a highly indispensable biopolymer with very wide application possibilities. Reports in the literature on the antibacterial effects of chitosan are very diverse, but our research has shown that they can be successfully improved through chemical modification. Therefore, in this study, results on the synthesis of new chitosan-based Schiff bases, dCsSB-SFD and dCsSB-PCA, are obtained using two aldehydes: sodium 4-formylbenzene-1,3-disulfonate (SFD) and 2-pyridine carboxaldehyde (PCA), respectively. Chitosan derivatives synthesized in this way demonstrate stronger antimicrobial activity. Carrying out the procedure of grafting chitosan with a caproyl chain allowed obtaining compatible blends of chitosan derivatives with κ-carrageenan, which are stable hydrogels with a high swelling coefficient. Furthermore, the covalently bounded poly(ε-caprolactone) (PCL) chain improved the solubility of obtained polymers in organic solvents. In this respect, the Schiff base-containing polymers obtained in this study, with special hydrogel and antimicrobial properties, are very promising materials for potential use as a controlled-release formulation of both hydrophilic and hydrophobic drugs in cosmetic products for skin health.

Thermally Reversible Gel-Sol Transition of Hydrogels via Dissociation and Association of an Artificial Protein Nanocage

Oligomeric protein nanocages often disassemble into their subunits and reassemble by external stimuli. Thus, using these nanocages as cross-linkers for hydrogel network structures is a promising approach to allow hydrogels to undergo stimuli-responsive gel-sol transitions or self-healing. Here, we report hydrogels that show a reversible gel-sol transition resulting from the heat-induced dissociation and reassociation of protein nanocages. The hydrogel contained the 60-mer artificial protein nanocage, TIP60, as a supramolecular cross-linker for polyethylene glycol network structures. The hydrogel showed a gel-to-sol transition upon heating at a temperature above the melting point of TIP60 and immediately returned to a gel state upon cooling to room temperature. During the heating and cooling treatment of the hydrogel, small-angle X-ray scattering analysis suggested the dissociation and reassociation of TIP60. Furthermore, we demonstrated redox-responsive cargo release from TIP60 in the hydrogel. These results showed the potential of TIP60 as a component of multi-stimuli-responsive hydrogels.

Natural Polysaccharide-Based Hydrogels Used for Dye Removal

Removal of contaminants from discharge water is vital and demands urgent assistance with the goal to keep clean water. Adsorption is one of the most common, efficient, and low-priced methods used in water treatment. Various polysaccharide-based gels have been used as efficient dye adsorbents from wastewater. This review summarizes cutting-edge research of the last decade of different hydrogels based on natural polysaccharides (chitin, chitosan, cellulose, starch, pullulan, and dextran) concerning their dye adsorption efficiency. Beyond their natural abundance, attributes of polysaccharides such as biocompatibility, biodegradability, and low cost make them not only efficient, but also environmentally sustainable candidates for water purification. The synthesis and dye removal performance together with the effect of diverse factors on gels retaining ability, kinetic, and isotherm models encountered in adsorption studies, are introduced. Thermodynamic parameters, sorbent recycling capacity along with conclusions and future prospects are also presented.

A review on natural biopolymers in external drug delivery systems for wound healing and atopic dermatitis

Despite the advantages of topical administration in the treatment of skin diseases, current marketed preparations face the challenge of the skin's barrier effect, leading to low therapeutic effectiveness and undesirable side effects. Hence, in recent years the management of skin wounds, the main morbidity-causing complication in hospital environments, and atopic dermatitis, the most common inflammatory skin disease, has become a great concern. Fortunately, new, more effective, and safer treatments are already under development, with chitosan, starch, silk fibroin, agarose, hyaluronic acid, alginate, collagen, and gelatin having been used for the development of nanoparticles, liposomes, niosomes and/or hydrogels to improve the delivery of several molecules for the treatment of these diseases. Biocompatibility, biodegradability, increased viscosity, controlled drug delivery, increased drug retention in the epidermis, and overall mitigation of adverse effects, contribute to an effective treatment, additionally providing intrinsic antimicrobial and wound healing properties. In this review, some of the most recent success cases of biopolymer-based drug delivery systems as part of nanocarriers, semi-solid hydrogel matrices, or both (hybrid systems), for the management of skin wounds and atopic dermatitis, are critically discussed, including composition and in vitro, ex vivo and in vivo characterization, showing the promise of these external drug delivery systems.

Preparation and efficacy verification of three-dimensional printed partitioned multi-effect precision-care gel facial mask

OBJECTIVE

A partition multi-effect precision-care gel facial mask conforming to facial skin characteristics was prepared using three-dimensional (3D) printing technology.

METHODS

First, the hydrogel matrix and humectant of a 3D-printed gel for facial masks were screened, and three 3D-printed gels of arbutin, hexapeptide, and salicylic acid were prepared with whitening, wrinkle removal, and oil control functions, respectively. Skin irritation tests were performed on the gels. Physicochemical properties such as pH, heat and cold tolerance were evaluated. The efficacy of three 3D-printed gels was assessed by measuring melanin value, wrinkle depression score, and oil secretion. Finally, the facial mask model design and printing parameters were studied, and a partition multi-effect precision-care gel facial mask was printed in line with facial skin characteristics.

RESULTS

For the 3D-printed facial mask, the gel prescription with 2% hydroxyethyl cellulose gel as matrix and 7% glycerol as humectant was the best. The prepared 3D-printed gel did not irritate the human skin, and its physicochemical properties met the Chinese facial mask industry standard (QB/T2872-2017). We showed that three types of 3D-printed gels containing arbutin, hexapeptide, and salicylic acid could be applied to the corresponding parts of the face to solve different problems, such as facial skin dullness, wrinkles, and oil secretion. Therefore, according to facial physiological characteristics, the facial mask model was designed for the forehead and nasolabial fold, which needs to be anti-wrinkled; the cheek, which needs to be whitened; and the nose and chin, which need oil control. The optimal printing parameters were 0.26 mm nozzle diameter, 90 mm/s printing speed, 30% filling density, 140% wire extrusion ratio, and 0.25 mm layer height. Different skin care effects can be achieved using a three-nozzle printer to print arbutin, hexapeptide, or salicylic acid gel on the mask's forehead and nasolabial fold, cheek, and nose and chin, respectively.

CONCLUSION

The 3D-printed partition multi-effect care gel facial mask prepared according to the skin features of different parts of the face can overcome the problem of the single skincare effect of the mass-produced facial masks.

Film-Forming, Moisturizing, and Sensory Properties of a Cosmetic Formulation Containing Tara Gum and Brazilian Berry Extracts

The development of cosmetic formulations with moisturizing and film-forming properties has been very important to help keep skin physiology and protection. In this context, this study aimed to develop a cosmetic formulation containing Tara gum and Brazilian berry extract and evaluate its physical-mechanical, film-forming, and sensory properties. A gel formulation was developed based on Tara gum added to Plinia cauliflora extract and was characterized by its spreadability profile and sensory properties. A clinical study was carried out with ten participants to evaluate the skin microrelief, stratum corneum water content, transepidermal water loss (TEWL), and skin morphological characteristics by reflectance confocal microscopy (RCM) before and after 2 h of application of the formulations. The formulation with Brazilian berry significantly decreased the work of shear parameter, which can be correlated with improved spreadability in the sensory analysis. The clinical study showed that both formulations improved skin hydration and reduced the TEWL. The RCM imaging analysis showed the visible film on the skin surface, a decrease in the size of furrows, an increase in the reflectance of the interkeratinocytes, and reflectance of the stratum corneum for both formulations. These results were more pronounced for the formulation containing Brazilian berry. The Tara gum in the gel formulation promoted the formation and visualization of a polymeric net on the stratum corneum surface, demonstrated by the images obtained from RCM. However, the formulation added with the Brazilian berry extract improved the skin microrelief, honeycomb pattern of the epidermis, and skin hydration in deeper layers of the epidermis.

The Influence of Gamma Radiation on Different Gelatin Nanofibers and Gelatins

Gelatin nanofibers are known as wound-healing biomaterials due to their high biocompatible, biodegradable, and non-antigenic properties compared to synthetic-polymer-fabricated nanofibers. The influence of gamma radiation doses on the structure of gelatin nanofiber dressings compared to gelatin of their origin is little known, although it is very important for the production of stable bioactive products. Different-origin gelatins were extracted from bovine and donkey hides, rabbit skins, and fish scales and used for fabrication of nanofibers through electrospinning of gelatin solutions in acetic acid. Nanofibers with sizes ranging from 73.50 nm to 230.46 nm were successfully prepared, thus showing the potential of different-origin gelatin by-products valorization as a lower-cost alternative to native collagen. The gelatin nanofibers together with their origin gelatins were treated with 10, 20, and 25 kGy gamma radiation doses and investigated for their structural stability through chemiluminescence and FTIR spectroscopy. Chemiluminescence analysis showed a stable behavior of gelatin nanofibers and gelatins up to 200 °C and increased chemiluminescent emission intensities for nanofibers treated with gamma radiation, at temperatures above 200 °C, compared to irradiated gelatins and non-irradiated nanofibers and gelatins. The electron paramagnetic (EPR) signals of DMPO adduct allowed for the identification of long-life HO● radicals only for bovine and donkey gelatin nanofibers treated with a 20 kGy gamma radiation dose. Microbial contamination with aerobic microorganisms, yeasts, filamentous fungi, Staphylococcus aureus, Escherichia coli, and Candida albicans of gelatin nanofibers treated with 10 kGy gamma radiation was under the limits required for pharmaceutical and topic formulations. Minor shifts of FTIR bands were observed at irradiation, indicating the preservation of secondary structure and stable properties of different-origin gelatin nanofibers.

Natural gums and their derivatives based hydrogels: in biomedical, environment, agriculture, and food industry

The hydrogels based on natural gums and chemically derivatized natural gums have great interest in pharmaceutical, food, cosmetics, and environmental remediation, due to their: economic viability, sustainability, nontoxicity, biodegradability, and biocompatibility. Since these natural gems are from plants, microorganisms, and seaweeds, they offer a great opportunity to chemically derivatize and modify into novel, innovative biomaterials as scaffolds for tissue engineering and drug delivery. Derivatization improves swelling properties, thereby developing interest in agriculture and separating technologies. This review highlights the work done over the past three and a half decades and the possibility of developing novel materials and technologies in a cost-effective and sustainable manner. This review has compiled various natural gums, their source, chemical composition, and chemically derivatized gums, various methods to synthesize hydrogel, and their applications in biomedical, food and agriculture, textile, cosmetics, water purification, remediation, and separation fields.

A Smart Skin for Hydrogels That Enables Switchable Solute Release

Many applications of hydrogels rely on their ability to deliver encapsulated solutes, such as drugs; however, small hydrophilic solutes rapidly leak out of gels by diffusion. A need exists for a way to regulate solute release out of gels─to ensure zero release until a desired time (the OFF state) and thereafter for the release to be switched ON at a high rate. This should ideally be a repeatable switch; i.e., the gel should be cyclable repeatedly between the ON and OFF states. Such perfect, cyclical ON-OFF release of solutes from gels is demonstrated for the first time through a "smart skin" that is synthesized rapidly (in ∼10 min) around an entire gel. The thin (∼100 μm) and transparent polymer skin is endowed with redox-responsive properties through the use of urethane and acrylate monomers, one of which contains a thioether group. Initially, the skin is hydrophobic (water contact angle 102°), and it completely prevents hydrophilic solutes from leaking out of the gel. When contacted with oxidants such as hydrogen peroxide (H2O2), the thioethers are converted to sulfoxides, making the skin hydrophilic (water contact angle 42°) and thereby turning ON the release of solutes. Conversely, solute release can be turned OFF subsequently by adding a reducing agent such as vitamin C that reverts the sulfoxides to thioethers and thus returns the skin to its hydrophobic state. The release rate in the ON state can be tuned via the skin thickness as well as the oxidant concentration. The ability to regulate solute delivery from gels using smart skins is likely to prove significant in areas ranging from separations to agriculture and drug delivery.

Cellulose-alginate hydrogels and their nanocomposites for water remediation and biomedical applications

In the last decade, both cellulose and alginate polysaccharides have been extensively utilized for the synthesis of biocompatible hydrogels because of their alluring characteristics like low cost, biodegradability, hydrophilicity, biodegradability, ease of availability and non-toxicity. The presence of abundant hydrophilic functional groups (like carboxyl and hydroxyl) on the surface of cellulose and alginate or their derivatives makes these materials promising candidates for the preparation of hydrogels with appealing structures and characteristics, leading to growing research in water treatment and biomedical fields. These two polysaccharides are typically blended together to improve hydrogels' desired qualities (mechanical strength, adsorption properties, cellulose/alginate yield). So, keeping in view their extensive applicability, in the present review article, recent advances in the development of cellulose/nanocellulose-alginate-based hydrogels and their relevance in water treatment (adsorption of dyes, heavy metals, etc.) and biomedical field (wound healing, tissue engineering, drug delivery) has been reviewed. Further, impact of other inorganic/organic additives in cellulose/nanocellulose-alginate-based hydrogels properties like contaminants adsorption, drug delivery, tissue engineering, etc., has also been studied. Moreover, the current difficulties and future prospects of nanocellulose-alginate-based hydrogels regarding their water purification and biomedical applications are also discussed at the end.

Direct Detection of Tobacco Mosaic Virus in Infected Plants with SERS-Sensing Hydrogels

The impact of plant pathogens on global crop yields is a major societal concern. The current agricultural diagnostic paradigm involves either visual inspection (inaccurate) or laboratory molecular tests (burdensome). While field-ready diagnostic methods have advanced in recent years, issues remain with detection of presymptomatic infections, multiplexed analysis, and requirement for in-field sample processing. To overcome these issues, we developed surface-enhanced Raman scattering (SERS)-sensing hydrogels that detect pathogens through simple contact with a leaf. In this work, we developed a novel reagentless SERS sensor for the detection of tobacco mosaic virus (TMV) and embedded it in an optimized hydrogel material to produce sensing hydrogels. To test the diagnostic application of our sensing hydrogels, we demonstrate their use to detect TMV infection in tobacco plants. This technology has the potential to shift the current agricultural diagnostic paradigm by offering a field-deployable tool for presymptomatic and multiplexed molecular identification of pathogens.

Cosmetic Injection of Illicit Foreign Materials: Imaging Features and Patterns of Migration in 413 Cases

BACKGROUND

The injection of illicit, nonregulated foreign materials is increasingly common and has negative consequences relative to the inflammatory process that ensues.

OBJECTIVES

The aim of this study was to identify anatomical and imaging characteristics after the cosmetic injection of illicit foreign materials.

METHODS

A retrospective review of clinical and imaging records was performed. The issues analyzed were the anatomical site, type of injected substance, imaging method for diagnosis, and patterns of migration.

RESULTS

Data on 413 patients were collected. Most patients were female, with a mean age of 44 years. The most commonly infiltrated region was the buttocks (n = 284; 53.58%) followed by the breast (n = 99; 18.67%). Magnetic resonance imaging was the most common method of diagnosis in those patients who had an imaging study (159 out of 168). The most frequent depth of foreign material detected by imaging was the muscular plane (n = 103; 61.30%). Migration was detected in 56.55% of patients who had an imaging study. Most infiltrated substances were unknown; biopolymers were the most commonly identified substances. Depending on the type of substance, migration rates varied from 13% to 29%; rate differences were not statistically significant (P = .712). Migration was more common when the depth of infiltration was in muscle (77.66%) than in subcutaneous tissue (23.4%); this difference was statistically significant (P < .0001).

CONCLUSIONS

Deep infiltration is related to greater migration rates, apparently regardless of the substance injected.

LEVEL OF EVIDENCE: 3

Organogels: "GelVolution" in Topical Drug Delivery - Present and Beyond

Topical drug delivery holds immense significance in dermatological treatments due to its non-invasive nature and direct application to the target site. Organogels, a promising class of topical drug delivery systems, have acquired substantial attention for enhancing drug delivery efficiency. This review article aims to explore the advantages of organogels, including enhanced drug solubility, controlled release, improved skin penetration, non-greasy formulations, and ease of application. The mechanism of organogel permeation into the skin is discussed, along with formulation strategies, which encompass the selection of gelling agents, cogelling agents, and additives while considering the influence of temperature and pH on gel formation. Various types of organogelators and organogels and their properties, such as viscoelasticity, non-birefringence, thermal stability, and optical clarity, are presented. Moreover, the biomedical applications of organogels in targeting skin cancer, anti-inflammatory drug delivery, and antifungal drug delivery are discussed. Characterization parameters, biocompatibility, safety considerations, and future directions in optimizing skin permeation, ensuring long-term stability, addressing regulatory challenges, and exploring potential combination therapies are thoroughly examined. Overall, this review highlights the immense potential of organogels in redefining topical drug delivery and their significant impact on the field of dermatological treatments, thus paving the way for exciting prospects in the domain.

Biomolecules based hydrogels and their potential biomedical applications: A comprehensive review

The need for biocompatible drug carriers has been significantly increased from the past few years. Researchers show great interest in the development of more versatile and sophisticated biomaterials based drug carriers. Hydrogels are beneficial drug carriers and easily release the controlled amount of drug at target site due to its tunable structure. The hydrogels made-up of potent biological macromolecules including collagen, gelatin, fibrin, elastin, fibroin, chitosan, starch, alginate, agarose and carrageenan have been proven as versatile biomaterials. These are three-dimensional polymeric networks, synthesized by crosslinking of hydrophilic polymers. The biological macromolecules based hydrogels containing therapeutic substances are used in a wide range of biomedical applications including wound healing, tissue engineering, cosmetics and contact lenses. However, many aspects related to hydrogels such as the mechanism of cross-linking and molecular entanglement are not clear. So, there is a need to do more research and exploration toward the extensive and cost-effective use of hydrogels. The present review article elaborately discusses the biomolecules based hydrogels and their possible biomedical applications in different fields.

Magnetic xanthan gum-silk fibroin hydrogel: A nanocomposite for biological and hyperthermia applications

A magnetic xanthan hydrogel/silk fibroin nanobiocomposite (XG hydrogel/SF/Fe3O4) was designed, fabricated, and characterized using analyzing methods such as FT-IR, EDX, FE-SEM, XRD, TGA, and VSM to evaluate the exact structure of product nanobiocomposite. The FE-SEM images reveal the presence of spherical shapes exhibiting a narrow size range and homogeneous distribution, measuring between 30 and 35 nm in diameter. The VSM analysis demonstrates the superparamagnetic properties of the XG hydrogel/SF/Fe3O4 nanobiocomposite, exhibiting a magnetic saturation of 54 emu/g at room temperature. The biological response of the nanobiocomposite scaffolds was assessed through cell viability and red blood cell hemolytic assays. MCF10A cells were exposed to a concentration of 1.75 mg/mL of the nanobiocomposite, and after 2 and 3 days, the cell viability was found to be 96.95 % and 97.02 %, respectively. The hemolytic effect was nearly 0 % even at higher concentrations (2 mg/mL). Furthermore, the magnetic nanobiocomposite showed excellent potential for hyperthermia applications, with a maximum specific absorption rate of 7 W/g for 1 mg/mL of the sample under a magnetic field in different frequencies (100, 200, 300, and 400 MHz) and 5 to 20 min time intervals.

Rheological insights on Carboxymethyl cellulose hydrogels

Hydrogels are copiously studied for tissue engineering, drug delivery, and bone regeneration owing to their water content, mechanical strength, and elastic behaviour. The preparation of stable and mechanically strengthened hydrogels without using toxic crosslinkers and expensive approaches is immensely challenging. In this study, we prepared Carboxymethyl cellulose based hydrogels with different polymer concentration via a less expensive physical crosslinking approach without using any toxic crosslinkers and evaluated their mechanical strength. In this hydrogel system, the carbopol concentration was fixed at 1 wt/v% and the Carboxymethyl cellulose concentration was varied between 1 and 5 wt/v%. In this hydrogel system, Carbopol serves as the crosslinker to bridge Carboxymethyl cellulose polymer through hydrogen bonds. Rheological analysis was employed in assessing the mechanical properties of the prepared hydrogel, in particular, the viscoelastic behaviour of the hydrogels. The viscoelastic nature and mechanical strength of the hydrogels increased with an increase in the Carboxymethyl cellulose polymer concentration. Further, our results suggested that gels with Carboxymethyl cellulose concentration between 3 wt/v % and 4 wt/v % with yield stresses of 58.83 Pa and 81.47 Pa, respectively, are potential candidates for use in transdermal drug delivery. The prepared hydrogels possessed high thermal stability and retained their gel network structure even at 50 °C. These findings are beneficial for biomedical applications in transdermal drug delivery and tissue engineering owing to the biocompatibility, stability, and mechanical strength of the prepared hydrogels.

The extraction, structure characterization and hydrogel construction of a water-insoluble β-glucan from Poria cocos

Most reported polysaccharides from Poria cocos (PCPs) in traditional Chinese medicine decoctions were water-soluble heteropolysaccharides while the water-insoluble PCPs were scarcely researched due to the poor water-solubility. In this study, a water-insoluble polysaccharide with high yield of 59%, and high purity with a glucan content of 98.8%, was isolated by diluted sodium hydroxide at low temperature and coded as PCPA. The chemical structure of PCPA was identified as a liner β-glucan with 1, 3-linked glycosidic bond by the fourier infrared spectrum (FT-IR), ion chromatography (ICP), gas chromatography and mass spectrometry (GC-MS), and nuclear magnetic resonance (NMR) measurements. Importantly, PCPA was successfully used to construct hydrogels (PCPA-Gs) with good thermal stability, water retention ability and swelling property through simple physical cross-linking, due to the abundance of hydroxyl groups on glucan chains. Moreover, the rheology analysis of PCPA-Gs showed a rapid transition between gel and sol as well as the shear-thinning property. The hydrogel developed in this study holds promise for applications in the food, pharmaceutical, and cosmetic fields.

Trends in biopolymer science applied to cosmetics

The term biopolymer refers to materials obtained by chemically modifying natural biological substances or producing them through biotechnological processes. They are biodegradable, biocompatible and non-toxic. Due to these advantages, biopolymers have wide applications in conventional cosmetics and new trends and have emerged as essential ingredients that function as rheological modifiers, emulsifiers, film-formers, moisturizers, hydrators, antimicrobials and, more recently, materials with metabolic activity on skin. Developing approaches that exploit these features is a challenge for formulating skin, hair and oral care products and dermatological formulations. This article presents an overview of the use of the principal biopolymers used in cosmetic formulations and describes their sources, recently derived structures, novel applications and safety aspects of the use of these molecules.

Effect of Hyaluronic Acid on the Self-Assembly of a Dipeptide-Based Supramolecular Gel

The combination of polymers and low molecular weight (LMW) compounds is a powerful approach to prepare new supramolecular materials. Here we prepare two-component hydrogels made by a well-known and biologically active polymer, hyaluronic acid (HA), and a dipeptide-based supramolecular gelator. We undertake a detailed study of materials with different compositions including macroscopic (hydrogel formation, rheology) and micro/nanoscopic characterization (electron microscopy, X-ray powder diffraction). We observe that the two components mutually benefit in the new materials: a minimum amount of HA helps to reduce the polymorphism of the LMW network leading to reproducible hydrogels with improved mechanical properties; the LMW component network holds HA without the need for an irreversible covalent crosslinking. These materials have a great potential for biomedical application as, for instance, extracellular matrix mimetics for cell growth. As a proof of concept, we have observed that this material is effective for cell growth in suspension and avoids cell sedimentation even in the presence of competing cell-adhesive surfaces. This may be of interest to advanced cell delivery techniques.

Stretchable, Adhesive, and Biocompatible Hydrogel Based on Iron-Dopamine Complexes

Hydrogels' exceptional mechanical strength and skin-adhesion characteristics offer significant advantages for various applications, particularly in the fields of tissue adhesion and wearable sensors. Herein, we incorporated a combination of metal-coordination and hydrogen-bonding forces in the design of stretchable and adhesive hydrogels. We synthesized four hydrogels, namely PAID-0, PAID-1, PAID-2, and PAID-3, consisting of acrylamide (AAM), N,N'-methylene-bis-acrylamide (MBA), and methacrylic-modified dopamine (DA). The impact of different ratios of iron (III) ions to DA on each hydrogel's performance was investigated. Our results demonstrate that the incorporation of iron-dopamine complexes significantly enhances the mechanical strength of the hydrogel. Interestingly, as the DA content increased, we observed a continuous and substantial improvement in both the stretchability and skin adhesiveness of the hydrogel. Among the hydrogels tested, PAID-3, which exhibited optimal mechanical properties, was selected for adhesion testing on various materials. Impressively, PAID-3 demonstrated excellent adhesion to diverse materials and, combined with the low cytotoxicity of PAID hydrogel, holds great promise as an innovative option for biomedical engineering applications.