Green Chemistry Principles for Nano- and Micro-Sized Hydrogel Synthesis

Hydrogel promotes bone regeneration through various mechanisms: a review

Large defects in bone tissue due to trauma, tumors, or developmental abnormalities usually require surgical treatment for repair. Numerous studies have shown that current bone repair and regeneration treatments have certain complications and limitations. With the in-depth understanding of bone regeneration mechanisms and biological tissue materials, a variety of materials with desirable physicochemical properties and biological functions have emerged in the field of bone regeneration in recent years. Among them, hydrogels have been widely used in bone regeneration research due to their biocompatibility, unique swelling properties, and ease of fabrication. In this paper, the development and classification of hydrogels were introduced, and the mechanism of hydrogels in promoting bone regeneration was described in detail, including the promotion of bone marrow mesenchymal stem cell differentiation, the promotion of angiogenesis, the enhancement of the activity of bone morphogenetic proteins, and the regulation of the microenvironment of bone regeneration tissues. In addition, the future research direction of hydrogel in bone tissue engineering was discussed.

Graphene oxide/chitosan hydrogels for removal of antibiotics

Antibiotic contamination in aquatic environments is a growing concern, posing risks to public health and ecosystems. To address this issue, advanced materials like graphene oxide (GO) and chitosan-based hydrogels are being extensively explored for their ability to effectively remove antibiotics from wastewater, owing to their distinct characteristics and synergistic benefits. This review comprehensively examines the synthesis, characterization, and applications of GO/chitosan hydrogels in addressing antibiotic pollution. The synthesis methods, including solution casting, crosslinking, and in situ polymerization, are discussed for their simplicity and scalability. The hydrogels' key properties, such as porosity, surface area, and mechanical strength, are essential for their efficient adsorption capabilities. Adsorption mechanisms, including electrostatic interactions, π-π stacking, hydrogen bonding, and surface functional groups, enable these hydrogels to achieve high adsorption capacities. Notable examples include rGO@ZIF-67@CS hydrogels, which achieved higher adsorption capacities of 1685.26 mg·g-1 for tetracycline at pH 4 and 1890.32 mg·g-1 for norfloxacin at pH 5, while the sulfonated CMC/GO-GCC composite hydrogel achieved 312.28 mg·g-1 for sulfamethoxazole at 298 K. Moreover, high adsorption efficiencies of 90.42% with GO-CTS and 97.06% were achieved using AGO-CTS hydrogel for diclofenac adsorption. The review also highlights the practical applications of these hydrogels in wastewater treatment, comparing their performance with other adsorbents and addressing challenges such as scalability and regeneration. Finally, the review explores future research directions to enhance the effectiveness and sustainability of GO/chitosan hydrogels, emphasizing their potential as scalable, eco-friendly solutions for antibiotic removal from water.

A bibliometric analysis of hydrogel research in various fields: the trends and evolution of hydrogel application

Hydrogel, a polymer material with a three-dimensional structure, has considerably expanded in research across multiple fields lately. However, the lack of a comprehensive review integrating the research status of hydrogel across diverse fields has hindered the development of hydrogel. This bibliometric analysis reviewed the hydrogel-related research over the past decades, emphasizing the evolution, status, and future directions within a multitude of fields, such as materials science, chemistry, polymer science, engineering, physics, biochemistry molecular biology, pharmacology pharmacy, cell biology, biotechnology applied microbiology, etc. We encapsulated applications and the potential of hydrogel in wound healing, drug delivery, cell encapsulation, bioprinting, tissue engineering, electronic products, environment applications, and disease treatment. This study integrated the current matrix system and characteristics of hydrogels, aiming to offer a cross-field reference for hydrogel researchers and promote the advancement of hydrogel research. Furthermore, we proposed a novel and reproducible bibliometric research paradigm, which can provide a more comprehensive analysis of the trends and trajectory of a research field.

Synthesis of PVA-Based Hydrogels for Biomedical Applications: Recent Trends and Advances

There is ongoing research for biomedical applications of polyvinyl alcohol (PVA)-based hydrogels; however, the execution of this has not yet been achieved at an appropriate level for commercialization. Advanced perception is necessary for the design and synthesis of suitable materials, such as PVA-based hydrogel for biomedical applications. Among polymers, PVA-based hydrogel has drawn great interest in biomedical applications owing to their attractive potential with characteristics such as good biocompatibility, great mechanical strength, and apposite water content. By designing the suitable synthesis approach and investigating the hydrogel structure, PVA-based hydrogels can attain superb cytocompatibility, flexibility, and antimicrobial activities, signifying that it is a good candidate for tissue engineering and regenerative medicine, drug delivery, wound dressing, contact lenses, and other fields. In this review, we highlight the current progresses on the synthesis of PVA-based hydrogels for biomedical applications explaining their diverse usage across a variety of areas. We explain numerous synthesis techniques and related phenomena for biomedical applications based on these materials. This review may stipulate a wide reference for future acumens of PVA-based hydrogel materials for their extensive applications in biomedical fields.

Synthesis and Characterization of Metal Particles Using Malic Acid-Derived Polyamides, Polyhydrazides, and Hydrazides

Malic acid-derived polyamides, polyhydrazides, and hydrazides exhibit strong potential for a variety of biological applications. This study demonstrates the synthesis of cobalt, silver, copper, zinc, and iron particles by a facile chemical reduction approach utilizing malic acid-derived polyamides, polyhydrazides, and hydrazides as stabilizing and reducing agents. Comprehensive characterization of the particles was performed using UV-Vis spectroscopy, FTIR, XRD, SEM, and EDX analysis. The synthesized particles included both zero-valent metals and oxides exhibiting mixed-phase compositions that may influence their functional properties. UV-vis analysis confirmed the formation of particles represented by the surface plasmon resonance (SPR) peaks specific to each metal particle. FTIR spectroscopy revealed the interaction of the metal particles with the polymer matrix owing to the significant contribution of functional groups in the processes of reduction and stabilization. Further structural insights were obtained via X-ray diffraction (XRD), which identified crystalline phases, and scanning electron microscopy (SEM), which demonstrated uniform morphologies. Additionally, energy-dispersive X-ray (EDX) analysis provided compositional details, affirming the purity and distribution of metallic elements. These findings highlight the potential of malic acid-derived polymers as versatile agents for nanoparticle synthesis with applications in catalysis, sensing, and biomedical technologies.

Exploring the Potentials of Chitin and Chitosan-Based Bioinks for 3D-Printing of Flexible Electronics: The Future of Sustainable Bioelectronics

Chitin and chitosan-based bioink for 3D-printed flexible electronics have tremendous potential for innovation in healthcare, agriculture, the environment, and industry. This biomaterial is suitable for 3D printing because it is highly stretchable, super-flexible, affordable, ultrathin, and lightweight. Owing to its ease of use, on-demand manufacturing, accurate and regulated deposition, and versatility with flexible and soft functional materials, 3D printing has revolutionized free-form construction and end-user customization. This study examined the potential of employing chitin and chitosan-based bioinks to build 3D-printed flexible electronic devices and optimize bioink formulation, printing parameters, and postprocessing processes to improve mechanical and electrical properties. The exploration of 3D-printed chitin and chitosan-based flexible bioelectronics will open new avenues for new flexible materials for numerous industrial applications.

Sodium alginate/gelatin hydrogel spheres loaded with Fructus Ligustri Lucidi essential oil: Preparation, characterization and biological activity

The application of plant essential oils in the food industry is often hindered by their poor water solubility and high volatilize. Encapsulation has emerged as an effective solution to this problem. This study focuses on the preparation of Fructus Ligustri Lucidi essential oil gel spheres (FEOH) based sodium alginate and gelatin. The optimum formulation for FEOH was established by Box-Behnken Design response surface testing, resulting in a composition of 10 % FEO, 5 % TW20 and 2 % CaCl2. This formulation achieved an encapsulation efficiency of 85.56 %. FTIR and SEM results indicated the successful encapsulation of FEO within the gel spheres. Furthermore, DSC and TGA results showed that encapsulation enhanced the thermal stability of the essential oil. At room temperature, the water content of FEOH exceeded 90 %, and it showed the highest swelling ratio of 62.5 % in an alkaline medium at different pH conditions. The in vitro release behavior showed that FEOH was released up to 85.28 % in oil-based food simulants within 2 h. FEOH showed strong antibacterial activity, with a Minimum Inhibitory Concentration (MIC) of 128 mg/mL against Staphylococcus aureus and 256 mg/mL against Escherichia coli. The gel spheres obtained in this research show significant potential as food preservatives in food matrices.

Current advances of nanocellulose application in biomedical field

Nanocellulose (NC) is a natural fiber that can be extracted in fibrils or crystals form from different natural sources, including plants, bacteria, and algae. In recent years, nanocellulose has emerged as a sustainable biomaterial for various medicinal applications including drug delivery systems, wound healing, tissue engineering, and antimicrobial treatment due to its biocompatibility, low cytotoxicity, and exceptional water holding capacity for cell immobilization. Many antimicrobial products can be produced due to the chemical functionality of nanocellulose, such disposable antibacterial smart masks for healthcare use. This article discusses comprehensively three types of nanocellulose: cellulose nanocrystals (CNC), cellulose nanofibrils (CNF), and bacterial nanocellulose (BNC) in view of their structural and functional properties, extraction methods, and the distinctive biomedical applications based on the recently published work. On top of that, the biosafety profile and the future perspectives of nanocellulose-based biomaterials have been further discussed in this review.

Sustainable Elastomers for Actuators: "Green" Synthetic Approaches and Material Properties

Elastomeric materials have great application potential in actuator design and soft robot development. The most common elastomers used for these purposes are polyurethanes, silicones, and acrylic elastomers due to their outstanding physical, mechanical, and electrical properties. Currently, these types of polymers are produced by traditional synthetic methods, which may be harmful to the environment and hazardous to human health. The development of new synthetic routes using green chemistry principles is an important step to reduce the ecological footprint and create more sustainable biocompatible materials. Another promising trend is the synthesis of other types of elastomers from renewable bioresources, such as terpenes, lignin, chitin, various bio-oils, etc. The aim of this review is to address existing approaches to the synthesis of elastomers using "green" chemistry methods, compare the properties of sustainable elastomers with the properties of materials produced by traditional methods, and analyze the feasibility of said sustainable elastomers for the development of actuators. Finally, the advantages and challenges of existing "green" methods of elastomer synthesis will be summarized, along with an estimation of future development prospects.