Novel polyelectrolyte complex (PEC) chitosan/carboxymethyl cellulose (CMC) scaffolds are prepared using a freeze-dry process. The microstructure is characterized by SEM and the average pore diameters and internal porosities are calculated. The morphology and distribution of pulp cells on these three-dimensional scaffolds are investigated by SEM and confocal laser scanning microscopy (CLSM). The expression of osteonectin (ON) and dentin sialophosphoprotein (DSPP) is detected by reverse transcription polymerase chain reaction (RT-PCR). The scaffolds are then implanted subcutaneously into BALB/c mice. The addition of CMC to chitosan decreases the pore diameter and increases internal porosity. The pulp cells co-cultured in these PEC scaffolds show improved adhesion, spreading, cell capacity, and three-dimensional configurations compared to pure chitosan scaffolds. Based on the data obtained, the chitosan/CMC complex provides an improved scaffold material for pulp tissue engineering.

Although titanium and titanium alloys have become the preferred materials for various medical implants, surface modification technology still needs to be strengthened in order to adapt to the complex physiological environment of the human body. Compared with physical or chemical modification methods, biochemical modification, such as the introduction of functional hydrogel coating on implants, can fix biomolecules such as proteins, peptides, growth factors, polysaccharides, or nucleotides on the surface of the implants, so that they can directly participate in biological processes; regulate cell adhesion, proliferation, migration, and differentiation; and improve the biological activity on the surface of the implants. This review begins with a look at common substrate materials for hydrogel coatings on implant surfaces, including natural polymers such as collagen, gelatin, chitosan, and alginate, and synthetic materials such as polyvinyl alcohol, polyacrylamide, polyethylene glycol, and polyacrylic acid. Then, the common construction methods of hydrogel coating (electrochemical method, sol–gel method and layer-by-layer self-assembly method) are introduced. Finally, five aspects of the enhancement effect of hydrogel coating on the surface bioactivity of titanium and titanium alloy implants are described: osseointegration, angiogenesis, macrophage polarization, antibacterial effects, and drug delivery. In this paper, we also summarize the latest research progress and point out the future research direction. After searching, no previous relevant literature reporting this information was found.

The integration of conductive hydrogels and advanced three-dimensional (3D) printing is a trigger of the development of biomedical sensors for healthcare diagnostics and personalized treatment. Poly(3,4-ethylenedioxythiophene):poly(styr ene sulfonate) (PEDOT:PSS) is a versatile conductive hydrogel materials renowned for its exceptional conductivity and hydrophilicity, and 3D printing technology allows for precise and customized fabrication of electronic components and devices. In this review, we aim to explore the potential of 3D-printed PEDOT/PSS conductive hydrogel in the fabrication of biomedical sensors, with a focus on their distinct characteristics, application potential, and systematic classification. We also discuss the methods for fabricating PEDOT:PSS hydrogel electronic devices by employing 3D printing techniques, including extrusion-based 3D printing technology (fused deposition modeling, direct ink writing, and inkjet printing), powder-based 3D printing technology (selective laser sintering and selective laser melting), and photopolymerization-based 3D printing technology (stereolithography and digital light processing). The applications of 2D/3D-printed PEDOT:PSS hydrogels in biomedical sensors, such as strain sensors, pressure sensors, stretchable sensors, electrochemical sensors, temperature sensors, humidity sensors, and electrocardiogram sensor, are also summarized in this review. Finally, we provide insights into the development of 3D-printed PEDOT:PSS-based biomedical sensors and the innovative techniques for biomedical sensor integration.

The S-Scheme heterojunction design offers a promising pathway to enhance the photocatalytic activity of semiconductors for antibiotic degradation in aquatic environments. Graphitic carbon nitride (g-C₃N₄) stands out due to its robust visible light absorption, exceptional charge separation efficiency, and abundant active sites, rendering it an ideal candidate for sustainable and energy-efficient photocatalysis. This review delves into the potential of g-C₃N₄-based S-Scheme heterojunctions in antibiotic degradation, with a particular emphasis on the photocatalytic principles, inherent advantages, and application prospects. We discuss various semiconductor materials, including metal oxides, multicomponent metal oxides, magnetic oxides, multicomponent magnetic oxides, metal sulfides, and multicomponent metal sulfides, which can be paired with g-C₃N₄ to fabricate S-Scheme heterojunctions. Furthermore, we explore common preparation techniques for synthesizing g-C₃N₄-based S-Scheme heterojunction composites, such as the hydrothermal method, solvothermal method, calcination method, self-assembly method, in situ growth, etc. Additionally, we summarize the applications of these g-C₃N₄-based S-Scheme heterojunctions in the degradation of antibiotics, focusing specifically on quinolones and tetracyclines. By providing insights into the development of these heterojunctions, we actively contribute to the ongoing exploration of innovative technologies in the field of photocatalytic antibiotic degradation. Our findings underscore the vast potential of g-C₃N₄-based S-Scheme heterojunctions in addressing the challenge of antibiotic contamination in water sources.

The integration of two-dimensional Ti₃C₂T_x nanosheets and other materials offers broader application options in the antibacterial field. Ti₃C₂T_x-based composites demonstrate synergistic physical, chemical, and photodynamic antibacterial activity. In this review, we aim to explore the potential of Ti₃C₂T_x-based composites in the fabrication of an antibiotic-free antibacterial agent with a focus on their systematic classification, manufacturing technology, and application potential. We investigate various components of Ti₃C₂T_x-based composites, such as metals, metal oxides, metal sulfides, organic frameworks, photosensitizers, etc. We also summarize the fabrication techniques used for preparing Ti₃C₂T_x-based composites, including solution mixing, chemical synthesis, layer-by-layer self-assembly, electrostatic assembly, and three-dimensional (3D) printing. The most recent developments in antibacterial application are also thoroughly discussed, with special attention to the medical, water treatment, food preservation, flexible textile, and industrial sectors. Ultimately, the future directions and opportunities are delineated, underscoring the focus of further research, such as elucidating microscopic mechanisms, achieving a balance between biocompatibility and antibacterial efficiency, and investigating effective, eco-friendly synthesis techniques combined with intelligent technology. A survey of the literature provides a comprehensive overview of the state-of-the-art developments in Ti₃C₂T_x-based composites and their potential applications in various fields. This comprehensive review covers the variety, preparation methods, and applications of Ti₃C₂T_x-based composites, drawing upon a total of 171 English-language references. Notably, 155 of these references are from the past five years, indicating significant recent progress and interest in this research area.