Xinyu Zhang

In this study, a methodology that combines ultrasound-enhanced extraction with the use of hydrophobic deep eutectic solvents (DESs) and three-phase partitioning (TPP) was presented for the green isolation of polysaccharides from longan shells (LSP). The extraction system was a DES composed of an equal molar ratio of dodecanoic acid and octanoic acid, which was used as the separation medium. Generally, the main phase separation mechanisms involved in the purification of the polysaccharide were investigated. The ideal operational parameters were found through systematic optimization by the single-variable experiment with the response surface methodology, i.e., the extraction temperature of 63.8 °C, the phase volume ratio of 1:1.04 (v/v), and the ammonium sulfate concentration of 26.3%. The extraction efficiency is 2.42 ± 0.03% for LSP when the above operational parameters are used. The structural characterization showed that the isolated LSP is an acidic heteropolysaccharide rich in galacturonic acid and arabinose. It was also shown that the molecular architecture of LSP includes both types of glycosidic bonds, which are also of importance for its physicochemical properties. The polysaccharide exhibits an open fibrous network structure. Notably, the DES maintained stable performance over five successive reuses without significant degradation. Concerning the antioxidant capacity, LSP at 0.4 mg/mL showed 96.6 ± 2.0% inhibition of ABTS radical, and showed an iron-reducing capacity of 68.67 ± 2.02 micromol Trolox per gram (concentration-dependent effect). These results are present a new method for the sustainable extraction of bioactive macromolecules.

An innovative ultrasound-assisted deep eutectic solvent-based three-phase partitioning (UA-DES-TPP) system was developed for the sustainable extraction of Ficus carica polysaccharide (FCP). Using a hydrophobic DES composed of dodecanoic acid and octanoic acid (1:1 molar ratio), a phase behavior-driven separation mechanism was established. The system was systematically optimized through single-factor experiments and response surface methodology (RSM), achieving a maximum FCP yield of 9.22 ± 0.20% under optimal conditions (liquid–solid ratio 1:24.2 g/mL, top/bottom phase volume ratio 1:1.05 v/v, ammonium sulfate concentration 25.8%). Structural characterization revealed that FCP was a heteropolysaccharide primarily composed of glucose and mannose with α/β-glycosidic linkages and a loose fibrous network. Remarkably, the DESs demonstrated excellent recyclability over five cycles. Furthermore, FCP exhibited significant concentration-dependent antioxidant activities: 82.3 ± 3.8% DPPH radical scavenging at 8 mg/mL, 76.8 ± 0.8% ABTS⁺ scavenging, and ferric ion reducing power of 45.53 ± 1.07 μmol TE/g. This study provides a new path for the efficient and sustainable extraction of bioactive macromolecules.

Hydrogels have emerged as promising candidates for biomedical applications, especially in the treatment of skin wounds, as a result of their unique structural properties, highly tunable physicochemical properties, and excellent biocompatibility. The integration of smart-response features into hydrogels allows for dynamic responses to different external or internal stimuli. Therefore, this paper reviews the design of different smart-responsive hydrogels for different microenvironments in the field of skin wound therapy. First, the unique microenvironments of three typical chronic difficult-to-heal wounds and the key mechanisms affecting wound healing therapeutic measures are outlined. Strategies for the construction of internal stimulus-responsive hydrogels (e.g., pH, ROS, enzymes, and glucose) and external stimulus-responsive hydrogels (e.g., temperature, light, electricity, and magnetic fields) are highlighted from the perspective of the wound microenvironment and the in vitro environment, and the constitutive relationships between material design, intelligent response, and wound healing are revealed. Finally, this paper discusses the severe challenges faced by smart-responsive hydrogels during skin wound repair and provides an outlook on the combination of smart-responsive hydrogels and artificial intelligence to give scientific direction for creating and using hydrogel dressings that respond to stimuli in the clinic.

Over millions of years of evolution, nature has developed a myriad of unique features that have inspired the design of adhesives for wound healing. Bionic hydrogel adhesives, capable of adapting to the dynamic movements of tissues, possess superior biocompatibility and effectively promote the healing of both external and internal wounds. This paper provides a systematic review of the design and principles of these adhesives, focusing on the treatment of skin wounds, and explores the feasibility of incorporating nature-inspired properties into their design. The adhesion mechanisms of bionic adhesives are analyzed from both chemical and physical perspectives. Materials from natural and synthetic polymers commonly used as adhesives are detailed regarding their biocompatibility and degradability. The multifunctional design elements of hydrogel adhesives for skin trauma treatment, such as self-healing, drug release, responsive design, and optimization of mechanical and physical properties, are further explored. The aim is to overcome the limitations of conventional treatments and offer a safer, more effective solution for the application of bionic wound dressings.