Chitosan and β-cyclodextrin doubly coated with Fe₃O₄ nanoparticles was prepared and applied as magnetic solid-phase extraction adsorbent to separate ibuprofen.

Herein, Fe₃O₄ magnetic nanoparticles (CD-MNPs, CM-CD-MNPs and MA-CD-MNPs) surface-modified with β-cyclodextrin (β-CD) and its derivatives, carboxymethyl-β-CD (CM-β-CD) and maleated-β-CD (MA-β-CD), respectively, were successfully synthesized via a layer-by-layer method, and the resulting nanocarriers possessed good magnetic character and biocompatibility. Using carmofur as a model drug, the results of loading and release experiments indicate that these magnetic nanocarriers can serve as targeted drug delivery systems in the future, and the loading capacity and release behaviour are highly dependent on the surface properties of the nanocarriers. Based on the molecular docking technique, for the first time, the correlation between the lowest binding energy (ΔG_binding) of the inclusion complex and the loading and release performances of the corresponding magnetic nanocarriers was investigated to establish a method to fast select an effective β-CD-based surface coating for the construction of high-performance magnetic nanocarriers. The results revealed a ΔG_binding-dependent manner demonstrating that the magnetic nanocarriers surface modified with the cyclodextrin unit with a larger absolute value of ΔG_binding would possess better loading and release performances. This encouraging result suggested that the ΔG_binding obtained from molecular docking could provide a significant reference for the fast selection of an effective surface coating during the construction of high-performance β-CD-based magnetic nanocarriers. Although it is clear that the present study should be considered only as a preliminary study, the good results obtained herein demonstrate the feasibility of this new type of approach.

Polysaccharide-based wound dressings face challenges in mechanical properties and effective wound repair for infected wound surfaces. This study presents a novel polyvinyl alcohol (PVA)/Salecan (Sal) composite hydrogel dressing with high toughness, biocompatibility, and wound healing capabilities, developed using an interpenetrating polymer network strategy. The primary network was formed through electrostatic interactions between polydopamine (PDA) and biocompatible polysaccharide Salecan, followed by incorporation of AgNO₃, which was in situ reduced to silver nanoparticles within the hydrogel. PVA was introduced as a secondary matrix, further reinforcing the hydrogel network through cyclic freeze–thawing. The resulting hydrogel exhibited a tensile strength of 0.31 MPa, an elongation at break of 158.9%, and a toughness of 31.16 J·m⁻², demonstrating enhanced mechanical performance compared to both Salecan/PDA and previously reported Salecan/Fe³⁺ hydrogel. Co-culture experiments showed the hydrogel’s strong antibacterial effects, inhibiting 80.1% of Escherichia coli (E. coli) and 99.5% of Staphylococcus aureus (S. aureus). Fibroblast culture tests confirmed its excellent cytocompatibility. In vivo studies on infected wounds showed nearly complete healing in the S. aureus + hydrogel group within 12 days. Quantitative immunohistochemical analysis of CD31 revealed that hydrogel treatment significantly upregulated CD31 expression, indicating enhanced neovascularization. Complementary Western blot analysis further demonstrated that hydrogel-treated groups exhibited a marked downregulation of pro-inflammatory factors alongside CD31 upregulation. In summary, the PVA/Sal-based hydrogel represents a valuable strategy for reducing inflammation and promoting regeneration in the management of infected wounds.

Salecan-based hydrogel (thereafter called Sal-hydrogel) dressings and gut microbiota have been associated with enhanced wound healing. However, the relationship between these two factors remains unclear. This study investigated the dynamic characteristics of the intestinal microbiota in relation to the Sal-hydrogel dressings and their role in promoting wound healing. Fecal samples were collected at day 0, 3, 7, and 12 after wounds were inflicted on 48 mice, which were treated with either Sal-hydrogel, Staphylococcus aureus, or a combination of S. aureus and Sal-hydrogel, using a full-thickness skin perforation wound model. The samples were subjected to 16S rRNA V3-V4 gene sequencing. The results indicated a general trend for Shannon diversity of the intestinal microbiota to increase by day 3 following injury. On the final day, the diversity in both the hydrogel group and the S. aureus plus hydrogel group was significantly higher compared to the control group (p < 0.05). Additionally, the bacterial community structure in the mouse gut exhibited substantial changes when comparing the hydrogel-treated groups to the controls (hydrogel group: p = 0.027; S. aureus plus hydrogel group: p = 0.039). The genus uncultured_Oscillospiraceae, which was significantly associated with wound closure (R-squared = 0.2154, p = 6.657e-05), was found to be dominant in the gut of the hydrogel group during the wound healing process. Overall, our findings suggest that significant and rapid alterations in gut microbiota occur in response to skin injury and wound infection. The enhanced wound healing properties of the Sal-hydrogel dressing are associated with increased intestinal microbiota diversity and the presence of the bacterium uncultured_Oscillospiraceae.