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Timely antibacterial treatment of wounds reduces the probability of wound infection and promotes wound healing. However, the materials used to treat wounds often fail to provide both sterilization (especially for super bacteria) and moisture, and some may even cause secondary injury to the wound. In this study, gold nanoparticles (Au NPs) of average grain diameter of 3 ± 1 nm were prepared using egg white as the reductant. These particles showed no aggregation and pink fluorescence. Au NPs were mixed with gentamicin sulfate (GS) and loaded into a mixture of konjac glucomannan (KGM) and gelatin as wound dressing (KGM/Gelatin@Au NPs/GS). Antibacterial experiments showed that the Au NPs amplified the antibacterial activity of GS; Au NPs/GS efficiently eliminated bacteria, especially super bacteria. Cytotoxicity tests indicated that KGM/Gelatin@Au NPs/GS showed basically no cytotoxicity to L929 cells. In addition, KGM/Gelatin@Au NPs/GS possesses good water absorption, water retention, and enhanced mechanical properties, which can provide a moist environment for wounds and promote healing. In conclusion, our study showed that the antibacterial activity of KGM/Gelatin@Au NPs/GS is better than that of only GS and that it efficiently eliminated super bacteria. Therefore, KGM/Gelatin@Au NPs/GS can be used for killing superbugs, inhibiting bacterial growth, and promoting wound healing. • Gold nanoparticles with high fluorescence were prepared in an environmentally friendly way. • A composite sponge of konjac and gelatin can provide and maintain moisture for the wound. • The combination of nano-gold and gentamicin sulfate provided a new method for killing superbacteria. • Konjac gelatin composite sponge loaded with Au NPs/GS can be used as a new dressing to promote wound healing. [ABSTRACT FROM AUTHOR]

Abstract In recent years, silver nanoparticles have widely been used in antibacterial dressings to solve antibiotic resistance problems. However, traditional methods for reducing silver nanoparticles are usually toxic. To overcome this problem, Sanghuangporus sanghuang polysaccharides (FSHPs) were used as a green reducing agent to prepare silver nanoparticles (AgNPs) with a size of 3–35 nm. The FSHPs‑silver nanoparticles (FSHPs-Ag) composite with chitosan solution were then freeze-dried to obtain a porous sponge dressing of chitosan-FSHPs-Ag (CS-FSHPs-Ag). The internal pores of CS-FSHPs-Ag were between 50 and 100 μm and had good swelling and water retention properties, which could provide a moist environment for wounds. Based on the experimental results, the appropriate concentration of AgNPs required for CS-FSHPs-Ag to inhibit Escherichia coli and Staphylococcus aureus was determined. Moreover, there was no statistically significant difference between the material treatment and the blank control group, indicating that the material almost showed no toxicity to L929 cells. Finally, this material was used for dressing animal wounds. The results showed that the CS-FSHPs-Ag promoted wound contraction and internal tissue growth better than the wounds treated with Aquacel® Ag, which indicated that the CS-FSHPs-Ag has a great potential as an ideal wound dressing material. [ABSTRACT FROM AUTHOR]

Spongy composites with silver nanoparticles (AgNPs) were synthesized by freeze-drying a mixture of silver nitrate (AgNO 3 ) and chitosan- l -glutamic acid (CG) derivative loaded with hyaluronic acid (HA) solution. CG/AgNP spongy composites had an interconnected porous structure and rough surfaces. When AgNPs (5–20 nm) were immobilized on these spongy composites, AgNP aggregation was dependent on AgNO 3 concentration. The spongy composites exhibited good mechanical properties, swelling, and water retention capacity. In vitro antibacterial activity showed that the CG/AgNP spongy composites effectively inhibited bacterial ( Escherichia coli and Staphylococcus aureus ) growth and penetration. Spongy composites containing low concentrations of AgNP were non-toxic to L929 cells, while CG/HA/AgNP spongy composites promoted wound healing, as determined by in vivo tests, wound contraction ratio, average healing time, and histological examination. These results indicate that the spongy composites can serve as effective antibacterial wound dressings. [ABSTRACT FROM AUTHOR]

Silk fibroin materials have shown some success in wound dressing applications; however, their use for this purpose remains limited by a complex production process and wasted sericin. In the present study, Bombyx mori cocoon materials are used because the protective function of the silkworm cocoon resembles the manner in which the skin protects the human body. A series of silkworm cocoon sol-gel film (SCSF) wound dressings are prepared by immersion in a CaCl 2 -ethanol-H 2 O solution for different treatment times. The accelerated wound-healing capabilities of SCSFs are systematically evaluated. Among them, the SCSF sample immersed for 90 min exhibits stronger biocompatibility and antibacterial performance compared to other SCSFs. SCSF-90 also exhibits excellent transparency, a high swelling ratio, and good extensibility. Furthermore, in vivo experiments indicate that SCSF-90 can significantly accelerate the healing rate of wounds in New Zealand white rabbits, compared to the standard Mepitel ® dressing, and histological examinations reveal that SCSF-90 aided in the successful reconstruction of intact and thickened epidermis. These results demonstrate that the proposed approach may be utilized in the design of antibacterial materials with promising applications in wound dressing. [ABSTRACT FROM AUTHOR]