Electrospinning Machine| Multifunctional Electrospun Fiber Sponge for Hemostasis andInfected Wound Healing

Prof. Li Zhongming & Prof. Xu Jiazhuang at Sichuan University in *Small*: Multifunctional Electrospun Fiber Sponge for Hemostasis and Infected Wound Healing

Electrospinning offers significant advantages in manufacturing wound dressings. However, constructing 3D fiber dressings remains challenging. 

Recently, Prof. Li Zhongming and Prof. Xu Jiazhuang at Sichuan University developed a multifunctional electrospun fiber sponge (EFS) for chronic wound healing by combining humidity-controlled electrospinning with freeze-drying solidification technology. Their findings were published in *Small* under the title "Multifunctional Electrospun Fiber Sponge for Hemostasis and Infected Wound Healing."

Figure 1:Schematic illustration of multifunctional electrospun fiber sponge preparation and application. A) CC@EFS preparation process and corresponding microstructure evolution. B) Application of multifunctional CC@EFS for infected wound healing and skin reconstruction.

Moisture-induced phase separation triggered spontaneous curling and stacking of polylactic acid electrospun fibers, forming a unique fluffy structure that endowed EFS with excellent water/blood absorption and hemostatic properties. Subsequent freeze-drying further enhanced EFS's shape stability and compression elasticity.Compared to electrospun membranes, drug-loaded EFS (CC@EFS containing curcumin and ciprofloxacin hydrochloride) demonstrated superior antibacterial and antioxidant capabilities due to its high porosity facilitating effective drug release. In vivo experiments showed CC@EFS significantly accelerated infected wound healing by killing bacteria, reducing inflammation, and promoting angiogenesis.

Figure 2:Morphology and structure of EFS. A) CLSM and B) SEM images of EFS and EFM. C) FTIR spectra. D) Bulk density. E) Porosity. F) Water absorption rate.

Figure 3:EFS processing parameter adjustment and characteristics. A) Effect of humidity on EFS macroscopic morphology and spinning solution changes at corresponding RH. B) Necessity of freeze-drying for EFS solidification. C) SEM images, D) bulk density, E) porosity, and F) water absorption rate of EFS prepared with different DCM/DMA ratios. G) EFM and H) EFS cyclic compression performance in loading-unloading tests.

Figure 4:In vitro biological property evaluation. A) CU cumulative release from CC@EFM and CC@EFS with same sample area/weight. B) Inhibition zone images and diameters against S. aureus. C) Colony photos and D) bacterial killing rates of E. coli and S. aureus after CC@EFM/CC@EFS treatment. E) Live/dead staining images of S. aureus. F) DPPH radical scavenging rates. G) DPPH solution absorbance at 450-600 nm.

Figure 5:In vitro biocompatibility and hemostatic properties. A) MTT assay of L929 cell viability after 1-day incubation with extracts. B) Hemolysis rate and images. C) Hemoglobin capture rate and images. D) Blood absorption rate. E) Hemostatic process images in rat tail amputation model. F) Blood loss statistics.

Figure 6:In vivo wound regeneration evaluation. A) Timeline schematic. B) Representative images and C) wound tracing analysis with quantitative closure data at days 0, 3, 7, and 14. D) H&E staining at days 7 and 14. E) Masson's trichrome staining with local magnification at day 14. F) Width, G) granulation tissue thickness, and H) re-epithelialization thickness.

Figure 7:In vivo wound immunofluorescence analysis. A) TNF-α (red)/IL-6 (red) at day 7 and CD31 (green)/VEGF (green) at day 14. B) TNF-α, C) IL-6, D) CD31, and E) VEGF relative expression levels.

In summary, this study combined humidity-controlled electrospinning with freeze-drying to prepare an advanced wound dressing - electrospun fiber sponge for infected skin regeneration.The optimized sponge exhibited excellent water absorption and shape stability. Incorporating CU and CIP endowed CC@EFS with outstanding antibacterial and ROS-scavenging abilities, as the high porosity provided ample exchange space for drug release. Moreover, the unique fluffy morphology enhanced hemostasis both in vitro and in vivo. CC@EFS effectively accelerated epithelialization, stimulated collagen deposition, and promoted angiogenesis by eradicating pathogenic bacteria and suppressing inflammatory responses. This work provides a novel and efficient strategy for manufacturing sponge dressings with great potential against wound infection and accelerated healing.

**Paper link:** https://doi.org/10.1002/smll.202409969