Core-shell nanofiber dressings with zinc oxide nanoparticles and cell-free fat extract: boosting fibroblast activity and antibacterial efficacy

Abstract

Background: This study presents the development and characterization of innovative core-shell nanofiber wound dressings incorporating zinc oxide nanoparticles (nZnO) and cell-free fat extract (CEFFE) to enhance fibroblast activity and antibacterial efficacy.

Results: CEFFE was prepared and analyzed, revealing high concentrations of essential growth factors, particularly bFGF and TGF-β1, supporting its therapeutic potential in tissue regeneration. The fabricated nanofibers (PLCL, nZnO/PLCL, PLCL-CEFFE/HA, and nZnO/PLCL-CEFFE/HA) were examined using FE-SEM and TEM, demonstrating successful encapsulation and morphological variations due to nZnO incorporation. XRD analysis confirmed the structural integrity and effective loading of nZnO and CEFFE. Hydrophilicity assessment via water contact angle measurements showed that CEFFE/HA significantly enhanced the hydrophilicity of PLCL membranes, crucial for wound exudate management. Mechanical tests indicated that CEFFE/HA addition maintained the scaffold's mechanical robustness, while nZnO slightly reduced mechanical properties. In vitro release studies revealed a biphasic release pattern of Zn²⁺ ions and growth factors from nZnO/PLCL-CEFFE/HA nanofibers, ensuring prolonged antibacterial activity and sustained therapeutic effects. Antibacterial assays demonstrated significant efficacy against E. coli and S. aureus, attributed to nZnO. MTT assays and FE-SEM analysis confirmed enhanced NIH-3T3 cell proliferation and adhesion on PLCL-CEFFE/HA nanofibers due to the controlled release of growth factors. The scratch assay showed superior cell migration and wound healing potential for PLCL-CEFFE/HA formulations.

Conclusions: These findings underscore the potential of nZnO/PLCL-CEFFE/HA core-shell nanofibers as multifunctional wound dressings, combining antibacterial properties with enhanced tissue regeneration capabilities. However, further studies are needed to assess long-term stability and in vivo performance, which represent key challenges for future research.

Keywords: Cell-free fat extract; Core-shell nanofiber; Wound dressing; Zinc oxide nanoparticles.

Fig. 1

Schematic illustration of the CEFFE preparation

Fig. 2

Schematic illustration of fabrication process for the electrospun core-shell nanofibrous mats

Fig. 3

The concentration of various growth factors in CEFFE detected by ELISA (n = 3)

Fig. 4

Morphology and size characterization of nanofibers. (A) FE-SEM images with (B) diameter distribution of PLCL, nZnO/PLCL, PLCL-CEFFE/HA, and nZnO/PLCL-CEFFE/HA. (C) TEM images of the fabricated fibers

Fig. 5

Physicochemical characterization of electrospun nanofibers. (A) the XRD patterns of HA, nZnO, and electrospun fiber membranes composed of PLCL, nZnO, HA, and CEFFE, (B) Water contact angle of the various electrospun fibers, and (C) typical stress-strain curve of various electrospun nanofibers. n = 3, *p < 0.05 vs. Control

Fig. 6

Cumulative release of (A) Zn ion from nZnO/PLCL and nZnO/PLCL-CEFFE/HA, and (B) release of bFGF, TGF-β1, and VEGF from nZnO/PLCL-CEFFE/HA core-shell nanofibers. The data are presented as mean ± SD (n = 3)

Fig. 7

Antibacterial activity against (A) E.coli and (B) S. aureus measured through turbidity method. The data are presented as mean ± SD (n = 3), *p < 0.05 vs. control was considered significant

Fig. 8

Cell viability and adhesion on the various electrospun nanofibers. (A) graph of MTT results showing the absorbance proportional to the viability of NIH-3T3 cells, and (B) FE-SEM images, showing the growth of NIH-3T3 cells on fiber membrane, taken at day 4 and 7 (scale bar = 30 μm)., The data are presented as mean ± SD (n = 3), *p < 0.05

Fig. 9

Representation of cell migration performed by the scratch assay. (A) Scratch results showing the migration of cells co-cultured with the various electrospun nanofibers as analyzed by taken images at 0 h and 48 h. (B) The quantification results of the cell migration images by using the Image J software. * p < 0.05 vs. control was considered significant. Results are mean ± SD (n = 3)