Electrospun nanofibers, due to their extremely small diameter, high specific surface area, an‎d ability to mimic the extracellular matrix structure, are considered one of the most suitable scaffolds for tissue engineering applications. Electrospinning is also an efficient technique for producing continuous fibers with controlled morphology. Among the available materials, polycaprolactone (PCL), as a stable synthetic polymer, an‎d gelatin, as a bioactive natural component, are appropriate choices for fabricating biocompatible scaffolds. Additionally, the use of nanomaterials such as MXene has recently attracted considerable attention due to properties such as desirable conductivity, high hydro‎philicity, an‎d the ability to enhance mechanical an‎d biological characteristics. The present study focuses on the fabrication an‎d eva‎luation of composite nanofibers based on polycaprolactone (PCL), gelatin, an‎d MXene nanosheets for tissue engineering applications. Initially, MXene nanosheets were synthesized from the Ti₃AlC₂ precursor via chemical etching using the LiF/HCl method, an‎d FESEM, XRD, an‎d HRTEM analyses confirmed the layered an‎d wrinkled morphology of the MXene structure. Subsequently, three categories of nanofibers were produced through electrospinning: pure polycaprolactone fibers an‎d PCL/gelatin blends with a 70:30 ratio; PCL nanofibers containing various MXene concentrations (0, 1, an‎d 2 wt%); an‎d PCL/gelatin nanofibers containing different MXene contents (0, 1, 2, 3, an‎d 4 wt%). The samples were eva‎luated in terms of microstructure, mechanical behavior, surface properties, degradability, an‎d antibacterial activity. The results showed that the addition of gelatin reduced the contact angle from 122° in pure PCL to approximately 62° in the blended sample, significantly improving surface hydro‎philicity. In PCL/MXene samples, the average fiber diameter decreased from 106±18 nm in pure PCL to 99±26 nm in the sample containing 1 wt% MXene. The tensile strength of polycaprolactone increased from 6/15 ± 0/16 MPa to 13/75 ± 0/33 MPa in the 1 wt% MXene sample. Fourteen-day degradability in phosphate-buffered saline (PBS) increased from 28/79% in pure PCL to 69/08% in the 1 wt% MXene sample. In the ternary PCL/gelatin/MXene nanofibers, the average diameter decreased from 113±28 nm in the MXene-free sample to 104±27 nm in the 2 wt% sample, while at 4 wt% MXene, fiber diameter increased again due to nanosheet agglomeration. Complete absorption of a water dro‎plet occurred after approximately 45 seconds in the 2 wt% sample an‎d after about 30 seconds in the 3 wt% sample. The tensile strength of the base sample (without MXene) was 7/73 ± 0/31 MPa, which increased to 13/68 ± 0/53 MPa in the sample containing 2 wt% MXene. The antibacterial performance of MXene-containing samples ranged from 85% to 95% against both Gram-negative an‎d Gram-positive bacteria, an‎d this efficiency was slightly enhanced with increasing MXene content.

كميل نصوري , لاله قاسمي مباركه

اميرحسين جلالي

حسين توانايي , فرزانه علي حسيني