Constructing Chitosan/Poly(L-lactide-co-ε-caprolactone) nanofiber yarns with highly aligned structure for biomedical applications

Abstract

The development of advanced electrospun nanofiber yarns (ENYs) featuring highly aligned structures has garnered considerable attention, as these ENYs serve as fundamental building blocks for biomedical textile fabrication. In this work, we successfully fabricated highly aligned chitosan (CS)/poly(L-lactide-co-ε-caprolactone) (PLCL) ENYs through an innovative combination of electrospinning and thermal stretching techniques. Four CS/PLCL compositions were subjected to thermal stretching at 60 °C to generate 4 times stretching range, resulting in markedly improved fiber alignment and morphological characteristics. Mechanical characterization revealed an interesting trade-off: while Young’s modulus decreased post-stretching, elongation at break increased substantially, indicating enhanced material flexibility. Degradation studies demonstrated composition-dependent behavior, with higher CS content accelerating biodegradation rates. Notably, surface wettability was effectively tuned, as evidenced by water contact angle measurements decreasing dramatically from 130° to 69° with increasing CS content. Most importantly, the 1 % CS/PLCL formulation emerged as particularly promising, demonstrating exceptional antibacterial performance (86.2 % inhibition against E. coli) coupled with outstanding human dermal fibroblast adhesion and proliferation. Comprehensive evaluation revealed that these highly aligned nanofibers, especially the 1 % CS/PLCL variant, achieved an optimal combination of structural properties (morphology and crystallinity), degradation kinetics, antibacterial efficacy, and biocompatibility.