Electrospinning Trilayer Dressing of PLA/ZnO with Controlled Released Profiles for Visible pH Monitoring and Effective Exudate Management

To address persistent challenges in wound care, including exudate management, infection prevention, and healing monitoring, this study developed a multifunctional fiber dressing using electrospinning technology. The system integrates a patterned hydrophobic polylactic acid/zinc oxide (PLA/ZnO) inner layer providing antimicrobial protection and exudate drainage; a polyacrylonitrile/polydopamine (PAN/PDA) intermediate water transport layer enabling unidirectional exudate transfer; and an outer PAN-based functional membrane incorporating sodium polyacrylate (SPA), phenol red (PSP), and tetracycline hydrochloride (TCH) for controlled drug release and visual wound status monitoring. The comprehensive evaluation revealed exceptional performance: rapid exudate removal within 3.35 s, 96 h sustained antibacterial drug release (68.6% cumulative release), pH-responsive chromatic transition (yellow-to-red at pH 5-9), and significant antimicrobial efficacy against Escherichia coli and Staphylococcus aureus (inhibition zone diameters of 10 and 18 mm, respectively). The dressing exhibited a balance of mechanical strength (6.1 MPa tensile strength) and breathability (13.4 mm/s air permeability rate). By integrating three core functions─efficient exudate management, antimicrobial regulation, and intelligent healing monitoring─this multifunctional architecture demonstrates clinical applicability in postoperative care and chronic wound therapy.