Wounds, burns, and trauma-induced lacerations that disrupt the skin’s protective bacterial barrier create favourable environments for the entry, survival, and proliferation of microorganisms. In such compromised tissues, pathogens such as Staphylococcus aureus (S. aureus), Pseudomonas aeruginosa (P. aeruginosa), and Escherichia coli (E. coli) can rapidly multiply [1]. However, relying solely on antibiotics to overcome these bacteria and their extracellular matrix-based biofilm structures has contributed to the global escalation of antibiotic resistance [2]. Antimicrobial resistance (AMR) has emerged as a critical global health concern, and the World Health Organization (WHO) reports that the diminishing effectiveness of existing antibiotics has led to the rise of infections that are increasingly difficult to treat [3], [4], [5]. Biofilm-producing bacteria are known to exhibit resistance levels that can be ten to a thousand times higher than those observed with standard antimicrobial treatments. Biofilms are structured microbial communities encased within a self-produced extracellular polymeric matrix. Biofilm-associated infections that develop in chronic wounds, on implant surfaces, and on various medical devices pose significant therapeutic challenges [6]. Therefore, it is crucial to develop innovative strategies to combat the problem of antimicrobial resistance.

Among natural alternative bioactive compounds, phenolic acids—particularly caffeic acid (CA), which is commonly found in coffee, fruits, and vegetables—stand out due to their notable antibacterial and antioxidant properties. It demonstrates antimicrobial activity against multiple types of bacteria and has the ability to inhibit biofilm formation [7]. Its antibacterial activity has been reported to stem from its ability to disrupt the integrity of bacterial cell membranes. Additionally, CA has been shown to inhibit biofilm formation by modulating bacterial adhesion and quorum-sensing mechanisms, thereby reducing the persistence of pathogenic microorganisms [8].

Gentamicin (GEN) is a broad-spectrum aminoglycoside antibiotic widely employed in clinical and biological applications due to its potent activity against a wide range of bacterial infections, particularly those caused by Gram-negative species [9]. Its primary mechanism of action involves binding to the 30S ribosomal subunit, thereby inhibiting bacterial protein synthesis, and ultimately leading to cell death [10]. In addition to its bactericidal properties, GEN has been shown to inhibit biofilm formation. Its ability to eliminate planktonic bacteria while also contributing to the disruption of biofilm structures makes GEN a promising candidate for advanced antibacterial strategies [11].

CA and GEN together have special potential for creating synergistic antibacterial treatments. Given their complementary mechanisms—CA's biofilm-inhibitory and antioxidant properties and GEN's potent bactericidal effect—co-application of these two drugs may increase antibacterial activity while lowering the likelihood of resistance development. Thus, examining the synergistic interactions between CA and GEN may yield fresh perspectives on cutting-edge anti-biofilm tactics with substantial therapeutic value [12], [13]. The synergistic effect of CA and GEN presents significant potential for anti-biofilm strategies.

Nanofiber technology, in particular, is gaining increasing attention in biomedical applications such as tissue engineering [14], wound healing [15], and drug delivery systems [16]. This is due to its unique properties, including a porous structure, a high surface-area-to-volume ratio, and the ability to provide controlled release of bioactive agents. Nanofibrous structures can serve as carriers for a range of antimicrobial and anti-biofilm agents, thereby enhancing their efficacy [17]. Electrospinning is one of the commonly used techniques for producing nanofibers, wherein a polymer solution is drawn from a needle toward a collector under high voltage, resulting in the formation of fine nanofibrous structures [18]. Nanofiber-based drug delivery systems obtained are considered an effective approach in various clinical applications, including postoperative local chemotherapy and wound dressing [2].

In the biomedical field, the polymers provide temporary support for tissue regeneration or therapeutic delivery, thereby preventing long-term complications associated with permanent implants. In this context, polylactic acid (PLA) and poly(ε-caprolactone) (PCL) are among the most extensively studied biopolymers in tissue engineering, and controlled drug delivery systems because of their suitability for biomedical applications, and versatility in fabrication processes [19]. Although PLA and PCL share certain advantages, their fundamental structural characteristics differ markedly. PLA is more brittle and rigid, yet it degrades much faster and exhibits higher tensile strength; therefore, it is favoured in applications that require rapid resorption or short-term mechanical support [19]. PCL, on the other hand, is a semi-crystalline aliphatic polyester characterized by high elasticity, and an exceptionally slow rate of hydrolytic degradation [20]. Blending these polymers to form PLA/PCL mixtures brings together the advantages of both materials and enables the creation of matrices optimized for mechanical strength, biodegradability, and biocompatibility, particularly for nanofibrous structures [21].

This study aims to develop anti-biofilm nanofibers fabricated via electrospinning from a PLA/PCL polymer matrix co-loaded with caffeic acid (CA) and gentamicin (GEN), as schematically summarized in Fig. 1. In this study, we present a nanofiber wound dressing platform that delivers GEN and CA together, aiming to achieve dual therapeutic function. GEN provides localized antibacterial activity, while CA offers antioxidant and anti-inflammatory effects supporting tissue regeneration. To our knowledge, this is the first systematic study investigating the incorporation of these two agents combined within a single nanofiber matrix for wound dressing applications. The combined delivery of GEN and CA, as well as their separate delivery to the nanofiber layers, contributed to the comparison of the dual therapeutic efficacy. This multifunctional approach distinguishes the present study from previous ones and highlights its potential for improved wound care.