Enhanced Fibrous Scaffolds for Drug Delivery Applications: Core–Shell Fiber Scaffolds with Antibiotic-Encapsulated Poly(lactic-co-glycolic acid) Nanoparticles

For the past decade, the utilization of nanoparticles (NPs) and nanofabrication techniques has dramatically advanced drug delivery systems in transdermal medication research. Among these advancements, core–shell fiber scaffolds (CSFS) incorporating drug carriers have emerged as particularly promising for the development of innovative transdermal materials due to their properties of (i) sustainable release profiles, (ii) modifiable open sites, and (iii) expensive material replacements. While existing research has predominantly focused on incorporation of inorganic NPs (metals, metal/semimetal oxides, and drug-only) into CSFS, there remains a notable gap in the literature regarding integration of polymeric NPs. In this study, a double emulsion solvent evaporation method was employed to synthesize gentamicin (Gen)-encapsulated poly(lactic acid- co -glycolic acid) (PLGA) NPs. These Gen/PLGA NPs were then incorporated into polyurethane (PU)/poly(ethylene oxide) (PEO) CSFS using a coaxial electrospinning technique. The resulting fibrous scaffolds were characterized to study their morphology, chemical composition, structure, release profiles, and antibacterial activity. The results indicated successful incorporation of Gen/PLGA NPs into PU/PEO CSFS. The resulting CSFS exhibited inner and outer diameters of 1.38 and 2.22 μm, respectively. Utilization of PEO in the shell spinning solution was found to effectively mitigate immiscibility between core and shell solutions while also facilitating the controlled release of gentamicin. Drug release profiles and antimicrobial tests further supported the efficacy of Gen/PLGA NPs-PU/PEO CSFS in inhibiting Escherichia coli growth, demonstrating sustained release of 19.02% gentamicin over 12 h. Overall, the study offers a promising strategy for (i) long-term therapeutic drug delivery with (ii) controlled release rates, (iii) effective antimicrobial activity, and (iv) stable structure against E. coli affections. These findings underscore the potential of this methodology for advancing the development of innovative transdermal materials.