Antibacterial Properties of PLGA Electrospun Scaffolds Containing Ciprofloxacin Incorporated by Blending or Physisorption

Abstract

Electrospun fibers are excellent candidates for wound dressings and tissue engineering scaffolds. To actively prevent infection during wound healing, the electrospun fibers can be loaded with antimicrobial agents, such as antibiotics or natural antimicrobials. Different methods have been used to incorporate antimicrobial agents in electrospun fibers during the electrospinning process, including blending, coaxial electrospinning, and emulsion electrospinning, to provide controlled release of the agent. Some evidence suggests that a burst release of antimicrobials through physical adsorption, or physisorption, may offer improved antibacterial properties, but a comparison between physisorbed and blended antimicrobial agents has not been conducted. In this study, the antimicrobial and release properties of poly(lactide-co-glycolide) electrospun fibers containing either blended or physisorbed ciprofloxacin are compared using disks containing similar initial amounts of ciprofloxacin. The results demonstrate that physically adsorbed ciprofloxacin provides more effective antibacterial properties than blended ciprofloxacin up to 48 h against P. aeruginosa PA14, S. aureus, and S. epidermidis regardless of initial loading due to a faster release of the antibiotic in the first 6 h. However, beyond 24 h, blended ciprofloxacin retained the clear zones better than physisorbed ciprofloxacin due to a continuous release. Physisorption offers a simple approach for incorporating antibiotics in electrospun fibers for stronger short-term antibacterial effects and may be applied to scaffolds containing blended antibiotics to sustain antibacterial properties for long-term wound dressings.

Ciprofloxacin-loaded polymeric nanoparticles incorporated electrospun fibers for drug delivery in tissue engineering applications

“…Controlling the release kinetics of drug and biomolecules from the electrospun fibers is critical in regenerative tissue engineering [15,19]. Different methods have been used to incorporate antimicrobial agents in electrospun fibers during the ES process, including blending [6], coaxial ES [6], and emulsion ES [6], to provide controlled release of the agent [20]. All these strategies result in the encapsulation of the antibiotic within the electrospun fibers, where its release is directly dependent on the degradation of the polymeric nanofibers.…”

Drug-eluting wound dressings having sustained release of antimicrobial compounds

“…and the efficient entrapment of THY in PLGA after the first hours, as previously reported [35,36]. As mentioned above, the sustained and prolonged release of antimicrobials from dressings are highly desired as infections may take place during wound healing.…”

Electrospun Asymmetric Membranes as Promising Wound Dressings: A Review

“…Moreover, the synthesis of these polymers can be scaled up, lowering the costs [ 52 ]. Some examples of synthetic polymers used in the electrospinning technique are PCL [ 55 ], PVA [ 49 ], poly(lactide- co -glycolide) (PLGA) [ 56 ], and poly( l , d -lactic acid) (PLA) [ 57 ]. Otherwise, these polymers also have some limitations, such as their lower biocompatibility as well as the lack of cell-specific recognition and attachment moieties [ 52 ].…”

“…These different approaches allow the selection of the optimal loading method according to the bioactive agent as well as the possibility to develop wound dressings with tailored release profiles [ 24 ]. For example, Buck et al compared the antimicrobial and release properties of PLGA electrospun fibers incorporating ciprofloxacin (CIP) through blend or physical adsorption [ 56 ]. The blend nanofibers were produced by the electrospinning of a CIP-PLGA solution, whereas in the physical adsorption PLGA nanofibrous mats were immersed in a CIP solution and dried.…”

“…The authors observed that upon the immersion of PLGA mats in phosphate-buffered saline solution (PBS) (pH 7.4), at 37 °C, the CIP loading by physical absorption resulted in a fast release, reaching its maximum at 6 h. In turn, the blend counterparts presented a sustained release for 48 h. Moreover, the authors also reported that the antibacterial capacity against Pseudomonas aeruginosa ( P. aeruginosa ), Staphylococcus aureus ( S. aureus ), and S. epidermidis was influenced by the loading method. In fact, the physical absorption resulted in higher-sized inhibitory halos, whereas the blended disks retained a higher percentage of the inhibitory zone after 48 h of incubation [ 56 ]. In turn, Jin and co-workers compared the incorporation of multiple epidermal induction factors (EIF) by coaxial electrospinning and blend electrospinning, in poly( l -lactic acid)- co -poly(ε-caprolactone) (PLLCL) and Gel nanofibers (Gel-PLLCL-EIF (coaxial electrospinning) and Gel-PLLCL-EIF (blend electrospinning), respectively) [ 84 ].…”