Electrospun poly(lactic acid) nanofibers loaded with silver sulfadiazine/[Mg-Al]-layered double hydroxide as an antimicrobial wound dressing

Poly(lactic acid) (PLA) is a versatile, bioabsorbable, and biodegradable polymer with excellent biocompatibility and ability to incorporate a great variety of active agents. Silver sulfadiazine (SDZ) is an antibiotic used to control bacterial infection in external wounds. Aiming to combine the properties of PLA and SDZ, hydrotalcite ([Mg-Al]-LDH) was used as a host matrix to obtain an antimicrobial system efficient in delivering SDZ from electrospun PLA scaffolds intended for wound skin healing. The structural reconstruction method was successfully applied to intercalate silver sulfadiazine in the [Mg-Al]-LDH, as evidenced by X-ray diffraction and thermogravimetric analyses. Observations by scanning electron microscopy revealed a good distribution of SDZ-[Mg-Al]-LDH within the PLA scaffold. Kinetics studies revealed a slow release of SDZ from the PLA scaffold due to the intercalation in the [Mg-Al]-LDH. In vitro antimicrobial tests indicated a significant inhibitory effect of SDZ-[Mg-Al]-LDH against Escherichia coli and Staphylococcus aureus. This antibacterial activity was sustained in the 2.5-wt% SDZ-[Mg-Al]-LDH-loaded PLA nanofibers, which also displayed excellent biocompatibility towards human cells. The multifunctionality of the PLA/SDZ-[Mg-Al]-LDH scaffold reported here is of great significance for various transdermal applications.