The polycaprolactone/chitosan (PCL/CS) spun membranes loaded with astragalus polysaccharide by emulsion spinning technology for anti-infective wound dressings

In this study, astragalus polysaccharide / hydroxypropyl-β-cyclodextrin (APS@HP-β-CD) was efficiently loaded into polycaprolactone/chitosan (PCL/CS) by electrospinning and encapsulation techniques. Then, using Span80 as an emulsifier, PCL/CS/APS@HP-β-CD nanofibers were produced through electrospinning of water-in-oil emulsions. The physicochemical and antimicrobial properties of the nanofibrous materials were subsequently evaluated in vitro. Compared with the PCL/CS nanofiber membranes (PC membrane) without added active substances, the tensile test showed that the flexibility of the PCL/CS/APS@HP-β-CD nanofiber membrane (PCA membrane) was significantly enhanced. The thermodynamic test results show that the thermal stability of the PCA membrane is enhanced. The results of 1 H NMR, FTIR, and XRD showed that APS was successfully encapsulated in HP-β-CD. The biodegradation test results showed that the PC and PCA nanofiber membranes had no pollution to the environment and could biodegrade. In addition, PCA membranes exhibited strong antibacterial activity against both Gram-positive and Gram-negative bacteria as well as outstanding free radical scavenging capacity. The APS release mechanism was determined through the Higuchi and Korsmeyer-Peppas kinetic models. Among all the PCA nanofiber membranes, the APS release was more consistent with the Korsmeyer-Peppas kinetic model, and the transport mechanism was Fickian diffusion. Finally, this study also optimized the experimental protocol by introducing carboxymethyl groups to modify PCL/CS nanofiber membranes by chemical grafting. In conclusion, the PCA nanofibrous membranes prepared in this study have a strong potential to become wound dressings.