The fluoroquinolone ciprofloxacin (CIP) hidrophobic drug and its inclusion complex, β-cyclodextrin-CIP (IC) were encapsulated into micro- and nano-fibers of polylactic acid (PLA) via electrospinning technique to evaluate CIP release. The IC was characterized by 13C solid-state nuclear magnetic resonance (SSNMR) and thermogravimetric analysis (TGA) to investigate the inclusion complex formation and fiber encapsulation. The PLA-IC and PLA-CIP fibers were characterized by TGA, Raman spectroscopy and scanning electron microscopy (SEM). The release behavior of CIP and loading efficiency percentage (LE%)were evaluated via UV-Vis at 276 nm. The LE% of CIP was higher to PLA-IC with respect to the fibers with only CIP. IC release behavior was more sustained from PLA-IC fibers versus PLA-CIP as an effect of the IC formation. The CIP was released in a more prolonged and sustained manner from PLA-IC fibers versus PLA-CIP fibers. Different PLA-CIP and PLA-IC fiber diameters did not affect the release profile. The experimental results of CIP and IC were approximated with three commonly used semi-empirical models: Korsmeyer-Peppas, zero-order, and first-order kinetic equation to explain the release mechanism.

Developing gelled environmentally friendly dispersions in oil media is a hot topic for many applications. This study aimed to investigate the production of electrospun cellulose triacetate (CTA) nanofibers and to explore their potential application as a thickening agent for castor oil. The key factors in the electrospinning process, including the intrinsic properties of CTA solutions in methylene chloride (DCM)/ethanol (EtOH), such us the shear viscosity, surface tension, and electrical conductivity, were systematically studied. The impact of the CTA fiber concentration and the ratio of DCM/EtOH on the rheological properties of the gel-like dispersions in castor oil was then investigated. It was found that dispersions with a non-Newtonian response and above a critical concentration (5 wt.%), corresponding to approximately 2–2.5 times the entanglement concentration, are required to produce defect-free nanofibers. The average fiber diameter increased with CTA concentration. Further, the morphology and texture of the electrospun nanofibers are influenced by the ratio of solvents used. The rheological properties of dispersions are strongly influenced by the concentration and surface properties of nanofibers, such as their smooth or porous textures, which allow their modulation. Compared to other commonly used thickeners, such as synthetic polymers and metal soaps, CTA electrospun nanofibers have a much higher oil structuring capacity. This work illustrated the potential of using CTA nanofibers as the foundation for fabricating gel-like dispersions in oil media, and thus exerting hierarchical control of rheological properties through the use of a nanoscale fabrication technique.