Characterization and Release Behavior of a Thiosemicarbazone from Electrospun Polyvinyl Alcohol Core-Shell Nanofibers

Abstract

<jats:p>Mats of polyvinyl alcohol (PVA) core–shell nanofibers were produced using coaxial electrospinning in the presence of a thiosemicarbazone (TSC) N4-(S)-1-phenylethyl)-2-(pyridin-2-yl-ethylidene)hydrazine-1-carbothioamide (HapyTSCmB). Monolithic fibers with 0% or 5% TSC and core–shell fibers with 10% TSC in the spinning solution were studied to compare stability and release rates. SEM showed the formation of uniform, bead-free, cylindrical, and smooth fibers. NMR spectroscopy and thermal analysis (TG/DTA) gave proof for the chemical integrity of the TSC in the fiber mats after the electrospinning process. Attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy showed no TSC on the surface of the PVA/TSC-PVA fibers confirming the core–shell character. The TSC release profiles of the fibers as studied using UV-vis absorption spectroscopy showed a slower release from the PVA/TSC-PVA core–shell structure compared with the monolithic PVA/TSC fibers as well as lower cumulative release percentage (17%). Out of several release models, the Korsmeyer–Peppas model gave the best fit to the experimental data. The main release phase can be described with a Fick-type diffusion mechanism. Antibacterial properties were tested against the Gram-positive Staphylococcus aureus bacterium and gave a minimal inhibitory concentration of 12.5 μg/mL. 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazoliumbromide (MTT)-based cytotoxicity experiments showed that the cell viability of fibroblast at different contents of TSC was slightly decreased from 1.5% up to 3.5% when compared to control cells.</jats:p>

Bio-Based Electrospun Fibers for Wound Healing

“…In this case, the sheath protects the unstable biological agent from an aggressive environment and delivers it in a sustained way by minimizing the burst release. Superior mechanical properties, and the possibility to functionalize the surface without affecting the core material are other advantages [6,59,63,64]. Besides the morphological features, the architecture of the wound dressings and arrangement of the fibers in their structure also greatly affect the adhesion, proliferation, and penetration of the cells, and release behavior of the bioactive molecules from the structure.…”

“…The porous morphology of the electrospun fibers with small pore size can enhance hemostasis, and effectively protect the wound from bacterial permeation [ 56 ]. Those with tiny pores and increased surface to volume ratio can also influence the release behavior of the loaded biomolecules in the fibrous structures [ 57 , 58 , 59 ]. Although beadless fibers are usually preferred to improve the uniformity of the electrospun nanofibers, bead-on-string nanofibers ( Figure 2 d), with suitable control of the bead diameter, shape, and surface morphology, have provided efficient encapsulation of biomolecules and controlled release suitable for tissue engineering and wound dressing applications.…”

“…In this case, the sheath protects the unstable biological agent from an aggressive environment and delivers it in a sustained way by minimizing the burst release. Superior mechanical properties, and the possibility to functionalize the surface without affecting the core material are other advantages [ 6 , 59 , 63 , 64 ].…”

Improvement of Drug Release and Compatibility between Hydrophilic Drugs and Hydrophobic Nanofibrous Composites

“…In the past decades, the use of polymers, as a carrier and release controller for drug delivery systems, has been the major research focus due to the improvement of healing effectiveness and the reduction in toxic side-effect [ 19 ]. In addition, the interaction between drugs and their carriers is paramount to control a sustained drug release [ 20 , 21 ]. Hydrophobic drugs including clindamycin, ciprofloxacin, and cephalexin can be simply incorporated with, and thus interacted with hydrophobic polymers.…”

Core–Shell Eudragit S100 Nanofibers Prepared via Triaxial Electrospinning to Provide a Colon-Targeted Extended Drug Release

“…In 2002, the first publication of the applications of electrospun non-woven fiber mats for providing a drug-extended-release profile was reported [ 16 ]. From then on, electrospun medicated nanofibers for pharmaceutical applications have always been increasing until now [ 17 , 18 , 19 , 20 , 21 ]. A simple search in the Web of Science with “electrospinning or nanofibers and drug delivery” as the main topic can find 43,557 items (8 August 2020).…”