Encapsulating drugs in biodegradable ultrafine fibers through co‐axial electrospinning

Abstract

This article describes an electrospinning process to fabricate double-layered ultrafine fibers. A bioabsorbable polymer, Polycaprolactone (PCL), was used as the outer layer or the shell and two medically pure drugs, Resveratrol (RT, a kind of antioxidant) and Gentamycin Sulfate (GS, an antibiotic), were used as the inner layers or the cores. Morphology and microstructure of the ultrafine fibers were characterized by scanning electron microscope (SEM) and transmission electron microscopy (TEM), whereas mechanical performance of them was understood through tensile test. In vitro degradation rates of the nanofibrous membranes were determined by measuring their weight loss when immersed in pH 7.4 phosphate-buffered saline (PBS) mixed with certain amount of Pseudomonas lipase for a maximum of 7 days. The drug release behaviors of the RT and GS were measured using a high performance liquid chromatography (HPLC) and ultraviolet-visible (UV-vis) spectroscopy, respectively. It has been found that the drug solutions without any fiber-forming additive could be encapsulated in the PCL ultrafine fibers, although they alone cannot be made into a fiber form. Beads on the fiber surface influenced the tensile behavior of the ultrafine fibers remarkably. When the core solvent was miscible with the shell solvent, higher drug concentration decreased the bead formation and thus favored the mechanical performance. The situation, however, became different if the two solvents were immiscible with each other. The degradation rate was closely related to hydrophilicity of the drugs in the cores. Higher hydrophilicity apparently led to faster degradation. The release profiles of the RT and GS exhibited a sustained release characteristic, with no burst release phenomenon.

Electrospun nanofibrous materials for tissue engineering and drug delivery

“…Electrospinning can yield continuous fibers with diameters ranging from nano-to micro-scale in a randomly oriented and non-woven form [18]. Mechanical strength of electrospun fibers is often significantly lower than that of textile fibers made from the same polymer, and this may limit their applications in many fields.…”

Solid dispersions in the form of electrospun core-sheath nanofibers

“…The sheath solution is critical, and the sheath polymer-solvent system selected should be electrospinnable by itself to facilitate formation of a core-sheath structure in the nanofibers. [40][41][42] Thus, although the core solution consisting of 10% (w/v) PVP and 2% (w/v) acyclovir in a mixed solvent of DMAc:ethanol (4:6, v:v) was nonelectrospinnable, the electrospinnable sheath fluid consisting of 10% (w/v) PVP, 0.5% (w/v) SDS, and 0.2% (w/v) sucralose in a mixed solvent of water:ethanol (2:8, v:v) was able to ensure a smooth coaxial electrospinning process and formation of core-sheath nanofibers.…”

Porous Polymeric Bioresorbable Scaffolds for Tissue Engineering

“…This opportunity has been extensively exploited to load fibres with biomolecules that were intended to be released upon contact with the biological environment. Among the several drugs employed, antibiotics [87][88][89], anti-inflammatory drugs [90][91][92] and anticancer drugs [93] have been mainly investigated.…”