Composite core-double sheath fibers based on some biodegradable polyesters obtained by self-organization during electrospinning

Obtaining core-sheath fibers by single-spinneret electrospinning is a recent and straightforward approach to prepare composite fibers. Fibers of more complex architecture consisting of poly(ethylene oxide) (PEO) core, inner poly(l-lactide) sheath sd and outer beeswax (BW) sheath may also be obtained using this method. In the present study we report its applicability for a large series of (bio)degradable polyesters such as poly(epsilon-caprolactone), poly(d,l-lactide-co-glycolide), poly(butylene succinate), poly(3-hydroxybutyrate), and poly(l-lactide-co-d,l-lactide). The fibers have a well-differentiated PEO core, polyester inner sheath and BW outer sheath. The possibility for targeted location of hydrophilic or hydrophobic substances in the core or in the sheaths of the PEO/polyester/BW fibers has been demonstrated using nanosized zinc oxide with unmodified (hydrophilic) or silanized (hydrophobic) surface. PEO/polyester/BW fibrous materials loaded with a model drug (5-nitro-8-hydroxyquinoline) exhibit antimicrobial activity. The obtained results show that single-spinneret electrospinning is a novel and versatile method to prepare core-double sheath composite fibers prospective for various applications such as biomedicine, cosmetics, and food packaging. Composite electrospun fibers were prepared from biodegradable polyesters, poly(ethylene oxide) (PEO), and beeswax (BW). The fibers consisted of outer sheath of BW, inner sheath of polyester, and PEO core. The composition of the inner sheath and of the core was affected by the ratio polyester/PEO molar masses. Fibers containing an 8-hydroxyquinoline derivative as a model drug exhibited antimicrobial activity.image