In this study, twisted drug-loaded poly(L-lactide) (PLLA) and hybrid poly(L-lactide)/poly(vinyl alcohol) (PLLA/PVA) yarns were produced using an electrospinning technique based on two oppositely charged nozzles. Cefazolin, an antibiotic drug was incorporated in the yarn fibers by addition to the PLLA electrospinning solution. Morphological studies showed that independent of the twist rate, uniform and smooth fibers were formed. The diameter of the electrospun fibers in the yarns decreased at higher twist rates but produced yarns with larger diameters. At increasing twist rates the crystallinity of the fibers in the yarns increased. In the presence of cefazolin the fiber diameter, yarn diameter and crystallinity were always lower than in the non-drug loaded yarns. In addition the yarn mechanical properties revealed a slightly lower strength, modulus and elongation at break upon drug loading. The effect of the twist rate on the cefazolin in vitro release behavior from both PLLA and hybrid yarns revealed similar profiles for both types of drug-loaded yarns. However, the total amount of drug released from the hybrid PLLA/PVA yarns was significantly higher. The release kinetics over a period of 30 d were fitted to different mathematical models. Cefazolin release from electrospun PLLA yarns was governed by a diffusion mechanism and could best be fitted by Peppas and Higuchi models. The models that were found best to describe the drug release mechanism from the hybrid PLLA/PVA yarns were a first-order model and the Higuchi model.

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Silver nanoparticles were synthesized and stabilized by a simple, environment-friendly method in a liposomes structure. Liposomes were prepared by facing lecithin to the aqueous-phase solutions while stirring vigorously. The ratio of lecithin concentration to silver nitrate (K(Lec/Ag) = [Lecithin]/[AgNO(3)]) is the influencing factor in the synthesis of silver nanoparticles. The stability, size distribution, and antibacterial properties of synthesized silver nanoparticles were studied by ultraviolet (UV)-visible, dynamic light scattering, and antibacterial assay. The UV spectra indicated a single symmetric extinction peak at 400 nm, confirming the spherical shape of the synthesized silver nanoparticles. A high K(Lec/Ag) value leads to a reduction in the intensity of extinction spectra and increases the size of Ag-liposomes nanocomposites. The large Ag-liposomes nanocomposites are transformed to the smaller Ag-liposomes nanocomposites (from 342 to 190 nm) due to sonication treatment. The stabilized silver nanoparticles with various lecithin concentrations showed a good antibacterial activity against Staphylococcus aureus, a Gram-positive bacterium, and Escherichia coli, a Gram-negative bacterium.

Liposomes are lipid vesicles that are composed of amphiphile molecules and can carry hydrophobic and hydrophilic materials. In this research work liposomes used as carrier for transfer of dye molecules into wool fibers. The preparation and production of multilamellar liposomes (MLV) from Soya lecithin were carried out and the behavior of liposomes at different temperature was studied. The effect of different concentration of liposomes in the dye exhaustion profile of two dyes (Namely, Irgalan Blue FBL and Lanaset Blue 2R) at two different temperatures of 85 degrees C and 95 degrees C on the wool fabric was investigated. The results showed that presence of liposomes in the dye-bath helps to increase the dye absorption on the wool fabric before 80 degrees C. Dyeing at higher temperature and longer time leads to a decrease in the final exhaustion along with increase in the liposomes concentration. Liposomes at high temperature converted to the disperse phospholipids unimers that may deposited on the fabric surface and may produce a hydrophobic barrier against absorption of dye. The presence of 1% o.w.f. (on weight of fabric) of liposomes at 85 degrees C improved the dye exhaustion of Irgalan Blue FBL on the wool fabric. The wash fastness properties of samples which dyed in the dye-bath containing liposomes also improved.