John Layman

Release of tetracycline hydrochloride from electrospun poly(ethylene-co-vinylacetate), poly(lactic acid), and a blend.

Electrospun fiber mats are explored as drug delivery vehicles using tetracycline hydrochloride as a model drug. The mats were made either from poly(lactic acid) (PLA), poly(ethylene-co-vinyl acetate) (PEVA), or from a 50:50 blend of the two. The fibers were electrospun from chloroform solutions containing a small amount of methanol to solubilize the drug. The release of the tetracycline hydrochloride from these new drug delivery systems was followed by UV-VIS spectroscopy. Release profiles from the electrospun mats were compared to a commercially available drug delivery system, Actisite (Alza Corporation, Palo Alto, CA), as well as to cast films of the various formulations.

Electrospinning of poly (ethylene-co-vinyl alcohol) fibers

Solutions of poly(ethylene-co-vinyl alcohol) or EVOH, ranging in composition from 56 to 71 wt% vinyl alcohol, can be readily electrospun at room temperature from solutions in 70% 2-propanol/water (rubbing alcohol). The solutions are prepared at 80 degrees C and allowed to cool to room temperature. Interestingly, the solutions are not stable at room temperature and eventually the polymer precipitates after several hours. However, prior to precipitation, electrospinning is extensive and rapid, allowing coverage of fibers on various substrates, including a grounded metal plate, dielectrics interposed between the charged jet and the metal ground, and on the human body. Fiber diameters of ca. 0.2-8.0 microm were obtained depending upon the solution concentration, an attractive range for tissue engineering, wound healing, and related applications. Electrospun EVOH mats have been shown to support the culturing of smooth muscle cells and fibroblasts.