Morphology and Surface Properties of Poly (L-lactic acid)/Captopril Composite Nanofiber Membranes

In this study, Poly (L-lactic acid)/Captopril composite nanofiber membranes were electrospun for drug delivery. Different mass fractions of Poly (L-lactic acid), different ratios of Captopril and the influences of PEG4000 added in the spinning solution are discussed. The morphology, chemical components, the surface areas and pore sizes, wettability of the composite nanofiber membranes were investigated. The results showed that the diameters of the composite nanofibers increased with the increase of Poly (L-lactic acid) mass fractions, the diameters decreased with the increase of Captopril content as well as the addition of the surfactant. Fourier Transform Infrared (FT-IR) showed the chemical components of Captopril remained unchanged when it was electrospun into the composite nanofibers. The surface areas pore width and pore volume of the composite nanofibers became a little larger than those of poly (L-lactic acid) nanofibers, and the wettability of the composite nanofiber membranes was better than those of poly (L-lactic acid) nanofiber membranes. Wettability was improved by an increase of the drug load amount. INTRODUCTION Captopril is used widely for the treatment of hypertension and congestive heart failure [1]. In clinic, the general Captopril tablets often need to be used three times a day for a long time, it is easy to lead to some side-effects such as making patients feel vertigo and headache [2]. So it is necessary to develop a new kind of dosage form for Captopril to overcome these side-effects. The electrospun nanofibers are a new kind of novel formulation with promising clinical applications in the future. The drug is dissolved in the polymer solution, then electrospun into the composite nanofibers, which can make the drug load in the carrier of polymer nanofibers. It not only can achieve a relatively high bioavailability of the loaded drug but also can minimize their severe side-effects, and more than one drug can be encapsulated directly into the electrospun fibers. Since Kenawy first studied drug delivery from poly(ethylene-co-vinyl-acetate), poly(lactic-acid) and a 1:1 blend of the two polymers electrospun from chloroform solution with tetracycline hydrochloride as the model drug[3], many researchers have paid attention to this field. Sascha studied the release characteristics of four model drugs from drug-loaded electrospun cellulose acetate fiber mats [4]. Xiabin Jing prepared the ultrafine PEG–PLA fibers loaded with both paclitaxel and doxorubicin hydrochloride and discussed their in vitro cytotoxicity [5]. However, their work focused on the release regularity of loaded drugs, little work has been done on the surface properties of the electrospun nanofiber membranes. In the present study, poly (L-lactic acid) (PLLA) was chosen and used as the drug carrier because of its good biocompatibility and biodegradability [6]. The nanofiber membranes of PLLA/Captopril were prepared by electrospinning. Scanning Electron Microscopy (SEM) was used to observe the fibers morphology and Fourier transform infrared spectrophotometer was used to confirm the composite chemical components. The surface area and pore analyzer, surface/interface tension meter were applied to investigate the surface structures and properties of the electrospun nanofiber membranes.