Publications

The sustained administration of lactate for several days promotes mammalian cardiac tissue regeneration. In this work, electrical stimulation is used for tuning the kinetic release profile of electro-responsive fiber mats loaded with lactate, which are prepared from electrospun solutions containing polylactic acid (PLA), polyaniline (PAni) at different amounts (0.1-0.5 % w/w), and lactate. The resulting PLA/PAni fibers, with average diameters ranging between 1.9 and 2.3 mu m, depending on the PAni content, are electroactive, biocompatible, and exhibit higher resistance to elastic deformation than PLA fibers. The release profiles obtained without and with electrical stimuli only show an uncontrolled burst lactate delivery, which is significantly boosted when a negative voltage is applied. Thus, electrical stimulation appears to promote the migration of lactate from the interior of the fibers to the surface, from where it is immediately released. In order to delay the lactate delivery and allow some control on the system, a polycaprolactone (PCL) coating was applied to the PLA/PAni fiber mats. Electrically stimulated PCL/PLA/PAni shows a controlled and sustained release of lactate, which is progressively delivered over time. While the burst release, which is similar without and with stimulation, is smaller for coated than for uncoated fibers, the application of a voltage to PCL/PLA/PAni provides an appreciable and sustained cumulative lactate release that increases linearly with time over nine days. This control, which is attributed to the effect of the voltage on the polyester altering its porosity, renders the electroactive lactate-loaded PLA/PAni fibers promising for cardiac tissue engineering applications.

JTD Keywords: Biocompatibility, Cardiac tissue, Conducting polymers, Drug release, Drug-delivery, Energy, Poly(lactic acid), Polyaniline, Polycaprolactone, Polylactic acid, Polythiophene, Release, Scaffolds, Thermal-properties