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

© 2020 Wiley-VCH GmbH Conducting polymers have been increasingly used as biologically interfacing electrodes for biomedical applications due to their excellent and fast electrochemical response, reversible doping–dedoping characteristics, high stability, easy processability, and biocompatibility. These advantageous properties can be used for the rapid detection and eradication of infections associated to bacterial growth since these are a tremendous burden for individual patients as well as the global healthcare system. Herein, a smart nanotheranostic electroresponsive platform, which consists of chloramphenicol (CAM)-loaded in poly(3,4-ethylendioxythiophene) nanoparticles (PEDOT/CAM NPs) for concurrent release of the antibiotic and real-time monitoring of bacterial growth is presented. PEDOT/CAM NPs, with an antibiotic loading content of 11.9 ± 1.3% w/w, are proved to inhibit the growth of Escherichia coli and Streptococcus sanguinis due to the antibiotic release by cyclic voltammetry. Furthermore, in situ monitoring of bacterial activity is achieved through the electrochemical detection of β-nicotinamide adenine dinucleotide, a redox active specie produced by the microbial metabolism that diffuse to the extracellular medium. According to these results, the proposed nanotheranostic platform has great potential for real-time monitoring of the response of bacteria to the released antibiotic, contributing to the evolution of the personalized medicine.

JTD Keywords: bacterial detection, chloramphenicol, conducting polymers, drug, drug release, electrochemical sensors, electrochemistry, electrostimulated release, mechanism, peptide, polythiophene, sensor, sulfonate, Bacterial detection, Chloramphenicol, Conducting polymers, Controlled-release, Drug release, Electrochemical sensors, Electrostimulated release, Polythiophene