3D Printing of Conductive Urinary Catheters and their Applications in Electro-Therapies to Overcome Antibiotic Resistance of Bacterial Biofilms

Abstract

Today, antibiotic-resistant bacteria represent a global health challenge, especially for the control of catheter-associated urinal tract infections (CAUTI). Conventional antibacterial treatment for CAUTI requires a high dose of antibiotics that could cause side effects in the patients. For this reason, it is necessary to develop effective antibacterial therapies that require less amount of antibiotics. Recent studies indicate that some electro-therapies are promising alternatives to avoid the growth of bacterial films in some metallic implants. However, to apply this concept to address CAUTI, it is necessary to develop biocompatible materials and urinary catheters with the required mechanical and electrical properties. Therefore, the present work aims to explore the viability of integrating 3D printed conductive polymer catheters in electrotherapy to fight against CAUTI. For this purpose, catheters (small tubes) were 3D printed using a commercial (Protopasta®) and different conductive filaments fabricated at PUPR. Filaments were fabricated via extrusion using a solvent-free method and activated carbon as the filler. After growing E.coli biofilms on the surface of the 3D printed structures, these were integrated into an electro-therapy system to study their performance. Mechanical and electrical properties of the fabricated materials were also evaluated via tensile test and impedance spectroscopy. Preliminary qualitative results indicate that the proposed electro-therapy has the potential to eliminate biofilms of E.coli bacteria growth onto the conductive polymer materials (3D printed catheter models). The materials characterization experiments suggest that all the fabricated materials exhibit lower elastic module and tensile strength than the commercial material. Regarding the electrical properties, some of the fabricated filaments exhibit a higher electrical conductivities than the commercial material. This results is promising, since one of the highest limitations of Protopasta® is its limited electrical conductivity.