Fused Deposition Modeling as an Effective Tool for Anti-Infective Dialysis Catheter Fabrication

Abstract

Catheter associated infections are a common complication that occurs in dialysis patients. Current strategies to prevent infection include catheter coatings containing heparin, pyrogallol or silver nanoparticles, which all have an increased risk of causing resistance in bacteria. Therefore, a novel approach for manufacture, such as the use of additive manufacturing (AM), also known as 3D-printing, is required. Filaments were produced by extrusion using thermoplastic polyurethane (TPU) and Tetracycline Hydrochloride (TC) in various concentrations (e.g. 0%, 0.25%, 0.5% and 1%). The extruded filaments were used in a fused deposition modelling (FDM) 3D-printer to print catheter constructs at varying concentrations. Release studies in phosphate buffered saline (PBS), microbiology studies, thermal analysis, contact angle, ATR-FTIR, scanning electron microscopy (SEM) and X-ray Micro Computer Tomography (μCT) analysis were conducted on the printed catheters. The results suggested that TC was uniformly distributed within the TPU matrix. The microbiology testing of the catheters showed that devices containing TC had an inhibitory effect on the growth of Staphylococcus aureus NCTC 10788 bacteria. Catheters containing 1% TC maintained inhibitory effect after 10day release studies. After an initial burst release in the first 24 h, there was a steady release of TC in all concentrations of catheters. 3D-printed antibiotic catheters were successfully printed with inhibitory effect on S. aureus bacteria. Finally, TC containing catheters showed resistance to S. aureus adherence to their surfaces when compared with catheters containing no TC. Catheters containing 1% of TC showed a bacterial adherence reduction of up to 99.97%. Accordingly, the incorporation of TC to TPU materials can be effectively used to prepare antiinfective catheters using FDM. This study highlights the potential for drug impregnated medical devices to be created through AM.

3D Printing of Drug-Loaded Thermoplastic Polyurethane Meshes: A Potential Material for Soft Tissue Reinforcement in Vaginal Surgery

“…TPU pellets (30 g) were placed in 50 mL Falcon tubes and castor oil (30 µL) was added and vortexed for a few min in order for the pellets to be covered homogeneously by the oil. The pellets were transferred to a new 50 mL Falcon tubes to avoid drug wastage that could remain attached due to excess oil on the wall of the previous tubes, as previously reported [14]. Then, LFX was added in ratio of 0.25% w/w and the tube was vortexed in order to coat the pellets.…”

“…A potential technology to produce the aforementioned meshes is 3D printing. This technology allows clinicians to prepare devices adapted to patient's anatomy and requirements [14][15][16][17]. Furthermore, a wide range of materials can be used for 3D printing applications.…”

“…However, as described before, due to its biodegradable nature, it is not the ideal candidate for vaginal mesh preparation. Interestingly, poly(urethane), a promising material for pelvic floor surgery, has been used before for 3D printing applications [14].…”

“…The flexibility of 3D printing also allows to combine polymeric materials with drugs to prepare drug eluting devices [14,19,22]. This is extremely useful for implantable devices that have a relatively high risk of infection [14,19,23]. If the device is loaded with antibiotics this will prevent bacterial colonisation of its surface preventing infections [14,19].…”

“…This is extremely useful for implantable devices that have a relatively high risk of infection [14,19,23]. If the device is loaded with antibiotics this will prevent bacterial colonisation of its surface preventing infections [14,19]. There are a wide variety of techniques within 3D printing technology [16].…”