3D-printing technique for fabrication of biodegradable PDLLA tympanostomy tube and examination of biofilm formation

Abstract

In this study, it is presented that the new fabrication method for biodegradable PDLLA tympanostomy tube by examining its degradation and swelling behavior, bacterial attachment, and biofilm formation with a comparison of Fluoroplastic one. The novelty of the study lies in the 3D printing fabrication technique. No research work studied the fabrication of samples in these dimensions (2 mm in length) and design. The samples are printed at 190 ◦C temperature under 7.9 bar pressure with 0.1 mm/min speed. The fabrication of one sample took 9 minutes with a 0.3 mm nozzle, and structural collapsing was able to be prevented. After the fabrication of 3D-printed PDLLA samples, they are examined for the degradation and swelling characteristics at 37 ◦C in PBS for 5 weeks. The degradation rate of 3D-printed PDLLA samples is 5%, and the swelling ratio is 40 % for 5 weeks. Scanning Electron Microscopy (SEM) was used for the surface examination, and results showed that PDLLA samples have fewer surface faults than control group of Fluoroplastic tubes in microscale level. For examining bacterial attachment on the layer-by-layer surface of the PDLLA sample, a biofilm assessment was done for 4 days. According to colony counting and CFU/mL results, 3D-printed samples had less biofilm formation despite the layered surface structure coming from the fabrication process. Overall, biodegradable tympanostomy tube fabrication by using the 3D-printing technique needs to be improved. However, according to experimental results, if the fabrication method can be improved to produce more precise structures in that dimension, it is possible to further this study to produce more perfectly tympanostomy tubes.|Keywords : 3D-printing, Poly-lactic acid, biodegradable implant, bacterial attachment, tympanostomy tube, otitis media.