Development and In Vivo Evaluation of a Novel Bioabsorbable Polylactic Acid Middle Ear Ventilation Tube

TL;DR

A new dissolvable ear tube made from polylactic acid was developed and tested in animals, showing promise for treating ear infections without needing removal surgery.

Contribution

A novel bioabsorbable polylactic acid middle ear ventilation tube was developed and evaluated for biocompatibility and degradation in vivo.

Findings

PLA tubes showed biocompatibility in vitro and no significant inflammation in vivo.

ABR measurements indicated no adverse effects on hearing function.

Micro-CT and histology confirmed tube integrity and favorable tissue response over 9 months.

Abstract

Background: Otitis media with effusion (OME) is a widespread condition that causes hearing impairment, particularly in pediatric populations. Existing non-absorbable tubes often require elective or unplanned removal surgery. Bioabsorbable polylactic acid (PLA) offers a promising alternative due to its inherent biocompatibility and tunable degradation characteristics. In this study, we designed, fabricated, and comprehensively evaluated a novel PLA middle-ear ventilation tube. Methods: Bioabsorbable PLA tubes were designed and fabricated based on commercial models. In vitro biocompatibility was assessed according to ISO 10993 guidelines. A guinea pig model was used to perform in vivo evaluations, including otoscopic examinations, auditory brainstem response (ABR) measurements, micro-computed tomography (micro-CT) imaging, and histological analyses. Results: The PLA tubes were successfully designed and fabricated, exhibiting dimensions comparable to those of commercially available products. In vitro testing confirmed their biocompatibility. In vivo observations revealed that the PLA segments remained stable, with no significant inflammation detected. ABR measurements revealed no adverse impacts on hearing function. Micro-CT imaging confirmed tube integrity and indicated initial signs of degradation over a 9-month period, as evidenced by radiographic morphology. Histological analyses indicated a favorable tissue response with minimal foreign body reaction. Conclusions: The developed PLA middle-ear ventilation tube represents a highly promising alternative to conventional non-absorbable tubes. It demonstrates excellent biocompatibility, preserves auditory function, and exhibits a controlled degradation profile. This preclinical study provides strong support for further investigation and subsequent clinical trials to validate its safety and efficacy in human patients.

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