RESUMO
Acute recurrent tonsillitis is a chronic, biofilm-related infection that is a significant burden to patients and healthcare systems. It is often treated with repeated courses of antibiotics, which contributes to antimicrobial resistance. Studying biofilms is key to understanding this disease. In vitro modelling using 3D bioprinted hydrogels is a promising approach to achieve this. A novel gelatin-PEGDA pseudomonas fluorescens-laden bioink was developed and bioprinted in a 3D hydrogel construct fabricated using computer-aided design to mimic the tonsillar biofilm environment. The bioprinted constructs were cultured at 37 °C in lysogeny broth for 12 days. Bacterial growth was assessed by spectrophotometry. Cellular viability analysis was conducted using optical fluorescence microscopy (FDA/PI staining). A biocompatible 3D-printed bacteria-laden hydrogel construct was successfully fabricated. Bacterial growth was observed using optical fluorescence microscopy. A live/dead cellular-staining protocol demonstrated bacterial viability. Results obtained after the 12-day culture period showed higher bacterial growth in the 1% gelatin concentration construct compared to the 0% control. This study demonstrates the first use of a bacteria-laden gelatin-PEGDA hydrogel for biofabrication of a 3D-printed construct designed to model acute recurrent tonsillitis. Initiating a study with clinically relevant ex vivo tonsil bacteria will be an important next step in improving treatment of this impactful but understudied disease.
RESUMO
PURPOSE: Magnification with accurate optic reproduction of the surgical field is essential in otology surgery, but current technologies are subject to specific disadvantages. This study aims to evaluate a novel 3D digital stereo viewer, the Deep Reality Viewer (DRV), in otology surgery, in comparison to both a 2D monitor and the gold standard of microscopy. METHODS: In this prospective clinical research study, ENT consultants and trainees evaluated visual and practical applications of the DRV. In visual assessment, participants (n = 11) viewed pre-recorded in vivo mastoid exploration displayed on a 2D monitor and the DRV screen. In practical assessment, participants (n = 9) performed otology surgical tasks on a cadaveric human head using both the microscope and DRV. Face, task-specific (TSV) and global content (GCV) outcomes were assessed using 5-point Likert scale questionnaires. Construct validity was assessed separately. RESULTS: The DRV achieved the pre-determined validation threshold of 4 for all validation parameters in both visual and practical assessment. The DRV significantly outperformed the 2D monitor in fourteen of 16 parameters. In comparison to microscopy, there was no significant difference in 13 of 16 parameters, with the DRV significantly outperforming in the remaining 3: defining anatomy (GCV), assessing middle ear anatomy (TSV) and overall TSV. Construct validity was not demonstrated for either technology. CONCLUSION: The DRV achieved the validation threshold for all parameters, and outperformed the 2D monitor and microscopy in several parameters. This validates the DRV for performing otological procedures, and suggests that it would be a useful alternative to the gold standard of microscopy in otology surgery. LEVEL OF EVIDENCE: N/A.
