Description
- Abstract:
- Objective: Polylactic acid (PLA) has emerged as an attractive material for alloplastic craniofacial grafts owing to its established use in FDA-approved orthopedic medical devices, its biocompatibility and bioresorbable property, and its processability via fused deposition modeling (FDM), which enables fabrication of patient-specific scaffolds directly from clinical imaging data. However, the degradation and erosion behavior of FDM-printed PLA scaffolds remains poorly characterized, limiting the ability to predict scaffold performance over its functional lifetime. Existing degradation studies also employ degradation conditions that result in year-long experimental timeframes. This study therefore aims to characterize the degradation and erosion behavior of FDM-printed PLA scaffolds using alkaline-accelerated degradation protocols, and to investigate the effect of porosity on the rate and extent of degradation. Methods: FDM-printed PLA scaffolds at 60%, 65%, and 70% porosity were subjected to degradation at 37 °C under three pH conditions: 7.4, 9.6, and 12. Degradation and erosion behavior of these scaffolds were assessed through mass loss analysis and water uptake measurements, as well as characterization via optical microscopy and scanning electron microscopy (SEM). A geometrical surface erosion model derived from cylindrical strut geometry and an independent model fitted to mass loss data were compared for their ability to predict strut diameter reductions. Results: Only scaffolds at pH 12 demonstrated progressive mass loss over the experimental timeframe. Both optical microscopy and SEM characterization were consistent with a surface erosion mechanism; however, underestimation of strut diameter reductions from the geometric model suggested a more complex erosion mechanism. SEM micrographs further revealed two distinct surface morphologies in degraded scaffolds: distributed pitting and fibrous structures. Conclusions: This study provides insights into the erosion behavior of FDM-printed PLA scaffolds at pH 12 through characterization of mass loss and surface morphology changes. Paired molecular weight and crystallinity analyses are recommended to elucidate underlying degradation mechanisms, and extended degradation experiments across all pH conditions are recommended to characterize the full erosion profile.
- Notes:
- Thesis (Sc. M.)--Brown University, 2026
Citation
Fang, Matthew,
"Characterization of Alkaline-Accelerated Degradation of 3D-Printed Polylactic Acid Scaffolds"
(2026).
Biomedical Engineering Theses and Dissertations.
Brown Digital Repository. Brown University Library.
https://repository.library.brown.edu/studio/item/bdr:h44jydvp/
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Biomedical Engineering Theses and Dissertations
Theses and Dissertations for the Biomedical Engineering department....