Related Experiment Video
Updated: Jun 20, 2025
14:49
Direct and Indirect Culture Methods for Studying Biodegradable Implant Materials In Vitro
Published on: April 15, 2022
5.1K
Accelerated degradation testing impacts the degradation processes in 3D printed amorphous PLLA
Luke P Malone1, Serena M Best1, Ruth E Cameron1
1Department of Materials Science and Metallurgy, Cambridge Centre for Medical Materials, University of Cambridge, Cambridge, United Kingdom.
Frontiers in Bioengineering and Biotechnology
|July 22, 2024
Summary
Accelerated degradation testing of amorphous poly-l-lactic acid (PLLA) fibers requires careful temperature control. Testing at elevated temperatures alters PLLA fiber degradation pathways, affecting crystallinity and microstructure.
Area of Science:
- Biomaterials Science
- Polymer Chemistry
- Additive Manufacturing
Background:
- Additive manufacturing and electrospinning are key techniques for producing degradable biomedical components.
- Poly-l-lactic acid (PLLA) is a widely used biodegradable polymer in biomedical applications.
- Understanding the degradation behavior of PLLA is crucial for its effective use in implants and drug delivery systems.
Purpose of the Study:
- To investigate the impact of accelerated testing temperatures on the degradation of amorphous 3D printed PLLA fibers.
- To identify the stages and mechanisms of PLLA fiber degradation under varying thermal conditions.
- To determine the optimal temperature for predictive degradation testing of amorphous PLLA fibers.
Main Methods:
- Amorphous PLLA fibers (approx. 100 µm diameter) were subjected to degradation in a fluid environment at 37°C, 50°C, and 70°C for 6 months.
- Degradation was monitored by measuring changes in fluid pH, PLLA fiber mass, molecular weight, and polydispersity index.
- A short-term hydration study was conducted to assess the effect of temperature on the glass transition temperature (Tg) and subsequent crystallization.
Main Results:
- PLLA fibers underwent bulk homogeneous degradation across all tested temperatures.
- A three-stage degradation process was identified.
- At 37°C, fibers remained amorphous, while higher temperatures induced crystallization, even below the dry Tg, due to reduced glass transition temperature after hydration.
- Elevated temperatures altered the degradation pathway, affecting sample crystallinity and microstructure.
Conclusions:
- Accelerated degradation testing temperature significantly influences the degradation pathway of amorphous PLLA fibers.
- Testing at elevated temperatures can lead to crystallization, altering the material's properties and potentially misrepresenting in vivo degradation behavior.
- For accurate predictive testing of amorphous PLLA fiber degradation, testing should be conducted at 37°C.
