In vitro degradation of porous PLLA/pearl powder composite scaffolds

• PLLA/pearl powder scaffolds release more Ca2 + than pearl powders in PBS.
• Increase of pH in PLLA/pearl powder scaffolds declines the hydrolysis rate of PLLA.
• PLLA/vaterite and PLLA/aragonite scaffolds show similar degradation behaviors.

The in vitro degradation behavior of poly-l-lactide (PLLA), PLLA/aragonite pearl powder and PLLA/vaterite pearl powder scaffolds was investigated. The scaffolds were soaked in phosphate buffer solution (PBS) up to 200 days. Scanning electron microscopy (SEM), gel permeation chromatography (GPC), and differential scanning calorimetry (DSC) were used to observe any degradation of the scaffolds. Degradation behaviors such as changes in pH, porosity, bulk density, water absorption, weight loss and mechanical properties were discussed. The results show that a gradual increase of the pH in composite scaffolds can decrease the rate of hydrolysis of PLLA. PLLA/vaterite and PLLA/aragonite scaffolds have a similar degradation behavior but a slower rate of degradation than PLLA.