Bioactive, PDMS-containing shape memory composite scaffolds with accelerated degradation rates.

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Polymer Chemistry

Background:

• Craniomaxillofacial (CMF) bone defects require effective regenerative engineering solutions.
• Previous work established poly(ε-caprolactone) (PCL)-based shape memory polymer (SMP) scaffolds for conformal fitting.
• Incorporating polydimethylsiloxane-dimethacrylate (PDMS-DMA) and 45S5 Bioglass® (BG) can enhance mineralization and degradation.

Purpose of the Study:

• To prepare and characterize polydimethylsiloxane (PDMS)-containing composite SMP scaffolds with varying compositions and Bioglass® (BG) concentrations.
• To evaluate the effects of PDMS and BG on scaffold properties, including shape memory behavior, brittleness, degradation, and bioactivity.

Main Methods:

• Fabrication of PCL/PDMS co-matrix scaffolds and PCL/PLLA/PDMS co-matrix semi-interpenetrating networks (semi-IPNs).
• Inclusion of BG (5 and 10 wt%) concentrated on pore walls using a modified solvent-cast particulate leaching (SCPL) method.
• Assessment of shape memory properties, in vitro degradation, and hydroxyapatite (HAp) mineralization in simulated body fluid (SBF).

Main Results:

• PDMS-containing scaffolds maintained shape memory characteristics and exhibited reduced brittleness.
• In vitro degradation rates were accelerated in PDMS-containing composites due to polymer phase separation and BG hydrophilicity.
• Significant bioactivity was observed, with HAp mineralization initiating within 1 day in simulated body fluid (SBF).

Conclusions:

• Composite SMP scaffolds incorporating PDMS and BG demonstrate promising properties for CMF bone defect regeneration.
• The developed scaffolds offer tunable degradation, enhanced bioactivity, and preserved shape memory functionality.
• These findings support the potential of these advanced biomaterials for self-fitting, regenerative CMF defect treatment.