Interfacial Compatibilization into PLA/Mg Composites for Improved In Vitro Bioactivity and Stem Cell Adhesion

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Tissue Engineering

Background:

• Polylactic acid (PLA)/Magnesium (Mg) composites show promise for bone regeneration but suffer from poor interfacial adhesion.
• Enhancing the interface is crucial for improving the composite's bioactivity and biological performance.

Purpose of the Study:

• To design and synthesize an amphiphilic diblock copolymer for interfacial compatibilization of PLA/Mg composites.
• To investigate the effects of the copolymer on the morphological, thermal, mechanical, and biological properties of PLA/Mg composites.
• To evaluate the potential of the modified composites for bone regeneration applications.

Main Methods:

• Synthesis of an amphiphilic poly(ethylene oxide-b-L,L-lactide) diblock copolymer.
• Incorporation of the copolymer into PLA/Mg composites.
• Characterization of composite properties: morphology, wettability, thermal, thermo-mechanical, and mechanical analysis.
• In vitro degradation studies in simulated body fluid (SBF).
• Biological evaluation using stem cells.

Main Results:

• The copolymer successfully improved interfacial adhesion between PLA and Mg, creating a new interphase.
• Composite hydrophilicity, protein adsorption, and bioactivity were modulated by the copolymer.
• Hydroxyapatite formation was observed after 8 weeks of immersion in SBF, indicating enhanced bioactivity.
• Interface stabilization was confirmed by a decrease in the damping factor (tanδ).

Conclusions:

• The amphiphilic diblock copolymer effectively enhances interfacial compatibilization in PLA/Mg composites.
• The modified composites exhibit improved bioactivity and potential for bone regeneration.
• The copolymer acts as a bridge, promoting interactions between the metallic filler and biopolymer matrix for osteoregeneration.