Preparation and properties of oriented microcellular Poly(l-lactic acid) foaming material

Area of Science:

• Biomaterials Science
• Polymer Engineering
• Tissue Engineering

Background:

• Poly(l-lactic acid) (PLLA) is crucial for bone repair materials due to its repair and regeneration properties.
• Enhancing PLLA's mechanical strength and biocompatibility is vital for successful clinical applications.
• Developing biomimetic structures that mimic native bone is key for advanced bone regeneration.

Purpose of the Study:

• To fabricate an oriented microcellular structure in PLLA using novel processing techniques.
• To investigate the mechanical properties and cellular response of the engineered PLLA.
• To explore the potential of this PLLA biomaterial for bone fixation and tissue engineering.

Main Methods:

• Solid hot drawing (SHD) technology was employed to create an oriented shish-kebab like structure.
• Low-temperature supercritical carbon dioxide (SC-CO2) foaming was utilized, with interface-oriented grain boundaries controlling nucleation.
• The mechanical properties (tensile strength, elastic modulus, elongation at break) and osteoblast cell (MC3T3) behavior were evaluated.

Main Results:

• An oriented microcellular structure, biomimetic of load-bearing bone, was successfully fabricated.
• The oriented microcellular PLLA exhibited enhanced mechanical properties: 98.4 MPa tensile strength, 3.3 GPa elastic modulus, and 16.4% elongation at break.
• The biomimetic structure significantly improved osteoblast cell attachment, proliferation, and propagation.

Conclusions:

• The developed oriented microcellular PLLA demonstrates promising mechanical strength and biocompatibility.
• The biomimetic structure effectively supports osteoblast cell functions, crucial for bone regeneration.
• This approach offers a novel pathway for designing advanced biomaterials for bone tissue engineering and fixation devices.