Surface microtopography construction and osteogenic properties evaluation of bulk polylactic acid implants

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Surface Engineering

Background:

• Polylactic acid (PLA) is a widely used biodegradable polymer for medical implants.
• Controlling surface topography is crucial for enhancing implant biocompatibility and osseointegration.
• Developing methods to create tunable surface microstructures on PLA implants is of significant interest.

Purpose of the Study:

• To construct bulk polylactic acid (PLA) implants with controllable surface microtopography.
• To investigate the effect of PLA microsphere size on the resulting surface structures.
• To evaluate the impact of surface microtopography on the mechanical properties, hydrophobicity, and cellular response of PLA implants.

Main Methods:

• Utilized polylactic acid (PLA) microspheres as raw material.
• Employed hot pressing and heat treatment to fabricate bulk implants with surface microtopography.
• Analyzed surface morphology using microscopy and measured mechanical properties via nanoindentation.
• Assessed cellular responses, including morphology and osteogenic activity, on different implant surfaces.

Main Results:

• Successfully constructed PLA implants with wave-like surface microtopographies (micron-sized bulges).
• Surface topography dimensions (ridge width, valley depth) were regulated by PLA microsphere size.
• Increased modulus and hardness of PLA implants were observed with decreasing microsphere size.
• Microtopography slightly increased surface hydrophobicity but significantly enhanced cellular osteogenic activity.

Conclusions:

• PLA microspheres can be effectively used to create tunable surface microtopographies on bulk implants.
• The developed surface microstructures positively influence cellular behavior, notably promoting osteogenic activity.
• This approach offers a promising strategy for designing advanced PLA-based implants with enhanced bone regeneration capabilities.