In Situ Printing of Polylactic Acid/Nanoceramic Filaments for the Repair of Bone Defects Using a Portable 3D Device

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• 3D Printing Technology

Background:

• In situ 3D printing offers a direct approach for bone defect repair, particularly in resource-limited settings.
• Current limitations include the lack of suitable filaments made from FDA-approved biopolymers and nanoceramics for portable printing strategies.

Purpose of the Study:

• To investigate the osseointegration of novel nanocomposite filaments for in situ 3D printing of bone defects.
• To evaluate the biocompatibility and efficacy of polylactic acid (PLA), laponite (Lap), and hydroxyapatite (Hap) based filaments using a portable 3D printer.

Main Methods:

• Filaments were produced using a single-screw extruder without solvents.
• In vitro assessments included mesenchymal stem cell (MSC) differentiation, mineralization, cell viability, and total protein.
• In vivo studies involved printing PLA/Lap composite filaments directly into bone defects in Wistar rats.

Main Results:

• In vitro tests indicated good biocompatibility and support for cell differentiation.
• In vivo results demonstrated successful osseointegration with minimal fibrous encapsulation and inflammation.
• The in situ 3D printing technique with rapid cooling proved effective for bone tissue engineering.

Conclusions:

• The developed PLA/Lap/Hap nanocomposite filaments are suitable for in situ 3D printing bone defects.
• The portable 3D printing approach combined with the novel filament material shows significant potential for bone regeneration.
• The absence of adverse inflammatory responses highlights the material's biocompatibility for bone tissue engineering applications.