Biological and Mechanical Evaluation of Integrated Nano-Hydroxyapatite in 3D-Printed Polylactic Acid Scaffold

Abstract

INTRODUCTION: Tissue engineering is a technique for simulating nature. It involves the development of artificial substitutes to restore the functions of damaged tissues. It includes the usage of porous matrix to allow its loading with cells to produce a regenerative construct. Most synthetic polymers including polylactic acid used in 3D printing are not designed to act as a scaffold to promote cellular adhesion and has limited bioactivity, so they need modification to increase bioactivity, promote cellular adhesion and then tissue regeneration. OBJECTIVE: Our purpose was to study the bioactivity, compressive strength, elastic modulus and toughness of 3D-printed PLA scaffold modified with 5% nano-hydroxyapatite (nano-HA) versus PLA scaffold. METHODS: The fused deposition modeling method was used to print PLA, and PLA with embedded 5% nano-HA particles in the matrix. The chemical composition and surface properties of scaffolds were characterized by Energy Dispersive X-ray Analysis and Scanning Electron Microscope, the mechanical properties of scaffolds were tested using universal testing machine testing. The scaffold bioactivity was determined by monitoring the deposition of calcium phosphate compounds after simulated body fluid immersion. RESULTS: The nano-HA loaded PLA scaffold showed decreasing compressive strength and toughness which recorded 16.02 MPa and 226.82 J respectively compared to blank PLA scaffold which recorded 27.87 MPa and 1026.7 J, but it showed increasing calcium phosphate crystals deposition. CONCLUSIONS: This study explored the efficacy of modifying PLA scaffold with inductive nano-HA incorporated in the matrix, which improved its bioactivity without interfering with the compressive strength of PLA material significantly.