Mechanical, Computational, and Biological Evaluation of 3D-Printed PLA-Bioactive Glass Scaffolds for Bone Tissue Regeneration

Additive manufacturing enables the production of patient-specific biodegradable scaffolds for tissue regeneration. Polylactic acid (PLA), an FDA-approved polymer widely used in tissue engineering, suffers from hydrophobicity that limits cell adhesion, slows degradation, and may trigger inflammatory responses. To address these limitations, PLA was combined with bioactive glass (BG) particles to obtain printable composite filaments. Four BG compositions (45S5, S53P4, 45S5_MS, and S53P4_MS) were evaluated to determine whether Mg- and Sr-doped formulations improve biological performance of composites. The composites were characterized from morphological, physical, and mechanical standpoints, while scaffold wettability was further enhanced through alkaline surface treatment prior to in vitro cytocompatibility assays. BG incorporation increased brittleness and reduced compressive strength, while tensile properties remained comparable to pure PLA. Alkaline treatment effectively improved hydrophilicity and promoted cell adhesion and proliferation. Fluorescence microscopy revealed that scaffolds containing doped BG compositions supported particularly dense and well-spread cell populations. These findings demonstrate the synergistic effect of BG incorporation and surface modification in enhancing the performance of FDM-printed PLA scaffolds, supporting their potential use in bone tissue engineering.