Novel 3D Printed PLA-SAPs Scaffold for Enhanced Bone Tissue Regeneration

Objectives: 3D printing provides precise control over scaffold shape and internal geometry for applications in bone regeneration and repair in oral surgery and beyond. The use of biomimetic scaffolds mimicking natural bone extracellular matrix (ECM) have also been used as scaffolds in tissue regeneration but these may lack precision. Our aim was to combine a 3D printed scaffold with a biomimetic self-assembling peptide (SAP), to potentially gain complementary benefits from both technologies.
Methods: Polylactic acid (PLA) scaffolds were prepared via 3D fused deposition modelling. Human dental pulp stromal cells (hDPSCs) were obtained from extracted teeth donated following informed consent to the Leeds Skeletal Tissues Research Tissue Bank and used at passage 4. hDPSCs were seeded on to the PLA scaffolds ± biomimetic SAP P₁₁-4 (Ace-QQRFEWEFEQQ-NH₂). After four hours, hDPSC attachment was evaluated using a fluorescent live marker and indirect cell counting. All constructs were then cultured for up to 5 weeks in osteogenic medium. At week 4, cellular growth and viability were assessed via SEM and live/dead fluorescent staining. After 5 weeks, all constructs were processed for histology and immunohistochemistry.
Results: There was significantly higher cellular attachment on PLA/SAP constructs compared to PLA alone (p<0.05). At 4 weeks, constructs in both groups showed good viability with few dead cells. However, SEM indicated denser cell sheets and more ECM formation in the PLA/SAP group compared to constructs with PLA alone. This was confirmed histologically at week 5, where marked tissue-like formation was detected in the PLA/SAP constructs, showing stronger immunoreactivity for bone markers (collagen I, osteocalcin and osteopontin) compared to controls without SAP.
Conclusions: Incorporating SAP P₁₁-4 into 3D printed PLA scaffolds enhanced hDPSC attachment and osteogenesis in vitro, illustrating the potential use of this composite scaffold for enhanced bone tissue engineering, combining the advantages of precision 3D printing with enhanced osteoinduction.