Bio-inks with PRF Increase Human Osteosarcoma Cell Line (SaOS-2) Viability in Extrusion-Based 3D-Bioprinted Constructs

Purpose: The growing demand for functional tissues and organs has driven advances in tissue engineering, particularly through 3D bioprinting. However, the mechanical stress associated with extrusion can compromise cell viability, limiting its clinical applicability. This study aimed to evaluate the viability of mature osteoblast-like cells (SaOS-2) in alginate-based bioinks supplemented with different platelet concentrates, platelet-rich plasma (PRP), platelet-poor plasma (PPP), platelet-rich fibrin (PRF), and injectable PRF (iPRF) to identify formulations that enhance cell survival post-printing. Methods: Bioinks composed of alginate and varying concentrations (10% and 20%) of platelet concentrates were prepared and characterized rheologically. SaOS-2 cells were embedded in the bioinks and printed using extrusion-based 3D bioprinting. Printed scaffolds were analyzed for cell viability using the LIVE/DEAD assay and confocal microscopy at 24, 48, and 72 hours post-printing. Results: Rheological analysis confirmed the printability of constructs containing 10% PPP, 10% PRF, and 20% PRF. Cell viability exceeded 58% at 24 hours and 80% at 48 hours across all tested bioinks. Notably, PRF-containing constructs demonstrated viability recovery up to 86% at 72 hours, suggesting a protective and regenerative role. Conclusion: PRF-enriched bioinks significantly improve cell viability after extrusion and enhance the physical integrity of bioprinted scaffolds. These results support the potential of PRF-based bioinks as promising candidates for clinically relevant bone tissue engineering applications.