Cytocompatibility Assessment of L-PBF-Manufactured Zinc-Silver-Copper Alloys for Customized Biodegradable Medical...

Area of Science:

• Biomaterials Science
• Additive Manufacturing
• Biocompatibility Testing

Background:

• Biodegradable zinc (Zn) alloys are promising for temporary implants due to moderate degradation.
• Laser powder bed fusion (L-PBF) enables patient-specific, customized Zn alloy implants.
• Concerns exist regarding the biocompatibility and cytotoxic effects of Zn alloys.

Purpose of the Study:

• To investigate the biocompatibility of additively manufactured ZnAgCu, ZnAgCuMn, and ZnAgCuTi alloys.
• To evaluate the effect of as-printed and post-processed conditions on alloy performance.
• To assess cytocompatibility using L929 and SAOS-2 cell lines.

Main Methods:

• Utilized laser powder bed fusion (L-PBF) to manufacture Zn alloys.
• Assessed biocompatibility through L929 and SAOS-2 cell culture assays.
• Analyzed Zn2+ ion release and cell proliferation over time.
• Compared as-printed, post-processed, and aged (3-month) surfaces.

Main Results:

• Increased porosity in L-PBF samples negatively impacted biocompatibility.
• Initial cytotoxicity observed, with significant improvement from day 3 onwards due to passivation.
• Zn2+ ion release peaked at 24h and decreased by day 10.
• ZnAgCuMn showed the lowest cytocompatibility; aged surfaces had reduced osteoblast compatibility.

Conclusions:

• Additively manufactured Zn alloys exhibit time-dependent cytocompatibility, improving post-passivation.
• Porosity and initial ion release impact biocompatibility, necessitating surface modification strategies.
• Further research is required to optimize Zn alloy degradation kinetics for clinical applications.