A 3D printed biomimetic composite scaffold based on graphene/gelatin/sodium alginate bioink: Cell proliferation effects and toxicity assessments

Peripheral nerve injuries are a major global health issue, with current treatments showing significant limitations. Neural tissue engineering provides a promising solution by creating supportive environments for nerve regeneration. This study used advanced 3D bioprinting to produce biomimetic scaffolds from graphene-enhanced bio-inks, integrating cells, scaffold materials, and growth signals. Compared to traditional methods, 3D printing ensures precise material distribution, improving cell density. The bio-ink, made of graphene (Gr), gelatin (Gel), and sodium alginate (SA), was tested at concentrations of 0.02%, 0.08%, and 0.2% to find the best formula for neural repair. Among four scaffold groups (Gel/SA, 0.02% Gr/Gel/SA, 0.08% Gr/Gel/SA, 0.2% Gr/Gel/SA), the 0.08% Gr scaffold showed the best mechanical strength, structural integrity, and biocompatibility. Graphene improved the scaffolds' compressive strength and degradation balance but reduced water absorption, porosity and increased the contact angle at higher concentrations. PC12 cells on the scaffolds showed excellent proliferation and minimal toxicity at lower graphene levels. The 0.08% Gr scaffold was most effective in nerve regeneration, highlighting the potential of graphene-enhanced 3D-printed scaffolds for neural tissue engineering. This research underscores the importance of 3D bioprinting in advancing nerve repair treatments.