Design and optimization of 3D-bioprinted scaffold framework based on a new natural polymeric bioink

y Objectives This aimed at the design and production of engineered 3D scaffold prototypes using a natural polymeric bioink made of chitosan and poly-gamma-glutamic acid with a specific focus on 3D-bioprinting process and on 3D framework geometry. Methods Prototypes were produced using a 3D bioprinter exploiting layer-by-layer deposition technology. The 3D scaffold prototypes were fully characterized concerning pore size and size distribution, stability in different experimental conditions, swelling capability, and human dermal fibroblasts viability. Key findings Hexagonal framework combined with biopaper allowed stabilizing the 3-layers structure during process manufacturing and during incubation in cell culture conditions. The stability of 3-layers structure was well preserved for 48 h. Crosslinking percentages of 2-layers and 3-layers prototype were 88.2 and 68.39, respectively. The swelling study showed a controlled swelling capability for 2-layers and 3-layers prototype, similar to 5%. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay results showed good biocompatibility of 3-layers prototype and their suitability for preserving 48 h cell viability in 3D cultures. Moreover, a significant increment of absorbance value was measured after 48 h, demonstrating cell growth. Conclusions Bioink obtained combining chitosan and poly-gamma-glutamic acid represents a good option for 3D bioprinting. A stable 3D structure was realized by layer-by-layer deposition technology; compared with other papers, the present study succeeded in using medical healthcare-grade polymers, no-toxic crosslinker, and solvents according to ICH Topic Q3C (R4).

Automated summary

The study aimed to design and produce 3D scaffold prototypes using a natural polymeric bioink made of chitosan and poly-gamma-glutamic acid. The prototypes were characterized for pore size, stability, swelling capability, and cell viability. The results showed a stable 3D structure with good biocompatibility and cell growth potential.