Three-dimensional printing of cell-laden microporous constructs using blended bioinks

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Bioprinting Technology

Background:

• Hydrogels like alginate and gelatin are promising for 3D bioprinting.
• Limited characterization exists for hydrogel-based construct performance, influenced by viscosity, porosity, and printability.
• Uncrosslinked gelatin offers potential for microporosity and cellular response modulation.

Purpose of the Study:

• To investigate the impact of varying alginate and gelatin concentrations on 3D bioprinted construct properties.
• To evaluate the printability, structural integrity, and cellular viability of bioinks with uncrosslinked gelatin.
• To determine optimal bioink formulations for enhanced 3D bioprinting outcomes.

Main Methods:

• Utilized a syringe-based extrusion bioprinter to create 3D constructs.
• Formulated bioinks with different concentrations of alginate, gelatin, fibrinogen, and endothelial cells.
• Performed mechanical, biochemical, and cell viability characterization on printed constructs.

Main Results:

• Higher total alginate and gelatin concentrations improved construct stability and structural integrity post-culture.
• Increased gelatin ratios (e.g., 1:9 alginate:gelatin) significantly enhanced bioink printability.
• Higher gelatin content positively impacted surface morphology and improved biocompatibility.
• A 10% (w/v) bioink concentration with minimal alginate and higher gelatin showed optimal printability, cell survival, and viability.

Conclusions:

• Uncrosslinked gelatin provides tunable printing parameters and surface morphologies in 3D bioprinting.
• Careful control over bioink composition, particularly gelatin content, is crucial for successful bioprinting.
• Optimized bioinks with higher gelatin concentrations enhance printability, cell viability, and biocompatibility for tissue engineering.