Method for manufacturing body substitutes by additive deposition

A method of fabricating a body tissue substitute, the method comprising:

• fabricating a bio-ink by:
• providing a first aqueous solution containing between 6% and 30% by mass of gelatin and between 0% and 5% by mass of NaCl,
• providing a second aqueous solution containing between 1% and 8% by mass of alginate and between 0% and 5% by mass of NaCl,
• providing a third aqueous solution containing between 3% and 15% by mass of fibrinogen and living cells in suspension, and
• forming a mixture is containing, about 35% to 65% by volume of the first solution, about 15% to 35% by volume of the second solution, and about 15% to 35% by volume of the third solution, such that the proportions add up to 100%,
• wherein:
• the content of NaCl is chosen such that in a combination of said first solution and said second solution, it is between 0.4% and 2% by mass, and
• said living cells are primary cells isolated from all human or animal tissue or organs,
• providing a polymerization solution containing between 1% and 5% by mass of calcium ions and between 10 U/mL and 30 U/mL of thrombin;
• forming an untreated printed object by heating said bio-ink to a first temperature above a gel point of said bio-ink, and then depositing said heated bio-ink on a substrate at a second temperature below the gel point of said bio-ink;
• treating said untreated printed object with said polymerization solution to consolidate said untreated printed object into a body tissue precursor;
• incubating said body tissue precursor in a cell culture medium.

A bio-ink formed by:

• providing a first aqueous solution containing between 6% and 30% by mass of gelatin and between 0% and 5% by mass of NaCl;
• providing a second aqueous solution containing between 1% and 8% by mass of alginate and between 0% and 5% by mass of NaCl;
• providing a third aqueous solution containing between 3% and 15% by mass of fibrinogen and living cells in suspension;
• and
• forming a mixture is containing, about 35% to 65% by volume of the first solution, about 15% to 35% by volume of the second solution, and about 15% to 35% by volume of the third solution, such that the proportions add up to 100%,
• wherein:
• the content of NaCl is chosen such that in a combination of said first solution and said second solution, it is between 0.4% and 2% by mass, and
• said living cells are primary cells isolated from all human or animal tissue or organs.