Method and apparatus for printing biological tissues and organs
The invention relates to medicine and biology, particularly to the means for artificial manufacturing of biological tissues and organs, and can be used in biotechnology, bioengineering, tissue engineering, regenerative medicine, and in the 3D-printing of biological tissues and organs. Technical character of the invention consists in the development of a method of printing living tissues and organs as well as of the apparatus for its implementation. The proposed apparatus consists of at least: a printing platform, a bioink printing module with at least one nozzle designed for bioink dosing, a gel-forming composition printing module, containing a UV-module, and at least one nozzle capable of dosing gel-forming composition that starts polymerizing under the influence of UV radiation, a module for relatively displacing the nozzles and/or the platform, and in which the bioink printing module is separated from the gel-forming-composition printing module in such a way so as to prevent UV radiation from reaching the bioink printing module, the radiation from the UV module being directed predominantly parallel to the platform for printing, in such a way so as to prevent UV radiation from reaching the biological tissues and/or organs being printed. The technical result of the invention is the development of a multi-functional device capable of combining various printing modes, providing a method of high-resolution printing of living tissues and organs based on UV-induced hydrogel polymerization, and a method of cell protection from UV radiation during the printing process.
1. A layer by layer method of biological tissue and organ printing using bioink or a gel-forming composition polymerizing when exposed to UV light, and including the following stages for each individual layer formation:
a. acquiring data on the object's layer selected for printing;
b. depositing on the final surface a gel-forming composition polymerizing when exposed to UV light and which in the process of the deposition, after being released from the nozzle and before deposition of the biological tissue or organ being printed, is exposed to UV radiation;
wherein a bioink printing module is separated from a gel-forming-composition printing module so as to prevent UV radiation from reaching the bioink printing module, the radiation from the UV module being directed predominantly parallel to the platform for printing, so as to prevent UV radiation from reaching the biological tissues and/or organs being printed, and wherein the amount of gel-forming composition is calculated so as to form the required hydrogel layer upon completion of the polymerization;
c. applying bioink on the layer formed with the gel-forming composition in (b) in accordance with the data acquired in (a); and
d. waiting on hydrogel polymerization completion,
wherein spheroids are used as bioink, and
wherein the ratio between the spheroid diameter and the thickness of the polymerized hydrogel layer is selected so that the thickness of the latter is less than the spheroid diameter.
2. The method of claim 1 , wherein the spheroid diameter is between 100 μm and 2.108 mm, and the polymerized hydrogel layer thickness is between 80 μm and 0.6414 mm.
3. The method of claim 1 , wherein at least one layer is printed using live-cell hydrogel as bioink.
4. The method of claim 1 , wherein polymerization completion time is 5 s to 5 min.
5. The method of claim 1 , wherein the gel-forming composition comprises a controlled alginate gel-forming system containing liposomes with bound calcium ions, released from the liposome matrix upon exposure to UV light.
6. The method of any of claims 1 - 5 , wherein at least one layer is printed using bioink and at least two substances capable of polymerization when contacting each other.
7. The method of claim 6 , wherein fibrinogen and thrombin are used as the substances capable of polymerization upon contact with each other.
8. The method of claim 6 , wherein alginate and calcium ions are used as the substances polymerizing upon getting in contact with each other.