Tissue array printing

1. A method of printing a bio-ink layer onto a tissue defect, comprising:

i) positioning a printhead comprising a plurality of rows comprising a plurality of print nozzles, such that at least one print nozzle of the plurality of print nozzles is within 5 cm of the tissue defect;

ii) ejecting a bio-ink through the at least one print nozzle onto the tissue defect without movement of the printhead relative to the tissue defect, thereby forming a bio-ink layer,

wherein the plurality of print nozzles is configured to be positioned at varying heights; and

iii) repeating step ii a plurality of times without moving the printhead relative to the tissue defect between repeated steps,

wherein the tissue defect comprises a vascular defect, an osteochondral defect, an epidermal defect, a muscular defect, an intestinal defect, a neuronal defect, a reproductive defect, a pancreatic defect, an ocular defect, or any combination thereof.

2. The method of claim 1 , wherein the bio-ink layer comprises a plurality of bio-ink layers.

3. The method of claim 1 , wherein the at least one print nozzle is independently actuated to print an individual droplet.

4. The method of claim 1 , wherein the plurality of print nozzles is fired simultaneously.

5. The method of claim 1 , wherein the plurality of print nozzles is fired in a specified sequence.

6. The method of claim 1 , wherein a spacing between a first print nozzle and a second print nozzle of the plurality of print nozzles is between 5 micrometers and 500 micrometers.

7. The method of claim 1 , wherein the printhead is mounted on a robotic arm for positioning the printhead relative to the tissue defect.

8. The method of claim 7 , further comprising controlling the robotic arm by a computer system.

9. The method of claim 1 , wherein the printhead comprises a piezoelectric ink-jet printhead.

10. The method of claim 1 , wherein the plurality of print nozzles is mounted in fixed positions relative to one another.

11. The method of claim 1 , wherein the printhead comprises an area that greater than an area of the tissue defect.

12. The method of claim 1 , wherein a diameter of the at least one print nozzle is between 5 micrometers and 150 micrometers.

13. The method of claim 12 , wherein the diameter of the at least one print nozzle is between 120 micrometers and 150 micrometers.

14. The method of claim 1 , further comprising blocking a portion of the plurality of print nozzles from ejecting the bio-ink by applying a mask.

15. The method of claim 1 , wherein ejecting the bio-ink from the at least one print nozzle comprises ejecting a volume of bio-ink that is between 1 picoliter and 1 nanoliter.

16. The method of claim 1 , wherein the plurality of print nozzles is in a parallel configuration.

17. The method of claim 1 , wherein the plurality of print nozzles is in a diverging configuration.

18. The method of claim 1 , wherein the plurality of print nozzles is in a non-parallel configuration that corresponds to the tissue defect's area.

19. The method of claim 1 , wherein the plurality of print nozzles is not in the same plane and a pattern of the plurality of print nozzles is customized to the tissue defect's pattern.

20. The method of claim 1 , wherein an individual print nozzle of the plurality of print nozzles is configured to be at an angle to another individual print nozzle.

21. A method of printing a bio-ink layer onto a tissue defect, comprising:

i) positioning a printhead comprising a plurality of rows comprising a plurality of print nozzles, such that at least one print nozzle of the plurality of print nozzles is within 5 cm of the tissue defect;

wherein said positioning of the printhead is maintained by a robotic arm;

ii) ejecting a bio-ink through the at least one print nozzle directly onto the tissue defect without movement of the printhead relative to the tissue defect, thereby forming a bio-ink layer,

wherein the plurality of print nozzles is configured to be positioned at varying heights; and

iii) repeating step ii a plurality of times without moving the printhead relative to the tissue_defect between repeated steps,

wherein the tissue defect comprises a vascular defect, an osteochondral defect, an epidermal defect, a muscular defect, an intestinal defect, a neuronal defect, a reproductive defect, a pancreatic defect, an ocular defect, or any combination thereof.

22. The method of claim 21 , wherein an individual print nozzle of the plurality of print nozzles is configured to be at an angle to another individual print nozzle.

23. A method of printing a bio-ink layer onto a tissue defect, comprising:

i) positioning a printhead comprising a plurality of rows comprising a plurality of print nozzles, such that at least one print nozzle of the plurality of print nozzles is within 5 cm of the tissue defect;

ii) ejecting a bio-ink through the at least one print nozzle directly onto the tissue defect without movement of the printhead relative to the tissue defect, thereby forming a bio-ink layer,

wherein the plurality of print nozzles is configured to be positioned at varying heights; and

iii) repeating step ii a plurality of times without moving the printhead relative to the tissue defect between repeated steps; and

wherein the plurality of print nozzles are not in the same plane and the a pattern of the plurality of print nozzles is customized to the tissue defect's pattern, and

wherein the tissue defect comprises a vascular defect, an osteochondral defect, an epidermal defect, a muscular defect, an intestinal defect, a neuronal defect, a reproductive defect, a pancreatic defect, an ocular defect, or any combination thereof.

24. The method of claim 23 , wherein an individual print nozzle of the plurality of print nozzles is configured to be at an angle to another individual print nozzle.