Page 391 - IJB-9-2

International Journal of Bioprinting In situ 3D bioprinter for skin wound healing

A B

Figure 3. Structure of printhead in in situ bioprinting system: (А) External view and (B) sectional view.

software has been developed for the robotic bioprinter. also includes information about the volume of the material
The user interface with the ability to display a 3D being squeezed out. The trajectory is a set of short lines.
representation of trajectories was written in the Python Next, the program waits for the operator’s permission to
programming language using the Pyqt5 and OpenGL start printing. If the resolution is obtained, the robot starts
libraries. The trajectory generated by the program takes moving along each line with a minimum smoothing radius,
into account the curvature of the surface, which allows while maintaining a constant linear speed. This allows for
for bioprinting on surfaces of complex shape. The use of uniform application of the material. At the same time, to
distance sensors on the end effector allows users to take ensure non-stop operation, commands are executed on
into account the change in the position of the surface, the robot in asynchronous mode, that is, the internal robot
which occurs due to breathing. It is worth noting that controller responsible for interpolating robot movements
all the software is publicly available and gives interested is several commands ahead of the upper level robot
parties the opportunity to improve it and use it for their controller.
own purposes. The developed software is focused not only The following algorithm is used to synchronize the
on narrow specialists but also on operators with minimal movement of the robot and the extrusion of the material.
training, since the program structure is designed in such a During the execution of the trajectory, the robot sends
way to minimize the human factor. a command to build the next line only after it passes the
point of the line two commands back. To do this, the robot
2.5. The algorithm of the bioprinter system
checks its current coordinate and compares it with the
The controller of the printing device operates according to coordinate of the end of the current line.
the following algorithm. The program is in an infinite loop
and is waiting for a message from the control computer, 2.6. Reagents
which contains information about how fast and how Dulbecco’s Modified Eagle’s Medium (DMEM, cat.#
many steps the nozzle piston should move, and whether 12491-015), M200 medium (cat.# M200500), fetal bovine
the cooling system should be turned on now or not. In serum (FBS, cat.# 16000-044), antibiotic-antimycotic
turn, the robot controller first sends the coordinates of the (cat.# 15240-062), trypsin/EDTA (cat.# 25200-114), and
points that characterize the wound surface. Then, an array phosphate-buffered saline (PBS, cat.# 18912-014) were
of trajectory data comes from the control computer, which obtained from Gibco (USA). L-glutamine (cat.# F032),

Volume 9 Issue 2 (2023) 383 https://doi.org/10.18063/ijb.v9i2.675