Bioprinting in situ
3D printers are widely used in medicine for the manufacture of artificial joints, prostheses, bone fragments, skin flaps and blood vessels. Most of these tissues are created outside the body and then implanted into the body. Such a procedure may be accompanied by large surgical incisions, an increased risk of infection and an increase in the patient's recovery time. Additional complications may be associated with the presence of a time interval between the creation of tissue and its implantation to the patient. To prevent them, a group of scientists has developed a technology for printing tissues directly in the body.
Two main components are needed for the production of artificial fabric:
1) liquid biochernils consisting of a frame material and living cells;
2) growth factors that help cells grow and develop into regenerated tissue.
When creating tissues for direct implantation into the body, various factors should be taken into account: printing is performed at body temperature (37 ° C), the tissue must be firmly fixed on the soft surface of a living organ, manipulation must be safe for the patient. One of the most dangerous stages in modern methods of creating artificial tissue is the use of harmful ultraviolet light necessary for the solidification of the constructed tissue.
Renowned bioengineer Ali Khademhoseini, who heads the Terasaki Institute, and engineers David Hoelzle from the Faculty of Mechanical Engineering and Aerospace Engineering at Ohio State University and Amir Sheikhi from the Faculty of Chemical Engineering at the University of Pennsylvania have created bio-ink designed to be printed directly in the body of a living organism.
The composition of biochernil allows for three-dimensional printing at normal human temperature, the implant can be safely fixed with visible light. To create the fabric, the authors used robotic 3D printing, in which bio-ink is distributed through a nozzle, like a paste that is squeezed out of a pen rod, only with high precision and in a programmable way.
A photo of a fabric created by a three-dimensional printer, which is printed directly on the soft, warm surface of a living organ.
The group also worked on methods for attaching fragments of tissue created by biochernils to the soft surface of organs. In experiments, researchers placed artificial tissue on fragments of raw chicken breast and agarose using a unique fixation technique. The tip of the printer has been modified so that it can penetrate into the soft tissue and fill the puncture site with bio-ink as it is removed, creating a so-called anchor for the installation of artificial tissue. When the tip reaches the surface, it gives out an additional portion of bio-ink to "fix" the anchor. Such a locking mechanism ensures a stronger attachment of the frames to the soft tissues inside the patient's body.
The new bioprinting technique can be used with lower risk in minimally invasive laparoscopic surgeries to repair tissue or organ defects, install bioengineered implants to improve ovarian function, or create biofunctional meshes for hernia treatment. This procedure will be safer for the patient, save time and reduce the cost of treatment and rehabilitation.
Article by A.A.Adib et al. Direct-write 3D printing and characterization of a GelMA-based biomaterial for intracorporeal tissue engineering is published in the journal Biofabrication.
Aminat Adzhieva, portal "Eternal Youth" http://vechnayamolodost.ru based on the materials of the Terasaki Institute: Directly Printing 3D Tissues Within the Body.