3D bioprinting with control
An international group of researchers led by Professor Michael Kuhl from the University of Copenhagen has published the results of work that can be called a breakthrough in the field of three-dimensional bioprinting. Together with German colleagues from the Technical University of Dresden, Professor Kuhl's group has developed a gel-like material that can be used to print complex structures like biofilms and tissues, which include living cells and chemical sensors that monitor cell metabolism.
Currently, three-dimensional printing is already widely used for the production of objects made of plastic, metal and other materials. Similarly, living cells immersed in biocompatible gel-like materials (biochernils) can be used for three-dimensional printing. Now such bioprinting is rapidly developing as a direction of biomedical research. An example is the cultivation of stem cells in three-dimensional scaffolds that reproduce the complex structure of bones and cartilage. Unfortunately, existing technologies do not allow us to monitor parameters such as metabolic activity and the sufficiency of oxygen supply to cells growing on sufficiently large skeletons without violating the integrity of the structure.
A structure obtained using three-dimensional bioprinting containing green algae (Chlamydomonas) in a hydrogel.
The authors propose a solution to the problem in the form of biochernils developed by them, which include luminescent nanoparticles sensitive to oxygen. Under the influence of blue light, nanoparticles are excited and begin to luminesce with red light, the intensity of which is inversely proportional to the local oxygen concentration – the more oxygen, the weaker the luminescence. A special camera allows you to visualize the distribution of the intensity of the glow and, accordingly, the oxygen concentration in living structures created with the help of bioprinting and monitor the dynamics of changes in these indicators without destroying the structure.
It is important to note that the addition of nanoparticles does not change the mechanical properties of biochernils, which avoids stress effects on cells and their death during printing. Moreover, the developers managed to ensure that the nanoparticles do not suppress the functionality of cells and generally do not affect their vital activity.
They have already demonstrated the possibility of using their approach to monitor photosynthesis and respiration of microalgae, as well as respiration of stem cells in bioprinted structures consisting of one or more cell types.
A diagram of the process of three-dimensional bioprinting using functionalized biochernils and examples of color changes at different oxygen concentrations.
The authors are interested in developing other areas of application of a new approach to bioprinting, for example, microbiology and biophotonics, where three-dimensional bioprinting is already used to study bacterial interactions and photobiological processes.
Article by Erik Trampe et al. Functionalized Bioink with Optical Sensor Nanoparticles for O2 Imaging in 3D-Bioprinted Constructs is published in the journal Advanced Functional Materials.
Evgenia Ryabtseva, portal "Eternal Youth" http://vechnayamolodost.ru based on the materials of Faculty of Science – University of Copenhagen: 3D bioprinting of living structures with built-in chemical sensors.