A novel method has been developed by scientists at the Jožef Stefan Institute in Slovenia that allows for the 3D printing of structures directly into live cells. This groundbreaking technique opens avenues for a new category of intracellular bioengineering applications.
For the first time, researchers successfully created numerous intracellular structures, ranging from barcodes and lasers to the amusingly large shape of an elephant. 3D printing has become a powerful tool in various fields such as electronics, robotics, and biomedicine. This specific research employed a method known as two-photon polymerization (TPP), which utilizes a photo-sensitive resin that is illuminated by a femtosecond laser, achieving resolutions down to 100 nanometers.
Previously, 3D printing had been used in living organisms, but it had not been implemented within live cells. The conventional techniques for delivering micro-scale objects into non-phagocytic cells were limited to methods such as microinjection and membrane poration, which are not effective for inserting larger objects directly into the cytosol.
To address this challenge, the researchers created a technique that enables the insertion of custom micrometer-sized structures seamlessly into living cells. Their breakthrough involved injecting a droplet of a negative-tone photoresist into a live HeLa cell and selectively polymerizing it with a femtosecond laser in a designed pattern. This process allowed for the creation of complex microstructures within the cell, including innovative barcodes and microlasers.
Additionally, the team studied how 3D printing affected the cells, observing normal cellular morphology and continued cell division while confirming that the printed structures were inherited by daughter cells. Imaging techniques revealed that the cells, including their nuclei, adapted to accommodate the 3D-printed objects.
Co-author Maruša Mur indicated that this method offers a new way to manipulate living cells internally, paving the path for future research into their mechanical and biological responses. While still in preliminary stages, the technique holds potential for various applications like intracellular sensing, biomechanical manipulation, bioelectronics, and targeted drug delivery.
For further details, the original research can be found in the publication: Two-Photon 3D Printing of Functional Microstructures Inside Living Cells.