In a groundbreaking development, scientists have successfully tattooed living tissue with gold nanoparticles and nanowires. This innovative technique, based on nanoimprint lithography, holds immense potential for integrating human cells with electronic devices. The researchers at Johns Hopkins University, led by engineer David Gracias, believe that this step towards more complex circuitry could revolutionize healthcare by enabling remote monitoring and treatment of individual cells in real time.
Challenges in Integrating Electronics with Human Biology
For a long time, engineers have been attempting to integrate electronics with human biology. However, they have faced significant hurdles in doing so. One major challenge lies in the incompatibility of living tissue with the manufacturing techniques used in electronic construction. The existing methods, which involve harsh chemicals, high temperatures, or vacuums, often jeopardize living tissue and soft, water-based materials.
The researchers at Johns Hopkins University took inspiration from nanoimprint lithography, a fabrication technique that involves imprinting nanoscale patterns onto a material using a stamp. In this case, the material of choice was gold. However, imprinting the pattern onto the material was just the initial step of the process. The next challenge was to transfer and adhere the pattern to living tissue.
Tattooing Living Cells without Jeopardizing their Viability
To ensure the attachment of the gold pattern to living cells without causing any harm, the researchers utilized a multi-step process. Initially, they printed the nanoscale gold onto a silicon wafer coated in polymer. Subsequently, the polymer was dissolved, allowing the pattern to transfer onto thin films of glass. The glass was then treated with a biological compound called cysteamine and coated with a hydrogel. Afterward, the pattern was removed from the glass, treated with gelatin, and finally transferred to a fibroblast cell. By dissolving the hydrogel, the researchers successfully ensured the long-term bonding of the gold with the cell for up to 16 hours.
The team also experimented with attaching gold nanowire arrays to ex vivo rat brains. However, the most exciting outcome was the successful attachment of complex nanopatterns to living fibroblast cells without causing cell death. This achievement is crucial as it overcomes the incompatibility between living cells and conventional electronic fabrication methods. The simplicity and cost-effectiveness of nanoscale lithography offer a way forward to developing more intricate electronics, such as electrodes, antennas, and circuits. Moreover, this technique paves the way for integrating electronics not only with living tissues but also with hydrogels and other soft materials that are incompatible with harsher fabrication methods.
Expanding Horizons in Cell Culture and Electronics
The researchers envision that the nanopatterning process, combined with various materials and microfabrication techniques like photolithography and e-beam lithography, will open doors to new possibilities. These include the development of novel cell culture substrates, biohybrid materials, bionic devices, and biosensors. The integration of electronics with human cells represents a significant leap towards real-time monitoring, early disease diagnosis, and targeted treatment at the cellular level.
The groundbreaking technique of tattooing living tissue with gold nanoparticles and nanowires brings us one step closer to merging human cells with electronic devices. The potential for remote cell monitoring and real-time health management holds immense promise for the future of healthcare. With additional advancements in nanoscale lithography and the integration of diverse materials, the possibilities for complex circuitry, electrodes, and biosensors are endless. The bridge between human biology and electronics is being built, revolutionizing the way we understand and treat diseases.