Scientists Study Melanin for Organic Pigments
A team from the Daegu Gyeongbuk Institute of Science and Technology has reportedly developed a new technology that can create multi-functional organic pigments by copying natural melanin formation processes.
Named Progressive Assembly on an Initiator-loaded Template, or PAINT, the findings were recently published in the journal Nature Communications.
About PAINT Tech
Melanin is a natural pigment that can adhere to various surfaces due to its high underwater adhesive properties, attributed to numerous catechol functional groups. This is reportedly similar to the adhesive proteins in mussels.
However, during the process of creating new elements by integrating new organic materials with various material groups, researchers can face challenges when unintended areas become coated with organic matter due to the adhesive properties.
For one solution, researchers used photolithography to specify the coating location. However, DGIST says, this method has drawbacks like involvement of complex multi-step reactions and the need to use expensive equipment.
To solve these issues, professor of the Department of Physical and Chemistry Seon-ki Hong's research team investigated the formation processes of natural melanin and reportedly found that the catalytic activity of the protein template significantly affects the process of specifying the pattern formation location.
Scientists copy melanin formation processes to fabricate multi-functional organic pigments https://t.co/dMTGHuyljH— Chemistry News (@ChemistryNews) October 31, 2023
The team conducted an experiment on the synthesis reaction of organic pigments copying the natural melanin formation process. Organic pigments were reportedly produced by initiating the synthesis reaction on the surface that was initially modified to have localized catalytic activity.
According to DGIST, the scientists confirmed that organic pigments had not spread to neighboring regions based on excellent adhesive properties, and that they adhered selectively and voluntarily only to the initiated areas to form patterns.
Organic pigment patterns locally formed on the surface exhibited broad optical absorption characteristics in the ultraviolet, visible and near-infrared spectral regions, similar to natural melanin, the researchers found.
The absorbed near-infrared light was spontaneously converted into thermal energy by the material and generated localized heat. The research team then verified that these processes can be applied to induce selective cell death on the surface, or to drive actuators.
“The PAINT technology that we developed in this research is a novel technology that can selectively apply materials with universal adhesive properties to only desired areas,” said Hong.
“We anticipate that the PAINT technology will establish the foundation for the development of new melanin-like organic materials applying the characteristics of melanin, such as excellent optical absorption, activity of scavenging reactive oxygen species, and biocompatibility.”
Back in 2019, a project and installation at the Mediated Matter Group at Massachusetts Institute of Technology’s Media Lab designed using liquid channels of melanin—the skin pigment that is believed will serve a future purpose in architecture—within a series of 3D-printed sculptures.
Named “Totems” by Neri Oxman, the project was meant to represent the unity in the diversity of life and the choice to use melanin for the installation was its standing as a “universal pigment.” The natural substance is found in skin, hair and eyes, as well as feathers and wings.
The melanin substance in the installations was created in two ways: one being the reaction between an active chemical and a certain enzyme extracted from mushrooms, which can convert the amino acid tyrosine into melanin.
The other method involved the extraction of pigments from bird feathers and cuttlefish ink, which were then purified and filtered until just the melanin remained.
Through the sculptures, a visual is created expressing the bigger picture in which melanin’s materials could be integrated into buildings, a use that Oxman believes is “inevitable.”
By using techniques that would tie in the assistance of bacteria, mycelium or algae, buildings could one day have a skin-like exterior.
This new type of biological material would hopefully be able to tan in the presence of UV rays, protect inhabitants from the elements and possibly even generate energy or absorb unwanted environmental metals.