Scientists at NTU Singapore-CEA Alliance for Research in Circular Economy (SCARCE) repurposed the e-waste plastics, subjecting them only to sterilization, before being trialed in lab experiments. The team found that over 95 percent of the human stem cells seeded on plastics scavenged from discarded computer components remained healthy after a week, a result comparable to cells grown on conventional cell culture plates. Plastics found in electronic waste (e-waste) are rarely recycled due to their complex composition and hazardous additives, but scientists at Nanyang Technological University, Singapore (NTU Singapore) have developed a new use for them -- by repurposing them as an alternative to the plastics used in laboratory cell culture containers, such as Petri dishes.
Plastics found in electronic waste (e-waste) are rarely recycled due to their complex composition and hazardous additives, but scientists at Nanyang Technological University, Singapore (NTU Singapore) have developed a new use for them -- by repurposing them as an alternative to the plastics used in laboratory cell culture containers, such as Petri dishes. These findings, described in a study published online in the scientific journal Science of the Total Environment, indicate a potential new sustainable use for e-waste plastics, which account for about 20 percent of the 50 million tonnes of e-waste produced worldwide each year.
The new findings build on a 2020 study led by the same NTU team, which investigated the effect of e-waste plastics on six different human cell types and found healthy cell growth despite the hazardous elements to be found in e-waste plastics. These findings inspired the research team to upcycle e-waste plastic scraps and trial them in advanced cell culture applications.
Professor Dalton Tay of the NTU School of Materials Science and Engineering and School of Biological Sciences, who led this interdisciplinary study, said: "E-waste plastics contain hazardous components which may get released into the environment if not disposed of properly. Interestingly, we found through our studies that certain e-waste plastics could successfully maintain cell growth, making them potential alternatives to the cell culture plastics used in labs today."
"Repurposing them for immediate use rather than recycling them enables the immediate extension of the lifespan of e-waste plastics and minimizes environmental pollution. Our approach is in line with the zero-waste hierarchy framework, which prioritizes the reuse option through materials science and engineering innovation."
The NTU team used plastic scavenged from e-waste collected by a local waste recycling facility. Three kinds of e-waste plastic were chosen for their varied surface features -- the keyboard pushbuttons and diffuser sheet obtained from LCDs have a relatively flat and smooth surface, while the prism sheet, also found in LCDs, has highly aligned ridges. To test the viability of using e-waste plastics for cell cultures, the NTU team seeded stem cells onto 1.1cm-wide circular discs of sterilized e-waste plastics. A week later, the scientists found that more than 95 percent of live and healthy stem cells seeded on the e-plastics remained -- a result comparable to the experimental control of stem cells grown on commercially available cell culture plates made of polystyrene.
Prof Tay said: "In tissue engineering, we use advanced techniques to engineer surfaces and study how they can influence stem cell differentiation. Now, we have shown that e-waste plastics is a ready source of such microstructures that allow us to further study how stem cell development can be directed -- the 'holy grail' of regenerative medicine and more recently, lab-grown meat. There are important biomaterials and scaffold design rules and lessons we can learn from these e-waste plastic scraps."
To promote sustainable practices in research and innovative waste-to-resource solutions for the industry, say the scientists. The research is supported by Singapore's National Research Foundation and the National Environment Agency, under the Closing the Waste Loop Funding Initiative.