The researchers have reported their findings in micro-scale focused journal Lab on a Chip in a paper which explains how the temporary structures can be ‘degraded away on demand’ with a biocompatible chemical trigger.
“We can attach polymers together to build 3D structures, and then gently detach them again under biocompatible conditions,” explained lead researcher Ian Wong.
The structures are made using a 3D printing technique called stereolithography, which links photoactive polymers together to create reversible bonds.
A computer-aided design system, in conjunction with an ultraviolet laser, traces patterns across the surface of a sodium alginate (a compound derived from seaweed) polymer solution, which causes the polymers to link together and form solid 3D structures.
“Conventional light-based 3D printing uses covalent crosslinking, which is static and irreversible,” Wong told us.
“The key innovation here is to use noncovalent (ionic) crosslinking, which enables stimuli-responsive, reversible biomaterial patterning,” he explained.
According to Wong, the team developed the technology with the use of an outdated stereolithography system purchased second-hand.
“We purchased an industrial light-based stereolithography system off eBay which dates back to the 1980s.”
“These systems are incredibly robust and their operation is completely open source, allowing us to easily “hack” them for biofabrication,” he explained.
Wong told us the technology could be used by drug manufacturers to make intricate microtissues for biopharmaceutical production.
“This technology can 3D print biomaterials with well-controlled shapes and tunable degradation kinetics, which could be used for biofabrication of microtissues with perfusable, vascular-like channels.”
Further, the researchers said experiments showed the agent used to dissolve the 3D-printed structures had no appreciable toxicity to the cells
“These biomaterials could also be used for the controlled release of living cells or drugs,” Wong added.
Wong told us the technology is affordable, and he expects it will be easily adopted.
“This biomaterial is based on alginate, a seaweed-derived polysaccharide which is commercially available and used in the food industry.”
“We expect this biomaterial will be reasonably inexpensive and easily implemented, since it does not require any additional synthetic chemistry,” he said.