Bioprinting in the Palm of Your Hand

A handheld 3D bioprinter, called BioPen, is able to deposit a hydrogel scaffold containing adipose stem cells (1). “For decades, we and others around the world have discovered and developed amazing new materials, but they weren’t amenable to fabrication. Now, 3D printing allows us to utilize them surgically,” says Gordon Wallace, lead researcher and Executive Research Director of the Australian Research Council Center of Excellence for Electromaterials Science.

The researchers used a gelatin-methacrylamide/hyaluronic acid-methacrylate (GelMa/HAMa) hydrogel (or “bio-ink”), mixed with human adipose stem cells taken from fat. The mixture was loaded into the BioPen, and solidified at the point of extrusion by a UV light. One week after the mixture was extruded from the BioPen, over 97 percent of the stem cells were still viable.

The hydrogel–cell combination used in this study was specifically formulated for use in cartilage injuries, commonly seen in knee joints. However, different mixtures could be used to replace other tissues. “There is a need to customize for the task at hand. Each cell type presents a unique set of challenges in BioPen implementation. Each may require a customized bio-ink but this is readily achievable,” says Wallace.

The device still has several limitations and the team are already hard at work on a next-generation BioPen. “We are conscious of the fact that regulatory issues need to be addressed in parallel so this does not become the rate determining factor,” says Wallace, “We will start animal trials soon, so we have a way to go to reach the clinical stage. Our ongoing challenges involve the refinement and customization of bio-ink and the on-pen light-induced curing system.”

Not everyone has embraced the concept, but Wallace is philosophical, “As with many developments at the research frontier there are supporters and detractors. Both are important – the detractors help us identify deficiencies that we will rectify to ensure our supporters (many in the clinical field) can implement these advances as soon as possible.”