When technologies combine: how a laser-based, 3D printing system could advance biotechnological solutions

It’s a technologist’s dream come true: biomedical engineers from Tufts University have figured out how to combine laser technology with 3D printing capabilities for the purpose of advancing biotechnology. 

Their work was published in PNAS, entitled “Laser-based three-dimensional multiscale micropatterning of biocompatible hydrogels for customized tissue engineering scaffolds.”

Let’s break that title down some, and get into just what exactly was created here. The team figured out how to use low-energy, ultrafast laser technology to make high-resolution, 3D structures in silk protein hydrogels (a soft, transparent biomaterial that supports cell growth and allows cells to penetrate deep within it). 

Specifically, the team used a femtosecond laser to generate voids within the gel at multiple scales, ranging from as small as 10 microns to as large as 500 microns, all over a large volume of the material. Doing this encourages faster artificial tissue growth, as the voids bring oxygen and nutrients to the proliferating cells in the tissue scaffold; with so many different sized holes in the biomaterial’s structure, the ability for the oxygen / nutrients to reach the cells is drastically improved. 

Laser treatment can be done while keeping the cell culture sealed and sterile. Worth noting: the transparency of the silk gel allows the laser’s photons to be absorbed as much as 1cm below the surface of the gel—that’s roughly 10 times deeper than with other materials, and it gets there without damaging any adjacent material. It’s a helpful perk though, unlike most 3D printing techniques, the Tufts solution doesn’t require photoinitiators. 

“Because the femtosecond laser pulses allow us to target specific regions without any damage to the immediate surroundings, we can imagine using such micropatterning to controllably design around living cells, guide cell growth and create an artificial vasculature within an already densely seeded silk hydrogel,” said senior author Fiorenzo G. Omenetto, Ph.D. Omenetto is associate dean for research, professor of biomedical engineering and Frank C. Doble professor at Tufts School of Engineering and also holds an appointment in physics in the School of Arts and Sciences.

In studies involving mice, the team found similar results in vitro as well as in vivo.

Via Tufts University