Researchers Make Biological Tissue Using 3-D Printer

LOS ANGELES (CN) – Using a custom 3-D printer developed by a University of California, Los Angeles, professor, a team of bioengineers has developed a technique for on-demand printing of complex skin-like tissues for use in transplants and other surgeries.

According to a study published Monday, a team led by UCLA professor of engineering Ali Khademhosseini pushed synthetic gels through a specially modified 3-D printer to create skin-like tissues that can act as a vehicle for drug delivery in the body or be used as “therapeutic biomaterials.”

Khademhosseini said the study offers an accessible method for creating material that mimics human tissue – a critical and unique material in surgeries – since it can be made from multiple materials.

“Tissues are wonderfully complex structures, so to engineer artificial versions of them that function properly, we have to recreate their complexity,” Khademhosseini said in a statement published by UCLA. “Our new approach offers a way to build complex biocompatible structures made from different materials.”

Researchers first used the 3-D printing process to make manufacture simple shapes, such as pyramids.

As the study progressed, researchers manufactured complex 3-D structures that “mimicked parts of muscle tissue and muscle-skeleton connective tissues,” according to the study.

Researchers printed shapes mimicking tumors with networks of blood vessels. In an experiment that sought to use the biological models to study cancers, they implanted the blood vessel-like structures in rats.

The rats’ bodies incorporated the artificial materials, allowing researchers to test the printed biomaterials’ use in studies on tumors.

Chronic diseases affect more than half the population of the United States. Researchers predict the prevalence of chronic illnesses will continue to rise as people live longer and more sedentary lifestyles.

Researchers said diseases can be managed by using the long-term implantation of printed medical materials as drug delivery vehicles or engineered tissues.

Khademhosseini’s 3-D printer has two key components. The first is a custom-built microfluidic chip – a small, flat platform similar in size to a computer chip – with multiple inlets that each “prints” a different material.

The other component is a digital micromirror, an array of more than a million tiny mirrors that each move independently.

To create the tissue, researchers used hydrogels – synthetic materials which, after passing through the printer, form scaffolds for tissue to grow into.

The micromirrors direct light onto the printing surface, and the illuminated areas indicate the outline of the 3-D object that’s being printed.

The light also triggers molecular bonds to form in the materials, which causes the gels to firm into solid material.

The study’s demonstration device used four types of bio-inks to print materials, but the study’s authors said the printer could accommodate as many inks as needed.

Khademhosseini also leads the Center for Minimally Invasive Therapeutics, which as the goal to create “implantable and regenerative therapies’ by merging biology, engineering, and materials sciences.

The study’s co-authors include Amir Miri of Harvard Medical School and Yu Shrike Zhang of Brigham and Women’s Hospital and Harvard Medical School. Other authors contributed from the University of Santiago de Compostela, Sharif University of Technology, and the University of California, San Diego.

The Office of Naval Research and the National Institutes of Health funded the study.

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