Engineers at the University of California, San Diego, have developed a groundbreaking 3D printing method that could significantly advance sustainable and environmentally friendly manufacturing. The innovative technique, detailed in Nature Communications, utilizes a polymer ink and a saltwater solution to create solid structures with remarkable simplicity.

The process revolves around a liquid polymer solution known as poly(N-isopropylacrylamide), or PNIPAM. When this ink is extruded through a needle into a calcium chloride salt solution, it immediately solidifies upon contact. This rapid transformation is driven by a phenomenon known as the “salting-out effect,” where the salt ions attract water molecules away from the polymer solution. The removal of water causes the hydrophobic polymer chains in the PNIPAM ink to densely aggregate, forming a solid structure.

Lung diseases claim millions of lives globally each year, with limited treatment options and inadequate animal models for research. Now, researchers have made a significant advancement by developing a mucus-based bioink for 3D printing lung tissue, as detailed in a study published in ACS Applied Bio Materials. This innovation holds promise for better understanding and treating chronic lung conditions.

While lung transplants offer a lifeline to some, the shortage of donor organs limits this option. Medications and treatments can manage symptoms of diseases like chronic obstructive pulmonary disease (COPD) and cystic fibrosis, but no cure exists. Traditional research methods using rodents often fall short in accurately replicating human pulmonary diseases and predicting drug safety and efficacy. In response, bioengineers are turning to lab-grown lung tissue, aiming to create more precise models or potential implant materials.

Engineers at the University of California, San Diego have developed an innovative 3D printing method that utilizes a polymer ink and a salt water solution to create solid structures, offering a more sustainable and environmentally friendly approach to materials manufacturing. Published in Nature Communications, this breakthrough process simplifies 3D printing and reduces its environmental impact.

The method employs a liquid polymer solution known as poly(N-isopropylacrylamide), or PNIPAM. When extruded through a needle into a calcium chloride salt solution, the PNIPAM ink instantly solidifies upon contact. This rapid solidification is driven by the salting-out effect, where salt ions attract water molecules from the polymer solution. This attraction causes the hydrophobic polymer chains in the PNIPAM ink to aggregate densely, forming a solid structure.