New research by scientists at the National Institute of Standards and Technology (NIST) demonstrates that three-dimensional scaffolds made with cells and supporting materials known as hydrogels can serve as life-like measurement platforms for evaluating how tiny engineered materials interact with cells and tissues. Their proof-of-concept study suggests that hydrogel tissue scaffolds can be a "powerful bridge" between current laboratory tests and tests that use animal models.

In their experiment, the team used polyethylene glycol—a common polymer used in skin creams, toothpaste, lubricants and other products—to create three hydrogels with different mesh sizes. One set of hydrogels was populated with rat cells containing ultrasmall semiconducting materials known as quantum dots. When exposed to light, quantum dots emit strong fluorescent signals that enabled the researchers to track the fate of treated cells in the synthetic scaffolds.

Results were compared with those for similarly treated cells grown in a single layer on a substrate, akin to standard laboratory toxicology tests.

The NIST researchers found that cells diffused through the hydrogel scaffold, forming a persisting tissue-like structure. Quantum dots attached to cell membranes and, over time, were absorbed into the cells.

Three-dimensional scaffolds often are used to test cells for multi-week experiments, and NIST researchers found quantum dots can be detected for four or more days inside the scaffold.

As significant, cells that populated the hydrogel scaffolds were exposed to lower levels of quantum dots, yielding a more representative scenario for evaluating biological effects.

The NIST team concludes that, compared with conventional cell cultures, hydrogel scaffolds provide a more realistic, longer-lived biological environment for studying how engineering nanoparticles interact with cells. In addition, the scaffolds will accommodate studies of how these interactions evolve over time and of how the physical features of nanoparticles may change.

This story is reprinted from material from NIST, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.