There are many challenges facing researchers looking for ways to create tissue-like materials for medical research and clinical use. Much progress has been made with various types of hydrogel, as they can replicate the pliable, watery habitats of biological cells, but they lack the mechanical structure of soft tissue.

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The new liquid crystalline hydrogel – shown here in a dry state – should enable the design of biomaterials that interact with body fluids, say the authors.
Image credit: Syracuse University

Now, a study from Syracuse University in New York describes how it is possible to combine the properties of hydrogels with those of liquid crystals to produce new medical materials that have the same mechanical properties as the soft tissues of the body.

The researchers report their findings in the Journal of Polymer Science B: Polymer Physics.

Hydrogels – polymer chains that can absorb water – are increasingly being used as biomaterials because they are fluid-like and water-loving, and can have elastic properties. For example, they are being investigated for wound repair.

Liquid crystals are fluid-like, but they also maintain a crystal structure – so they do not lose their 3D shape. However, because they are not water-loving, on their own, they do not make good candidates for biomaterials to use in the body.

Scientists have been experimenting with biomaterials that combine the properties of hydrogels with those of liquid crystals. Such materials could have important applications because they keep their shape and mimic tissue so well that they are not viewed as a foreign body.

But there are many challenges to producing such medical materials. For example, adding the hydrogel to the liquid crystals does make them water-loving; it can also destroy the structural order of their crystallinity.

The new study, however, describes a process that produces a polymer that is elastic and soft, can swell with water and retains shape memory in response to heat and water.

Senior author Pat Mather, a professor in the Department of Biomedical and Chemical Engineering, says:

It is a balancing act of not having too many water-loving groups in the polymer and balancing that with other chemicals in the polymer that promote structure.”

He and his coauthor Amir Torbati – who worked on the study while he was a student in Mather’s lab and who is now a post-doctoral researcher at the University of Colorado-Denver – conclude that the process they describe should enable the “future design of materials or devices for a variety of applications such as biomaterials interacting with body fluids in a hydrated state.”

The study follows another that Medical News Today learned of in September 2015, where scientists at the University of Illinois at Urbana-Champaign developed synthetic tumor tissue using hydrogels. Their aim is to quickly create near-real tumor environments to study how cancer grows and behaves.