New tissue chip offers drug testing and medical applications

A new advance in tissue chip technology could potentially usher in a range of promising drug testing and medical treatment applications.

Devised by the National Institute of Biomedical Imaging and Bioengineering in the US, the chip has been engineered using a silk gel, thereby circumventing many of the problems associated with existing devices.

Tissue chips consist of collections of cells that mimic the anatomy and physiology of a tissue or organ. They require a three-dimensional structure to grow, with these scaffolds often made of polydimethylsiloxane (PDMS).

However, PDMS has a number of drawbacks, such as the fact it is non-degradable and sucks up lipids such as fat molecules or steroid hormones, making it making it difficult to test lipid-based drugs.

By contrast, silk provides different levels of stiffness to match the target tissue and offers long-term stability in a variety of conditions, yet still fully degrade over time. It also provides transparency to facilitate the observation of biological processes such as enzymatic activity.

The chip better represents human tissues than current chips and could therefore be more widely used for drug testing, while it also has the potential to someday be an implantable treatment itself.

Dr Rosemarie Hunziker, programme director for tissue engineering at the National Institute of Biomedical Imaging and Bioengineering, said: "This might even be an improved design that enables us to build little micro-tissues and make them implantable."