Chemistry has been joined with physics and biology in the development of a new class of materials that carry built-in "intelligence". These materials respond to and interact with their environment in a sophisticated way and offer great promise, particularly in new medical treatments.
Ideas under development include wound dressings that only respond to the presence of infections or act against substances that slow healing, eliminating them and encouraging cell renewal. Intelligent drug delivery systems are possible which chemically block the release of a medication, keeping it out of circulation until it is actually needed. Another idea is coatings for medical implants that prevent cells from sticking to them.
These materials arise in what some scientists, including a team at University College Dublin, would argue is a fourth state of matter. To solid, liquid and gas they now add a collection of materials such as gels, liquid crystals and "soft glass" that have characteristics of both solids and liquids.
Prof Kenneth Dawson is an expert in these substances which can be grouped together as "soft condensed matter". He holds UCD's chair in physical chemistry and is director of its Irish Centre for Colloid Science and Biomaterials.
The substances range from gels and foams to many biological systems, even humans. "It is matter that is held together by weak forces," Prof Dawson explained.
He was asked to return to Ireland from abroad to take the chair and established the centre with financial support from the International Fund for Ireland. He wanted a "new tilt" on soft materials and wanted to reach a new understanding of the fundamental science behind them. "I wanted to find a way forward for the field."
He therefore set up an interdisciplinary centre that combined the three sciences within a single research group. "You make the thing in chemistry, you assemble it in the chemical context. You characterise it in physics and understand its properties. And you make it useful in biology."
In keeping with the fact that the centre is working with hybrid materials, the research group also has a hybrid structure that includes a number of international partners. It involves between 30 and 40 researchers with about 15 based here while the others move back and forth between Dublin and other research centres.
UCD collaborates with teams in Italy, Britain, the US, Germany, France and Sweden and post doctoral researchers move between these centres. "It is a linkage that has grown up organically."
The work includes fundamental research in an effort to discover the "unified rules" which dictate the way these materials act. "I am trying to see whether these materials have got more things to teach us, more secrets buried in them."
This work progresses in particular with La Sapienza or "Rome 1" the city's main university. It has particular expertise in glass and has studied the soft glasses, materials that can't decide whether to be solid or liquid.
Research is also advancing in the development of novel applications for these substances. They are built using lipids, which are non-water soluble fats, and water-soluble polymers. These are constructed into "intelligent biomaterials", Prof Dawson explained. "I can build a certain amount of intelligence into each building block."
The constructs are relatively simple, acting like a switch, but they offer a way to provide elegant control over biochemical activity. For example they could keep a drug out of circulation until the local acidity reached a given level. Ph rises close to the site of a local infection and when encountered the biomaterial would release its cargo.
Gels used in wound dressings would provide dynamic interaction, responding to the presence of an infection or mopping up potentially damaging enzymes at the wound site if they become too plentiful.
This technology may hold promise in gene therapy, which involves treating genetic diseases such as cystic fibrosis by replacing missing or mutated genetic material. One gene therapy approach is based on using a weakened virus to invade a cell and implant the missing genetic code. There are always risks however that some component of the virus might remain a danger.
Research at the centre offers the possibility to build artificial viruses, Prof Dawson suggested, which would be able to invade a cell and deliver new genetic information without posing an infective risk. The biomaterial would imitate the way viruses enter a cell, using similar techniques to evade the cell's natural defences.