Smart materials a step towards the artificial heart
Italian researchers report success with polymers that can change shape. Gabriella Bernardi reports.
Italian researchers are developing innovative photo-responsive materials they believe are capable of reproducing the mechanical properties of a human heart.
Writing in the journal Circulation Research, they describe their use of liquid crystalline elastomers (LCEs) – biocompatible polymers able to reversibly change shape in response to a given stimulus and generate movement.
The aim, and the potential, they say, is to create a first prototype of artificial muscle.
The research brings together expertise in material chemistry, optics, physiology and experimental medicine from the National Optical Institute of the Italian National Research Council (CNR-INO), the University of Florence (Unifi) and the European non-linear spectroscopy laboratory (Lens).
The field of tissue engineering has been growing exponentially in the last decade, the researchers say in their paper, such that restoring heart functionality is now an affordable target. However, new materials are still needed to effectively provide rapid and long-lasting interventions.
They note that until now the application of LCEs in biology has been limited by slow response times and difficulties modulating tension levels during activation.
In their new work, they designed and synthesised what Camilla Parmeggiani, of Lens and Unifi, describes as “a veritable palette of elastomeric liquid crystals capable of contracting under light stimulation”.
“These materials were mechanically characterised as if they were muscles, with the aim of identifying those with the properties most similar to those of our heart,” she adds.
And the results exceeded expectations. “We have created a biocompatible material that can produce strength levels comparable to or greater than those of the original muscle, replicating its kinematic properties,” says CNR-INO’s Leonardo Sacconi.
Unifi’s Cecilia Ferrantini says the research has potential application for both genetic and acquired heart pathologies.
“For example, after a massive heart attack or in presence of a cardiomyopathy, the tissue is irreversibly damaged and the heart reduces its pumping functionality,” she says. Currently, in severe cases, the available surgical alternatives are extremely limited and invasive, heart transplant being the only long-term solution.
“We have shown how these materials, working as a replacement of or coupled to the damaged muscle, could be used in the future to effectively assist the contractile function of a sick heart.”
The researchers say that while they have developed the materials to assist cardiac contraction, their use could be extended to assist the impaired function of other muscles, including those compromised by muscular dystrophies, neurodegenerative diseases and spinal injuries.