Researchers at the Institute for Bioengineering of Catalonia (IBEC, a BIST centre) have developed new multi-responsive molecules able to self-assemble in water, forming fiber-like structures. The so-called discotic molecules show responsiveness to temperature, light, pH, and ionic strength, and they might show great potential for medical applications such as drug delivery systems, diagnosis, or tissue engineering.
Edgar Fuentes is a PhD student in the Nanoscopy for Nanomedicine Group led by Lorenzo Albertazzi at IBEC, a BIST centre. Within this group, Edgar and his colleagues focus on the synthesis of novel smart supramolecular materials for drug delivery.
More than a year ago, Albertazzi’s Group started a fruitful collaboration with Ilja Voets‘ Group at ICMS, at the Technical University in Eindhoven. Two other groups of experts also joined this collaboration: the IBEC Nanoprobes and Nanoswitches Group led by Pau Gorostiza and the Polymer Chemistry and Materials Group led by José Berrocal at the Adolphe Merkle Institute in Switzerland. As a result of this great collaboration, researchers have recently reported a highlight paper published in the Journal of the American Society of Chemistry (JACS).
The disk-like molecule synthesised in Barcelona incorporated a peptidic part made of lysine (pH responsive), an octaethylene glycol chain responsive to temperature, and an azobenzene part which responds to light stimuli. Researchers observed that when combining these parts into a single molecule, the final compound maintains responsiveness, changing its charge and shape. What’s even more fascinating, these changes can promote the disc-like molecules to stack one on top of another, forming a pile of molecules.
According to the researchers: “Our system responds in a controlled and reversible fashion to light, temperature, pH, and ionic strength, modulating the assembly−disassembly equilibrium. This is especially interesting for biological applications, such as drug delivery or tissue engineering, where controlling the material performance in a complex environment is challenging”.
Edgar Fuentes, first author of the paper who spent one week in Eindhoven working directly with the Voets-Group, thanks to the IBEC-ICMS collaboration agreement, explains the finding in a very comprehensive way: “We have developed very small ‘lego pieces’ which behave like a switch able to change depending on light or other environmental conditions. But the most fascinating is the following: under certain conditions these small pieces can spontaneously interact with many other pieces, forming fiber-like objects in water, 10000-fold thinner than a hair.”
More information can be found on the IBEC website.