title: Converting drugs into gelators: supramolecular hydrogels from N-acetyl-L-cysteine and coinage-metal salts.
abstract: Here we present the concept of metallophilic hydrogels, supramolecular systems in which the gelator species are metal-thiolates that self-assemble through metallophilic attractions. The principle is applied for a small drug, the mucolytic agent N-acetyl-l-cysteine (NAC), which readily forms hydrogels in the presence of Au(iii), Ag(i) and Cu(ii) salts. The resulting transparent hydrogels present pH induced sol/gel transition. Scanning electron microscopy (SEM) measurements reveal a microporous structure in form of flakes for the three of them. The low pH at which these hydrogels are formed (pH < 4) limits their direct use as drug-delivery systems, but still this system constitutes a novel method for easy and fast conversion of small drugs into potent hydrogelators. Future developments will help to fully develop the idea in order to create a new class of supramolecular drug-delivery systems.
authors.affiliation: CIDETEC, Centre for Electrochemical Technologies, New Materials Department, Paseo Miramón 196, 20009 Donostia-San Sebastián, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Casuso
authors.forename: Pedro
authors.initials: P
authors.lastname: Carrasco
authors.forename: Iraida
authors.initials: I
authors.lastname: Loinaz
authors.forename: Hans J
authors.initials: HJ
authors.lastname: Grande
authors.forename: Ibon
authors.initials: I
authors.lastname: Odriozola
mesh_terms: D000111:Acetylcysteine / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D020100:Hydrogels / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008855:Microscopy, Electron, Scanning; D015394:Molecular Structure; D012492:Salts / Q000737:chemistry; D012834:Silver / Q000737:chemistry*
chemical_list: D020100:Hydrogels; D012492:Salts; D012834:Silver; D006046:Gold; D003300:Copper; D000111:Acetylcysteine