Chemical polymerization of pyrrole in the presence of L-serine or L-glutamic acid: Electrically controlled amoxicillin release from composite hydrogel

Polypyrrole (PPy) was chemically prepared from aqueous solutions individually containing l-serine or l-glutamic acid, with the addition of ammonium persulfate as the oxidant. The electrical, XPS and FTIR characterizations indicated that the amino acids co-doped the PPy backbone. TEM revealed that PPy presented a quasi-spherical morphology with diameters in nanometric scale. The nanostructures of PPy-glutamic acid efficiently adsorbed therapeutic doses of amoxicillin. Composite hydrogels were obtained by the entrapment of amoxicillin-loaded PPy in polyacrylamide network. The antibiotic molecules can be subsequently released (or sustained) from composite hydrogel in response to application (or removal) of electrical stimulation. This tuning release profile can lead to promising drug delivery applications such as implantable devices and iontophoretic systems. (C) 2014 Wiley Periodicals, Inc.