title: Chitosan coated alginate beads containing poly(N-isopropylacrylamide) for dual-stimuli-responsive drug release.
abstract: Chitosan coated alginate beads containing poly(N-isopropylacrylamide) (PNIPAAM), were prepared to be used as a controlled pH/temperature sensitive drug delivery system with improved encapsulation efficiency and delayed release rate. The studied beads were characterized by differential scanning calorimetry, scanning electron microscopy, and Fourier transform infrared spectroscopy. Water uptake and release studies using indomethacin as a model drug were also performed. The drug loading efficiency of the beads with the polyelectrolyte complex coating is significantly higher (84%) than that of the uncoated ones (74%). The equilibrium swelling of the developed materials was found to be pH- and thermo- responsive. For all the conditions it was found that the release profile was slower for the coated beads, indicating that the polyelectrolyte complex coating could slow down the release rate effectively. These results suggest that the studied smart system has potential to be used as an effective pH/temperature sustainable delivery system for biomedical applications.
authors.affiliation: 3B's Research Group - Biomaterials, Biodegradables and Biomimetics, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
authors.forename: Jun
authors.initials: J
authors.lastname: Shi
authors.forename: Natália M
authors.initials: NM
authors.lastname: Alves
authors.forename: João F
authors.initials: JF
authors.lastname: Mano
mesh_terms: D000178:Acrylamides / Q000737:chemistry; D000180:Acrylic Resins; D000464:Alginates / Q000737:chemistry; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage; D048271:Chitosan / Q000737:chemistry; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D007213:Indomethacin / Q000008:administration & dosage; D008863:Microspheres; D011108:Polymers / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D000178:Acrylamides; D000180:Acrylic Resins; D000464:Alginates; D000894:Anti-Inflammatory Agents, Non-Steroidal; D020099:Coated Materials, Biocompatible; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D006603:Hexuronic Acids; D011108:Polymers; C052970:poly-N-isopropylacrylamide; D020723:Glucuronic Acid; D048271:Chitosan; D007213:Indomethacin