title: 5-Fluorouracil delivery from metal-ion mediated molecularly imprinted cryogel discs.
abstract: The objective of this study is to prepare imprinted cryogel discs for delivery of 5-fluorouracil. The coordinate bond interactions are utilized to accomplish a coordination complex between metal-chelate monomer N-methacryloyl-L-histidine and 5-FU with the assistance of Cu(2+) ion. The complex is copolymerized with hydroxyethyl methacrylate to produce poly(hydroxyethyl methacrylate-N-methacryloyl-(L)-histidine methyl ester) cryogel discs. The cryogel discs are characterized thoroughly by performing swelling tests, scanning electron microscopy, differential scanning calorimetry and X-ray diffraction studies. In vitro delivery studies are performed to investigate the effects of cross-linker ratio, medium pH and drug concentration. 5-FU imprinted cryogel discs have highly macroporous structures. Drug molecules are homogeneously dispersed in the 5-FU imprinted cryogel matrix. The cumulative release of 5-FU decreased by increasing the cross-linker density in the polymer matrix. Delivery rate of 5-FU varied with different pH values in a coordination complex since metal ion acts as a Lewis acid, and the ligand, i.e. 5-FU acts as a Lewis base. The cumulative release of 5-FU increased with increasing drug concentration in polymer matrix. The nature of the 5-FU transport mechanism is non-Fickian.
authors.affiliation: Department of Chemistry, Biochemistry Division, Hacettepe University, Ankara, Turkey.
authors.forename: Kemal
authors.initials: K
authors.lastname: Çetin
authors.affiliation: Department of Chemistry, Biochemistry Division, Hacettepe University, Ankara, Turkey. Electronic address: denizli@hacettepe.edu.tr.
authors.forename: Adil
authors.initials: A
authors.lastname: Denizli
mesh_terms: D003300:Copper / Q000737:chemistry*; D059985:Cryogels / Q000737:chemistry*; D016503:Drug Delivery Systems; D065546:Drug Liberation; D005472:Fluorouracil / Q000032:analysis* / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007477:Ions / Q000737:chemistry; D007700:Kinetics; D008689:Methacrylates / Q000737:chemistry; D054802:Molecular Imprinting; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D059985:Cryogels; D007477:Ions; D008689:Methacrylates; D009942:Organometallic Compounds; C005044:hydroxyethyl methacrylate; D003300:Copper; D005472:Fluorouracil
keywords: 5-Fluorouracil delivery; Coordinate bonding; Cryogels; Molecular imprinting