title: Preparation of grafted microspheres CPVA-g-PSSS and studies on their drug-carrying and colon-specific drug delivery properties.
abstract: Sodium 4-styrene sulfonate (SSS) was graft-polymerized on the surfaces of crosslinked polyvinyl alcohol (CPVA) microspheres in a manner of surface-initiated graft-polymerization by using cerium salt-hydroxyl group redox initiation system, obtaining the grafted microspheres CPVA-g-PSSS. The chemical structure and physicochemical characters of CPVA-g-PSSS microspheres were fully characterized with infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and zeta potential determination. The aim of this work is to constitute a novel colon-specific drug delivery system via molecular design by using CPVA-g-PSSS microspheres as the drug-carrying material and by taking metronidazole (MTZ) as the model drug. The drug-carrying ability and mechanism of the grafted microspheres CPVA-g-PSSS for MTZ were investigated. Finally, in-vitro release tests for the drug-carrying microspheres were conducted. The experimental results show that in an acidic medium, the grafted microspheres CPVA-g-PSSS exhibit strong adsorption ability for MTZ by driving of electrostatic interaction, and have an adsorption capacity of 112 mg/g, displaying the high efficiency of drug-carrying. The in-vitro release behavior of the drug-carried microspheres is highly pH-sensitive. In the medium of pH=1, the drug-carrying microspheres do not release the drug, whereas in the medium of pH=7.4, a sudden delivery phenomenon of the drug will occur, displaying an excellent colon-specific drug delivery behavior.
authors.affiliation: Department of Chemical Engineering, North University of China, Taiyuan 030051, People' s Republic of China. gaobaojiao@126.com
authors.forename: Baojiao
authors.initials: B
authors.lastname: Gao
authors.forename: Li
authors.initials: L
authors.lastname: Fang
authors.forename: Jiying
authors.initials: J
authors.lastname: Men
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000327:Adsorption; D001826:Body Fluids / Q000187:drug effects; D003106:Colon / Q000187:drug effects / Q000378:metabolism*; D003432:Cross-Linking Reagents / Q000737:chemistry*; D004337:Drug Carriers / Q000138:chemical synthesis* / Q000737:chemistry; D016503:Drug Delivery Systems; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D008795:Metronidazole / Q000737:chemistry / Q000494:pharmacology; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D009928:Organ Specificity; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry; D011142:Polyvinyl Alcohol / Q000138:chemical synthesis* / Q000737:chemistry; D013055:Spectrophotometry, Infrared; D055672:Static Electricity; D013451:Sulfonic Acids / Q000138:chemical synthesis* / Q000737:chemistry; D013696:Temperature; D013997:Time Factors
chemical_list: D003432:Cross-Linking Reagents; D004337:Drug Carriers; D011108:Polymers; D013451:Sulfonic Acids; D008795:Metronidazole; D011142:Polyvinyl Alcohol; C077114:styrenesulfonic acid polymer
keywords: Colon-specific drug delivery; Crosslinked polyvinyl alcohol; Dependence of pH; Graft polymerization; Metronidazole; Sodium 4-styrene sulfonate