title: Silica sol-gel for the controlled release of antibiotics. I. Synthesis, characterization, and in vitro release.
abstract: Room temperature processed silica sol-gel (xerogel) was investigated as a novel controlled release carrier of antibiotics (vancomycin). Xerogel characteristics, in vitro release properties, and bactericidal efficacy of the released antibiotic were determined. The xerogel/vancomycin composite showed a long-term sustained release (up to 6 weeks). In addition, bactericidal efficacy of released vancomycin was retained. The kinetics of release and the amount released were dose dependent. The initial, first-order release was followed by a near-zero-order release. The time to transition from the first- to zero-order release increased with vancomycin load (from 2 to 3 weeks with load increase from 2.2 to 11.1 mg/g). Regardless of the load, about 70% of the original vancomycin content was released by the transitional point, and the cumulative release after 6 weeks of immersion was about 90%. This study, combined with other reports documenting biocompatibility and controlled resorbability of the xerogel/drug composite in vivo, suggests that silica xerogel is a promising controlled release material for the treatment of bone infections.
authors.affiliation: University of Pennsylvania, Department of Bioengineering, Center for Biomaterials and Tissue Engineering, 3320 Smith Walk, Philadelphia, Pennsylvania 19104, USA.
authors.forename: S
authors.initials: S
authors.lastname: Radin
authors.forename: P
authors.initials: P
authors.lastname: Ducheyne
authors.forename: T
authors.initials: T
authors.lastname: Kamplain
authors.forename: B H
authors.initials: BH
authors.lastname: Tan
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D005782:Gels / Q000737:chemistry; D008826:Microbial Sensitivity Tests; D058428:Silica Gel; D012822:Silicon Dioxide / Q000138:chemical synthesis / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D014640:Vancomycin / Q000737:chemistry / Q000493:pharmacokinetics* / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D005782:Gels; D058428:Silica Gel; D014640:Vancomycin; D012822:Silicon Dioxide