title: Long-term controlled release of125I-tagged BMP-2 by mesoporous bioactive glass with ordered nanopores.
abstract: The aim of this study was to investigate the ability of mesoporous bioactive glass with ordered nanopores (80S MBG) to adsorb and provide the delayed release of125I-tagged bone morphogenetic protein-2 (BMP-2). A 50 mg piece of 80S MBG was produced, which comprised SiO2, CaO and P2O5in a component molar ratio of 80:15:5. Each MBG piece adsorbed 30 μg125I-BMP-2. Persistent radioactivity in the MBG was periodically measured in simulated body fluid. The total amount of BMP-2 released and the mean amount released per day were calculated. A delayed release curve of BMP-2 was constructed. SPSS 15.0 software was used to perform a statistical analysis. The amount of BMP-2 released in the first two days was one-quarter of the total load. A line equation, y = 490.55×1/2+ 7268.82, was obtained from the square root of protein release doses value at 3-94 days. The total amount of BMP-2 released over 94 days was 11.894 μg, which was ~39.6% of the total load. The half-life of the release time was 248 days. From the second week, the rate of BMP release had stabilized to a mean of 37.42±18.67 ng/day and the difference of the mean amount released per day had no statistical significance (P>0.05). High adsorption and delayed release effects of BMP-2 were observed in 80S MBG. The delayed release conforms to the Higuchi equation, which indicates possible applications in promoting bone healing.
authors.affiliation: Department of Orthopaedic Surgery, Huashan Hospital Affiliated to Fudan University, Shanghai 200040, P.R. China.
authors.forename: Quan
authors.initials: Q
authors.lastname: Zhang
authors.forename: Ye
authors.initials: Y
authors.lastname: Zhang
authors.forename: Wenjun
authors.initials: W
authors.lastname: Chen
authors.forename: Bingwen
authors.initials: B
authors.lastname: Zhang
authors.forename: Shilong
authors.initials: S
authors.lastname: Wang
keywords: bone morphogenetic protein-2; delayed release; nanometer mesoporous bioactive glass