羟基磷灰石纳米颗粒对BMP-2的体外吸附和释放

The in vitro absorption and release kinetics of BMP-2 by hydroxyapatite nanoparticles

目的研究羟基磷灰石纳米颗粒（HANPs）对BMP-2的吸附和释放,探讨HANPs作为BMP-2药物载体的应用潜能。方法采用Iodogen法对BMP-2进行^125I标记,将HANPs分散于不同浓度的BMP-2溶液中,利用ITLC/SG对溶液进行展开,通过γ计数仪检测HANPs对BMP-2的吸附量。将吸附有BMP-2的HANPs（HANPs/^125I-BMP-2）分散于生理盐水溶液中,15 d内每天利用ITLC/SG对溶液进行展开,通过γ计数仪检测BMP-2的释放量。结果在BMP-2浓度为31.25-1 000μg/m L时,HANPs对^125I-BMP-2的吸附量与^125I-BMP-2的浓度成正比,1 mg HANPs最高可吸附BMP-2达70μg（70μg/mg）。在15 d内,BMP-2能持续性从HANPs/^125I-BMP-2释放,累计释放率能达到43%。结论 HANPs对BMP-2具有良好的体外吸附和释放效果,提示HANPs作为BMP-2的药物载体在骨组织工程具有极大应用潜能。

Objective To investigate the absorption and release kinetics of BMP-2 by hydroxyapatite nanoparticles（ HANPs）,and to analyze the potential of HANPs as a carrier for drug delivery systems. Methods BMP-2 was radiolabeled with ^125I according to the Iodogen method. HANPs were dispersed in BMP-2 solutions with different concentrations. The absorption of BMP-2 onto HANPs was detected using ITLC-SG and γ-counter. A suspension of HANPs /^125I-BMP-2 was prepared in normal saline and incubated at 37 ℃ for 15 days. On each day,the release kinetics of BMP-2 from HANPs was detected using ITLC-SG and γ-counter too. Results When the concentrations of BMP-2 solutions ranged from 31. 25-1 000 μg / m L,the absorption rate and the concentration of ^125I-BMP-2 were positively correlated,and the amount of125I-BMP-2 absorbed onto HANPs could be as high as 70 μg / mg. The release profile showed sustained release of BMP-2during the period of the investigation and the release ratio could increase moderately to about 43%. Conclusions These results suggest that HANPs has the potential function as a carrier for drug delivery systems and a scaffold material for bone tissue engineering.