Jayasuriya A Champa, Shah Chiragkumar, Ebraheim Nabil A, Jayatissa Ahalapitiya H
Department of Orthopaedics, University of Toledo, Toledo, OH 43614, USA.
Biomed Mater. 2008 Mar;3(1):015003. doi: 10.1088/1748-6041/3/1/015003. Epub 2007 Dec 19.
The delivery of growth factors and therapeutic drugs into bone defects is a major clinical challenge. Biomimetically prepared bone-like mineral (BLM) containing a carbonated apatite layer can be used to deliver growth factors and drugs in a controlled manner. In the conventional biomimetic process, BLM can be deposited on the biodegradable polymer surfaces by soaking them in simulated body fluid (SBF) for 16 days or more. The aim of this study was to accelerate the biomimetic process of depositing BML in the polymer surfaces. We accelerated the deposition of mineral on 3D poly(lactic-co-glycolic acid) (PLGA) porous scaffolds to 36-48 h by modifying the biomimetic process parameters and applying surface treatments to PLGA scaffolds. The BLM was coated on scaffolds after surface treatments followed by incubation at 37 degrees C in 15 ml of 5x SBF. We characterized the BLM created using the accelerated biomineralization process with wide angle x-ray diffraction (XRD), Fourier transform infrared (FTIR) microscopy, and scanning electron microscopy (SEM). The FTIR and XRD analyses of mineralized scaffolds show similarities between biomimetically prepared BLM, and bone bioapatite and carbonated apatite. We also found that the BLM layer on the surface of scaffolds was stable even after 21 days immersed in Tris buffered saline and cell culture media. This study suggests that BLM was stable for at least 3 weeks in both media, and therefore, BLM has a potential for use as a carrier for biological molecules for localized release applications as well as bone tissue engineering applications.
将生长因子和治疗药物输送到骨缺损部位是一项重大的临床挑战。含有碳酸磷灰石层的仿生制备骨样矿物质（BLM）可用于以可控方式输送生长因子和药物。在传统的仿生过程中，通过将可生物降解聚合物表面浸泡在模拟体液（SBF）中16天或更长时间，可以在其表面沉积BLM。本研究的目的是加速在聚合物表面沉积BML的仿生过程。我们通过修改仿生工艺参数并对聚乳酸-乙醇酸共聚物（PLGA）多孔支架进行表面处理，将矿物质在3D PLGA多孔支架上的沉积时间缩短至36 - 48小时。在表面处理后，将BLM涂覆在支架上，然后在37℃下于15 ml 5倍浓度的SBF中孵育。我们使用广角X射线衍射（XRD）、傅里叶变换红外（FTIR）显微镜和扫描电子显微镜（SEM）对通过加速生物矿化过程制备的BLM进行了表征。矿化支架的FTIR和XRD分析表明，仿生制备的BLM与骨生物磷灰石和碳酸磷灰石之间存在相似性。我们还发现，即使将支架浸泡在Tris缓冲盐水和细胞培养基中21天后，其表面的BLM层仍然稳定。这项研究表明，BLM在两种介质中至少3周内都是稳定的，因此，BLM有潜力用作生物分子的载体，用于局部释放应用以及骨组织工程应用。
