磷酸钙微粒作为非病毒性载体具有转染基因的能力。此研究目的是，用磷酸钙微粒作为基因载体转染BMP-2进入大鼠DPSCs，并评价转染的效率和生物活性。我们也研究了接种在三维纤维钛支架上的转染细胞的特性。首先，准备好经DNA质粒处理过的磷酸钙微粒（增强型绿色荧光蛋白质粒-BMP-2）。然后，使用这些微粒转染STRO-1筛选的大鼠DPSCs，检测转染效率和分泌BMP-2的生物活性。此后，被转染的细胞培养在三维纤维钛支架上，电子显微镜观察细胞培养情况并评价细胞增殖、ALP活性和钙含量。最后通过real-time PCR检测牙本质相关基因表达。结果表明：微粒上的DNA直径大小约为100nm，微粒能保护内部DNA避免DNase酶影响，并且在pH 3.0的弱酸环境下能释放负载的DNA，体外微粒有着较高的转染率，同时又促进和提高了三维支架材料上的大鼠DPSCs牙向分化。基于此研究，发现负载DNA质粒的磷酸钙微粒通过BMP-2转染后，是一种有效的基因传递非病毒载体，同时有着较好牙向分化的能力。

Tissue Eng Part A. 2008 Jan;14(1):71-81.

Non-Viral Bone Morphogenetic Protein 2 Transfection of Rat Dental Pulp Stem Cells Using Calcium Phosphate Nanoparticles as Carriers.

Calcium phosphate nanoparticles have shown potential as non-viral vectors for gene delivery. The aim of this study was to induce bone morphogenetic protein (Bmp)2 transfection in rat dental pulp stem cells using calcium phosphate nanoparticles as a gene vector and then to evaluate the efficiency and bioactivity of the transfection. We also intended to investigate the behavior of transfected cells when seeded on 3-dimensional titanium fiber mesh scaffolds. Nanoparticles of calcium phosphate encapsulating plasmid deoxyribonucleic acid (DNA) (plasmid enhanced green fluorescent protein-BMP2) were prepared. Then, STRO-1-selected rat dental pulp stem cells were transfected using these nanoparticles. Transfection and bioactivity of the secreted BMP2 were examined. Thereafter, the transfected cells were cultured on a fibrous titanium mesh. The cultures were investigated using scanning electron microscipy and evaluated for cell proliferation, alkaline phosphatase activity and calcium content. Finally, real-time polymerase chain reaction was performed for odontogenesis-related gene expression. The results showed that the size of the DNA-loaded particles was approximately 100nm in diameter. Nanoparticles could protect the DNA encapsulated inside from external DNase and release the loaded DNA in a low-acid environment (pH 3.0). In vitro, nanoparticle transfection was shown to be effective and to accelerate or promote the odontogenic differentiation of rat dental pulp stem cells when cultured in the 3-dimensional scaffolds. Based on our results, plasmid DNA–loaded calcium phosphate nanoparticles appear to be an effective non-viral vector for gene delivery and functioned well for odontogenic differentiation through Bmp2 transfection.