|Institution:||University of Toledo|
|Keywords:||Biomedical Engineering; Magnesium phosphate, calcium magnesium phosphate, hydroxyapatite|
|Full text PDF:||http://rave.ohiolink.edu/etdc/view?acc_num=toledo1418327070|
The focus of this dissertation is synthesis and biomedical applications of magnesium phosphate nanoparticles. Phosphates of alkaline earths such as calcium phosphates (CaPs; also synonymously referred to as apatites) have long been known as biocompatible orthopedic substituents. Like calcium, magnesium belongs to the alkaline earths. However, magnesium phosphates (MgPs) are not as well studied as the CaPs even though they are effective scaffold materials and potential nonviral DNA carriers. Hence, it is important to investigate MgPs in depth. Relatively open structures of apatites provide them with possibilities for various substitutions. Present research focuses on the applications of magnesium phosphate nanoparticles as promising biomaterials with a focus towards orthopedic uses. The relevance of these apatite nanoparticles in biomedical applications depends on the efficiency and speed of the synthesis process as well as the biocompatibility since the ease of production method and lack of cytotoxicity are some of the most crucial factors for mass production of biomaterials. Consequently, as explained below, the goal of this study is to provide an efficient production method for these apatites via a novel microwave assisted synthesis method (MAS), investigate their bioactivity, and examine their applications as scaffolds in orthopedics, and carriers in gene delivery. Amorphous magnesium phosphate nanoparticles were synthesized utilizing a novel, and rapid microwave assisted synthesis (MAS) method. In this methods, the household microwave generated rapid heating and cooling to promote generation of nanoparticles. The ability to control the heating time and power, and speed are some advantages of the applied methods for quick production of nanoparticles of interest.The as-synthesized materials were characterized using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-ray Diffraction (XRD), and Fourier Transform Infrared Spectroscopy (FTIR). In vitro studies were conducted on mouse osteoblasts using CytoTox96 assay. The fluorescent microscopy was used as the imaging method.The goal of this study is to investigate the application of MgPs as orthopedic scaffolds, stimulator of osteoblastic proliferation, and gene delivery vectors. To evaluate the applicability of MgPs in orthopedics, first, magnesium phosphate nanoparticles were compared to commonly used calcium phosphates, and magnesium substituted calcium phosphate nanoparticles. Subsequently, amorphous magnesium phosphates (AMP) mixed with the electrospun polylactic acid (PLA) fibers demonstrated the ability to stimulate a series of cell responses leading to proliferation and differentiation of preosteoblasts. Later, the ability of AMP nanoparticles to transfect the mouse osteoblasts were studied via fluorescent microscopy. Plasmid vectors containing green fluorescent protein (GFP) were used to examine the nanoparticles as efficient gene carriers.