| To improve the effective utilization of drugs and reduce the toxic, the polymer carrier of combined with small molecule drugs for widespread concerned. Biological macromolecule- albumin containing hydrophobic cavity can bind the small molecule, is used as a carrier for hydrophobic drugs. However, there are some flaws in the proteins, such as the stability is not high, so perishable, have some limited with widespread application in the biomedical field. Amphiphilic block copolymers can self-assemble in solution to form micelles, vesicles and other micro-structure, as drug carriers have a very wide range of applications, at the same time, there is release time, loading of rates and other issues restricting its application. Albumin and polymers can be through non-covalent interactions to form a polymer-albumin, it is an important way to improve the nature of albumin. In this paper, biocompatible block copolymer (PLA-PEG-PLA) and bovine serum albumin (BSA) through non-covalent method to self-assemble into the albumin microspheres, in order to obtain a new biocompatible polymer drug carrier.In Chapter One, the author reviews the researching situation from the perspectives of the structure and properties of albumin, albumin as a drug carrier and polymer modified albumin as a drug carrier, and comments on the previous studies to propose the motivation and significance of this study.In Chapter two, the combining condition of PLA-PEG-PLA and BSA binding through the non-covalent method is studied. (PLEL / BSA = 4:1, pH = 7.4, T = 25°C), 1% glutaraldehyde are the crosslinking agents, the author use the TEM, DLS and AFM to represent their micro-structures and morphology, the results show that the micro-sphere with BSA as its core and PLA-PEG-PLA as its shell is formed. We launch Circular Dichroism(CD) and Fluorescence spectra to analyze the self-assembling mechanism of the micro-sphere and conclude that the internal hydrophobic cavity of BSA combines with the hydrophobic segments at the end of PLA-PEG-PLA through hydrophobic function. In Chapter Three, the author takes doxorubicin as the model drug to investigate the action of vitro releasing and calculates the entrapment efficiency of the carrier, and the drug carrying quantity. The results show that compared with the amphiphilic copolymer PLEL, the microsphere self-assembeld in our test improved the drug carrying quantity from 30% to 58%, and with good vitro releasing function its, its releasing period can reach as long as more than 240 hours.In Chapter Four, the author launches the new cationic drug carrier with calcium ions and bovine serum albumin as its core and PLA-PEG-PLA as its shell to investigate the function of calcium, pH, and temperature on PLEL-BSA and gets the optimal conditions: calcium concentration is 2%, pH=7 and room temperature. After analyzing its structure with the help of TEM and AFM, the results show that the microspheres have the obvious core-shell structure.In Chapter Five, we take doxorubicin as model drug to study vitro releasing, the results show that this kind of carrier has better cationic carrying quality and higher carrying rate. Compared with the carrier PLEL / BSA in the second chapter, its carrying quantity can reach 78% and it has a good general releasing result within 100 hours.In conclusion, with simple forming process, good result of vitro releasing and high carrying rate, PLEL-BSA micro-sphere broadens the studying range of polymer albumin drug carrier, meanwhile, it has bright application prospect in biomedical field.
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