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The Preparation, Characterization and Biological Evaluation of Concentrated PNIP/BMA Nanogel Dispersions for Interventional Therapy of Liver Cancer

Author: LiaoYuanXia
Tutor: LiuWei
School: Huazhong University of Science and Technology
Course: Biochemistry and Molecular Biology
Keywords: N- isopropyl acrylamide Butyl methacrylate Nanogels Thermosensitive Compatibility Embolism
CLC: R735.7
Type: Master's thesis
Year: 2009
Downloads: 24
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Abstract

A high concentration of poly (N-isopropyl acrylamide-co-methyl butyl acrylate) (PNIP / BMA) iohexol water dispersion surface exhibit inversion sensitization phase behavior, the concentration of iohexol, gel concentration, temperature and other factors are strongly influenced by the behavior of this can be the temperature inversion sensitized phase. Thermodynamics, kinetics, and the rheology studies have shown that high concentrations of nanogels iohexol water dispersion has a good interventional treatment of vascular thrombosis performance. The this study PNIP / BMA Nanogel particle diameter of 270 ± 20nm hydrogel nanoparticles, with a negative charge. The high concentration Nanogel iohexol water dispersion having a remarkable thixotropy and rapid temperature response. The main contents and results are as follows: (1) were prepared with a soap-free emulsion polymerization method, PNIP / BMA Nanogel, dynamic light scattering (DLS) to detect the particle diameter of 270 ± 20nm, and monodisperse. The charge number -10 ± 3mv, its nano-particles of an electrically negative gradually increases as the temperature increases. The morphology of the nanogels were characterized by transmission electron microscopy. Dynamic light scattering method for the determination of iohexol on the the nanogels Thermosensitivity impact, results found that the water nano gel particle size decreases with increasing temperature; the iohexol aqueous solution, nano gel particle size with the significantly elevated temperature is gradually increased, and then decreased at a temperature increases again as the temperature continues to rise the particle diameter of the nanogels. Dispersion in iohexol the higher the concentration, this effect is more obvious. (2) using the bottle upside down with the iohexol water combined with the visual method of high concentration PNIP / BMA nanogels dispersion can be temperature inversion sensitive phase transition behavior. Higher concentrations PNIP / BMA Nanogel iohexol aqueous dispersion as the temperature increases generally experienced four phase states: translucent solid, translucent fluid, milky fluid and a white gel. Dispersion gelling temperature (GT) with Nanogel concentration, the concentration of iohexol increases significantly elevated; shrinkage temperature (ST) with the concentration of Nanogel iohexol concentration increases slightly drop. Nanogel concentration, the higher the concentration of iohexol, Nanogel at 37 ℃, the more the phenomenon of two-phase separation does not occur easily, the formation of a more stable white gel, suitable for in vivo embolization; addition, dispersion of the clouding temperature ( GPT) almost independent of the concentration of the nanogels, the iodine sea Chunnong impact. Also found that the the PNIP / BMA Nanogel aqueous dispersion at 37 ℃ not form a stable white gel is not suitable as interventional therapy embolic agents. When when iohexol dispersion content reached 150mgI/mL, higher concentrations PNIP / BMA Nanogel iohexol aqueous dispersion at 37 ℃ can form a stable white gel, is expected as a new type of developing interventional treatment of embolic material. (3) used the turbidity method to study the temperature range of in vitro and in vivo gel concentration, the iohexol concentration of the dispersion phase transformation kinetics. The greater the temperature range, the PNIP / BMA Nanogel iohexol aqueous dispersion of the volume phase transition more slowly; Nanogel concentration slight influence on the dispersion of the phase transition rate, but little effect on the concentration of iohexol. The Nanogel dispersion viscosity is influenced by the temperature, shear rate, gel concentration. The dispersion viscosity with temperature trend and its temperature varies with temperature sensitive phase behavior correspond to each other. In addition, dispersion viscosity over the the Nanogel concentration, shear rate increases with increasing apparent shear thinning characteristics. (4) by UV spectrophotometric spectrophotometric determination of nanogels iohexol release the nanogel iohexol water dispersion to form a temperature-sensitive release system into a dialysis bag. When the experiment 6h, the iohexol's release reached about 90%, the basic release completely. (5) 6.0 wt / v% of the PNIP / BMA Nanogel iohexol aqueous dispersion at room temperature for the fluid, at 37 ℃ quickly into a white gel. Rabbit in vivo tumor vascular thrombosis experiments show that the nanogels dispersed physical ability to effectively clog the blood vessels. Hemolytic experiments show that the gel dispersion of the nano hemolysis was 0.3%, not more than 5% of the standard comply with the ISO requirements. Cytotoxicity experiments showed that the PNIP / BMA Nanogel water dispersion having a low toxicity; while in the the PNIP / BMA Nanogel iohexol aqueous dispersion, when the the Nanogel concentration reaches 1.5wt / v% when cultured 24h cytotoxicity increased to two. This article also prepared four different particle size PNIP Nanogel, showed four Nanogel cytotoxic response in vitro cytotoxicity assays are less, having a low toxicity. In short, the study of poly (N-isopropyl acrylamide-co-butyl methacrylate), iohexol aqueous dispersion is a novel temperature-sensitive material with a developing function, as the temperature changes its exhibit reversible temperature sensitive phase behavior. Its temperature sensitivity, biocompatibility studies important.

The Preparation, Characterization and Biological Evaluation of Concentrated PNIP/BMA Nanogel Dispersions for Interventional Therapy of Liver Cancer

Abstract

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