Preparation and Application of Nanoparticles Based on Phenylalanine Ethyl Ester Modified Sodium Alginate
|School||Ocean University of China|
|Course||Biochemistry and Molecular Biology|
|Keywords||Sodium alginate Hydrophobic modification SP nanoparticles Sustained-release MTT|
This thesis to phenylalanine ethyl ester as a hydrophobic group, preparing a hydrophobic modified alginate - phenylalanine ethyl ester (SA-PE, SP) conjugates, such amphiphilic molecule in aqueous solution The self-assembly behavior; in order to vitamin B 2 (VB 2 ) mode nutrients to prepare the drug-loaded alginate nanoparticles (VB 2 sub >-SP), in vitro drug release effect; human colon cancer cells Caco-2 cell model to study the cytotoxicity of nanoparticles and to explore the mechanism of cell uptake of nanoparticles, and influencing factors. As a crosslinking agent, the use of EDC and NHS-phenylalanine ethyl ester (L-Phenylalanine Ethyl Ester PE) is connected via an amide bond covalently to sodium alginate (sodium alginate, SA) SP chemical conjugates were prepared, and a change in benzene alanine ethyl ester and the reaction of the sodium alginate, the molar ratio of the degree of substitution is made of three different samples (SP1, SP2, SP3). Using nuclear magnetic resonance and infrared spectroscopy proved that the structure of the product; elemental analyzer product replacement per 100 monosaccharide molecules contains about 3.5-4.7 PE molecules; nanoparticles suspension prepared by ultrasound SP use dynamic laser scattering, transmission electron microscopy and fluorescence spectra on the physicochemical properties of the nanoparticles were determined, the particle size of the nanoparticles with the substituted degree of increase and decrease the particle size distribution for the 226.7-425.3nm, nearly spherical nanoparticles, form a complete ; SP nanoparticles critical aggregation concentration (CAC) decreases as the degree of substitution increased, SP1, SP2 and SP3 CAC values ??are: 0.20mg/ml, 0.12mg/ml, 0.10mg/ml. VB 2 mode nutrients, ultrasound will the VB 2 package to nanoparticles, preparation of drug-loaded nanoparticles (VB 2 -SP). With the improvement of the dosage, the SP entrapment efficiency decreased to improve drug loading SP1 nanoparticles maximum drug loading was 12.76 ± 1.22%; increased with the degree of substitution, encapsulation efficiency and drug loading The amount has increased. VB 2 -SP sustained release dialysis study, within 48 hours of SP nanoparticles VB 2 has a good release effect; VB 2 release sub> by degree of substitution and the influence of the pH, the higher the degree of substitution, the better the effect of sustained release; with respect to at pH2.0, pH7.4, VB 2 -SP release others slow; SP nanoparticles suitable carrier as the nutritional substances VB 2 . The MTT Method degree of substitution blank SP nanoparticles cytotoxicity and fluorescence microplate reader with confocal laser scanning microscopy (CLSM) study Caco-2 cell uptake of fluorescently labeled SP nanoparticles. The results show that the addition to the 1mg/ml SP3 nanoparticles, SP nanoparticles for Caco-2 cells without significant toxicity after 24 h survival rate is still more than 95%; cell uptake of nanoparticles rate is affected by the degree of substitution, the concentration of nanoparticles, Incubation time and temperature effects, a high degree of substitution of a low concentration of a longer incubation time conditions, the cells of the nanoparticles having a high uptake rate; 4h within about 60% SP nanoparticles uptake by the Caco-2 cells; 4 ° C under cells is inhibited uptake of nanoparticles; confocal laser scanning microscopy results show that SP nanoparticles can be Caco-2 cell uptake.