These results indicated that the GA-PEG-GA micelles had lower CMC and higher stability and thereby might retain the integrity even upon strong dilution selleck bio during systemic circulation. Therefore, the GA-PEG-GA micelles were chosen to perform the subsequent experiments.Figure 3The CMC (critical micelle concentration) of GA-PEG-GA and GA-suc-PEG-suc-GA.3.3. Preparation and Characterization of Blank and Drug Loaded GA-PEG-GA MicellesThe PTX loaded GA-PEG-GA micelles were found to have a mean diameter of 159.21 �� 2.22 (mean �� SD; n = 3), with a distribution from 78.8 to 396.1nm (PDI = 0.123) (Figure 4(a)), which, compared with blank micelle, showed a slight increase in micelle size. The surface charges of GA-M-PTX were ?18.53 �� 0.80mV (mean �� SD; n = 3) in zeta potential measurement, which demonstrated the high stability of GA-M-PTX in water.

Polydispersity in the micelle diameter can be attributed to a molecular weight distribution. The micelle size represented in the TEM images appeared to be smaller than that detected by DLS (Figure 4(b)). The scheme for the preparation of the GA-PEG-GA micelles was displayed in Figure 4(c). Hydrodynamic radii of particles determined using DLS are typically found to be significantly larger than those determined by TEM. This is seen because the particle radius is based on the intensity of scattered light so the size is skewed toward larger particles. One additional possibility for this difference is the inability to view the corona of the micelle. One would see the corona if the micelles were very densely packed.

Figure 4Preparation and characterization of the paclitaxel loaded GA-PEG-GA micelles. (a) Size distribution of the paclitaxel loaded GA-PEG2000-GA micelles (GA-M-PTX); (b) TEM image of GA-M-PTX (size of the scale bar: 200nm); (c) diagram of the preparation …Encapsulating the insoluble drug is an important function of micelles. Dacomitinib To evaluate the characteristic of micelle loading PTX, 1mL methanol was added into 1mL GA-M-PTX solution and sonicated for 30min. HPLC was performed, and the quantity of PTX was determined based on a linear standard curve obtained at a concentration range of 0.002�C0.01mg/mL.The gradient ratio of PTX/GA-PEG-GA used in formulation was determined. When the ratio of PTX to GA-PEG-GA was 1:5, the loading efficiency and loading content reached an optimal value, which were equivalent to 59.8% �� 1.4% (mean �� SD) and 13.0% �� 0.3% (mean �� SD).3.4. In Vitro Release Profile of Paclitaxel from GA-PEG-GA MicelleThe in vitro release profile of paclitaxel from GA-PEG-GA micelles (GA-M-PTX) was studied at 37��C and pH 7.0. Data suggests that paclitaxel can be well encapsulated in GA-PEG-GA micelles and released in an extended period. As shown in Figure 5, after 10h, 91.