Thermogravimetric analysis (TGA) of the nanocomposite and chitosan was performed in a TGA Q500 from TA Instruments (New Castle, DE, USA). Analyzed samples were heated from 100°C to 800°C at a heating rate of 10°C/min under a nitrogen flow of 50 mL/min. Fourier transform infrared spectroscopy (FTIR) of the nanocomposite and chitosan was performed by Nicolet 5700 (Thermo Nicolet, Waltham, MA, USA). The adsorption ABT-888 cost of BSA on CS-coated Fe3O4 NPs was measured using a UV-2501PC spectrometer (Shimadzu Corporation, Tokyo,

Japan). Adsorption procedures of BSA Adsorption of BSA on the CS-coated Fe3O4 NPs was carried out by mixing 10 mg of dried CS-coated Fe3O4 NPs and 10 mL of BSA solution (0.1, 0.2, 0.3, and 0.4 mg/L, pH = 6.0, 0.05 mol/L of Tris-HCl). The mixture was left in a shaker operating at 200 rpm for 10 to 240 min to reach equilibrium. After reaching adsorption Salubrinal molecular weight equilibrium, the supernatant and the solid Protein Tyrosine Kinase inhibitor were separated by using a permanent

magnet. BSA concentrations were measured by a UV-2501PC spectrophotometer at 595 nm. The amounts of BSA adsorbed on the magnetic adsorbents were calculated from mass balance. The standard curve of BSA is Y = 0.867X + 0.033(R 2 = 0.9975). Results and discussion All reactions rendered a black powder at the end of the process. However, a difference between the composite nanoparticles loaded with different amounts of chitosan was visually detected. Figure 1 presents photos of Fe3O4 coated with different amounts of chitosan. As shown

in Figure 1a, the suspension color changed from black to tan and then turned to black with increasing amount of chitosan. Moreover, with increasing amount of chitosan of more than 1.25 g, there were lots of nonmagnetic black powder under the bottle (Figure 1e,f), which may be caused by the oxidization and aggregation of excessive chitosan. Figure 1 Photos of the naked and CS-coated Fe 3 O 4 NPs obtained. (a) All MFCS. (b) MFCS-1/3. (c) MFCS-1/2. (d) MFCS-2/3. (e) MFCS-5/6. (f) MFCS-1. The functional groups of chitosan are very important for various applications, especially for biotechnological purposes. Therefore, the present functional groups should be kept even if the shape was changed into a new form; FTIR analyses U0126 price were carried out. The FTIR spectra of MFCS-0, MFCS-1/3, MFCS-1/2, MFCS-2/3, and pure CS are given in Figure 2, which were exhaustively washed and magnetically recovered so that all the chitosan in the final products are chemically bound to the magnetic nanoparticles. In the spectrum of naked Fe3O4 (Figure 2a), the absorption at 586 cm−1 is assigned to the characteristic band of the Fe-O group [21]. For pure CS (Figure 2e), a broad band at 3,410 cm−1 assigned to the O-H stretching vibration can be seen, and the C-H group is manifested through peaks 2,922 and 2,861 cm−1.