3(a). The CH2 stretch is seen at 2846 cm−1 and 2924 cm−1, C C at 1645 cm−1, and CH3 stretching at 1462 cm−1, indicating the presence of oleic acid on nanoparticles surface.

Successful amide formation between amine groups in CSO and the carboxylic group of silane was confirmed by the appearance of characteristic bands such as OH group at 3352 cm−1, C O (secondary amide formation) at 1635 cm−1 and C O C at 1095 cm−1, for CSO in Fig. 3(b) [8], [22], [23] and [35]. PPMS magnetometer results showed magnetization properties as a function of applied field at 300 K obtained for dry powders of iron oxide nanoparticles Z-VAD-FMK solubility dmso and CSO coated iron oxide nanoparticles. The results indicate super-paramagnetic behaviour of synthesized nanoparticles, that is, net magnetization of the particles in the absence of an external magnetic field was found to be zero [6]. Fig. 4 shows that the saturation magnetization of the CSO coated sample (12 emu per g) is lower than that of the iron nanoparticles (32 emu per g). Zeta potential data in Fig. 5(a) shows the zeta potential of INPs coated with silane COOH. The particles consist of zeta potential −1.9, −36.5 and −51 mV at pH 3, 7 and 9 respectively, which may be attributed to negative charge on surface of Etoposide nanoparticles due to the presence of COOH group of oleic acid and carboxylic silane surface coating.

Zeta potential data in Fig. 5(b) indicates that CSO-INPs were positively charged with a surface potential greater than +37 mV at pH 3. This confirms the presence

of amino groups on the nanoparticle surface in their protonated form, and thus establishing the presence of chitosan oligosaccharide on the particle surface. Results indicate that with an increase of pH, the surface charge of the particle decreased which was probably due to the deprotonation tendency of the surface exposed amino groups at higher values of pH [22]. Fig. 5(b) also Methocarbamol shows that particles possess positive zeta potential of +11 mV at pH 7, which corresponds to the pH of natural water. However, at pH 9, particles show a negative zeta potential of −2.8 mV. These results confirm that the nanoparticles have sufficient colloidal stability which is necessary for biological and environmental applications [8]. MTT (3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium) assay for viability of various cell lines was performed. The assay is based on reduction of soluble yellow tetrazolium into insoluble purple formazan crystals by mitochondrial succinate dehydrogenase of viable cell. Therefore, the rate of formazan crystal formation is directly proportional to number of viable cells which is measured in terms of absorbance [25]. The results in Fig. 6 clearly indicate that the toxic effect of CSO-INPs on A549 and HeLa cells were moderate as compared to bare INPs treatment.