Colloidal HSA - Graphene oxide nanosheets for sustained release of oxaliplatin: Preparation, release mechanism, cytotoxicity and electrochemical approaches.

A novel sustained release carrier of graphene oxide nanosheets functionalized by human serum albumin nanoparticles (FGO-NSs) was synthesized and characterized by field emission scanning electron microscopy (FESEM), zeta sizer analysis, absorption spectroscopy (UV-vis) and Fourier transform infrared spectroscopy (FTIR) studies. The cell viability of GO-NSs, HSA-NPs and FGO-NSs has been tested against human foreskin fibroblast normal cell line, HFFF2 by MTT assay technique. Loading efficiency and release properties of oxaliplatin (OX), as an effective chemotherapeutic agent in the treatment of cancers, from HSA-NPs and FGO-NSs were studied. The results showed high drug loading (DL), drug entrapment efficiency (DEE) and sustained release of OX from FGO-NSs (DL = 61 ± 4% and DEE = 1.2 ± 0.2%) in comparison with HSA-NPs (DL = 51 ± 3% and DEE = 0.9 ± 0.04%) due to the large surface area of GO sheets. The diffusion coefficient was evaluated by cyclic voltammetry (CV) and confirmed the obtained results of UV-vis spectroscopy. Finally, release mechanism studies indicated that the release of OX from HSA-NPs is controlled by Fickian diffusion while the release mechanism of FGO-NSs/OX is occurred through non-Fickian diffusion. The results showed that the FGO-NSs could be suitable for reducing cytotoxicity of GO-NSs and enhancement of drug loading and sustained drug release in comparison with HSA-NPs in cancer therapy.