Enhanced therapeutic efficacy of drug encapsulated folic acid conjugated graphene oxide - gold nanorods for chemo-photothermal therapeutics of cervical cancer

Abstract

One of the deadliest forms of malignancy affecting females worldwide alongside breast cancer is cervical cancer, which urgently calls for novel treatment approaches. Gold nanocarriers are attaining acceptance due to their inert nature, minimal side-effects, low cytotoxicity and easy fabrication. Synthesis of gold nanorods conjugated with graphene and folic acid was carried out, which were finally loaded with bevacizumab for improved therapeutics. The drug loaded folic acid conjugated graphene-gold nanorods were irradiated with non-infrared laser for improved penetration of the drugs into the specifically targeted tissue. The graphene-gold nanorods with/without drugs and irradiation at different power densities (0.25 and 0.5 W/cm2) were studied. Transmission electron microscopy, zeta potential and polydispersity index established the integrity of prepared graphene nanorods carriers. The encapsulation efficiency and drug loading of the graphene-gold nanorods were determined. In vitro cytotoxicity assay was carried out via 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide, or MTT assay, with HeLa cells. There was non-significant difference between drug loading and encapsulation with irradiated and non-irradiated graphene-gold nanorods. But with irradiation the blank graphene-gold nanorods had increased cytotoxicity. The graphene-gold nanorods were released in a sustained manner as depicted by in vitro release studies. The drug loaded nanorods were also internalized by HeLa cells and distributed within the cellular compartment. We also tested drug loaded folic acid conjugated graphene-gold rods in vivo in U8GMG tumor bearing mice and results clearly indicated the irradiated ones were most efficient in suppressing tumors.

Keywords

• bevacizumab
• cervical cancer
• graphene
• photothermal
• gold nanorod