HPV-associated cervical cancer cells targeted by triblock copolymer gold nanoparticle curcumin combination

Curcumin (diferuloylmethane) has promising anti-cervical cancer properties but requires a stabilizing complex such as the Pluronic triblock copolymer gold nanoparticle (GNP). The objectives were to study cytotoxicity of curcumnin and to determine the effect of copolymer GNPs curcumnin complex on cancer cell necrosis.

The HeLa cells were maintained in Eagle Minimal Essential Medium, fetal bovine serum, and antibiotics, and passaged until 60% confluency was reached. The cells were exposed to either: (1) control medium, (2) 50 μM curcumin, (3) 100 μM curcumin, (4) 50 μM curcumnin with copolymer GNPs complex, or (5) 100 μM curcumnin with copolymer GNPs complex. The treated cells were incubated at 37°C with 5% CO(2) in air for 24 hours, and analyzed for viability, apoptosis or necrosis using the dual stains fluorescence procedure.

A dose-dependent increase in the HeLa necrosis was observed with increasing curcumnin concentrations. Cytotoxic effect was decreased by five- to ten-fold when the curcumin was complexed with copolymer GNPs. There were more apoptotic HeLa cells at the higher concentration of curcurnin but combination with copolymer GNPs resulted in decreased apoptosis. Cell viability was higher in curcumnin with copolymer GNPs (74.4 ± 4.8 versus 2.3 ± 2.2% live, mean ± SEM, with and without copolymer GNPs, respectively).

Curcumin increased HeLa cancer cell necrosis but its cytotoxicity was decreased by copolymer GNPs. The results suggested that this specific copolymer GNP did not enhance the curcumnin bioavailability in cultured cells possibly due to formation of copolymer GNP aggregates.