Enhanced Anticancer Activity of Nedaplatin Loaded onto Copper Nanoparticles Synthesized Using Red Algae

Abstract

Marine algae are a rich source of biologically active compounds that can be utilized in various food and pharmaceutical applications. In this study, ultrasound-assisted extraction (UAE) was optimized to maximize yield and total carbohydrate content extracted from the red algae, Pterocladia capillacea. The extract was shown to possess potent antioxidant activity of up to ~70%, and was successfully used as a reducing and capping agent in the green synthesis of copper nanoparticles, which were characterized by UV-spectroscopy, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), and dynamic light scattering (DLS). Primarily, CuO nanoparticles with an average size of 62 nm were produced. FTIR spectra for the extract and algal-mediated CuO nanoparticles showed characteristic polysaccharide peaks. The synthesized CuO nanoparticles were subsequently loaded with nedaplatin where UV data suggested a complex formation. Nedaplatin release profiles showed a sustained release that reached a maximum at 120 h. The formulation was shown to have greater cytotoxicity relative to nedaplatin on hepatocellular carcinoma, breast cancer and ovarian cancer cell lines with IC₅₀ values of 0.40 ± 0.08, 1.50 ± 0.12, and 0.70 ± 0.09 µg/mL, respectively. Loading nedaplatin onto CuO nanoparticles synthesized using red algae extract, greatly enhances its anticancer effect.

Keywords: CuO nanoparticles; algal extract; cancer cell lines; green synthesis; nedaplatin; ultrasound-assisted extraction.

Figure 1

Antioxidant activity (%) of different concentrations of the algal extracts (25, 50, 250, and 1000 μg/mL) obtained after various extraction times, shown in different colors. All experiments were done in triplicate, and values are expressed as mean values ± SD. Groups with the same letters are insignificantly different at p = 0.05. The inserted figure shows the % antioxidant activity of different concentrations of ascorbic acid as a reference.

Figure 2

(A) UV-vis spectrum, (B) XRD pattern, (C) TEM image, and (D) ring diffraction patterns for the copper nanoparticles.

Figure 3

Cumulative release of 0.09 mM nedaplatin formulation from CuO NPs-ND and free ND. Each value shown is the average of triplicate experiments. Error bars represent ± standard deviation.

Figure 4

Percent cell viability of (A) HEP-G2, (B) MCF-7, and (C) SKOV-3 cell lines. All the experiments were carried out in triplicate with mean values presented and error bars represent ± standard deviation.