Palladium nanoparticles: Potential for receptor-mediated chemotherapeutic drug delivery to cervical cancer cells

Novel therapeutic strategies are needed to mitigate the hurdles faced by traditional cancer therapy that involves surgery, chemotherapy, and radiotherapy. The advent of nanomedicine has led to the production of an array of nanomaterials for therapeutic delivery. Nanoparticles (NPs) are potential anticancer delivery systems due to their favorable physical and chemical characteristics. Palladium NPs (PdNPs) are easy to synthesize, stable, have low cytotoxicity and good biocompatibility, and can be modified for use in biomedicine. PdNPs were synthesized chemically and modified with the biopolymer chitosan and the targeting ligand transferrin (Tf). This was used to encapsulate the anticancer drugs doxorubicin (DOX) and 5-fluorouracil (5-FU) individually and as a dual-drug formulation. PdNPs were spherical, small (98.9 nm), and had good colloidal stability (zeta potential = −22.3 mV). High drug encapsulation efficiency (>70 %) was noted for both drugs, with a sustained release profile for the Tf-modified PdNPs at low pH for both drug formulations over 72 h. These PdNPs were targeted to a cervical cancer cell model (HeLa) that highly expresses the Tf receptor. Cytotoxicity was assessed on the human embryonic kidney (HEK293), breast adenocarcinoma (MCF-7), and HeLa cell lines. The anticancer activity confirmed the targeting specificity of the Tf-containing nanocomplexes to the HeLa cells, with good cell viability in the non-cancer (HEK293) cells. Tf-targeted nanocomplexes containing the dual-drug generated better anticancer activity than their non-targeted counterparts, confirming their potential as targeted therapeutic delivery vehicles that warrant further investigation. • Palladium nanoparticles were successfully formulated with chitosan and the targeting ligand transferrin. • Observed high encapsulation efficiency of anticancer drugs, 5-fluorouracil and doxorubicin. • High anticancer activity and apoptosis observed in the transferrin-expressing HeLa cells. • Low cytotoxicity in the non-cancer cells boded well for limiting side effects in normal cells. • Results highlight the suitability of these nanocomplexes as potential anticancer drug delivery vehicles.