The current investigation introduces an advanced and effective passive targeted tumor therapeutic nano biomedicine composed of pegylated gold nanoparticles (PEG-GNPs) conjugated with bovine pancreatic ribonuclease (RNase A) that induced reactive oxygen species (ROSs) mediating apoptosis pathway as effective strategies for colorectal cancer treatment. RNase A represents a new class of cytotoxic and non-mutagenic enzymes, has gained more attention as a potential anti-cancer modality, however, the cytosolic ribonuclease inhibitors (RIs) restricted the clinical application of this enzyme.

The GNPs synthesized, stabilized by polyethylene glycol (PEG), functionalized, and covalently conjugated with RNase A. The physicochemical properties of engineered nano biomedicine (GNPs-PEG-RNase A) were characterized by scanning electron microscope (SEM), dynamic light scattering (DLS), and UV-vis spectrum. Then, its biological impacts including cell viability, apoptosis, and ROS production were evaluated in the colorectal cancer cell line.

The engineered nano biomedicine was found to effectively induced apoptosis in SW-480 cells and resulted in a significant reduction in cancer cells viability. From the flow cytometry results, this nanoscale showed a significant apoptotic effect on cells. In addition, the maximum production of ROS was obtained after the treatment of cells with IC50 dose of GNPs-PEG-RNase A

Based on the efficient ROS-responsiveness and the anti-cancer activity of RNase A of the engineered nanomedicine, this nanoscaled biologics may be considered as a potential candidate for the treatment of colorectal cancer.