Scientists at the Indian Institute of Science (IISc) have developed a new approach to potentially detect and kill cancer cells, especially those that form a solid tumor mass. They have created hybrid nanoparticles made of gold and copper sulfide that can kill cancer cells using heat and enable their detection using sound waves, according to a study published in ACS Applied Nano Materials.
How the hybrid nanoparticles work
The hybrid nanoparticles have three properties that make them suitable for cancer diagnosis and treatment: photothermal, oxidative stress, and photoacoustic. When light is shined on these nanoparticles, they absorb the light and generate heat, which can kill cancer cells. These nanoparticles also produce singlet oxygen atoms that are toxic for the cells. “We want both these mechanisms to kill the cancer cell,” says Jaya Prakash, Assistant Professor at the Department of Instrumentation and Applied Physics (IAP), IISc, and one of the corresponding authors of the paper.
The photoacoustic property of the nanoparticles allows them to absorb light and generate ultrasound waves, which can be used to detect cancer cells with high contrast once the particles reach them. The ultrasound waves generated from the particles allow for a more accurate image resolution as sound waves scatter less when they pass through tissues compared to light. Scans created from the generated ultrasound waves can also provide better clarity and can be used to measure the oxygen saturation in the tumor, boosting their detection.
How the hybrid nanoparticles are made
The hybrid nanoparticles are less than 8 nm in size, which can potentially allow them to travel inside tissues easily and reach tumors. The IISc team used a novel reduction method to deposit tiny seeds of gold onto the copper sulfide surface. The resulting nanoparticles have a core-shell structure, with a copper sulfide core and a gold shell. The gold shell can be chemically modified to target specific cancer cells.
The researchers tested the hybrid nanoparticles on breast cancer cells in vitro and found that they were able to kill more than 90% of the cells after 10 minutes of exposure to near-infrared light. They also observed that the nanoparticles were able to generate strong photoacoustic signals that could be used for imaging.
How the hybrid nanoparticles can be integrated with existing systems
The researchers say that the hybrid nanoparticles can be integrated with existing systems of detection or treatment. For example, the nanoparticles can be triggered to produce heat by shining a light on them using an endoscope that is typically used for cancer screening. The endoscope can also be equipped with a transducer that can capture the ultrasound waves generated by the nanoparticles and create an image of the tumor.
The researchers also envision that the hybrid nanoparticles can be used for theranostics, which is a combination of therapy and diagnostics. By using the same nanoparticles for both purposes, they can reduce the risk of adverse effects and improve the efficacy of treatment.
The researchers now plan to take the results forward for clinical development. They hope that their approach can offer a new way to combat cancer, especially solid tumors that are difficult to treat with conventional methods.