• Tuesday, March 05, 2024


Ultrasound emerges as a promising technique for cancer treatment

Ultrasonic waves have the capability to penetrate deep into tissues, reaching up to 12 cm, enabling treatment of deep-seated tumours without harming healthy cells

By: Kimberly Rodrigues

Researchers have developed a promising cancer treatment approach utilising ultrasound as a potential tool.

Unlike laser light used in photodynamic cancer therapy, ultrasonic waves have the capability to penetrate deep into tissues, reaching up to 12 cm, enabling treatment of deep-seated tumours without harming healthy cells.

The team of researchers has created a sonodynamic cancer treatment method by utilising semiconducting polymer nanoparticles combined with immunomodulators.

These nanoparticles can be activated by ultrasound, as detailed in the journal Angewandte Chemie.

The concept of cancer immunotherapy revolves around harnessing or enhancing the body’s own defense mechanisms to combat cancer.

However, one of the challenges is overcoming the resistance of tumour cells against the immune system’s T cells.

By combining ultrasound activation with immunomodulators linked to semiconducting polymer nanoparticles, the researchers aim to develop an effective strategy to address these challenges and enhance the efficacy of cancer immunotherapy.

In certain immunotherapeutic medications, it is crucial to limit their impact solely to cancer cells to prevent an excessive and harmful immune system response.

One approach, known as photodynamic therapy, involves using activatable nanomedicines that are delivered to cancer cells via nanocarriers.

These nanocarriers accumulate within the cells and are subsequently released through a reaction triggered by laser light.

However, the limitations of laser light restrict its ability to reach deep-seated areas within the human body.

Consequently, photodynamic therapy is primarily applicable to superficial organs and does not offer a viable solution for treating deep and challenging cancers like pancreatic cancer.

In contrast, ultrasound waves offer the advantage of penetrating deeply into tissues while causing fewer side effects.

Taking advantage of this characteristic, a team of researchers led by Kanyi Pu from Nanyang Technological University in Singapore and Donghua University in China has successfully utilised ultrasound for an innovative sonodynamic treatment approach in a mouse model of orthotopic pancreatic cancer.

The researchers developed a sonodynamic immunomodulation molecular system by creating nanoparticles using a specific semiconducting polymer that exhibits a response to ultrasound.

When activated by ultrasound waves, these nanoparticles transfer their energy to molecular oxygen within the cells. This energy transfer process leads to the formation of singlet oxygen, a type of reactive oxygen species, which induces immunogenic cell death and effectively eliminates cancer cells.

Furthermore, the semiconducting pro-nanomodulator, which served as the polymer in the study carried two specific immunomodulators into the cells, which were released by singlet-oxygen-induced bond breakage after ultrasound activation.

The results of the study demonstrated the remarkable effectiveness of the sonodynamic treatment in mouse models.

Mice that were implanted with orthotopic pancreatic tumours exhibited complete recovery following the treatment.

This breakthrough research holds significant promise for the development of novel and highly effective therapeutic strategies against pancreatic cancer.

After being injected into the bloodstream, the researchers employed imaging techniques to monitor the accumulation of the nanomodulators specifically within the tumor tissue.

Subsequently, ultrasound treatment was administered to activate the drugs, leading to the breakdown of the tumors within a few days.

Importantly, in healthy tissues where the nanomodulators remained inactive, they posed no harm or adverse effects.

This selective activation of the nanomodulators in tumour tissue highlights the potential of this approach for targeted cancer treatment while minimising damage to healthy surrounding tissues.

“However, immune-related adverse events were observed in the liver after the injection of the free drugs,” Pu said, acknowledging that the prodrug development is only at an early state.

The team emphasises that this sonodynamic method can be used to reach much deeper parts of the body than photodynamic therapy, hugely expanding the potential uses of immunotherapies that are activated at tumour sites.


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