New Nanoparticles Designed for Cancer Chemotherapy and Immunotherapy

The usage of nanoparticles is established when it comes to treating cancer. To take nanotechnology even further, researchers from the University of Pittsburgh came up with cancer-combatting nanoparticles that provide chemotherapy and immunotherapy. Their findings were published in Nature Technology just last November 24.

Chemotherapy and Immunotherapy Packaged Into Nanoparticles

According to Phys Org, Song Li, one of the study's proponents, shared that the study contained two innovative facets. These are the discovery of another therapeutic aim and a novel nanocarrier potent for the selective delivery or transmission of chemotherapeutic medications and immunotherapy.

In their study, the innovative approach to immunotherapy stifled a particular gene that the researchers observed as part of immunosuppression. The novel therapy decreased the tumour size in mouse-modelled pancreatic and colon cancer after combining it with a certain chemotherapy drug and fitting it into minute nanoparticles.

(Photo: Pixabay / The Digital Artist)

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The Devising Of Nanoparticles

The team of researchers designed small pieces of a genetic code known as short interference RNA (siRNA). This code stops the production of particular proteins. In their case, the protein that was shut down was Xkr8, a protein that governs the dispensation of phosphatidylserine (PS) in the membrane of the cell.

PS is typically found in the inner layer of the tumor's cell membrane. However, this protein moves to the cell's surface as a response to chemotherapy medications. When stationed at the service, the protein serves as an immunosuppressant that protects cancer cells.

The researchers found that chemotherapy medications fluorouracil and oxoplatin "(FuOXP) increased Xkr8 levels. These findings thus suggested that stopping Xkr8 can inhibit the cancer cells from fending off PS to the surface of the cell. This may allow the cancer-immune cells to finish off the cancerous cells that remained after chemotherapy.

Hence, the team of researchers proceeded with packaging both FuOXP and siRNA into nanoparticles. After doing so, they moved on to the next step: aiming at tumors.

Song Li also shared that the team wanted to develop a mechanism that enables nanoparticles to enter intact blood vessels without having to depend on holes.

The researchers added PEG and chondroitin sulfate to the nanoparticles' surface to accomplish this. Such compounds enable the nanoparticles to aim at tumors and steer away from healthy tissues.

When injecting the nanoparticles into mice subjects, around 10% of the quantity reached the tumor. This was a significant development compared to other nanocarriers. In fact, in a study published in Nature Reviews, only 0.7%, on average, of the injected nanoparticles successfully reached the target.

Compared to nanoparticles that only had FuOXP, these nanoparticles greatly inhibited the migration of PS to the cell's surface.

Upon testing nanoparticles with siRNA and FuOXP in mouse pancreatic and colon cancer models, the researchers found that such subjects had comparatively better tumor microenvironments. They had more T cells to combat cancer and fewer immunosuppressive T cells.

These mice thus showed significant tumour size reductions compared to others treated with only one therapy.

The study also shows more potential and possibilities, such as combining siRNA-FuOXP with checkpoint inhibitors. But now, the researchers are working towards making this therapy available in a clinical setup. Hence, they are working on further validating their findings and evaluating possible side effects.