Chinese researchers have recently discovered that the use of calcium nanoparticles can weaken the defense mechanism of cancer cells, thus making treatments effective again.
Fight drug resistance with nanoparticles
If the chemotherapy is currently one of the most effective treatments for cancer, tumor cells can develop resistance to the substances used by producing a protein called P glycoprotein (P-gp). Located at the level of the cell membrane, it will use the molecule adenosine triphosphate (ATP) to push them back when they try to get inside the cell. A process that can make cancer multidrug resistance, thereby rendering chemotherapy ineffective, and reducing survival rates for some forms of the disease.
In the past, researchers have tried to avoid this resistance by directly targeting the P-gp or theATP, but failed to do so effectively or safely enough.
As part of the work presented in the journal Nano Letters, a team of researchers fromZhengzhou University based on previous studies showing that calcium ions could effectively reduce levels of P-gp and D’ATP, and has developed an innovative approach to allow them to find their way inside cancer cells.
Significant reduction in tumor size with no visible side effects
To do this, the team has developed calcium ion nanogenerators (TCaNG), which happen to be calcium phosphate nanoparticles that contain a chemotherapy drug called doxorubicin, covered with molecules guiding them to tumor cells. Once the nanogenerators are inside, the acidic environment causes them to decay, resulting in the release of ions and drug.
This approach has offered particularly promising results in experiments carried out on cancer cells cultured in the laboratory, with a marked decrease in the levels ofATP and of P-gp allowing doxorubicin to kill tumors (including those that have previously shown drug resistance). Follow-up tests in mice with different forms of cancer have shown a significant reduction in tumor size after 21 days without causing visible side effects.
The authors of the study point out, however, that the approach is still at an early stage of development, and that additional research will be necessary before considering trials on humans.