The phrase "to treat the cells" means taking care or providing special care to the cells in order to improve their condition or help them function better. Full definition
But the latter approach is currently unethical to attempt in humans, and the former faces many obstacles in delivering treated cells back to muscle tissues. (sciencedaily.com)
Putting this knowledge to use, scientists begin to use viruses to treat cells removed from patients with genetic diseases. (discovermagazine.com)