Russian Team Builds 'Smart' Capsule to Deliver Laser-Activated Cancer Drug into Tumours

Scientists at Saratov State University in Russia, with an international team, have developed a 'smart' microcapsule that carries a laser-activated cancer drug directly into tumour tissue. The findings were published in the journal Current Pharmaceutical Biotechnology.

Many side effects of cancer treatment arise because aggressive drugs attack malignant and healthy cells alike, the Saratov researchers noted. A gentler alternative is photodynamic therapy, in which a patient receives a photosensitiser — a compound that reacts to light — and the affected area is irradiated with a laser. “The light triggers the compound to produce reactive oxygen species that destroy cancer cells,” said Olga Inozemtseva, a study co-author and senior researcher at the Biomedical Photoacoustics Laboratory of the university's Medical Research Centre. The method is minimally invasive with few side effects, she said, but the photosensitiser struggles to penetrate and accumulate in the tumour.

To fix that, the Saratov group and colleagues from the National Academy of Sciences of Armenia built the capsule from calcium carbonate and ceruloplasmin, a protein that transports copper ions in the body. Ceruloplasmin shields the photosensitiser from degradation caused by temperature and by the chemical environment of different tissues. When the drug forms a complex with the protein, about nine out of ten molecules bind to ceruloplasmin, Inozemtseva said, and ceruloplasmin itself helps generate reactive oxygen species, adding to the therapeutic effect. The mineral shell delivers the protein and the drug specifically to tumour cells, she said, working like an intelligent targeting system.

Experiments showed that 86.9% of the photosensitiser was successfully loaded into the microspheres, with complete release after 48 hours, said Valery Tuchin, another co-author and head of the Saratov Medical Research Centre. “This gradual release is crucial — it allows us to achieve high drug concentrations precisely in the tumour area while minimising exposure to healthy tissues,” he said.

The researchers plan to move on to experiments in animal models in the near future.