In a study on mice, scientists have found that body implants that alter a person's immune cells could be used to treat a range of infectious diseases and even cancer.
It was found that when mice with an aggressive melanoma, which usually kills within 25 days, underwent the new treatment, 90 percent of the group was saved.
Usually, it is difficult to remove immune cells and prime them to attack malignant tissue and inject them back into a patient, because majority of re-injected cells die before showing any effect, said David Mooney of Harvard University.
Thus, the researchers have developed a technique that directs the immune system from within the body, a method that is more efficient and potentially cheaper too.
The method involves implanting cylinders of an FDA-approved biodegradable polymer into the body.
The implants generate a particular variety of the cell-signalling molecules called cytokines, which is a sort of molecular perfume that is irresistible to a certain kind of immune-system messenger cell.
The pores of the implant attract the dendritic cells, and they are exposed to antigens and a danger-signal chemical derived from bacterial DNA.
The alert signal triggers the dendritic cells flee to the nearest lymph node, where they meet up with the immune system's "killer" T-cells and program them to hunt down the invading cells.
In the trial, the researchers implanted cylinders with a diameter of 8.5 millimetres into mice and after two weeks injected the animals with highly aggressive melanoma cells.
And it was found that mice implanted with 'blanks' - cylinders lacking any chemical additives - developed large tumours within 18 days and had to be euthanised.
However, 90 percent of the mice that received the full treatment were cured.
"There have not been any reports of the traditional [external] dendritic cell activation having survival rates at the levels we find with our materials for the cancer model we used," New Scientist quoted Mooney as saying.
This is because the implants can recruit and activate very large numbers of dendritic cells.
"It is a continuous process - dendritic cells are attracted to the device, take up the [cancer] antigen and [the warning signal] ... and then they can leave. New cells are continuously arriving while activated cells are leaving," said Mooney.
The researchers hope that modified versions of the material could prove to be effective against a range of cancers and infectious diseases.
Such implants might also help reprogram the immune system to combat autoimmune diseases such as type 1 diabetes, caused by immune cells destroying insulin-producing cells in the pancreas.