Biodegradable plastics have played a leading role in the first successful elimination of tumors in mammals.
According to a report in the newest issue of Science Translational Medicine journal, bioengineers and immunologists at Harvard University in Cambridge, Mass. recently used fingernail-sized plastic disks impregnated with a cancer vaccine to kill tumors in laboratory mice. The vaccine inside the disks reprogrammed the mice’s immune systems to attack the tumors, the report said.
The slender implants developed by the group measure 8.5 millimeters in diameter and are made of an FDA-approved biodegradable polymer. Ninety percent air, the disks are highly permeable to immune cells and release so-called cytokines, powerful recruiters of immune-system messengers called dendritic cells.
These cells then enter an implant’s pores, where they are exposed to antigens specific to the type of tumor being targeted. The dendritic cells then report to nearby lymph nodes, where they direct the immune system’s T cells to hunt down and kill tumor cells.
The technique may have powerful advantages over surgery and chemotherapy, the report concluded, and may also be useful in combination with existing therapies. It only targets tumor cells, avoiding collateral damage elsewhere in the body. Researchers also anticipate that cancer vaccines will generate permanent and body-wide resistance against cancerous cells, providing durable protection against relapse.