Brightly glowing nanoparticles known as "Cornell dots" are a
safe, effective way to "light up" cancerous tumors so surgeons
can find and remove them. According to research at Memorial
Sloan-Kettering Cancer Center (MSKCC), Cornell dots, also known
as C dots, are biologically safe and stable and small enough to
be easily transported across the body's structures and
efficiently passed through the kidneys and out in urine. A
single dot consists of several dye molecules encased in a silica
shell that can be as small as 5 nanometers in diameter (a
nanometer is one-billionth of a meter, about three times the
diameter of a silicon atom). The silica shell, essentially
glass, is chemically inert. Coating the dots with polyethylene
glycol, a process called PEGylation, further protects them from
being recognized by the body as foreign substances, giving them
more time to find targeted tumors. The outside of the shell can
be coated with organic molecules that will attach to such
desired targets as tumor surfaces or even