Biomedical Engineering Reference
In-Depth Information
Fig. 17.5.
Fiber-coupled LED sources developed for mPDT use in rodent brain, and
a source in use to treat brain tumor in a rat model, with the battery and electronics
in a wearable backpack
light delivery components, (c) how to maintain sterility and biocompatibility
of such an implant and (d) how to provide power, for which one option is to
have an external power supply and remote coupling to the source, as is used
in some other implantable devices.
The fundamental biological issue with mPDT is whether or not it is pos-
sible to kill the target cells faster than their proliferation, while avoiding non-
apoptotic killing (to avoid inducing an inflammatory response that could cause
secondary damage to normal tissues) and avoiding direct PDT damage to nor-
mal tissues.
17.3.3 PDT Molecular Beacons
Molecular beacons were introduced several years ago as a way to enhance
the target specificity of molecular imaging agents [16]. In that case the con-
cept was to link a fluorescent reporter molecule (fluorophore) with a molecule
