Biomedical Engineering Reference
In-Depth Information
Chemotherapy is useful in oral cancers when used in combination with other treatment modali-
ties such as radiation therapy. It is not used alone as a monotherapy. When cure is unlikely, it can also
be used to extend life and can be considered palliative but not curative care. Biological agents such
as Cetuximab have recently been shown to be effective in the treatment of squamous cell head and
neck cancers, and are likely to have an increasing role in the future management of this condition
when used in conjunction with other treatments. Treatment of oral cancer will usually be by a multi-
disciplinary team, with treatment professionals from the realms of radiation, surgery, chemotherapy,
nutrition, dental professionals, and even psychology all possibly involved with diagnosis, treatment,
rehabilitation, and patient care.
19.7
NANOPARTICULATE-BASED DRUG DELIVERY IN CANCER TREATMENT
The critical step in cancer treatment is the detection of cancer at its initial stage of carcinogenesis.
Results of numerous scientific research studies done in nanotechnology and nanomedicine are inspir-
ing the scientific community to discover new, innovative, noninvasive tools at the nanoscale level for
such purposes. Nanoscale cantilevers
[16]
and quantum dots
[17]
are being studied as cancer detec-
tion tools at the cellular level. If the tumor has not been detected in its early stage, treatment methods
should be devised to eradicate the fully developed cancer cells without harming the normal, healthy
cells of human body. The various types of nanoparticles that are currently studied for their use as drug
delivery systems are polymeric micelles, magnetic nanoparticles, colloidal gold nanoparticles, and
ceramic nanoparticles
[18-20]
. These nanoparticulate-based drug delivery systems can be character-
ized for their localization in tumor cells by coating them with tumor-specific antibodies, peptides,
sugars, hormones, and anticarcinogenic drugs. These nanoparticles have been effectively coupled
with the above-mentioned anticarcinogenic chemotherapeutic agents and have been tested for their
target specificity. These nanoparticles are superior over conventionally available drug delivery sys-
tems, as the chemotherapeutic agents can be targeted to a specified area of the human body by adding
nanoscale surface receptors. These receptors specifically recognize the target tissue and bind to it and
release the drug molecules
[21]
. Thus, healthy cells are spared from cytotoxic effects of the drug.
Drugs can also be protected from degradation by encapsulating them with nanoparticle coatings
[22]
.
As nanoparticles are extremely small, they can penetrate through smaller capillaries and are easily
taken up by cancer cells. This causes efficient drug accumulation at the target site. The use of biode-
gradable nanoparticles allows sustained drug release over a period of time
[23]
. Thus, nanoparticles
as drug delivery systems, with enhanced target specificity, can overcome the limitations of conven-
tional cancer treatment techniques. There are numerous other nanobiotechnology-based approaches
being developed to formulate nanoparticles as carriers of anticarcinogenic agents. These include
dendrimers, chitosan nanoparticles, low-density lipoproteins, nanoemulsions, nanolipospheres,
nanoparticle composites, polymeric nanocapsules, nanospheres, and nanovesicles (
Figure 19.2
).
Their applications in nanoencapsulation and targeted drug delivery of anticancer drugs, in combina-
tion with radiotherapy, laser therapy, thermotherapy, photodynamic therapy, ultrasound therapy, and
nanoparticle-mediated gene therapy, have been extensively reviewed in the literature
[24]
. The fol-
lowing sections discuss the most promising groups of nanoparticles and their applications in drug
delivery for treatment of oral cancer.
