Biomedical Engineering Reference
In-Depth Information
1.2.5 Targeted Drug Delivery
The majority of current commercial applications of nanotechnology to medicine are
dedicated to drug delivery [
70
]. The aim of nano-enabled drug delivery is to
improve the interaction of the drug and its target in order to better locally combat
the disease. Delivery of a large proportion of novel drugs is difficult because they
are water insoluble. These drugs are either dispersed throughout the nanospheres or
confined in the aqueous or oily cavity of a nanocapsule, which is surrounded by a
single polymeric membrane. Nanoparticles used in drug delivery include virus-
based nanoparticles, lipid-based polymers, and dendrimers. Nanoparticles impact
drug delivery by improving medication uptake, altering exposure time and clear-
ance, site-specific targeting, allowing predetermined drug release, reducing side
effects, and allowing for immunoisolation.
The major difficulty of nanoparticle-mediated drug delivery is the poor penetra-
tion of the NP and the release of its therapeutic cargo. Powerful propulsion and
enhanced navigation capabilities are required for the efficient delivery of the
payloads to their site-specific targets. Fuel-free magnetically driven nanomotors
are an attractive solution for drug nanoshuttles [
71
]. However, despite recent
progress in drug nanoshuttle research, much challenges need to be overcome in
order to translate the technology to in vivo applications. Namely, these challenges
comprise biocompatibility of the nanocarriers, autonomous release of the drugs
carried, swimming against blood flow, and limited tissue penetration. Independent
unloading of the therapeutic drugs could be brought about by use of cleavable
linkers reactive to tumor microenvironments, such as acidic pH and protease
enzymes. Moreover, new research in ultrasound-triggered microbullets [
72
] allow
for the transportation of the therapeutic payloads for site-specific discharge while
overcoming cellular barriers and blood flow. Finally functionalization of the
nanocarriers with targeting ligand could confer tissue specificity, reducing substan-
tially the side effects of toxic drugs in cancer therapy.
1.3 Bridging Nanoscience and Nanomedicine
More than 40 years of research in biomedical engineering has brought about
revolutionary medical instruments, such as endoscopes for surgical practice. Effec-
tive biomedical research and successful development of medical instruments rely
on the ability to understand the requirements of the medical practitioner and the
unmet medical need. The main actors involved in the production of novel
technologies, namely, universities and industry, must cooperate extensively to
assure the process of knowledge flow between the various stakeholders.
Improving the individual sectors of education, research, and innovation is
imperative for the convergence of nanoscience and technology. Bridging medicine
and nanoscience requires an efficient transfer of knowledge between laboratories
