Biofilm Inhibition by Nanoparticles - Antibiofilm Agents: From Diagnosis to Treatment and Prevention - page 380

3.2 Nanoparticles in Biotechnology and Medicine
Carbon nanotubes have been used as probe tips in atomic force microscopy (AFM)
which is used for high-resolution imaging of nucleic acids, immunoglobulins, etc.
(Hafner et al. 2001 ). Molecular recognition and the chemical forces between the
interacting molecules can be studied by attaching AFM tips bearing these bio-
molecules (Hafner et al. 2001 ).
Nanofiber scaffolds have been employed in the regeneration of cells and organs.
Experiments on a hamster with a detached optic tract demonstrated that a peptide
nanofiber scaffold could facilitate the regeneration of axonal tissue (Ellis-Behnke
et al. 2006 ). Titanium dioxide and zinc oxide are used in sunscreens and cosmetics
to absorb and reflect UV light.
Nanotube membranes can act as channels for highly selective transport of
molecules and ions between solutions that are present on both sides of the mem-
brane (Jirage et al. 1997 ). For instance, membranes containing nanotubes with
small inner dimensions (less than 1 nm) were useful for the separation of small
molecules on the basis of molecular size, while the nanotubes with larger inner
diameters (20-60 nm) were used to separate proteins (Martin and Kohli 2003 ).
The ability of nanoparticles to target and penetrate specific cells and organs has
also been explored in nanomedicine. Nanospheres made of biodegradable (facili-
tating timely release) polymers and drugs have potential applications in acidic
microenvironments as in the case of tumor tissues or sites of inflammation (Kamaly
et al. 2012 ). Nanoparticles acted as drug carriers for the targeted release of a
conjugate containing chlorotoxin (a peptide that selectively binds to glioblastoma
cells) and liposomes encapsulating antisense oligonucleotides or small interfering
RNAs for effective treatment of glioblastoma (Costa et al. 2013 ). Similarly, numer-
ous other studies have independently demonstrated the utility of nanoparticles as
drug carriers in different tumor types (Amoozgar et al. 2013 ; Leifert et al. 2013 ; Liu
et al. 2013a ; Shi et al. 2013 ; Vivek et al. 2013 ).
In addition, surface-functionalized nanoparticles can be used to infuse cell
membranes at a much higher level than nanoparticles without a functionalized
surface, which can be employed for transfer of genetic material into living cells
(Lewin et al. 2000 ). Silica nanospheres coated with ammonium groups (cation) can
bind to DNA (anion) through electrostatic interactions, which could be used to
deliver the latter into the cells (Kneuer et al. 2000 ).
Nanospheres can act as carriers for antigens and toxoids for potential use in
vaccination. Studies involving antigen-coated polystyrene nanospheres as vaccine
carriers targeting human dendritic cells have been under trial for nasal vaccination
(Matsusaki et al. 2005 ). Studies have also unveiled the potential of nanoparticles in
the diagnosis and treatment of various cancers. For instance, a study by Yin
et al. ( 2013 ) showed enhanced anticancer action of curcumin upon coupling it
with nanoparticles made from methoxy poly(ethylene glycol)-polycaprolactone
(PCL) block copolymers (Yin et al. 2013 ). Similarly, the silver nanoparticles
were shown to inhibit lung cancer cells in a concentration-dependent manner