The functionalization of graphene makes it a promises candidate for various
applications. Several approaches have been developed for noncovalently and covalently functionalizing graphene (Table 10).
3.4.4 Fullerene
In recent years, studies on functionalized fullerenes for various applications in the
field of biomedical sciences have seen a significant increase (Table 11).
The most common technique used is to react pristine C 60 with a functionalized
polymer. Three examples are: (a) azido-functionalized polymers, which result in
the formation of aza[60]fulleroids and aziridino[60]fullerene-containing polymers
[157] when reacted with C 60 ; (b) polymers appended with aldehyde functional
groups have been used to produce fulleropyrrolidine-containing polymers [158];
and (c) the fullerene is functionalized in such a way so as to form a monomer, which
can then be polymerized. Polymerization of C 60 monomers has usually been done
by condensation, although examples of addition polymerization do exist. The wideranging reactivity of the remaining double bonds on the C 60 cage is one potential
drawback of this approach because further reaction of these double bonds will result
in the loss of the required properties of the mono-fullerene adduct.
3.5 Liposomes
The main advantages of liposomes are their biocompatibility, nontoxicity, adjustable
size [159], the possibility to functionalize their surface to make them targeting or
stealthy [160], and their ability to encapsulate hydrophilic molecules in their water
pool [161]. All these advantages have attracted scientists and researchers across the
world to work in liposomal chemistry. The great issue in liposome research is the
design of hybrid liposomes containing functional nanoparticles for use as nanoscale
therapeutics [162, 163]. Liposomes, which have a lipid bilayer shell of less than
5 nm thickness surrounding an aqueous core, can provide a means of dispersing and
concentrating nanoparticles via encapsulation or binding, thus shielding them from
biomolecular adsorption and delivering them through established liposome targeting
strategies. When loaded with drugs and nanoparticles, they resemble classic
liposome–drug formulations with additional functionality owing to the
nanoparticles. This functionality could be related to imaging [164], biosensing
[165], or heating through external activation using lasers [166] or alternating current
electromagnetic fields. Nanoparticles include inorganic nanocrystals such as iron
oxide, gold, and quantum dots; natural nanoparticles such as viruses, lipoproteins,
and apoferritin; and hybrid nanostructures composed of inorganic and natural
nanoparticles. Of these, the most investigated nanoparticles platforms for biomedical purpose are lipidic aggregates such liposomal nanoparticles, micelles, and
microemulsions. Their relative ease of preparation and functionalization, as well
Functionalized Nanoparticles and Chitosan-Based Functional Nanomaterials
23
applications. Several approaches have been developed for noncovalently and covalently functionalizing graphene (Table 10).
3.4.4 Fullerene
In recent years, studies on functionalized fullerenes for various applications in the
field of biomedical sciences have seen a significant increase (Table 11).
The most common technique used is to react pristine C 60 with a functionalized
polymer. Three examples are: (a) azido-functionalized polymers, which result in
the formation of aza[60]fulleroids and aziridino[60]fullerene-containing polymers
[157] when reacted with C 60 ; (b) polymers appended with aldehyde functional
groups have been used to produce fulleropyrrolidine-containing polymers [158];
and (c) the fullerene is functionalized in such a way so as to form a monomer, which
can then be polymerized. Polymerization of C 60 monomers has usually been done
by condensation, although examples of addition polymerization do exist. The wideranging reactivity of the remaining double bonds on the C 60 cage is one potential
drawback of this approach because further reaction of these double bonds will result
in the loss of the required properties of the mono-fullerene adduct.
3.5 Liposomes
The main advantages of liposomes are their biocompatibility, nontoxicity, adjustable
size [159], the possibility to functionalize their surface to make them targeting or
stealthy [160], and their ability to encapsulate hydrophilic molecules in their water
pool [161]. All these advantages have attracted scientists and researchers across the
world to work in liposomal chemistry. The great issue in liposome research is the
design of hybrid liposomes containing functional nanoparticles for use as nanoscale
therapeutics [162, 163]. Liposomes, which have a lipid bilayer shell of less than
5 nm thickness surrounding an aqueous core, can provide a means of dispersing and
concentrating nanoparticles via encapsulation or binding, thus shielding them from
biomolecular adsorption and delivering them through established liposome targeting
strategies. When loaded with drugs and nanoparticles, they resemble classic
liposome–drug formulations with additional functionality owing to the
nanoparticles. This functionality could be related to imaging [164], biosensing
[165], or heating through external activation using lasers [166] or alternating current
electromagnetic fields. Nanoparticles include inorganic nanocrystals such as iron
oxide, gold, and quantum dots; natural nanoparticles such as viruses, lipoproteins,
and apoferritin; and hybrid nanostructures composed of inorganic and natural
nanoparticles. Of these, the most investigated nanoparticles platforms for biomedical purpose are lipidic aggregates such liposomal nanoparticles, micelles, and
microemulsions. Their relative ease of preparation and functionalization, as well
Functionalized Nanoparticles and Chitosan-Based Functional Nanomaterials
23