nanostructure, and found that
198,199 Au@AF–GO had effective tumor targeting/
imaging as well as rapid clearance from the body [94].
The radioisotope
125
I has a long half-life of 60 days, which enables to trace
long-term biodistribution and potential toxicity and was used labeling PEG–GO
[95]. There was an exponential decrease of the activity of
125 I–PEG–GO administered in mice. Over the course of 60 days, this
125 I–PEG–GO was gradually
excreted from the liver and spleen. While it would be possible that
125 I would be
detached from
125 I–PEG–GO,
125 I–PEG–GO remained stable in plasma until
15 days and radioactivity of the thyroid radioactivity did not rise. Thus, radioactivity was supposed to indicate where the GO was located. Further investigation is
necessary to determine the exact mechanism of graphene sheet clearance in vivo.
Nevertheless, those findings could provide great insight into advancement of GO in
drug deliver application.
One significant advantage of using radio-graphene is the ability to use very small
amounts of radioactive materials for in vivo radionuclide imaging, successfully
overcoming the dose-dependent toxicity issue. In contrast to MRI, which has a low
sensitivity, highly sensitive radionuclide imaging uses lower doses and can utilizes
least amounts of nanoparticles, leading to apparently lower toxicity [96].
The functionalization of graphene surfaces and graphene itself present many
opportunities for combined cancer treatment. In a recent study, a combination
approach was done, with rGO-gold nanorod functionalized with anticancer
chemotherapy drug. It successfully enhanced therapeutic effects, in addition to
dramatically regressing the tumor with amplified photothermal effects [97]. Ideal
candidates for combination therapy can be selected among antisense oligonucleotides, chemical drugs, photothermal/photodynamic agents, and therapeutic
radionuclides [98, 99]. Furthermore, augmented therapy targeting DNA using
combination of doxorubicin and alpha particle could be made possible by graphene’s capability of easy penetration of cell membranes [100, 101].
The localization and kinetics of GO can be traced in small animals or in humans
by radionuclide imaging especially using PET so as to elucidate targeting ability
and other organ distribution. Photothermal capability of GO combined with therapeutic radioisotope such as
131 I or
177 Lu will synergize and this combination
enhance the effects of GO-based therapeutics in any disease of interest.
131 I-labeled
rGO induced effective photothermal heating and cancer killing by high energy beta
ray emitted from
131 I (Fig. 4.7) [102].
Radionuclide imaging is recognized as a more accurate and reliable imaging
modality than optical imaging, at least in terms of quantitation capability and
human application. These advantages will further enhance the advancement of
radio-graphene approaches in clinical application, and because radiolabeling of
graphene is simple and quick, harnessing radio-graphene platform for the targeted
cancer theranostics will be rapidly growing. Current lack of detailed knowledge
regarding in vivo characteristics will surely call for further studies using radiographenes for in vivo tracking of GO-based therapeutic drugs. Radio-graphene has
4 Graphene-Based Nanomaterials
97
198,199 Au@AF–GO had effective tumor targeting/
imaging as well as rapid clearance from the body [94].
The radioisotope
125
I has a long half-life of 60 days, which enables to trace
long-term biodistribution and potential toxicity and was used labeling PEG–GO
[95]. There was an exponential decrease of the activity of
125 I–PEG–GO administered in mice. Over the course of 60 days, this
125 I–PEG–GO was gradually
excreted from the liver and spleen. While it would be possible that
125 I would be
detached from
125 I–PEG–GO,
125 I–PEG–GO remained stable in plasma until
15 days and radioactivity of the thyroid radioactivity did not rise. Thus, radioactivity was supposed to indicate where the GO was located. Further investigation is
necessary to determine the exact mechanism of graphene sheet clearance in vivo.
Nevertheless, those findings could provide great insight into advancement of GO in
drug deliver application.
One significant advantage of using radio-graphene is the ability to use very small
amounts of radioactive materials for in vivo radionuclide imaging, successfully
overcoming the dose-dependent toxicity issue. In contrast to MRI, which has a low
sensitivity, highly sensitive radionuclide imaging uses lower doses and can utilizes
least amounts of nanoparticles, leading to apparently lower toxicity [96].
The functionalization of graphene surfaces and graphene itself present many
opportunities for combined cancer treatment. In a recent study, a combination
approach was done, with rGO-gold nanorod functionalized with anticancer
chemotherapy drug. It successfully enhanced therapeutic effects, in addition to
dramatically regressing the tumor with amplified photothermal effects [97]. Ideal
candidates for combination therapy can be selected among antisense oligonucleotides, chemical drugs, photothermal/photodynamic agents, and therapeutic
radionuclides [98, 99]. Furthermore, augmented therapy targeting DNA using
combination of doxorubicin and alpha particle could be made possible by graphene’s capability of easy penetration of cell membranes [100, 101].
The localization and kinetics of GO can be traced in small animals or in humans
by radionuclide imaging especially using PET so as to elucidate targeting ability
and other organ distribution. Photothermal capability of GO combined with therapeutic radioisotope such as
131 I or
177 Lu will synergize and this combination
enhance the effects of GO-based therapeutics in any disease of interest.
131 I-labeled
rGO induced effective photothermal heating and cancer killing by high energy beta
ray emitted from
131 I (Fig. 4.7) [102].
Radionuclide imaging is recognized as a more accurate and reliable imaging
modality than optical imaging, at least in terms of quantitation capability and
human application. These advantages will further enhance the advancement of
radio-graphene approaches in clinical application, and because radiolabeling of
graphene is simple and quick, harnessing radio-graphene platform for the targeted
cancer theranostics will be rapidly growing. Current lack of detailed knowledge
regarding in vivo characteristics will surely call for further studies using radiographenes for in vivo tracking of GO-based therapeutic drugs. Radio-graphene has
4 Graphene-Based Nanomaterials
97