350
N. Ashwin Kumar et al.
84]. Zhu et al. developed GNPs via citrate reduction method functionalized with
an anti-collagen-I antibody for determining the severity of the renal fibrosis. This
anti-collagen-I antibody binds with GTP protein regulates the morphology of the cell
[85].
6.4 Gold Nanoclusters for CT Imaging
Nanoclusters are produced using different protocols, among which citrate reduction technique is the most popular in the literature. Proteins and small molecules
such as bovine serum albumin (BSA), reduced glutathione (GSH), cysteine, cystidine, pepsin, cyclodextrin, chicken protein, and ovalbumin were used to act as
reducing and capping agent [86]. Pre-clinical CT imaging was studied using 1.9 nm
particles because of the smaller particle size and can excrete from the body like
Iodine. Also, the clearance of such particles is slower and reduces circulation in the
bloodstream. Injecting nanoclusters intravenously enables high-resolution imaging
of tumor volume and development of blood vasculature in tumors [87]. Other properties of GNCs are applicable as an adjuvant with image-guided therapy along with
radiotherapy and hyperthermia. Another type of particle that has few atoms of gold
called gold nanoclusters (GNCs) with a size range of ~1–2 nm. These GNCs not
only exhibit X-ray attenuation properties, but it also produces emission in red region
around 610 nm when excited at 365 nm using a UV lamp. Glutathione capped gold
nanoclusters have shown effective in vivo renal clearance studied with 3D CT images.
Compared to cysteine capped GNCs, glutathione capped GNCs showed 50% clearance via urine with 3.7% accumulation in the liver (see Fig. 9) [88]. Liu et al.
developed microwave-assisted multi-modal GNCs using lysozyme as a capping and
reducing agent as a dual-modal imaging probe [89]. These nanoclusters exhibited
good biocompatibility characteristics with enhanced imaging performance in both
CT and Near infra-red fluorescence. Histologically lysozyme capped GNCs (LyzGNCs) showed no necrosis and had a similar body trend as that of the control mice.
THE coronal CT view of Lyz-GNCs showed positive contrast compared to the control
Kunming mouse as shown in Fig. 9 [89].
GNC does not only help in CT imaging, but it also acts as promising radiosensitizer
material that can absorb and remit the energy [90]. However, this is outside the scope
of this chapter, but it is significant to mention the radiotherapy properties of GNCs.
Both radiotherapy and CT imaging are synchronous for the pre and post-treatment
of cancer [91]. Zhang et al. developed ultra-small glutathione capped GNCs as Xray contrast agents as well as radiotherapy to boost the killing efficacy [92]. These
GNCs have shown an increase in radiotherapy. U14 tumor models were imaged using
a micro CT scan for 10 min and reconstructed to know the tumor growth. Several
combinations of GNCs have been developed to enhance the bioavailability of the
particles. One such study performed by Domg Ma and his coworkers developed nonthiolate clusters using chitosan-graft-poly-(L)-Lysine in one step based on simple
azide-alkyne cyclization reaction [93]. X-ray attenuation of gold concentration versus
N. Ashwin Kumar et al.
84]. Zhu et al. developed GNPs via citrate reduction method functionalized with
an anti-collagen-I antibody for determining the severity of the renal fibrosis. This
anti-collagen-I antibody binds with GTP protein regulates the morphology of the cell
[85].
6.4 Gold Nanoclusters for CT Imaging
Nanoclusters are produced using different protocols, among which citrate reduction technique is the most popular in the literature. Proteins and small molecules
such as bovine serum albumin (BSA), reduced glutathione (GSH), cysteine, cystidine, pepsin, cyclodextrin, chicken protein, and ovalbumin were used to act as
reducing and capping agent [86]. Pre-clinical CT imaging was studied using 1.9 nm
particles because of the smaller particle size and can excrete from the body like
Iodine. Also, the clearance of such particles is slower and reduces circulation in the
bloodstream. Injecting nanoclusters intravenously enables high-resolution imaging
of tumor volume and development of blood vasculature in tumors [87]. Other properties of GNCs are applicable as an adjuvant with image-guided therapy along with
radiotherapy and hyperthermia. Another type of particle that has few atoms of gold
called gold nanoclusters (GNCs) with a size range of ~1–2 nm. These GNCs not
only exhibit X-ray attenuation properties, but it also produces emission in red region
around 610 nm when excited at 365 nm using a UV lamp. Glutathione capped gold
nanoclusters have shown effective in vivo renal clearance studied with 3D CT images.
Compared to cysteine capped GNCs, glutathione capped GNCs showed 50% clearance via urine with 3.7% accumulation in the liver (see Fig. 9) [88]. Liu et al.
developed microwave-assisted multi-modal GNCs using lysozyme as a capping and
reducing agent as a dual-modal imaging probe [89]. These nanoclusters exhibited
good biocompatibility characteristics with enhanced imaging performance in both
CT and Near infra-red fluorescence. Histologically lysozyme capped GNCs (LyzGNCs) showed no necrosis and had a similar body trend as that of the control mice.
THE coronal CT view of Lyz-GNCs showed positive contrast compared to the control
Kunming mouse as shown in Fig. 9 [89].
GNC does not only help in CT imaging, but it also acts as promising radiosensitizer
material that can absorb and remit the energy [90]. However, this is outside the scope
of this chapter, but it is significant to mention the radiotherapy properties of GNCs.
Both radiotherapy and CT imaging are synchronous for the pre and post-treatment
of cancer [91]. Zhang et al. developed ultra-small glutathione capped GNCs as Xray contrast agents as well as radiotherapy to boost the killing efficacy [92]. These
GNCs have shown an increase in radiotherapy. U14 tumor models were imaged using
a micro CT scan for 10 min and reconstructed to know the tumor growth. Several
combinations of GNCs have been developed to enhance the bioavailability of the
particles. One such study performed by Domg Ma and his coworkers developed nonthiolate clusters using chitosan-graft-poly-(L)-Lysine in one step based on simple
azide-alkyne cyclization reaction [93]. X-ray attenuation of gold concentration versus