Tissue Engineering And Nanotheranostics

b2815 Tissue Engineering and Nanotheranostics “9.61x6.69”

248 Tissue Engineering and Nanotheranostics

advantages of using PET are that a more sensitive 3D image with

low concentration of radionuclides it can be provided by PET. The

disadvantages of using PET contain spatial resolution limitations,

cost of the equipment, it can only image one radionuclide at a time,

and radiation concerns are present. Pang et al. reported a facile

synthesis of radiolabeled PdCu@Au core−shell tripods for use in

PET and image­guided photothermal cancer treatment by directly

incorporating radioactive^64 Cu atoms into the crystal lattice. The

result demonstrated the use of radioactive PdCu@Au tripods for

effective photothermal treatment in the 4T1 tumor model as guided

by PET imaging. The efficacy of treatment was confirmed by the

significant reduction in tumor metabolic activity revealed through

the use of^18 F­fluorodeoxyglucose PET/CT imaging.^299 SPECT

utilizes a camera to detect a dosage of γ radiation that is emitted

from the tissue of interest upon administration. Commonly used

radionuclides have 99mTc,^131 I, and^67 Ga and so on. Compared with

PET, the advantages of using SPECT are that it can allow for precise

measurements, have little background interference, require no sig­

nal amplification, less expensive, long half­lives of radionuclides,

high sensitivity. The disadvantages of using SPECT include a low

spatial resolution, high costs, and use of radiation and relatively

cumbersome size of detection equipment. Zhao et al. synthesized

Au nanoparticles doped with^199 Au atoms for targeted SPECT

tumor imaging in a mouse triple negative breast cancer model.^199 By

directly incorporating^199 Au atoms into the crystal lattice of each Au

nanoparticle, the stability of the radiolabel could be ensured. When

conjugated with D­Ala1­peptide T­amide, the Au nanoparticles

doped with^199 Au atoms can serve as a C–C chemokine receptor 5

(CCR5)­targeted nanoprobe for the sensitive and specific detection

of both triple negative breast cancer and its metastasis in a mouse

tumor model.^300 Zhao et al. reported chlorotoxin­conjugated mul­

tifunctional dendrimers labeled with radionuclide^131 I for SPECT

and radiotherapy of gliomas. The result indicated the^131 I labeling

render the dendrimer platform with an ability to be used for tar­

geted SPECT imaging and radiotherapy of an MMP2­overexpressing

glioma model in vivo.^301