Tissue Engineering And Nanotheranostics

b2815 Tissue Engineering and Nanotheranostics “9.61x6.69”

188 Tissue Engineering and Nanotheranostics

photocleavable linker covalently attached to the gold nanospheres, is

protected, was cleaved, resulting in drug release.^208 Prabaharan et al.

produces a pH­triggered drug release nanocarrier.^209 In this nanocar­

rier, DOX was covalently conjugated to surface via an acid­cleavable

hydrazon linkage, and the release rates of conjugated DOX were

greater at pH 5.3 and 6.6 than at pH 7.4.^209 Compared to nano­

sphere, nanorod significantly shifts their LSPR band by changing the

aspect ratios. Therefore, nanorod with different aspect ratios could be

applied to selective triggered release of multiple drugs.

In addition to drug loading on the nanoparticle surface, drug

encapsulation in the nanoparticle also exhibit high therapeutic effi­

cacy.^210 Gold nanocage have been proposed for controlling drug release.

Yavuz et al. applied PNiPAAm modified nanocage to control drug

release with NIR laser irradiation. PNiPAAm changes this conforma­

tion in response to small variations in temperature, when the modified

gold nanocages absorb incident light and convert into heat, resulting in

an increase in temperature and changing the polymer conformation to

expose the pores. This process leads to release of preloaded effectors.

Once the light was turned off, the polymer returned to its original state

and stopped the drug release.^211 Chan et al. developed a modular nan­

oparticle­delivery system that uses DNA to assemble nanoparticles into

“core­satellite” architecture, and DOX inserted into ds­DNA between

the core and satellite. They demonstrate that their nanocarrier have 2.1­

fold increase in therapeutic effect.^212

6.4. Photodynamic Therapy/Photothermal Therapy

Due to their ability to accumulate in tumor cells in vivo rather than

in normal tissues, AuNPs pose great promises in photodynamic ther­

apy (PDT) and PTT.

PDT is a non­invasive, highly selective, effective method for the

destruction of unwanted cells and tissues and is widely applied in

treating oncological diseases213–216 such as certain dermal or infectious

diseases. Plasmonic particles­assisted PDT involves light­sensitive

agents — photosensitizers (PS) adsorbing on the surface of particles,

and plasmonic nanoparticles passively targeting tumor cells. After NIR