Tissue Engineering And Nanotheranostics

b2815 Tissue Engineering and Nanotheranostics “9.61x6.69”

238 Tissue Engineering and Nanotheranostics

MSNs for safely carry and deliver anticancer therapeutics in a target­

specific, stimuli­responsive control fashion have demonstrated in vitro

and in vivo with a wide variety of cancers. In recent years, an increas­

ing number of researchers are focusing on the use of MSN nanocar­

riers for the enhancement of chemotherapy efficacy and inhibitions of

multidrug resistance (MDR) and cancer cell metastases.163,164 Besides,

in order to develop multifunctional MSNs, various contrast agents for

optical, MRI, CT, and PET have been readily incorporated to

MSNs.150,165–170 The combination of the capabilities of MSNs as a

therapeutic and diagnostic platform has resulted in theranostic sys­

tems.171,172 The advantages and efficacy of MSN­based theranostic

carriers has also been demonstrated in reported studies.166,173

2.6. Carbon-based Nanomaterials

Carbon­based nanomaterials can be categorized into fullerenes,

CNTs, nanohorns, nanodiamond, nanodots and graphene derivatives

according to their morphologies. Here, CNTs and graphene are dis­

cussed. According to the numbers of sheets of sp^2 carbon atoms,

CNTs can also be generally categorized into single­walled CNTs

(SWCNTs) and multiwalled CNTs (MWCNTs). CNTs have great

advantages in biomedical applications on antitumor drug delivery,

photothermal tumor ablation, or biological imaging due to their

unique physical and chemical properties.^1 74–180 CNTs have ultrahigh

area inside and outside that permits tremendous accommodation to

efficiently load multiple drug molecules. Thus, they have been inten­

sively investigated as drug carriers, with doxorubicin (DOX) being

the most common model drug.181–185 Supramolecular binding of aro­

matic molecules such as DOX can be easily achieved by π–π stacking

of those molecules onto the polyaromatic surface of nanotubes

through non­covalent interactions.^181 The studies indicate the DOX­

loaded CNTs have a potent accumulation in different tumor types

and the on­demand release of DOX depend on enhanced permeabil­

ity and retention effect (EPR) and acidic micro­environments of

extracellular tissues of tumors and intracellular lysosomes and

endosomes.^181 Light­controllable drug release of drug­CNTs complex