86
Z. Liu and Y. Liu
the targeting effect of TA6 and the high drug loading capacity. Besides, various drugs
can be simply loaded to the DNA double stands by physical intercalation, making it
a potential multiple-drug loaded platform for synergistic therapeutic effect.
4.4 Aptamer-Functionalized Nanoparticle Drug Delivery
Systems
The combination of aptamers and nanomaterials, including inorganic nanomaterials, organic nanomaterials, biological nanomaterials and other nanoparticles, has
been proposed as an effective strategy to construct drug delivery systems, providing
targeted therapy with expanded treatment methods.
4.4.1 Inorganic Nanomaterials
4.4.1.1 Gold Nanoparticles (AuNPs)
Recently, AuNPs have offered great promise for applications in drug delivery due to
their favorable properties such as comparatively chemical stability, surface plasmon
resonance, simple fabrication process, photothermal effect, low-toxicity, stability,
controlled size and functional surfaces that can be modified with different ligands
[49–52]. The aptamers are usually connected to AuNPs via gold–sulfur bonds. Kim
et al. developed a multifunctional nanoplatform (AS-LAGN) based on gold nanoparticle (AuNP) conjugated with drug and aptamer AS1411 [53]. Conjugating AS1411
aptamer on the surface of the gold nanoparticles significantly improved particle accumulation in cancer cells via specific affinity toward the nucleolin. Besides, the ability
of AuNPs to convert the excited photo energy into thermal heat enabled enhanced
therapeutic effect. Combinational treatment modalities revealed significant apoptosis
with higher cell killing efficiency (Fig. 4.5a). Niu et al. [54] prepared a novel Nheterocyclic carbine gold complex conjugated with CCRF-CEM-leukemia-specific
aptamer Sgc8c through an amine group. Compared with unmodified gold complex,
the aptamer-conjugated complex showed selective affinity to target cells and caused
enhanced cytotoxicity, but significantly reduced the damage to nontarget cells. A
multifunctionalized nanocomposite comprising gold nanorods (AuNRs) coated with
a super-stable, biocompatible and fluorescent carbon layer was developed by Wang
et al. (Fig. 4.5b) [55]. The AuNRs were modified with cell-specific aptamers and
loaded with DOX through π–π interactions. The uptake of AuNR@carbon-DOX
complex was near-infrared (NIR) laser-triggered and achieved controllable delivery
of DOX. Moreover, the complex possessed a fluorescent shell for tracking the drug
carrier before or after NIR laser irradiation. AuNR@carbon-DOX complex with
large superficial area, stable shells, particularly optical and photothermal properties
Z. Liu and Y. Liu
the targeting effect of TA6 and the high drug loading capacity. Besides, various drugs
can be simply loaded to the DNA double stands by physical intercalation, making it
a potential multiple-drug loaded platform for synergistic therapeutic effect.
4.4 Aptamer-Functionalized Nanoparticle Drug Delivery
Systems
The combination of aptamers and nanomaterials, including inorganic nanomaterials, organic nanomaterials, biological nanomaterials and other nanoparticles, has
been proposed as an effective strategy to construct drug delivery systems, providing
targeted therapy with expanded treatment methods.
4.4.1 Inorganic Nanomaterials
4.4.1.1 Gold Nanoparticles (AuNPs)
Recently, AuNPs have offered great promise for applications in drug delivery due to
their favorable properties such as comparatively chemical stability, surface plasmon
resonance, simple fabrication process, photothermal effect, low-toxicity, stability,
controlled size and functional surfaces that can be modified with different ligands
[49–52]. The aptamers are usually connected to AuNPs via gold–sulfur bonds. Kim
et al. developed a multifunctional nanoplatform (AS-LAGN) based on gold nanoparticle (AuNP) conjugated with drug and aptamer AS1411 [53]. Conjugating AS1411
aptamer on the surface of the gold nanoparticles significantly improved particle accumulation in cancer cells via specific affinity toward the nucleolin. Besides, the ability
of AuNPs to convert the excited photo energy into thermal heat enabled enhanced
therapeutic effect. Combinational treatment modalities revealed significant apoptosis
with higher cell killing efficiency (Fig. 4.5a). Niu et al. [54] prepared a novel Nheterocyclic carbine gold complex conjugated with CCRF-CEM-leukemia-specific
aptamer Sgc8c through an amine group. Compared with unmodified gold complex,
the aptamer-conjugated complex showed selective affinity to target cells and caused
enhanced cytotoxicity, but significantly reduced the damage to nontarget cells. A
multifunctionalized nanocomposite comprising gold nanorods (AuNRs) coated with
a super-stable, biocompatible and fluorescent carbon layer was developed by Wang
et al. (Fig. 4.5b) [55]. The AuNRs were modified with cell-specific aptamers and
loaded with DOX through π–π interactions. The uptake of AuNR@carbon-DOX
complex was near-infrared (NIR) laser-triggered and achieved controllable delivery
of DOX. Moreover, the complex possessed a fluorescent shell for tracking the drug
carrier before or after NIR laser irradiation. AuNR@carbon-DOX complex with
large superficial area, stable shells, particularly optical and photothermal properties