Simultaneous Imaging and Selective Photothermal Therapy through Aptamer-Driven Au Nanosphere Clustering

Abstract

Gold (Au) nanoparticles display enhanced near-infrared (NIR) photothermal effects upon the formation of clusters. We studied the photothermal properties of Au nanosphere clusters on the single-particle level using photothermal heterodyne imaging (PTHI) microscopy to understand the enhancement mechanisms. NIR photothermal responses of Au nanoparticle clusters were found to significantly increase from monomers to trimers. The averaged PTHI signal intensity of Au nanosphere dimers and trimers is ∼10 and ∼25 times that of monomers. The NIR photothermal effect of clustered nanospheres strongly correlates with their longitudinal plasmon mode. Clustered Au nanospheres were demonstrated to exhibit dual-capability NIR photothermal imaging and therapy of human prostate cancer cells with high efficiency and selectivity. This strategy can be potentially utilized for simultaneous cancer imaging and therapy with 3D selectivity.

Manipulating the confinement of electromagnetic field in size-specific gold nanoparticles dimers and trimers

“…The plasmonic interactions between the nanostructures that strongly localises the charges at the junctions of the particles imbues dramatic impact in materials science, such as non-linear optical properties, 28 surface-enhanced Raman spectroscopy, 29 surface-enhanced fluorescence, 30 two photon excitation photoluminescence, 31 plasmonic rulers, 32 optical trapping, 33 plasmonic sensing, 34 nanoscale photonic switches, 35 chiroplasmonic activity, 36 DNA cleavage dynamics, 37 and photothermal therapy of cancerous cells. 38 Different types of theoretical formalisms, such as generalised multiparticle Mie theory, 39 phenomenological surface collision damping theory, 40 hydrodynamic model including diffusion, 41 self-consistent theory, 42 jellium model, 43 plasmon hybridisation theory, 44 local analogue model, 45 dressed-states picture, 46 and group symmetry approach 47 have been adopted for an accurate description of these assemblies and to investigate their local and non-local attributes. Numerous computational techniques, such as discrete dipole approximation (DDA), 48 finite element method (FEM), 49 finite-difference time-domain (FDTD) method, 50 boundary element method (BEM), 51 and multipole expansion methods (MEM), 52 have been explored for studying the electrodynamics of such assembled nanostructures.…”

The Aptamer Functionalized Nanocomposite Used for Prostate Cancer Diagnosis and Therapy

“…The anti-PSA specific DNA aptamer Multimodal bioimaging, drug release, PDT, biosensing [54] Semiconductor nanoparticles (QDs) Inorganic The MUC1 aptamer-(CGA) 7 /S3.1/ S2.2 Bioimaging, biosensing, and drug delivery [55] Plasmonic nanocarriers (gold nanospheres, nanorods) Inorganic A9 Sgc8c CSC1/CSC13 Bioimaging [56], PTT [57,58], plasmonic sensors, gene therapy actively targeted nanoprobes [85,86]. Once entering the body, these multifunctional molecular probes conjugated with related tumor-targeted biomolecules are expected to be directly located at the target sites through specific binding, such as antigen-antibody reactions [87] and ligandreceptor reactions [88], thereby inducing changes in the local MR signal (Figure 3).…”

“…The aptamer-gold nanorod (AuNR) conjugate [57] showed good longitudinal plasmon resonance absorption in the NIR range and can effectively transfer NIR light to local area for heating, which has been used in PTT for leukemia. Wang et al [58] screened an aptamer (CSC1) specifically targeting DU145 prostate cancer cells and another targeting tumor stem cells (CSC13), then modified them on the surface of AuNRs. Through the covalent connection between aptamer and AuNRs, specific cell targeting and selective PTT were achieved under the NIR irradiation.…”

Gold Nanoparticle Self-Aggregation on Surface with 1,6-Hexanedithiol Functionalization

“…Gold nanoparticles (AuNPs) attract much attention owing to their unique optical, electronic, and catalytic properties. They have allowed development of different prototypes of devices for sensing [1,2], detecting [3], and imaging [4,5]. Further progress in designing AuNP-based devices depends on the ability to fabricate complex assemblies with tailored optoelectronic properties.…”