<p>The Pimpled Gold Nanosphere: A Superior Candidate for Plasmonic Photothermal Therapy</p>

Abstract

Background: The development of highly efficient nanoparticles to convert light to heat for anti-cancer applications is quite a challenging field of research. Methods: In this study, we synthesized unique pimpled gold nanospheres (PGNSs) for plasmonic photothermal therapy (PPTT). The light-to-heat conversion capability of PGNSs and PPTT damage at the cellular level were investigated using a tissue phantom model. The ability of PGNSs to induce robust cellular damage was studied during cytotoxicity tests on colorectal adenocarcinoma (DLD-1) and fibroblast cell lines. Further, a numerical model of plasmonic (COMSOL Multiphysics) properties was used with the PPTT experimental assays. Results: A low cytotoxic effect of thiolated polyethylene glycol (SH-PEG 400-SH-) was observed which improved the biocompatibility of PGNSs to maintain 89.4% cell viability during cytometry assays (in terms of fibroblast cells for 24 hrs at a concentration of 300 µg/ mL). The heat generated from the nanoparticle-mediated phantom models resulted in ΔT=30°C, ΔT=23.1°C and ΔT=21°C for the PGNSs, AuNRs, and AuNPs, respectively (at a 300 µg/mL concentration and for 325 sec). For the in vitro assays of PPTT on cancer cells, the PGNS group induced a 68.78% lethality (apoptosis) on DLD-1 cells. Fluorescence microscopy results showed the destruction of cell membranes and nuclei for the PPTT group. Experiments further revealed a penetration depth of sufficient PPTT damage in a physical tumor model after hematoxylin and eosin (H&E) staining through pathological studies (at depths of 2, 3 and 4 cm). Severe structural damages were observed in the tissue model through an 808-nm laser exposed to the PGNSs. Conclusion: Collectively, such results show much promise for the use of the present PGNSs and photothermal therapy for numerous anti-cancer applications.

Photothermal conversion of SiO2@Au nanoparticles mediated by surface morphology of gold cluster layer

“…Thermal energy diffuses into the surrounding environment to raise the temperature, resulting in a nano-scale localized high temperature. 2 Based on its unique photothermal effect, AuNPs have been extensively investigated for a variety of applications in photothermal therapy, [3][4][5][6] nano-surgery, 7,8 plasmonic photothermal delivery, [9][10][11] photothermal imaging, 12 plasmon enhanced thermophoresis 13 and plasmon-assisted optouidic. 14,15 The frequency of LSPR depends largely on the morphology, size, and dielectric environment of the AuNPs.…”

Recent Advances and Implication of Bioengineered Nanomaterials in Cancer Theranostics

“…Therefore, it is evident that the membrane coating strategy improves the biocompatibility of the nanoparticles and their bioavailability [94]. PTT is a non-conventional cancer treatment strategy, safer and non-invasive than other techniques because of higher accuracy [95]. Gold nanoparticles are the most promising PTT agents as they have high adjustable properties such as, particle size, shape uniformity, and surface modification, which improve their treatment efficacy [96].…”

Photo-Based Nanomedicines Using Polymeric Systems in the Field of Cancer Imaging and Therapy

“…Gold NPs can absorb light (photonic energy) effectively and convert it efficiently into heat energy [ 102 , 103 , 104 ]. The thermal energy created by gold NPs is dependent on the interactions between light and NP, which occur via a surface plasmon resonance effect [ 102 , 104 , 133 ].…”