The Pimpled Gold Nanosphere: A Superior Candidate for Plasmonic Photothermal Therapy

Abstract

Behzad Nasseri,1– 3 Mustafa Turk,4 Kemal Kosemehmetoglu,5 Murat Kaya,2 Erhan Piskin,1 Navid Rabiee,6 Thomas J Webster7 1Chemical Engineering Department, Bioengineering Division and Bioengineering Centre, Hacettepe University, Ankara 06800, Turkey; 2Chemical Engineering and Applied Chemistry Department, Atilim University, Ankara 06830, Turkey; 3Bioscience Faculty, Shahid Beheshti University, Tehran, Iran; 4Bioengineering Department, Kirikkale University, Kirikkale, Turkey; 5Department of Pathology, Hacettepe Medical Science University, Ankara, Turkey; 6Department of Chemistry, Shahid Beheshti University, Tehran, Iran; 7Department of Chemical Engineering, Northeastern University, Boston, MA 02115, USACorrespondence: Behzad Nasseri; Thomas J Webster Email [email protected]; [email protected]: 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-PEG400-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.Keywords: plasmonic, photothermal therapy, gold nanoparticles, colorectal cells, pathology

Keywords

• plasmonic
• photothermal therapy
• gold nanoparticles
• colorectal cells
• pathology