Tuning Optical and Granulometric Properties of Gold Nanostructures Synthesized with the Aid of Different Types of Honeys for Microwave-Induced Hyperthermia.

Malgorzata Rzegocka,Pawel Pohl,Anna Dzimitrowicz,Dorota Jermakowicz-Bartkowiak,Agnieszka Cwiklinska,Piotr Jamroz,Piotr Cyganowski

doi:10.3390/ma12060898

Abstract

Size-controlled gold nanoparticles (AuNPs) were synthesised with solutions of three types of Polish honeys (lime, multiflower, honeydew) and used in microwave-induced hyperthermia cancer treatment. Optical and structural properties of nanostructures were optimized in reference to measurements made by using UV/Vis absorption spectrophotometry (UV/Vis), transmission electron microscopy (TEM) supported by energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and attenuated total reflectance Fourier transformation infrared spectroscopy (ATR FT-IR). In addition, concentrations of reducing sugars and polyphenols of honeys applied were determined to reveal the role of these chemical compounds in green synthesis of AuNPs. It was found that the smallest AuNPs (20.6 ± 23.3 nm) were produced using a 20% (w/v) multiflower aqueous honey solution and 25 mg·L−1 of Au(III) ions. These AuNPs were then employed in microwave-induced hyperthermia in a system simulating metastatic tissues. This research illustrated that AuNPs, as produced with the aid of a multiflower honey solution, could be suitably used for microwave-induced heating of cancer. A fluid containing resultant Au nanostructures, as compared to water, revealed facilitated heating and the ability to maintain a temperature of 45 °C required for hyperthermia treatment.

Highlights

Gold nanoparticles (AuNPs) are classified as three-dimensional nanomaterials (NMs) in which at least one of the dimensions in the structure is less than 100 nm [1]
Since hyperthermia-based medical procedures rely on the susceptibility of metastatic tissues to be destroyed at elevated temperatures (41–47 ◦ C) [22], the increase in the thermal response of the area surrounding a tumour may lead to more effective treatment
It was noted that the formation of AuNPs, emanated by the appearance of the ruby-red colour of mixed solutions, strongly depended on the type of honey used for synthesis, as well as the concentration of honey, and the concentration of Au(III) ions in resultant mixed solutions

Summary

Introduction

Gold nanoparticles (AuNPs) are classified as three-dimensional nanomaterials (NMs) in which at least one of the dimensions in the structure is less than 100 nm [1]. Due to their high surface to volume ratio, AuNPs display unique conductive, catalytic, optical, structural, thermal, and thermoplasmonic properties [2,3,4,5,6,7] For that reason, they are widely utilized as conductors for flexible electronics [8], catalysts for polymerization of alkylosilanes [9], detectors for severe acute respiratory syndrome (SARS) coronavirus [10], contrast agents in X-ray imaging [11], vehicles for drug delivery [12], agents in photo-induced hyperthermia [13], and in microwave-induced hyperthermia treatment of cancer [14]. In2019, this12,work, the possibility of applying three different types of Polish honeys, i.e.,3 of lime, multi-flower, and honeydew, for green synthesis of size-defined AuNPs with a possible use in induced hyperthermia treatment of cancer was examined. By tuning the type of applied aqueous microwave-induced hyperthermia treatment of cancer was examined.

Methods

Characterization of AuNPs Produced under Optimal Conditions

Qualitative Analyses of Chemical Compounds in Honey Solutions

Thermal Behaviour of AuNPs in a Microwave Radiation Field

Results and Discussion

Morphology of AuNPs Synthesized under Selected Conditions

Application of AuNPs in Microwave-Induced Hyperthermia

Conclusions