Control of Arms of Au Stars Size and its Dependent Cytotoxicity and Photosensitizer Effects in Photothermal Anticancer Therapy

Abstract

Gold nanostars (AuS NPs) are a very attractive nanomaterial, which is characterized by high effective transduction of the electromagnetic radiation into heat energy. Therefore, AuS NPs can be used as photosensitizers in photothermal therapy (PTT). However, understanding the photothermal conversion efficiency in nanostars is very important to select the most appropriate shape and size of AuS NPs. Therefore, in this article, the synthesis of AuS NPs with different lengths of star arms for potential application in PTT was investigated. Moreover, the formation mechanism of these AuS NPs depending on the reducer concentration is proposed. Transmission electron microscopy (TEM) with selected area diffraction (SEAD) and X-ray diffraction (X-Ray) showed that all the obtained AuS NPs are crystalline and have cores with similar values of the diagonal (parameter d), from 140 nm to 146 nm. However, the widths of the star arm edges (parameter c) and the lengths of the arms (parameter a) vary between 3.75 nm and 193 nm for AuS1 NPs to 6.25 nm and 356 nm for AuS4 NPs. Ultraviolet-visible (UV-Vis) spectra revealed that, with increasing edge widths and lengths of the star arms, the surface plasmon resonance (SPR) peak is shifted to the higher wavelengths, from 640 nm for AuS1 NPs to 770 nm for AuS4 NPs. Moreover, the increase of temperature in the AuS NPs solutions as well as the values of calculated photothermal efficiency grew with the elongation of the star arms. The potential application of AuS NPs in the PTT showed that the highest decrease of viability, around 75%, of cells cultured with AuS NPs and irradiated by lasers was noticed for AuS4 NPs with the longest arms, while the smallest changes were visible for gold nanostars with the shortest arms. The present study shows that photothermal properties of AuS NPs depend on edge widths and lengths of the star arms and the values of photothermal efficiency are higher with the increase of the arm lengths, which is correlated with the reducer concentration.

Dual Imaging Gold Nanoplatforms for Targeted Radiotheranostics

“…Up to the present time, there are no Gd 3+ -bearing AuNPs that have been evaluated in clinical trials for MRI, and PET/MRI bimodal imaging studies are in general scarce [36][37][38][39]. While some studies have been done regarding the application of AuNPs for theranostics, their therapeutic function is mostly based on the photothermal properties of the AuNPs themselves or on the delivery of a payload acting as a cytotoxic drug [40][41][42][43][44][45][46]. There are some examples of AuNPs that have been evaluated in the delivery of medically relevant radionuclides, aiming to obtain "radiotheranostic" agents suitable to provide clear and sensitive tumor detection and selective therapeutic effects [47,48].…”

Next-generation engineered nanogold for multimodal cancer therapy and imaging: a clinical perspectives

“…Another study showed that Au nanostars have a unique symmetrical structure and sharp edges that enable the LSPR peak modulation of Au nanostars in the NIR region [ 39 ]. Depciuch et al showed that the PTT effect of Au nanostars depends on edge widths and lengths of the star arms and the values of photothermal efficiency are higher with the increase of the arm lengths, which is correlated with the reducer concentration [ 40 ]. Therefore, the dispersion and absorption properties of AuNPs can be changed by tuning the shapes and sizes of AuNPs [ 41 ].…”

<p>Assessing Cobalt Metal Nanoparticles Uptake by Cancer Cells Using Live Raman Spectroscopy</p>

“…14 Nanotheranostics, 15 which combine both therapeutic and diagnostic capabilities at the nanoscale, have broadened the perspectives of personalized medicine. 16,17 Other targeted applications in the field of nanomedicine have also been investigated, such as photodiagnostic and photothermal anticancer therapy (PTT) using platinum nanoparticles 18 or gold nanoparticles, [19][20][21] as well as nano-loaded stem cell delivery. 22 Moreover, cancer nanotechnology is a fast growing area of research in nanomedicine mainly because systemic application of anticancer drugs has certain drawbacks with regards to side-effects, non-effective drug concentration at the target area and its en-route degradation.…”