A Comparative Study of Cytotoxicity of PPG and PEG Surface-Modified 2-D Ti3C2 MXene Flakes on Human Cancer Cells and Their Photothermal Response

Abstract

The MXenes are a novel family of 2-D materials with promising biomedical activity, however, their anticancer potential is still largely unexplored. In this study, a comparative cytotoxicity investigation of Ti3C2 MXenes with polypropylene glycol (PPG), and polyethylene glycol (PEG) surface-modified 2-D Ti3C2 MXene flakes has been conducted towards normal and cancerous human cell lines. The wet chemical etching method was used to synthesize MXene followed by a simple chemical mixing method for surface modification of Ti3C2 MXene with PPG and PEG molecules. SEM and XRD analyses were performed to examine surface morphology and elemental composition, respectively. FTIR and UV-vis spectroscopy were used to confirm surface modification and light absorption, respectively. The cell lines used to study the cytotoxicity of MXene and surface-modified MXenes in this study were normal (HaCaT and MCF-10A) and cancerous (MCF-7 and A375) cells. These cell lines were also used as controls (without exposure to study material and irradiation) to measure their baseline cell viability under the same lab environment. The surface-modified MXenes exhibited a sharp reduction in cell viability towards both normal (HaCaT and MCF-10A) and cancerous (MCF-7 and A375) cells but cytotoxicity was more pronounced towards cancerous cell lines. This may be due to the difference in cell metabolism and the occurrence of high pre-existing levels of reactive oxygen species (ROS) within cancerous cells. The highest toxicity towards both normal and cancerous cell lines was observed with PEGylated MXenes followed by PPGylated and bare MXenes. The normal cell’s viability was barely above 70% threshold with 250 mg/L PEGylated MXene concentration whereas PPGylated and bare MXene were less toxic towards normal cells, even at 500 mg/L concentration. Moreover, the toxicity was found to be directly related to the type of cell lines. In general, the HaCaT cell line exhibited the lowest toxicity while toxicity was highest in the case of the A375 cell line. The photothermal studies revealed high photo response for PEGylated MXene followed by PPGylated and bare MXenes. However, the PPGylated MXene’s lower cytotoxicity towards normal cells while comparable toxicity towards malignant cells as compared to PEGylated MXenes makes the former a relatively safe and effective anticancer agent.

Safety Assessment of 2D MXenes: In Vitro and In Vivo

“…Rashid et al conjugated polypropylene glycol (PPG) and polyethylene glycol (PEG) to the surfaces of Ti 3 C 2 T x nanosheets [ 54 ] and assessed their cytotoxicity towards normal (HaCaT and MCF-10A) and cancerous (MCF-7 and A375) cells. PEG-modified Ti 3 C 2 T x nanosheets were the most toxic to normal and cancer cell lines, followed by PPG-modified nanosheets, and the least toxic were bare MXenes.…”

MXene-Assisted Ablation of Cells with a Pulsed Near-Infrared Laser

“…Reports from other groups studying the toxicity of MXenes also generally show a lack of the typical sigmoid dose–response relationship (e.g., refs − ). Thus, the HaCat cells with the Ti 3 C 2 MXene showed a detectable decrease in viability with the increase in concentration of MXenes from 0 to 1 μg/mL.…”

Ti3C2 MXene Nanosheets Functionalized with NaErF4:0.5%Tm@NaLuF4 Nanoparticles for Dual-Modal Near-Infrared IIb/Magnetic Resonance Imaging-Guided Tumor Hyperthermia

“…46 Noble metals were grown on MXenes for multimodal imaging-guided PTT. 37,47 However, there are still numerous obstacles and challenges in giving Ti 3 C 2 MXenes more functionalities for therapeutic application. NaErF 4 :0.5%Tm@NaLuF 4 is a new self-sensitized rare earth nanomaterial that we and other researchers recently discovered.…”

“…MXenes are obtained by stripping element A from the ternary carbide of the layered MAX phase, where M denotes a transition metal, A refers to the element from the periodic table’s group IIIA or IVA, and X is C or N, such as Ti 3 AlC 2 . − MXenes have been explored for catalysis, − energy storage, , and conversion ,, due to their metallic conductivities, hydrophilicities, and good mechanical properties. In particular, Ti 3 C 2 MXenes have recently attracted great interest in biomedical applications because of their remarkable chemical and physical properties. − For example, the constituent elements of Ti 3 C 2 are either necessary elements or inert to biological organisms, ensuring biosafety. Ti 3 C 2 MXenes exhibit a large surface area and strong absorbance in the near-infrared region, allowing for drug delivery and synergistic cancer therapy. ,,− A MnO x /Ti 3 C 2 composite, for example, was created for dual-modality photoacoustic (PA) and magnetic resonance (MR) imaging-guided PTT against cancer .…”

“…Ti 3 C 2 /g-C 3 N 4 heterostructures were fabricated for PDT and PTT . Noble metals were grown on MXenes for multimodal imaging-guided PTT. , However, there are still numerous obstacles and challenges in giving Ti 3 C 2 MXenes more functionalities for therapeutic application.…”