Promoting Cell Proliferation Using Water Dispersible Germanium Nanowires

Abstract

Group IV Nanowires have strong potential for several biomedical applications. However, to date their use remains limited because many are synthesised using heavy metal seeds and functionalised using organic ligands to make the materials water dispersible. This can result in unpredicted toxic side effects for mammalian cells cultured on the wires. Here, we describe an approach to make seedless and ligand free Germanium nanowires water dispersible using glutamic acid, a natural occurring amino acid that alleviates the environmental and health hazards associated with traditional functionalisation materials. We analysed the treated material extensively using Transmission electron microscopy (TEM), High resolution-TEM, and scanning electron microscope (SEM). Using a series of state of the art biochemical and morphological assays, together with a series of complimentary and synergistic cellular and molecular approaches, we show that the water dispersible germanium nanowires are non-toxic and are biocompatible. We monitored the behaviour of the cells growing on the treated germanium nanowires using a real time impedance based platform (xCELLigence) which revealed that the treated germanium nanowires promote cell adhesion and cell proliferation which we believe is as a result of the presence of an etched surface giving rise to a collagen like structure and an oxide layer. Furthermore this study is the first to evaluate the associated effect of Germanium nanowires on mammalian cells. Our studies highlight the potential use of water dispersible Germanium Nanowires in biological platforms that encourage anchorage-dependent cell growth.

Investigation of the cytotoxicity of aluminum oxide nanoparticles and nanowires and their localization in L929 fibroblasts and RAW264 macrophages

“…A recent study has shown the biocompatibility of SiC/SiO 2 NWs according to a cell viability assay (A549, HuDe, MCF‐7, and THP‐1 cells) . When germanium NWs were applied to L929 cells, an increase in cell proliferation was recorded using MTT and WST‐1 assays and by quantifying the number of cells . In contrast, another report has demonstrated that β‐SiC NWs induce apoptosis due to oxidative stress in MC3T3‐E1 cells after 48 h exposure to NWs, even though their cell viability remains high after 24 h exposure (MTT assay) .…”

A review on nanotoxicity and nanogenotoxicity of different shapes of nanomaterials

“…Therefore, the cytotoxicity of Ge NPs has been subject to some research over the years. For instance, researchers using MTT and WST-1 assays to measure cell viability in L929 cells upon exposure to Ge NWs observed an increased cell proliferation, concluding that water-soluble wires were non-toxic and biocompatible (Bezuidenhout et al, 2014). However, another study demonstrated that β-silicon carbide (SiC) NWs might induce apoptosis through oxidative stress in MC3T3-E1 cells after an incubation period of 48 h, although the cell viability remained relatively high after 24 h of exposure (MTT assay) (Xie et al, 2014).…”

Engineered nanoparticle bio-conjugates toxicity screening: The xCELLigence cells viability impact

“…14,21,[27][28][29]37 The in vivo animal model provided further toxicity information where 3 out of 9 of the in vivo animal model studies indicated partial nontoxic animal effect, one was toxic while the remaining results recommended ENPBCs as a potential candidate for drug therapy with limited information on toxicity (Table S2). Some of the in vivo ENPBCs toxicity effects demonstrated programmed cell death, causing the release of H 2 S. 29 The ENPBCs that exhibited in vivo nontoxic effect were mostly those that had the therapeutic effects of antibody-drug conjugate, 27 CTAB layers of gold for diagnosing rheumatoid arthritis, 30 surface coating polymeric NPs used for inhibiting cancerous cells 31,[38][39][40][41][42][43][44][45][46][47] and felodipine-loaded polymers for pathological examination of different organs of Wister albino mice 50. The ENPBCs with partial nontoxic effect were chitosan-coated polymers for drug delivery, 49 silver NPs coated polymers that were found localized in various body organs, 48 and drug delivery polymeric NPs for anticancer. 51 The findings indicated limited data and information regarding the regulation of ENPBCs toxicity.…”

“…Moreover, the limitations are also prevalent despite a host of other instruments including UV-Vis absorption spectroscopy, TEM, SEM, HrTEM, DLS, HPLC, ICP-MS, FTIR, and AFM for characterizing ENPBCs properties, 9 as listed in Table S1. 14 , 21 - 43 …”

“…The eligible studies were further screened for duplicates and other irrelevant studies. To reduce discrepancies, a clear screening and selection approach was used based on the headings generated in Tables S1 14 , 21 - 43 and S2 24 , 28 - 31 , 38 , 44 - 51 (see Supplementary file 1 ). Similarly, some findings were further discussed to find a suitable outcome especially for the same studies extracted from conference abstracts and the full published articles.…”