Mateusz Wierzbicki

In vitro evaluation of the effects of graphene platelets on glioblastoma multiforme cells.

Graphene is a single atom-thick material with exciting potential. It can be used in many fields, from electronics to biomedicine. However, little is known about its toxicity and biocompatibility. Herein, we report a study on the toxicity of graphene platelets (GPs) by examining the influence of GPs on the morphology, mortality, viability, membrane integrity, and type of cell death of U87 and U118 glioma cells. It was found that graphene is toxic to glioma cells, but it activated apoptosis only in the U118 cell line, without inducing necrosis, indicating the potential applicability of GP in anticancer therapy.

Nanoparticles of Copper Stimulate Angiogenesis at Systemic and Molecular Level

Copper is a key element affecting blood vessel growth and muscle development. However, the ions released from Cu salts are toxic. Given their specific physicochemical properties, nanoparticles of Cu (NanoCu) may have different bioactivity and affect the development of blood vessel and muscles in a different manner than Cu salts. The objective of the study was to evaluate the influence of NanoCu on embryo development and angiogenesis at the systemic and molecular level, in experiments using a chick embryo model. Fertilized chicken eggs were divided into a control group, and groups injected with a placebo, CuSO4 or NanoCu. Embryo development at the whole body level and molecular indices using an embryo chorioallantoic membrane model were measured during embryogenesis. The present study indicated for the first time that NanoCu have pro-angiogenic properties at the systemic level, to a greater degree than CuSO4 salt. The properties of NanoCu were confirmed at the molecular level, demonstrating significant effects on mRNA concentration and on mRNA gene expression of all pro-angiogenic and pro-proliferative genes measured herein.

In vitro and in vivo effects of graphene oxide and reduced graphene oxide on glioblastoma

Graphene and its related counterparts are considered the future of advanced nanomaterials owing to their exemplary properties. However, information about their toxicity and biocompatibility is limited. The objective of this study is to evaluate the toxicity of graphene oxide (GO) and reduced graphene oxide (rGO) platelets, using U87 and U118 glioma cell lines for an in vitro model and U87 tumors cultured on chicken embryo chorioallantoic membrane for an in vivo model. The in vitro investigation consisted of structural analysis of GO and rGO platelets using transmission elec tron microscopy, evaluation of cell morphology and ultrastructure, assessment of cell viability by XTT assay, and investigation of cell proliferation by BrdU assay. Toxicity in U87 glioma tumors was evaluated by calculation of weight and volume of tumors and analyses of ultrastructure, histology, and protein expression. The in vitro results indicate that GO and rGO enter glioma cells and have different cytotoxicity. Both types of platelets reduced cell viability and proliferation with increasing doses, but rGO was more toxic than GO. The mass and volume of tumors were reduced in vivo after injection of GO and rGO. Moreover, the level of apoptotic markers increased in rGO-treated tumors. We show that rGO induces cell death mostly through apoptosis, indicating the potential applicability of graphene in cancer therapy.

Nanoparticles of carbon allotropes inhibit glioblastoma multiforme angiogenesis in ovo

The objective of the study was to determine the effect of carbon nanoparticles produced by different methods on the growth of brain tumor and the development of blood vessels. Glioblastoma multiforme cells were cultured on the chorioallantoic membrane of chicken embryo and after 7 days of incubation, were treated with carbon nanoparticles administered in ovo to the tumor. Both types of nanoparticles significantly decreased tumor mass and volume, and vessel area. Quantitative real-time polymerase chain reaction analysis showed downregulated fibroblast growth factor-2 and vascular endothelial growth factor expression at the messenger ribonucleic acid level. The present results demonstrate antiangiogenic activity of carbon nanoparticles, making them potential factors for anticancer therapy.

Toxicity of pristine graphene in experiments in a chicken embryo model

Evaluation of the potential cytotoxicity of graphene is a key factor for medical applications, where flakes or a surface of graphene may be used as bioactive molecules, drug carriers, or biosensors. In the present work, effects of pristine graphene (pG) on the development of a living organism, with an emphasis on morphological and molecular states of the brain, were investigated using a chicken embryo model. Fertilized chicken eggs were divided into the control group and groups administered with pG suspended in milli-Q water at concentrations of 50 μg/L, 100 μg/L, 500 μg/L, 1,000 μg/L, 5,000 μg/L, and 10,000 μg/L (n=30 per group). The experimental solutions were injected in ovo into the albumin and then the eggs were incubated. After 19 days of incubation, the survival, weight of the body and organs, and blood serum biochemical indices were measured. The brain samples were collected for microscopic examination of brain ultrastructure and measurements of gene and protein expression. Survival of embryos was significantly decreased after treatment with pG, but the body and organ weights as well as biochemical indices were not affected. In all treatment groups, some atypical ultrastructures of the brain were observed, but they were not enhanced by the increasing concentrations of pG. Expression of proliferating cell nuclear antigen at the messenger ribonucleic acid level was downregulated, and the number of proliferating cell nuclear antigen-positive nuclei was significantly reduced in the 500–10,000 μg/L groups compared with the control group, indicating a decreased rate of deoxyribonucleic acid synthesis in the brain. The present results demonstrate some harmful effects of the applied pG flakes on the developing organism, including brain tissue, which ought to be considered prior to any medical applications.

Comparison of anti-angiogenic properties of pristine carbon nanoparticles

Angiogenesis is vital for tumour formation, development and metastasis. Recent reports show that carbon nanomaterials inhibit various angiogenic signalling pathways and, therefore, can be potentially used in anti-angiogenic therapy. In the present study, we compared the effect of different carbon nanomaterials on blood vessel development. Diamond nanoparticles, graphite nanoparticles, graphene nanosheets, multi-wall nanotubes and C60 fullerenes were evaluated for their angiogenic activities using the in ovo chick embryo chorioallantoic membrane model. Diamond nanoparticles and multi-wall nanotubes showed the greatest anti-angiogenic properties. Interestingly, fullerene exhibited the opposite effect, increasing blood vessel development, while graphite nanoparticles and graphene had no effect. Subsequently, protein levels of pro-angiogenic growth factor receptors were analysed, showing that diamond nanoparticles decreased the expression of vascular endothelial growth factor receptor. These results provide new insights into the biological activity of carbon nanomaterials and emphasise the potential use of multi-wall nanotubes and diamond nanoparticles in anti-angiogenic tumour therapy.

Influence of nanoparticles of platinum on chicken embryo development and brain morphology

Platinum nanoparticles (NP-Pt) are noble metal nanoparticles with unique physiochemical properties that have recently elicited much interest in medical research. However, we still know little about their toxicity and influence on general health. We investigated effects of NP-Pt on the growth and development of the chicken embryo model with emphasis on brain tissue micro- and ultrastructure. The embryos were administered solutions of NP-Pt injected in ovo at concentrations from 1 to 20 μg/ml. The results demonstrate that NP-Pt did not affect the growth and development of the embryos; however, they induced apoptosis and decreased the number of proliferating cells in the brain tissue. These preliminary results indicate that properties of NP-Pt might be utilized in brain cancer therapy, but potential toxic side effects must be elucidated in extensive follow-up research.

Interaction of graphene family materials with Listeria monocytogenes and Salmonella enterica

Graphene family materials have unique properties, which make them valuable for a range of applications. The antibacterial properties of graphene have been reported; however, findings have been contradictory. This study reports on the antimicrobial proprieties of three different graphene materials (pristine graphene (pG), graphene oxide (GO), and reduced graphene oxide (rGO)) against the food-borne bacterial pathogens Listeria monocytogenes and Salmonella enterica. A high concentration (250 μg/mL) of all the analyzed graphenes completely inhibited the growth of both pathogens, despite their difference in bacterial cell wall structure. At a lower concentration (25 μg/mL), similar effects were only observed with GO, as growth inhibition decreased with pG and rGO at the lower concentration. Interaction of the nanoparticles with the pathogenic bacteria was found to differ depending on the form of graphene. Microscopic imaging demonstrated that bacteria were arranged at the edges of pG and rGO, while with GO, they adhered to the nanoparticle surface. GO was found to have the highest antibacterial activity.

Nanoparticles containing allotropes of carbon have genotoxic effects on glioblastoma multiforme cells

The carbon-based nanomaterial family consists of nanoparticles containing allotropes of carbon, which may have a number of interactions with biological systems. The objective of this study was to evaluate the toxicity of nanoparticles comprised of pristine graphene, reduced graphene oxide, graphene oxide, graphite, and ultradispersed detonation diamond in a U87 cell line. The scope of the work consisted of structural analysis of the nanoparticles using transmission electron microscopy, evaluation of cell morphology, and assessment of cell viability by Trypan blue assay and level of DNA fragmentation of U87 cells after 24 hours of incubation with 50 μg/mL carbon nanoparticles. DNA fragmentation was studied using single-cell gel electrophoresis. Incubation with nanoparticles containing the allotropes of carbon did not alter the morphology of the U87 cancer cells. However, incubation with pristine graphene and reduced graphene oxide led to a significant decrease in cell viability, whereas incubation with graphene oxide, graphite, and ultradispersed detonation diamond led to a smaller decrease in cell viability. The results of a comet assay demonstrated that pristine graphene, reduced graphene oxide, graphite, and ultradispersed detonation diamond caused DNA damage and were therefore genotoxic in U87 cells, whereas graphene oxide was not.

carbon nanoparticles downregulate expression of basic fibroblast growth factor in the heart during embryogenesis

Carbon nanoparticles, with their high biocompatibility and low toxicity, have recently been considered for biomedical applications, including antiangiogenic therapy. Critical to normal development and tumor formation, angiogenesis is the process of forming capillary blood vessels from preexisting vessels. In the present study, we evaluated the effects of diamond and graphite nanoparticles on the development of chicken embryos, as well as vascularization of the chorioallantoic membrane and heart at the morphological and molecular level. Nanoparticles did not affect either body/heart weight or serum indices of the embryos’ health. However, vascularization of the heart and the density of branched vessels were significantly reduced after treatment with diamond nanoparticles and, to a lesser extent, graphite nanoparticles. Application of nanoparticles significantly downregulated gene and protein expression of the proangiogenic basic fibroblast growth factor, indicating that both diamond and graphite nanoparticles inhibit angiogenesis.