New Insight into the Fluorescence Quenching of Nitrogen-Containing Carbonaceous Quantum Dots-From Surface Chemistry to Biomedical Applications.

Carbon-based quantum dots are widely suggested as fluorescent carriers of drugs, genes or other bioactive molecules. In this work, we thoroughly examine the easy-to-obtain, biocompatible, nitrogen-containing carbonaceous quantum dots (N-CQDs) with stable fluorescent properties that are resistant to wide-range pH changes. Moreover, we explain the mechanism of fluorescence quenching at extreme pH conditions.

A New Approach to Obtaining Nano-Sized Graphene Oxide for Biomedical Applications.

Graphene oxide (GO) is one of the most exciting and widely used materials. A new method of nanographene oxide (n-GO) formation is presented. The described unique sequence of ultrasonication in dimethyl sulfoxide solution allows us to obtain different sizes of n-GO sheets by controlling the timing of the cutting and re-aggregation processes.

Cytotoxic or Not? Disclosing the Toxic Nature of Carbonaceous Nanomaterials through Nano-Bio Interactions.

The cytotoxic influence of two different carbonaceous nanomaterials on human mesenchymal stem cells (MSCs) cultured in vitro was compared in the short (1-3 days) and long term (up to 60 days). Amorphous carbon and single-walled carbon nanotubes were chosen and evaluated due to their contrasting physicochemical properties. Both materials, though supposed similarly low-toxic in basic short-term cytotoxicity assays, demonstrated dramatically different properties in the long-term study.

Electrophoretic Deposition of Layer-by-Layer Unsheathed Carbon Nanotubes-A Step Towards Steerable Surface Roughness and Wettability.

It is well known that carbon nanotube (CNT) oxidation (usually with concentrated HNO) is a major step before the electrophoretic deposition (EPD). However, the recent discovery of the "onion effect" proves that multiwalled carbon nanotubes are not only oxidized, but a simultaneous unsheathing process occurs. We present the first report concerning the influence of unsheathing on the properties of the thus-formed CNT surface layer.

Carbonaceous Nanomaterials-Mediated Defense Against Oxidative Stress.

The concept of nanoscale materials and their applications in industrial technologies, consumer goods, as well as in novel medical therapies has rapidly escalated in the last several years. Consequently, there is a critical need to understand the mechanisms that drive nanomaterials biocompatibility or toxicity to human cells and tissues. The ability of nanomaterials to initiate cellular pathways resulting in oxidative stress has emerged as a leading hypothesis in nanotoxicology.

Cystine-based MBioF for Maintaining the Antioxidant-Oxidant Balance in Airway Diseases.

Reactive oxygen species, contributing to oxidant-antioxidant imbalance, initiate damage to the airways cells, inflammatory processes, and further pathophysiological effects. Enhancing antioxidant properties is the main prophylactic and therapeutic challenge. In this work, a newly synthesized and biocompatible structure of the metal-biomolecule frameworks (MBioF) harnessing cystine as a linker and magnesium as metal nodes is presented.

Chemical and Biochemical Approach to Make a Perfect Biocatalytic System on Carbonaceous Matrices.

Enzymatic processes are widely used in food industry, pharmacy, cosmetic and household chemistry, and medicine. However, the common and efficient application of the biological catalysts is limited by a number of factors that influence enzymes activity. One of the most frequent methods to improve the biocatalysts' properties is immobilization.

Graphene Oxide-Mediated Protection from Photodamage.

This Letter presents the unique properties of graphene oxide (GO) as a multitask material protecting from UVB-induced photodamage. Three mechanisms of GO action on fibroblast in vitro cultures are verified here: physical - a barrier blocking UV radiation; chemical - antioxidative activity; and biological - activation of cellular antioxidative defense. The changes in GO physicochemical properties appearing due to UVB exposure underpin the observed UV protection phenomena.

Novel biocatalytic systems for maintaining the nucleotide balance based on adenylate kinase immobilized on carbon nanostructures.

In this study graphene oxide (GO), carbon quantum dots (CQD) and carbon nanoonions (CNO) have been characterized and applied for the first time as a matrix for recombinant adenylate kinase (AK, EC 2.7.4.

Controlling enzymatic activity by immobilization on graphene oxide.

In this study, graphene oxide (GO) has been applied as a matrix for enzyme immobilization. The protein adsorption capacity of GO is much higher than of other large surface area carbonaceous materials. Its structure and physicochemical properties are reported beneficial also for enzymatic activity modifications.

Air pollution, UV irradiation and skin carcinogenesis: what we know, where we stand and what is likely to happen in the future?

The link between air pollution, UV irradiation and skin carcinogenesis has been demonstrated within a large number of epidemiological studies. Many have shown the detrimental effect that UV irradiation can have on human health as well as the long-term damage which can result from air pollution, the European ESCAPE project being a notable example. In total, at present around 2800 different chemical substances are systematically released into the air.

Conscious Changes of Carbon Nanotubes Cytotoxicity by Manipulation with Selected Nanofactors.

We discuss eight major challenges in the field of carbon nanomaterial toxicity. Generally, we pick up some of them, and the most important challenge is searching of the qualitative relationships between nanofactors and cytotoxicity. This is important since it can provide the possibility of conscious changes of carbon nanotubes cytotoxicity by manipulation with selected nanofactors.