All-in-One Photoactivated Inhibition of Butyrylcholinesterase Combined with Luminescence as an Activation and Localization Indicator: Carbon Quantum Dots@Phosphonate Hybrids.

Photopharmacology is a booming research area requiring a new generation of agents possessing simultaneous functions of photoswitching and pharmacophore. It is important that any practical implementation of photopharmacology ideally requires spatial control of the medicinal treatment zone. Thus, advances in the study of substances meeting all the listed requirements will lead to breakthrough research in the coming years. In this study, CQDs@phosphonate nanohybrids are presented for the first time and combine biocompatible and nontoxic luminescent carbon quantum dots (CQDs) with photoactive phosphonate enabling inhibition of butyrylcholinesterase (BChE), which is a prognostic marker of numerous diseases. The conjunction of these components in hybrids maintains photoswitching and provides enhancement of BChE inhibition. After laser irradiation with a wavelength of 266 nm, CQDs@phosphonate hybrids demonstrate a drastic increase of butyrylcholinesterase inhibition from 38% up to almost 100% and a simultaneous luminescence decrease. All the listed hybrid properties are demonstrated not only for in vitro experiments but also for complex biological samples, i.e., chicken breast. Thus, the most important achievement is the demonstration of hybrids characterized by a remarkable combination of all-in-one properties important for photopharmacology: (i) bioactivity toward butyrylcholinesterase inhibition, (ii) strong change of inhibition degree as a result of laser irradiation, luminescence as an indicator of (iii) bioactivity state, and of (iv) spatial localization on the surface of a sample.

High-performance size exclusion chromatography with online fluorescence and multi-wavelength absorbance detection for isolation of high-purity carbon dots fractions, free of non-fluorescent material.

The carbon dots (CDs) from natural nanographite oxide mixture (NGO-MIX) and from its fraction NGO (3.5-10K) recovered after ultrafiltration and dialysis were analyzed by 3D-excitation/emission matrix and high-performance size exclusion chromatography (HPSEC) combined with online fluorescence and absorbance detections. HPSEC chromatograms obtained simultaneously with absorption within the wavelength range 200-500 nm and fluorescence detection at λexc/λem = 270/450 nm/nm showed that NGO-MIX sample is not homogeneous and consist of well resolved CDs fractions with different sizes, absorption spectra and distinct fluorescence and non-fluorescence properties. Despite the twice higher fluorescence intensity of fraction NGO (3.5-10K) compared to the NGO-MIX, some impurity of non-fluorescent components was detected by HPSEC. The absorbance spectra of chromatographic peaks, extracted from the data of multi-wavelength absorbance detector, demonstrated different combinations of absorbance maxima. It means that different chromatographic peaks correspond to sized and chemically different CDs fractions. This study demonstrated for the first time the possibility of separating oxidized nanographite into homogeneous free from non-fluorescent material CDs fractions with their simultaneous spectroscopic characterization.

Boron-Doped Nanodiamonds as Anticancer Agents: En Route to Hyperthermia/Thermoablation Therapy.

Local targeted "inside-out" hyperthermia of tumors via nanoparticles is able to sensitize tumor cells to chemotherapy, radiation therapy, gene therapy, immunotherapy, or other effects, significantly reducing the duration and intensity of treatment. In this article, new nanomaterials are proposed to be used as anticancer agents: boron-doped nanodiamonds with sizes of about 10 nm synthesized for the first time by the high-temperature high-pressure (HTHP) method. The heating ability of boron-doped nanodiamonds was investigated under different heating conditions in different environments: water, chicken egg white, and MCF-7 breast cancer cells. It was discovered that, with the same conversion of the absorbed energy into heat, the ability to heat the environment when excited at a wavelength of 808 nm of boron-doped nanodiamonds is much higher than that of detonation nanodiamonds. It was established that boron-doped nanodiamonds are extremely promising for carrying out hyperthermia and thermoablation of tumors.

Nanodiamonds and surfactants in water: Hydrophilic and hydrophobic interactions.

HYPOTHESIS: Nanodiamonds, one of the most promising nanomaterials for the use in biomedicine, placed in the organisms are bound to interact with various amphiphilic lipids and their micelles. However, while the influence of surfactants, the close relative of lipids, on the properties of colloidal nanodiamonds is well studied, the influence of nanodiamonds on the properties of surfactants, lipids, and, therefore, on the structure of surrounding tissues, is poorly understood. EXPERIMENT: In this work, the influence of interactions of hydrophobic and hydrophilic nanodiamonds with ionic surfactant sodium octanoate in water on hydrogen bonds, the properties of the surfactant and micelle formation were studied using Raman spectroscopy and dynamic light scattering technique. FINDINGS: Nanodiamonds are found to actively influence the bulk properties only of the premicellar surfactant solutions: the strength of hydrogen bonds, ordering and conformation of hydrocarbon tails, the critical micelle concentration. This influence is deduced to be dependent on two mechanisms not unique to nanodiamonds: (1) the induction of micro-flows around nanoparticles undergoing Brownian motions, and (2) the creation of the chaotic state in the surfactant solutions if two or more incompatible types of interactions between nanoparticles' surfaces and surfactants are similarly favorable, e.g. hydrophobic interaction and Coulomb attraction.

Optical imaging of fluorescent carbon biomarkers using artificial neural networks.

The principle possibility of extraction of fluorescence of nanoparticles in the presence of background autofluorescence of a biological environment using neural network algorithms is demonstrated. It is shown that the methods used allow detection of carbon nanoparticles fluorescence against the background of the autofluorescence of egg white with a sufficiently low concentration detection threshold (not more than 2 µg/ml for carbon dots 3 µg/ml and for nanodiamonds). It was also shown that the use of the input data compression can further improve the accuracy of solving the inverse problem by 1.5 times.