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Ця стаття присвячена вивченню різних наноматеріалів на основі вуглецю як фотоакустичних контрастних речовин. Дослідницька робота проводилася на фантомі тканини на основі агарози, що містить включення з карбоновими наноматеріалами та без них. Включення було створено з більш високою густиною порівняно з фантомом з метою імітування пухлини. Для вимірювання рівня фотоакустичного сигналу та його підсилення, спричиненого наявністю нановключень, було використано спеціально розроблений фотоакустичний зонд. Зонд складається з буфера для часового розділення сигналу, що надходить від джерела збудження, п'єзоелектричного перетворювача та підсилювача. Точкові вимірювання сигналу проводилися для отримання двовимірної карти величини фотоакустичного сигналу та фазової затримки реєстрації сигналу. На основі затримки фази реконструювали фотоакустичні 3D зображення шляхом оцінки координати глибини на основі швидкості звуку в тканині. Як джерело збудження було використано світлове випромінювання від Nd:YAG лазера з тривалістю імпульсу 16 нс та довжиною хвилі 1064 нм. По-перше, ми розглядали тканинний фантом із пухлиною, покритою оксидом графена (GO) в якості контрольного. Показано, що використання GO призводить до значного поліпшення контрасту зображення. Далі систематично вивчалися пухлини, покриті нанодіамантами (NDs) та наночастинками фтороксиду вуглецю (CFO). Амплітуда фотоакустичних сигналів, зареєстрованих від таких фантомів пухлини, на порядок менша, ніж сигнал, одержуваний від GO. Всі три типи досліджуваних наноматеріалів на основі вуглецю (GO, NDs, CFO) дають стабільний фотоакустичний сигнал, що дозволяє вважати їх хорошими кандидатами для подальших експериментів in vitro у фотоакустичній візуалізації для біологічних застосувань. Залежності рівня сигналу від концентрації наночастинок вимірювали для окремих типів наночастинок. Враховуючи набагато ефективніше проникнення NDs та CFO наночастинок всередину клітин, а також їх надзвичайно низьку цитотоксичність, ці обидва типи вуглецевих наноматеріалів можуть бути використані для подальших експериментів in vivo. This paper is devoted to the study of various carbon-based nanomaterials as photoacoustic contrast agents. The research work was performed on agarose-based tissue phantom containing inclusions with and without carbon-based nanomaterials. The inclusion was created with the higher density compared to phantom in order to simulate a tumor. A specially designed photoacoustic probe was introduced for measuring a level of photoacoustic signal and its enhancement caused by the nanoinclusions presence. The probe consists of a buffer for time separation of the signal coming from the excitation source, piezoelectric transducer, and amplifier. A point-by-point measurement of the signal was performed to obtain a two-dimensional map from magnitude of photoacoustic signal and phase delay of the signal registration. From phase delay the 3D photoacoustic images were reconstructed by evaluation of the depth coordinate based on the tissue sound velocity. As an excitation source the light radiation from Nd:YAG laser with a 16 ns pulse duration and a 1064 nm wavelength was used. Firstly, we considered tissue phantom with a tumor covered by graphene oxide as a reference one. It has been shown that the use of graphene oxide leads to significant improvement of the image contrast. Further, the tumors labelled with nanodiamonds (NDs) and carbon fluoroxide (CFO) nanoparticles (NPs) were studied systematically. Amplitude of the photoacoustic signals registered from such tumor phantoms are one order of magnitude lower than the signal ensured by graphene oxide. All three types of the studied carbon-based nanomaterials (GO, NDs, CFO) give stable photoacoustic signal, this allows to consider them as good candidates for further in-vitro experiments in photoacoustic imaging for biological applications. The dependences of the signal level as a function of the NPs concentration were measured for types of NPs. Considering much more efficient penetration of NDs and CFO NPs inside the cells as well as their extremely low cytotoxicity, these both types of carbon nanomaterials could be used for further in-vivo experiments.

Laser ultrasound enhancement with carbon-based nanomaterials incorporated into phantom tissues is reported. More specifically, impact of nanodiamonds and graphene oxide on the efficiency of photoinduced pressure excitation was investigated. Agarose-based phantom tissues with and without the nanoparticles were compared. The second harmonic of pulsed Nd:Yag laser (532 nm) was chosen for ultrasound generation. Specific acoustic probe was fabricated for laser-induced ultrasound registration. Dependence of the ultrasound amplitude on concentration of the nanoparticles incorporated into the phantom tissues was analyzed in details. The most significant enhancement of the amplitude ensured by graphene oxide was stated. Considering biocompatibility of the both types of carbon-based nanomaterials, they can be potentially used in future as contrast agents for bio-imaging and theranostic applications.

The research and development for biomedical applications are recently focused on multifunctional nanoparticles. To integrate various functionalities, different methods of modifying the particle’s physical properties are developed. Among the considered, nanodiamond (ND) is a promising candidate for the development of multifunctional complex due to its variable features in size, structure, surface chemistry, physical properties, and biocompatibility. In addition to its well-studied structural, surface, electrochemical and photonic properties, strong magnetism of ND can be observed. In the present work, magnetically modified ND is introduced in terms of its bioapplications. Along with the soft ferromagnetism of ND, the increased fluorescence at one- and two-photon excitation is realized. Utilizing the combined magnetic and fluorescence properties of the magnetically modified ND, fluorescence imaging, fluorescence lifetime imaging and manipulation of cells by magnetic field are demonstrated. The perspectives to use the magnetic ND for drug delivery, cells magnetic separation and filtration, in bioengineering to control the cell distribution combined with imaging and treatment are discussed.

This errata corrects an error in “Multifunctional biomedical applications of magnetic nanodiamond.”

Nanodiamond powder, first discovered in 1963 in the Soviet Union, has recently become one of the most promising and well-studied nanomaterials applied in various fields of science, technology and medicine. However, in spite of the unique properties of nanodiamonds, developed applications and the scaled manufacturing process, the nanodiamond global market still remains in its initial stage. The main factor limiting the extensive use of nanodiamonds in industry is the lack of consistency with regards to quality and there is wide variability in their performance in diverse technological processes. This is caused mainly by the uncontrolled character of the existing technology for nanodiamond fabrication, which is based on detonation in a closed chamber. Therefore, the development of alternative technologies, enabling control of the synthesis process, is important as it can provide high quality nanodiamonds for electronics, optics, energy and pharmacology. This chapter reports on a controlled green technology for the synthesis of nanodiamonds by the treatment of specially prepared hydrocarbon targets. Characterization of the nanodiamonds is performed by modern technology and some of the technological opportunities are discussed with regards to nanodiamond applications.

Nanodiamond powder (ND) has become one of the most promising and well-studied nanomaterials applied in various fields of science, technology and medicine. Recent achievements in the development of advanced ND applications present new demands to ND quality: purity, homogeneity of primary particle dimensions and surface area chemistry. ND produced by state-of-the-art technology of detonation synthesis doesn’t meet requirements for biomedical and optical applications. Therefore, alternative methods of ND synthesis from pure carbon raw materials enabling to control the process are of especial importance.The novel technology for ND laser synthesis has been developed by Ray Techniques Ltd. The method is based on high-intensive laser radiation treatment of the specially prepared target containing non-diamond carbon soot and hydrocarbons, placed in a liquid media. As a result, carbon atoms collect to form a cubic diamond crystalline lattice. To reach that, the appropriate parameters of the laser radiation, special composition of the target and the liquid media, as well as the treatment procedures were determined. The “winning” combination of these factors enables to obtain pure nanodiamonds (RayND). In contrast to the existing technology, the RT method is highly controllable, environment-friendly and efficient.RayND obtained under different conditions were studied and compared with detonation ND currently available at the market. It is proved that the higher level of purity and homogeneity of RayND constitutes significant advantages for most ND applications. Using RayND opens new frontiers in biomedicine (drug- and gene-delivery and bio-imaging agents), electronic industry (abrasives for wafer polishing, heat-conductive electrical-insulating compounds, CVD coatings, emitters, etc) and optics (displays, protective transparent films, laser lenses, optical windows and filters).