scholarly journals Toxicity of Upconversion Nanoparticles. Overview

2020 ◽  
Vol 20 (4) ◽  
pp. 268-277
Author(s):  
Irina Yu. Yanina ◽  
◽  
Vyacheslav I. Kochubey ◽  
Keyword(s):  
Maximum Permissible Concentration ◽  
Biological Tissues ◽  
The Body ◽  
Laboratory Animals ◽  
Fluorescent Light ◽  
Upconversion Nanoparticles ◽  
Concentration Dependences ◽  
Biochemical Studies ◽  
Living Objects

Background and Objectives: The object of the study was the toxicity of upconversion nanoparticles. The aim is to overview the literature on the toxicity of various types of upconversion nanoparticles and to search for their maximum permissible concentration when administered to laboratory animals in vivo. Materials and Methods: The approach used has been the analysis of recent publications on the topic. Results: Upconversion particles are promising for visualization of the structure of biological tissues and organs in fluorescent light, as well as for use in diagnostics of diseases and photoinduced therapy. Nanoparticles with additional shells or functionalized by surface coating with targeted or photoactive molecules, allowing the creation of particles with several modalities, are considered. The phototoxicity of such particles is considered separately. When using nanoparticles for therapy or diagnostics of the state of living objects, the issue of toxicity is urgent. The toxic effect of upconversion nanoparticles on the body depends on their concentration upon administration, as well as on the total amount of nanoparticles correlated with the body weight. Conclusion: From the considered concentration dependences, based on the results of histological and biochemical studies, it was shown that, as a rule, no noticeable toxicity was observed in such particles, and the maximum permissible concentration of particles can be considered 2 mg/ml.

Effect of highly porous bioceramics based on ZrO2 – Y2O3 – CeO2 system on the biological tissues of experimental animals

2020 ◽  
pp. 29-39
Author(s):  
M. V. Kalinina ◽  
◽  
N. Yu. Kovalko ◽  
D. N. Suslov ◽  
Yu. S. Andozhskaia ◽  
...  
Keyword(s):  
Soft Tissues ◽  
Pore Space ◽  
Biological Tissues ◽  
The Body ◽  
Laboratory Animals ◽  
Experimental Animals ◽  
Average Grain Size ◽  
Porous Bioceramics ◽  
Highly Porous

By reverse co-deposition of hydroxides synthesized highly dispersed powder (the average size 8 – 10 nm) of the composition (ZrO2)0.92(Y2О3)0.03(СеО2)0.05, based on it use comprehensive a blowing agent and mechanical activation of the obtained highly porous ceramics (average grain size 60 – 65 nm). The synthesized ceramic material-an implant with an open porosity of 55 % and a pore size of 40 – 800 nm was placed in the body of laboratory animals. The reaction of biological tissues of experimental animals to the introduction of plates made of composite highly porous materials based on t-ZrO2 15 months after their implantation was studied. It is revealed that enhanced revascularization is registered in capsules, and perfusion of tissues is registered in intact zone of ceramics introduction. The possibility of germination of vessels in soft tissues into the available pore space of ceramics is shown. The results obtained in vivo suggest that porous bioceramics based on t-ZrO2 can be used in the production of endoprostheses and implants in such areas of medicine as orthopedics and traumatology.

Measurement of Acoustic Emission Wave Attenuation by Bones and Muscles

2007 ◽  
Author(s):  
Benjamin Pruden ◽  
Ozan Akkus
Keyword(s):  
Acoustic Emission ◽  
Wave Attenuation ◽  
Physiological Activity ◽  
Acoustic Emissions ◽  
Biological Tissues ◽  
The Body ◽  
Frequency Range ◽  
Mode Separation ◽  
Viscous Losses

Stress fractures occur in bones of athletes and soldiers due to the accumulation of microcracks [1]. Detection of precursor acoustic emissions (i.e. ultrasonic stress waves) resulting from microcrack activity may help predict failure onset before continuous physiological activity results in full-blown fracture. An acoustic emission wave generated from a microcrack in bone will be diminished by dispersion, mode separation, reflection, and viscous losses induced by the biological tissues (skin, muscle, fat) between the source and the transducer. While others have recorded waves emanating from unknown loci in human knee in vivo using acoustic emission method [2], there is no means to appreciate how far these waves can travel in the body. Several studies have characterized the ultrasound attenuation in bone [3] and muscle analog homogenates [4] in the frequency range above 300 kHz. On the other hand, acoustic emissions are prominent in the range of 20 kHz to 300 kHz. The current study focused on identifying the attenuation of acoustic emission waves in bone and muscle tissues in a frequency range which is more relevant to acoustic emissions. This information is critical for predicting whether an emission of certain magnitude at the source can reach surface mounted sensors without being totally attenuated.

scholarly journals Nanocurcumin-Loaded UCNPs for Cancer Theranostics: Physicochemical Properties, In Vitro Toxicity, and In Vivo Imaging Studies

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2234
Author(s):  
Anbharasi Lakshmanan ◽  
Roman A. Akasov ◽  
Natalya V. Sholina ◽  
Polina A. Demina ◽  
Alla N. Generalova ◽  
...  
Keyword(s):  
Near Infrared ◽  
Therapeutic Potential ◽  
Ex Vivo ◽  
Laboratory Animals ◽  
In Vitro Toxicity ◽  
Upconversion Nanoparticles ◽  
Lewis Lung Cancer ◽  
Spectral Bands

Formulation of promising anticancer herbal drug curcumin as a nanoscale-sized curcumin (nanocurcumin) improved its delivery to cells and organisms both in vitro and in vivo. We report on coupling nanocurcumin with upconversion nanoparticles (UCNPs) using Poly (lactic-co-glycolic Acid) (PLGA) to endow visualisation in the near-infrared transparency window. Nanocurcumin was prepared by solvent-antisolvent method. NaYF4:Yb,Er (UCNP1) and NaYF4:Yb,Tm (UCNP2) nanoparticles were synthesised by reverse microemulsion method and then functionalized it with PLGA to form UCNP-PLGA nanocarrier followed up by loading with the solvent-antisolvent process synthesized herbal nanocurcumin. The UCNP samples were extensively characterised with XRD, Raman, FTIR, DSC, TGA, UV-VIS-NIR spectrophotometer, Upconversion spectrofluorometer, HRSEM, EDAX and Zeta Potential analyses. UCNP1-PLGA-nanocurcumin exhibited emission at 520, 540, 660 nm and UCNP2-PLGA-nanocurmin showed emission at 480 and 800 nm spectral bands. UCNP-PLGA-nanocurcumin incubated with rat glioblastoma cells demonstrated moderate cytotoxicity, 60–80% cell viability at 0.12–0.02 mg/mL marginally suitable for therapeutic applications. The cytotoxicity of UCNPs evaluated in tumour spheroids models confirmed UCNP-PLGA-nanocurcumin therapeutic potential. As-synthesised curcumin-loaded nanocomplexes were administered in tumour-bearing laboratory animals (Lewis lung cancer model) and showed adequate contrast to enable in vivo and ex vivo study of UCNP-PLGA-nanocurcumin bio distribution in organs, with dominant distribution in the liver and lungs. Our studies demonstrate promise of nanocurcumin-loaded upconversion nanoparticles for theranostics applications.

scholarly journals Frictional internal work of damped limbs oscillation in human locomotion

2020 ◽  
Vol 287 (1931) ◽  
pp. 20201410 ◽  
Author(s):  
Alberto E. Minetti ◽  
Alex P. Moorhead ◽  
Gaspare Pavei
Keyword(s):  
Energy Balance ◽  
Time Course ◽  
Ex Vivo ◽  
Biological Tissues ◽  
The Body ◽  
Lower Limbs ◽  
Metabolic Energy ◽  
External Work ◽  
Internal Work

Joint friction has never previously been considered in the computation of mechanical and metabolic energy balance of human and animal (loco)motion, which heretofore included just muscle work to move the body centre of mass (external work) and body segments with respect to it. This happened mainly because, having been previously measured ex vivo , friction was considered to be almost negligible. Present evidences of in vivo damping of limb oscillations, motion captured and processed by a suited mathematical model, show that: (a) the time course is exponential, suggesting a viscous friction operated by the all biological tissues involved; (b) during the swing phase, upper limbs report a friction close to one-sixth of the lower limbs; (c) when lower limbs are loaded, in an upside-down body posture allowing to investigate the hip joint subjected to compressive forces as during the stance phase, friction is much higher and load dependent; and (d) the friction of the four limbs during locomotion leads to an additional internal work that is a remarkable fraction of the mechanical external work. These unprecedented results redefine the partitioning of the energy balance of locomotion, the internal work components, muscle and transmission efficiency, and potentially readjust the mechanical paradigm of the different gaits.

scholarly journals Problems of metastasis (literature review)

MD-Onco ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 93-99
Author(s):  
N. Yu. Timofeeva ◽  
N. V. Bubnova ◽  
G. Yu. Struchko ◽  
I. S. Stomenskaya ◽  
O. Yu. Kostrova
Keyword(s):  
Experimental Studies ◽  
Clinical Manifestations ◽  
Distant Metastases ◽  
Positive Outcome ◽  
The Body ◽  
Laboratory Animals ◽  
Medical Sciences ◽  
Late Treatment ◽  
Success Of Treatment

Despite significant successes in the development of medical sciences, the study of oncopathology issues still occupies a leading place due to the identification of a large number of advanced cases of the disease. Firstly, this may be due to the rapid growth of a malignant tumor, for example, against the background of immunodeficiency. Secondly, with late treatment of patients, when they already have distant metastases. The success of treatment of any oncological process primarily depends on the timing of the diagnosis: the earlier the tumor is diagnosed, the greater the chance of a positive outcome and an increase in the life expectancy of the cancer patient. The most formidable complication of oncopathology and the main cause of death from it is metastasis, which often reduces to zero all the effects of therapy. Metastasis remains a mystery today. So, despite the large number of various theories, the question of the spread of the tumor throughout the body has not yet been resolved. There is no definite answer to the question: do metastases metastasize? The mechanisms of the influence of hormones on the processes of metastasis have not been fully studied. Difficulties in diagnosis are associated with the lack of clinical manifestations before the appearance of metastases, the inability to track and compare changes in tissues and organs in vivo, the non-specificity of the results of available research methods, and the lack of control of the spread of metastases throughout the body. Experimental studies on laboratory animals can provide answers to these and many other questions. In a review of the literature, a study of the main issues of metastasis is conducted.

scholarly journals Biogenic Ferrihydrite Nanoparticles: Synthesis, Properties In Vitro and In Vivo Testing and the Concentration Effect

Biomedicines ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 323
Author(s):  
Sergey V. Stolyar ◽  
Oksana A. Kolenchukova ◽  
Anna V. Boldyreva ◽  
Nadezda S. Kudryasheva ◽  
Yulia V. Gerasimova ◽  
...  
Keyword(s):  
Klebsiella Oxytoca ◽  
The Body ◽  
Blocking Temperature ◽  
Laboratory Animals ◽  
High Dispersion ◽  
Intracellular Regeneration ◽  
Minimum Concentration ◽  
In Vivo Testing

Biogenic ferrihydrite nanoparticles were synthesized as a result of the cultivation of Klebsiella oxytoca microorganisms. The distribution of nanoparticles in the body of laboratory animals and the physical properties of the nanoparticles were studied. The synthesized ferrihydrite nanoparticles are superparamagnetic at room temperature, and the characteristic blocking temperature is 23–25 K. The uncompensated moment of ferrihydrite particles was determined to be approximately 200 Bohr magnetons. In vitro testing of different concentrations of ferrihydrite nanoparticles for the functional activity of neutrophilic granulocytes by the chemiluminescence method showed an increase in the release of primary oxygen radicals by blood phagocytes when exposed to a minimum concentration and a decrease in secondary radicals when exposed to a maximum concentration. In vivo testing of ferrihydrite nanoparticles on Wister rats showed that a suspension of ferrihydrite nanoparticles has chronic toxicity, since it causes morphological changes in organs, mainly in the spleen, which are characterized by the accumulation of hemosiderin nanoparticles (stained blue according to Perls). Ferrihydrite can also directly or indirectly stimulate the proliferation and intracellular regeneration of hepatocytes. The partial detection of Perls-positive cells in the liver and kidneys can be explained by the rapid elimination from organs and the high dispersion of the nanomaterial. Thus, it is necessary to carry out studies of these processes at the systemic level, since the introduction of nanoparticles into the body is characterized by adaptive-proliferative processes, accompanied by the development of cell dystrophy and tension of the phagocytic system.

scholarly journals IN VIVO ENRICHMENT OF THE LAMB OF ESSENTIAL TRACE ELEMENTS FOR ITS USE IN THE TECHNOLOGY OF FUNCTIONAL FOODS

2018 ◽  
Vol 3 (3) ◽  
pp. 74-88 ◽  
Author(s):  
Tatiana M. Giro ◽  
Ivan F. Gorlov ◽  
Marina I. Slozhenkina ◽  
Sergey V. Kozlov ◽  
Nogman V. Tasmuchanov
Keyword(s):  
Raw Materials ◽  
Daily Intake ◽  
Test Group ◽  
Zinc Content ◽  
Physiological Effect ◽  
Thyroid Stimulating Hormone ◽  
The Body ◽  
Laboratory Animals ◽  
Experimental Animals

To provide preventive measures for solving the problem of micronutrient deficiency, a new effective biologically safe method of enrichment lamb through the intervention of the cattle rations with feed supplements containing iodine and selenium in organic form has been developed. An increase in the iodine, selenium and zinc content in meat of the test animals fed enriched diets was noted, with more significant localization of elements to be registered in the meat from the ram lamb fed the «Yoddar-Zn» feed supplement together with organic selen preparation «DAFS-25» (Zn - 980 mg/100g; Se — 53.9 mg/100 g; I — 77.6 mg/100 g). So, 100 g of m. longissimus dorsi contained 8.2; 77.0 and 51.7 % of the recommended daily intake of these elements, respectively, that proved the feasibility of further output of the functional products with balanced essential nutrients. Based on the data on greater localization of microelements in meat from the ram lamb fed «Yoddar-Zn» with «DAFS-25», we made jerked snacks from the raw materials obtained from the animals of this test group. In processing, the zinc content in the product decreased by 21.3 %, iodine — 26.5 %, selenium — 16.3 % and made 771 mg/100 g, 39.72 mg/100 g, and 57.01 mg/100 g, respectively, that met the daily norm for 6.4; 56.7 and 38.0 % (for 100 g of product). In the vacuum-packed snacks, the loss of zinc was 11.3 %, iodine — 14.3 %, selenium — 12.6 % from the original content. After 3 months of storage, the zinc content in 100 g of the finished products was 5.7; selenium — 49.6; iodine — 32.6 % of the daily requirement. Investigations of physiological effect of the jerked snacks on the body of the laboratory animals were performed. Stimulating effect of selenium and iodine on the hematopoietic function of the experimental animals was revealed. The study of the functional activity of the thyroid gland found that the experimental animals’ content of thyroid stimulating hormone in blood serum was significantly higher than that of the control rats.

A Comparison of Magnetometry and Relaxometry Measures of Magnetic Nanoparticles Deposited in Biological Samples

2015 ◽  
Vol 31 ◽  
pp. 129-137 ◽  
Author(s):  
Ana Lorena Urbano-Bojorge ◽  
Nazario Félix-González ◽  
Tamara Fernández ◽  
Francisco del Pozo-Guerrero ◽  
Milagros Ramos ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Magnetic Nanostructures ◽  
High Sensitivity ◽  
Biological Tissues ◽  
The Body ◽  
In Vivo Studies ◽  
Gradient Field ◽  
Measurement Protocol

The Alternating Gradient Field Magnetometer (AGFM) is an instrument whose high sensitivity (10-8 emu) allows the detection of small amounts of magnetic nanoparticles (MNPs) with high accuracy. Over the last few years, different magnetic techniques have been used for in vitro measurements of magnetic nanostructures inside biological tissues. However, in vivo studies about their distribution within the body are very scarce because their dispersion, after being delivered, reduces their magnetic signal and hinders detection. In this paper we compare the longitudinal relaxation time (T1) and magnetization measurements in mice's biological tissues for the tracking of MNPs after of an injection of iron oxide nanoparticles. Furthermore, we have correlated the AGFM data with Fast Field Cycling NMR Relaxometry (FFCNMR Relaxometry) measurements with histological analysis. The results have demonstrated that these techniques are useful for detecting minute amounts of MNPs in excised organs after in-vivo comparable to other more conventional techniques for the measurement of MNPs biodistribution and clearance. Details about the preparation of the in vivo samples, measurement protocol and statistical data processing are given.

scholarly journals Synthesis and Characterization of GdVO4:Nd Near-Infrared Phosphors for Optical Time-Gated In Vivo Imaging

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3564
Author(s):  
Ben Nimmegeers ◽  
Ewoud Cosaert ◽  
Tecla Carbonati ◽  
Daniela Meroni ◽  
Dirk Poelman
Keyword(s):  
Decay Time ◽  
Near Infrared ◽  
Imaging Techniques ◽  
Medical Personnel ◽  
Biological Tissues ◽  
The Body ◽  
Transparency Window ◽  
Optical Time ◽  
Gated Imaging

Many medical imaging techniques use some form of ionizing radiation. This radiation is not only potentially harmful for the patient, but also for the medical personnel. An alternative imaging technique uses near-infrared (NIR) emitting luminescent particles as tracers. If the luminescent probes are excited inside the body, autofluorescence from the biological tissues is also induced. This problem can be circumvented by using time-gated imaging. Hereby, the light collection only starts when the fluorescence of the tissue has decayed. This requires particles showing both excitation and emission in the near-infrared and a long decay time so that they can be used in time-gated imaging. In this work, Nd-doped GdVO4 NIR emitting particles were prepared using solid state reaction. Particles could be efficiently excited at 808 nm, right in the first transparency window for biological tissues, emitted in the second transparency window at around 1064 nm, and showed a decay time of the order of 70 μs, sufficiently long for time-gating. By using a Gd-containing host, these particles could be ideally suited for multimodal optical/magnetic imaging after size reduction and surface functionalization.

scholarly journals iRFP (near-infrared fluorescent protein) imaging of subcutaneous and deep tissue tumours in mice highlights differences between imaging platforms

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
C. Hall ◽  
Y. von Grabowiecki ◽  
S. P. Pearce ◽  
C. Dive ◽  
S. Bagley ◽  
...  
Keyword(s):  
Cancer Biology ◽  
Near Infrared ◽  
Fluorescent Protein ◽  
Dynamic Range ◽  
Fluorescent Proteins ◽  
Biological Tissues ◽  
The Body ◽  
Nsg Mice ◽  
Infrared Fluorescent Protein

Abstract Background In vivo imaging using fluorescence is used in cancer biology for the detection, measurement and monitoring of tumours. This can be achieved with the expression of fluorescent proteins such as iRFP, which emits light at a wavelength less attenuated in biological tissues compared to light emitted by other fluorescent proteins such as GFP or RFP. Imaging platforms capable of detecting fluorescent tumours in small animals have been developed but studies comparing the performance of these platforms are scarce. Results Through access to three platforms from Xenogen, Bruker and Li-Cor, we compared their ability to detect iRFP-expressing subcutaneous tumours as well as tumours localised deeper within the body of female NSG mice. Each platform was paired with proprietary software for image analyse, but the output depends on subjective decisions from the user. To more objectively compare platforms, we developed an ‘in house’ software-based approach which results in lower measured variability between mice. Conclusions Our comparisons showed that all three platforms allowed for reliable detection and monitoring of subcutaneous iRFP tumour growth. The biggest differences between platforms became apparent when imaging deeper tumours with the Li-Cor platform detecting most tumours and showing the highest dynamic range.

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