Tensiometric estimation of material properties of tissue spheroids

Tissue spheroids have been proposed to use as building blocks in biofabrication and as bioinks in 3D bioprinting technologies. Tissue fusion is an ubiqious phenomenon during embryonic development. Biomimetic tissue spheroid fusion is a fundamental constructional principle of emerging organ printing technology because closely placed tissue spheroids could fuse into tissue and organ-like constructs in fusion permissive bioprintable hydrogel. From physical point of view tissue spheroids could be considered as a visco-elastic-plastic soft matter or complex fluid. We hypothesize that quantitative estimation of material properties of tissue spheroids using tensiometry could predict their tissue spreading and tissue fusion behavior as well as provide a powerful insight about possible speed of post-printed tissue and organ-like constructs compaction and maturation. Tissue spheroids from human fibroblasts, ovine and human chondrocytes and immortalised human keratinocytes have been biofabricated using non-adhesive cell culture plates (Corning, USA). For estimation of material properties of tissue spheroids commercial tensiometer Microsquisher have been emploied (CellScale, Toronto, Canada). Modulus of elasticity of tissue spheroids have been calculated based on peformed tissue compression tests. In order to identify structural determinants of material properties of tissue spheroids standard perturbants of cytoskeleton such as Cytochalasin D (Sigma, USA) for disruption of microfilaments and Nocodazole (Sigma, USA) for disruption of microtubules have been used. Viability of tissue spheroids have been also estimated and their morphology have been analysed using light microscopy, histochemistry, immunohistochemistry, semithin sections stained wih toluidine blue and transmission and scanning electron microscopy. Kinetics of tissue spheroids spreading on electrospun polyurethane matrices have been analysed. Kinetics of two closely placed tissue spheroids fusion have been analysed in hanging drop. Additionally toxic effect of water solution of paramagnetic gadolinium salt (Omniscan®, GE Health Care, USA) on material properties of tissue spheroids have been investigated. It have been demonstrated that material properties of tissue spheroids biofabricated from different cell types have different modulus of elasticity. Even tissue spheroids biofabricated the same cell types but from different species have different material properties. Incubation with Cytochlasin D dramatically reduces estimated material properties of tissue spheroids. Incubation with Nocodazole does not significantly change material properties of tissue spheroids. Material properties of tissue spheroids from chondrocytes (chondrospheres) correlates very well with increasing deposition and accumulation of extracellular matrix (confirmed by expression of collagen type II and glycosoaminoglycans). The incubation with toxic concentration of gadolinium solution dramatically reduces material properties of chondrospheres. There is no any significant correlation between material properties of tissue spheriods and their spreading kinetics. However, there is a certain correction between material properties of tissue spheroids and their tissue fusion kinetics. Our data demonstrate that beside already well established role of cell adhesion receptors such as cadherin and integrins in the realisation of cell cohesion inside tissue spheroids the structural determinants of material properties of tissue spheroids also include components of cytoskeleton such as actin micofilaments and accumulated extracellular matrix. It is possible to predict post-printing tissue fusion behaviour of tissue spheroids based on preliminary estimation of their material properties. Finally, it have been also shown that material properties of tissue spheroids correlate with their viability. Thus, tensiometry is a valuable method for systematic characterization of material properties of tissue spheroids and for prediction of tissue spheroids post-printed tissue fusion behaviour

Аутотрансплантация Т-лимфоцитов как инструмент для антиген-специфической иммунотерапии онкологических заболеваний

Autotransplantation of immune cells to induce immunological rejection of tumors can be a useful approach in tumor treatment. Despite the low efficiency of this  approach demonstrated in the past, the active development of cell technologies and  genetic engineering has led to the significant improvement in clinical outcomes. A  great success was achieved in adoptive immunotherapy with the T-lymphocytes  specific to tumor antigens. This review describes the clinical experience in  application of various antigen-specific adoptive immunotherapy methods including  tumor-infiltrating T-lymphocytes, T-lymphocytes with redirected transgenic T-cell  and chimeric antigenrecognizing receptors. The possibilities and limitations of these  biomedical technologies are also analyzed in the article.Аутотрансплантация клеток иммунной системы с целью вызвать реакцию иммунологического отторжения опухоли может оказаться востребованным инструментом в руках врачей. Несмотря  на невысокую эффективность, продемонстрированную в прошлом, активное развитие  биомедицинских клеточных технологий и генной инженерии привело к значительному  улучшению результатов, получаемых при клинической апробации этого подхода. Наибольших  успехов удалось добиться в области адоптивной иммунотерапии с использованием Т-лимфоцитов,  специфичных к опухолевым антигенам. В данном обзоре описывается клинический опыт  применения различных вариантов антиген-специфической адоптивной иммунотерапии опухолей,  включая использование опухоль-инфильтрирующих T-лимфоцитов, T-лимфоцитов с перенаправленными трансгенными антигенраспознающими рецепторами, в том числе химерными.  В статье также анализируются возможности и ограничения этих биомедицинских технологий

Commercial articulated collaborative in situ 3D bioprinter for skin wound healing

In situ bioprinting is one of the most clinically relevant techniques in the emerging bioprinting technology because it could be performed directly on the human body in the operating room and it does not require bioreactors for post-printing tissue maturation. However, commercial in situ bioprinters are still not available on the market. In this study, we demonstrated the benefit of the originally developed first commercial articulated collaborative in situ bioprinter for the treatment of full-thickness wounds in rat and porcine models. We used an articulated and collaborative robotic arm from company KUKA and developed original printhead and correspondence software enabling in situ bioprinting on curve and moving surfaces. The results of in vitro and in vivo experiments show that in situ bioprinting of bioink induces a strong hydrogel adhesion and enables printing on curved surfaces of wet tissues with a high level of fidelity. The in situ bioprinter was convenient to use in the operating room. Additional in vitro experiments (in vitro collagen contraction assay and in vitro 3D angiogenesis assay) and histological analyses demonstrated that in situ bioprinting improves the quality of wound healing in rat and porcine skin wounds. The absence of interference with the normal process of wound healing and even certain improvement in the dynamics of this process strongly suggests that in situ bioprinting could be used as a novel therapeutic modality in wound healing.publishersversionPeer reviewe

ОФЭК/КТ в диагностике эктопированной аденомы паращитовидной железы (случай из практики)

Case study: a parathyroid tumor ectopic to the mediastinum. The diagnostic capabilities and advantages of the 99mТс-sestamibi SPECT/CT hybrid method in the preoperative localization of abnormally located parathyroma are demonstrated.Случай из практики: опухоль паращитовидной железы, эктопированная в средостение. Продемонстрированы диагностические возможности и преимущества гибридного метода ОФЭКТ/КТ с 99mТс-технетрилом в предоперационной локализации аномально расположенной паратиромы

RNA-Seq gene expression profiling of HepG2 cells: The influence of experimental factors and comparison with liver tissue

© Tyakht et al.; licensee BioMed Central. Background: Human hepatoma HepG2 cells are used as an in vitro model of the human liver. High-throughput transcriptomic sequencing is an advanced approach for assessing the functional state of a tissue or cell type. However, the influence of experimental factors, such as the sample preparation method and inter-laboratory variation, on the transcriptomic profile has not been evaluated. Results: The whole-transcriptome sequencing of HepG2 cells was performed using the SOLiD platform and validated using droplet digital PCR. The gene expression profile was compared to the results obtained with the same sequencing method in another laboratory and using another sample preparation method. We also compared the transcriptomic profile HepG2 cells with that of liver tissue. Comparison of the gene expression profiles between the HepG2 cell line and liver tissue revealed the highest variation, followed by HepG2 cells submitted to two different sample preparation protocols. The lowest variation was observed between HepG2 cells prepared by two different laboratories using the same protocol. The enrichment analysis of the genes that were differentially expressed between HepG2 cells and liver tissue mainly revealed the cancer-associated gene signature of HepG2 cells and the activation of the response to chemical stimuli in the liver tissue. The HepG2 transcriptome obtained with the SOLiD platform was highly correlated with the published transcriptome obtained with the Illumina and Helicos platforms, with moderate correspondence to microarrays. Conclusions: In the present study, we assessed the influence of experimental factors on the HepG2 transcriptome and identified differences in gene expression between the HepG2 cell line and liver cells. These findings will facilitate robust experimental design in the fields of pharmacology and toxicology. Our results were supported by a comparative analysis with previous HepG2 gene expression studies

Analysis of the restoration of cardiology diagnostics scope in the Russian Federation during the COVID-19 pandemic: results of the Russian segment of the INCAPS COVID 2 study under the auspices of the International Atomic Energy Agency

Aim. To assess the changes in cardiology diagnostics scope in the Russian Federation during the coronavirus disease 2019 (COVID-19) pandemic.Material and methods. In an online survey organized by the Division of Human Health of the International Atomic Energy Agency (IAEA), including questions about changes in the workflow of diagnostic laboratories and the scope of cardiac diagnostics from March 2019 (pre-pandemic) to April 2020 (first wave of the pandemic) and April 2021 (recovery stage), 15 Russian medical centers from 5 cities took part.Results. The decrease in the diagnostics scope by April 2020 by 59,3% compared to March 2019, by April 2021, stopped and was replaced by growth (+7,1%, the recovery rate, 112,1%). The greatest increase was in routine examinations, such as echocardiography (+11,6%), stress echocardiography (+18,7%), stress single photon emission computed tomography (+9,7%), and to a lesser extent resting computed tomography angiography (+7,0%) and magnetic resonance imaging (+6,6%). The performance of stress electrocardiography, stress magnetic resonance imaging and positron emission tomography for the diagnosis of endocarditis in April 2021 compared to March 2019 decreased by 10,3%, 63,2% and 62,5%, respectively.Conclusion. Due to the resumption of patient admissions for cardiac examinations during the ongoing COVID-19 pandemic, with the anti-epidemic measures taken and certain changes in the workflow, there has been a recovery in the diagnostics scope in most of the included centers

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection